Theses

Browse

Search Results

Now showing 1 - 9 of 12

Open Access
Enhancement of propagation efficiency in exotic varities of heliconia
(Department of Pomology and Floriculture, College of Agriculture, Vellayani, 2008) Reshmi, C R; KAU; Sheela, V L
Heliconias are among the most popular garden plants, both for the ease with which they can be grown and the sheer magnificence of the blooms. Studies were conducted to standardize rapid propagation techniques under in vitro and in vivo conditions. Three heliconia varieties belonging to three distinct groups viz., St. Vincent Red (small erect type), Golden Torch Adrian (hybrid) and Sexy Pink (large pendent type) were selected for the study. For in vitro culture establishment, shoot tip explants were effective. The treatment of shoot tips with 0.10 per cent mercuric chloride for ten minutes followed by dipping in 0.05 per cent mercuric chloride for five minutes (after trimming) resulted in better surface sterilization. Longitudinal cutting of the in vitro established shoot tip with apical dome into two halves and culturing them separately produced the highest number of axillary buds. Addition of 0.05 per cent activated charcoal to the establishment media reduced the media browning and hastened shoot initiation. For culture establishment of all the three varieties, MS medium supplemented with BA 5.00 mg l-1 was found to be the best. Murashige and Skoog medium supplemented with BA 2.00 mg l-1 resulted in the highest shoot proliferation in the variety St. Vincent Red. In Golden Torch Adrian, BA 2.00 mg l-1 + NAA 0.20 mg l-1 gave better results. In the variety Sexy Pink, Kinetin 5.00 mg l-1 + NAA 0.20 mg l-1 was the best. For further multiplication in Sexy Pink, BA 1.00 mg l-1 was sufficient. Solid culture medium was better for shoot proliferation in the variety Sexy Pink. Higher sucrose concentration (40.00 g l-1) increased the multiplication rate, but reduced the length of shoots as well as the number of leaves. Addition of activated charcoal to the media as well as exposure of cultures to light had negative effect on shoot proliferation. Full MS medium was found to be the best for in vitro rooting of the variety Sexy Pink. Addition of NAA 0.50 mg l-1 to the MS medium gave better results for in vitro rooting in Golden Torch Adrian and Sexy Pink. Sucrose @ 30.00 g l-1 was sufficient for in vitro rooting in the variety Sexy Pink. Activated charcoal delayed root initiation and reduced the number of roots in the variety Sexy Pink. Sand recorded 90.00 per cent survival in all the three varieties after two months of planting out. At varietal level, significant difference was evident in the total number of suckers. In the first experiment, the variety St. Vincent Red (3.82) was significantly superior in terms of total number of suckers. However, in the second experiment, St. Vincent Red (4.06) was on par with Golden Torch Adrian (4.10). The variety Sexy Pink produced comparatively taller suckers in both the trials. Varietal variation in the number of leaves was observed only in the earlier stages. During the preliminary field experiment, the variety Sexy Pink excelled in leaf area at almost all stages of observation. Among the three varieties, highest collar girth was recorded by suckers of Sexy Pink variety during the first two stages of observation. However, towards the later stages, it was statistically on par with St. Vincent Red. Foliar spray was superior to rhizome dip in terms of total number of suckers, height of suckers and the number of leaves. In the case of leaf area, both the treatments were more or less on par. Application of growth regulators had pronounced effect on sucker production at all the stages during the first experiment when BA 750 mg l-1 produced the highest number (4.19) of total suckers. In the second experiment, variation was evident only in the total number of suckers. Here, BA 850 mg l-1 produced the highest number (4.33) of suckers and it was on par with BA 700 mg l-1 (4.00) and GA3 650 mg l-1 (3.79). Irrespective of the stage of plant growth, gibberellic acid produced taller suckers and BA 500 mg l-1 resulted in the shortest suckers. BA treatments recorded comparatively higher number of leaves. Growth regulator application had remarkably influenced the leaf area of suckers also. Application of BA 1000 mg l-1 (3.53 cm) and GA3 800 mg l-1 (3.33 cm) recorded higher collar girth in suckers. VG interaction exerted significant variation in the number of suckers. At varietal level, BA 750 mg l-1 produced the highest number of suckers in St. Vincent Red (4.75), GA3 500 mg l-1 in Golden Torch Adrian (4.63) and GA3 750 mg l-1 in Sexy Pink (4.00). Among VG treatment combinations in the second experiment, the highest number of suckers (4.75) in the variety St. Vincent Red was produced by BA 700 mg l-1. The varieties Golden Torch Adrian (4.88) and Sexy Pink (3.75) recorded the highest with BA 850 mg l-1. Gibberellic acid produced taller suckers. In the second experiment, VG interaction had no significant effect on the height of suckers. Regarding the number of leaves, BA resulted in comparatively higher number of leaves in both the experiments. In all the three varieties, BA 850 mg l-1 produced the highest number of leaves. Collar girth was found to increase with increase in the concentrations of BA and GA3 in all the three varieties. The economics of foliar application of growth regulators revealed that BA 850 mg l-1 significantly enhanced the profit in the varieties Golden Torch Adrian and Sexy Pink. Although negligible, BA 700 mg l-1 recorded slight positive response in the variety St. Vincent Red with respect to profit.
Open Access
Effective agricultural information delivery system-an action research among farmers
(Department Of Agricultural Extension, College Of Agriculture, Vellayani, 2008) Nazreen Hassan, S; KAU; Kishore Kumar, N
Extension providers and client expectations include superior information accessing and dissemination, ongoing farmer-extension-research communications and marketing. AgIDS offer tremendous potential for accelerating development. They are transforming our lives, creating wealth and impacting every facet of human endeavor. Agricultural marketing requires connectivity between the market and exporters, growers, traders, industry consumers, through wide area network of national and international linkages in order to provide day-to-day information with regard to commodity arrivals and prevailing rates etc. this study was carried out with the objective of bringing out the underlying facts in the Information Communication technology available to the benefit of the farmers. Thiruvananthapuram district has been purposively selected for the study because this is the only district in Kerala having information kiosks being operated in the Krishibhavans. From the ten Krishibhavans three Krishibhavans were selected based on the maximum numbers of users of this ICT facility based on the records available in the Krishibhavans. The respondents were selected by random sampling method. 60 user farmers and 30 non-user farmers from each panchayat were selected and they formed the respondents of this study. A total of 270 farmers were contacted for the study. From a review of related literature and discussion with experts a comprehensive list of variables were selected. The dependent variables included attributes of ICT, Communication behaviour, information need and skill requirement. Majority of the farmers came under middle age group. Majority of the farmer in both the categories were found to be marginal farmers. Mostly the users were in a better socio economic group. The Extension Service must be able to provide information that makes a difference. ICTs are tools that help build human network, increase public awareness and provide access to information and knowledge for the use of people. They include Telephone, Fax, GIS, Radio, Television, Print, Internet, Video, Audio, Computer and technologies on the drawing boards. Possession of ICT tools by users was found to be higher than the nonusers except for farm magazines where the nonusers out-numbered the users. The mean of the socio technical variables was found to be the maximum for physical compatibility and desirability in the case of users. This was followed by social acceptability and simplicity. This was followed by physical compatibility and social acceptability. In both the cases user education had the minimum score. So this area needs more attention. Majority of farmers in both the categories perceived efficiency of ICT as ‘saving time and money in interacting’ and has ‘all information the farmer wants’ in the nonuser category. This was followed by one stop shop information by the users and supports marketing in the case of non users. There existed significant relation ship between the dependent variables. Also significant relationship was observed in the relationship that existed between some independent variables and dependent variables. A majority of the users claim that they slightly agree to the fact that their productivity has increased compared to the previous year. Analysis of variance showed a comparison between the user group and the non user group. It was found that the user group was higher in the case of all dependent variables. But in the case of information need it was found to be almost similar. A need assessment can help Extension educators to decide whether an extension program should be improved and how the services should be better delivered. The farmers needed information on agriculture such as market rates, bio pesticides, bio fertilizers. These areas ranked top in their information needs. This was followed by organic farming, plant protection and cropping practices. The skill requirement of the non-users farmers was more than the user farmers. The action research was conducted in the form of training on the skills of using computers. The participants for the research were selected by random sampling from the list of non user farmers’ interviewed. The farmers were exposed to the skills for five hours for two days i.e., for ten hours each to a group of thirty members. The influence of Training on the non-users observance on their knowledge gain, and skill acquisition at different intervals of time on the existing ICT facility was studied by documenting the knowledge gain, and skill acquisition at one week, one month and three months interval by the trainees. The results of paired‘t’ test on knowledge gain and skill acquisition showed high significance between different intervals of time. As perceived by the farmers it was found that lack in skill was the major problem that prevented most farmers in accessing through the ICT facility. The farmers also gave out some suggestions to bring this facility in a more effective manner. The study indicated anew strategy for solving the problems in technology dissemination by finding out the actual needs of the farmers in harnessing the benefits of ICT.
Open Access
Intra and inter generic hybridization and molecular charatrization in monopodial orchids
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2008) Beena, Thomas; KAU; Lekha Rani, C
A research programme entitled “Intra and inter generic hybridization and molecular characterization in monopodial orchids” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2005-2008 with the objective of undertaking intra and intergeneric hybridization, in vitro embryo culture and molecular characterization in monopodial orchids, as a preliminary step to develop novel hybrids. Fifteen monopodial orchid genotypes comprising of six genera viz., Aranda, Aranthera, Kagawara, Mokara, Renanthera and Vanda, with good cut flower qualities and high demand in the market were selected as parents after initial evaluation. They were evaluated adopting completely randomized design with five replications. Analysis of variance revealed significant differences for almost all the characters studied. Genotypic and phenotypic coefficients of variation were high for thickness of leaf, leaf area and number of aerial roots. High heritability (>70 %) combined with high genetic advance (>70 %) was observed for number of aerial roots, width of leaf, thickness of leaf, leaf area, number of spikes per shoot and number of flowers per inflorescence. Significant positive inter-correlation at genotypic and phenotypic levels was observed for length of flower and width of flower with number of spikes per shoot. The character number of spikes per shoot recorded significant positive correlation with leaf area. Number of flowers per inflorescence was positively correlated with number of leaves per shoot and length of inflorescence. Out of the six genera studied, four viz., Aranda, Aranthera, Kagawara and Mokara, exhibited free-flowering nature. Seasonal flowering was observed mainly from June to December in Vanda, whereas it was confined to two seasons, from February to March and August to October in Renanthera. Inflorescence axis was found to be arching in Aranthera and Renanthera while the rest of the genotypes produced erect inflorescence axis. The 15 parental genotypes were crossed in all possible combinations after preliminary studies on floral biology. A total of 225 cross combinations were attempted including 105 crosses, 105 reciprocals and 15 selfs. Incompatibility reactions were noticed at different stages ranging from flower abscission before the onset of any visible post pollination change to instances where seeds germinated but aborted in culture. Mature green capsules were harvested from 70 combinations at 70 to 90 per cent maturity. Among them 15 combinations did not yield any seeds in the capsule while the remaining 55 combinations were cultured axenically. Among the 55 combinations inoculated in vitro, no germination was obtained from seeds of 12 combinations. Out of the 43 combinations that germinated successfully, seven combinations showed arrested development. Thus out of the total 55 combinations inoculated in vitro 36 combinations developed successfully. These were subcultured three to four times. Seedlings having 2-3 leaves and 2-3 roots were deflasked and planted out. MS half strength was selected as the best basal medium. For improving the in vitro growth of hybrid monopodial orchid seedlings refinement of this medium by supplementing with IAA (8 mg l-1) and NAA (2 mg l-1) was beneficial. Significant differences among the combinations were observed with respect to number of days taken for germination initiation, number of days taken for development of protocorms, chlorophyll, first leaf, first shoot and first root primordia and for deflasking. Significant differences in seedling morphology were observed among the 36 hybrid combinations at deflasking. These were kept in humidity chamber for acclimatization for one month, transferred to net house for hardening and maintained there for further growth. In the present study, RAPD was employed for studying the genetic diversity and for the fingerprinting of 20 monopodial orchid hybrids, making use of arbitrary primers to amplify random DNA sequences in the genome. To identify the promising primers for RAPD analysis, 70 decamer primers of kit A, B, C and D were screened using the DNA of hybrid H-2. Based on the performance in DNA amplification, eight decamer primers were identified for RAPD analysis. Primers that produced highest number of polymorphic bands which were intense and reproducible were selected. They were OPB-07, OPB-15, OPB-l7, OPC-04, OPC-05, OPC-08, OPC-15 and OPD-02. a total of 57 scorable bands (average of 7.125 bands per primer) were generated by the selected eight primers of which six were monomorphic and the remaining 51 were polymorphic (89.47%). The estimation of Jaccard’s coefficients and construction of dendrogram by using UPGMA revealed the presence and extent of genetic similarities among the 20 monopodial orchid hybrids. The overall similarity coefficients ranged from 0.40 to 0.84. Cluster analysis revealed that at 0.69 similarity coefficient, the 20 monopodial orchid hybrids got divided into six groups. Among the 20 hybrids, H-18, H-7, H-13, H-17, H-19 and H-20 stood separately in clusters II, III A, III B, IV, V and cluster VI respectively. This substantiates the moderately broad distribution of genetic variability, which can be attributed to the broad genetic base in their ancestry. Cluster I A contained four hybrids viz., H-1, H-10, H-3 and H-9. This grouping is justified by the presence of a common parent i.e., Arachnis Maggie Oei Red Ribbon in their parentage. Moreover, two common species viz., Arachnis hookeriana and Arachnis flos-aeris are involved in their ancestry. All these support their belonging to the same cluster. The three hybrids such as H-5, H-6 and H-8 fell in cluster I B. RAPD technique is relatively simpler, quicker, less expensive and non-radioactive than other molecular characterization techniques. The results of present investigation proved that it can detect sufficient polymorphisms in genetic distance studies in monopodial orchids. A research programme entitled “Intra and inter generic hybridization and molecular characterization in monopodial orchids” was carried out in the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2005-2008 with the objective of undertaking intra and intergeneric hybridization, in vitro embryo culture and molecular characterization in monopodial orchids, as a preliminary step to develop novel hybrids. Fifteen monopodial orchid genotypes comprising of six genera viz., Aranda, Aranthera, Kagawara, Mokara, Renanthera and Vanda, with good cut flower qualities and high demand in the market were selected as parents after initial evaluation. They were evaluated adopting completely randomized design with five replications. Analysis of variance revealed significant differences for almost all the characters studied. Genotypic and phenotypic coefficients of variation were high for thickness of leaf, leaf area and number of aerial roots. High heritability (>70 %) combined with high genetic advance (>70 %) was observed for number of aerial roots, width of leaf, thickness of leaf, leaf area, number of spikes per shoot and number of flowers per inflorescence. Significant positive inter-correlation at genotypic and phenotypic levels was observed for length of flower and width of flower with number of spikes per shoot. The character number of spikes per shoot recorded significant positive correlation with leaf area. Number of flowers per inflorescence was positively correlated with number of leaves per shoot and length of inflorescence. Out of the six genera studied, four viz., Aranda, Aranthera, Kagawara and Mokara, exhibited free-flowering nature. Seasonal flowering was observed mainly from June to December in Vanda, whereas it was confined to two seasons, from February to March and August to October in Renanthera. Inflorescence axis was found to be arching in Aranthera and Renanthera while the rest of the genotypes produced erect inflorescence axis. The 15 parental genotypes were crossed in all possible combinations after preliminary studies on floral biology. A total of 225 cross combinations were attempted including 105 crosses, 105 reciprocals and 15 selfs. Incompatibility reactions were noticed at different stages ranging from flower abscission before the onset of any visible post pollination change to instances where seeds germinated but aborted in culture. Mature green capsules were harvested from 70 combinations at 70 to 90 per cent maturity. Among them 15 combinations did not yield any seeds in the capsule while the remaining 55 combinations were cultured axenically. Among the 55 combinations inoculated in vitro, no germination was obtained from seeds of 12 combinations. Out of the 43 combinations that germinated successfully, seven combinations showed arrested development. Thus out of the total 55 combinations inoculated in vitro 36 combinations developed successfully. These were subcultured three to four times. Seedlings having 2-3 leaves and 2-3 roots were deflasked and planted out. MS half strength was selected as the best basal medium. For improving the in vitro growth of hybrid monopodial orchid seedlings refinement of this medium by supplementing with IAA (8 mg l-1) and NAA (2 mg l-1) was beneficial. Significant differences among the combinations were observed with respect to number of days taken for germination initiation, number of days taken for development of protocorms, chlorophyll, first leaf, first shoot and first root primordia and for deflasking. Significant differences in seedling morphology were observed among the 36 hybrid combinations at deflasking. These were kept in humidity chamber for acclimatization for one month, transferred to net house for hardening and maintained there for further growth. In the present study, RAPD was employed for studying the genetic diversity and for the fingerprinting of 20 monopodial orchid hybrids, making use of arbitrary primers to amplify random DNA sequences in the genome. To identify the promising primers for RAPD analysis, 70 decamer primers of kit A, B, C and D were screened using the DNA of hybrid H-2. Based on the performance in DNA amplification, eight decamer primers were identified for RAPD analysis. Primers that produced highest number of polymorphic bands which were intense and reproducible were selected. They were OPB-07, OPB-15, OPB-l7, OPC-04, OPC-05, OPC-08, OPC-15 and OPD-02. a total of 57 scorable bands (average of 7.125 bands per primer) were generated by the selected eight primers of which six were monomorphic and the remaining 51 were polymorphic (89.47%). The estimation of Jaccard’s coefficients and construction of dendrogram by using UPGMA revealed the presence and extent of genetic similarities among the 20 monopodial orchid hybrids. The overall similarity coefficients ranged from 0.40 to 0.84. Cluster analysis revealed that at 0.69 similarity coefficient, the 20 monopodial orchid hybrids got divided into six groups. Among the 20 hybrids, H-18, H-7, H-13, H-17, H-19 and H-20 stood separately in clusters II, III A, III B, IV, V and cluster VI respectively. This substantiates the moderately broad distribution of genetic variability, which can be attributed to the broad genetic base in their ancestry. Cluster I A contained four hybrids viz., H-1, H-10, H-3 and H-9. This grouping is justified by the presence of a common parent i.e., Arachnis Maggie Oei Red Ribbon in their parentage. Moreover, two common species viz., Arachnis hookeriana and Arachnis flos-aeris are involved in their ancestry. All these support their belonging to the same cluster. The three hybrids such as H-5, H-6 and H-8 fell in cluster I B. RAPD technique is relatively simpler, quicker, less expensive and non-radioactive than other molecular characterization techniques. The results of present investigation proved that it can detect sufficient polymorphisms in genetic distance studies in monopodial orchids.
Open Access
Concurrent growing of green manure crops in dry and wet seeded rice
(Department of Agronomy, College of Horticulture, Vellanikkara, 2008) Anitha, S; KAU; Jose, Mathew
An investigation entitled ‘Concurrent growing of green manure crops in dry and wet seeded rice’ was conducted at Agricultural Research Station, Mannuthy to develop a comprehensive technology package for the system of concurrent growing of green manure crops in direct seeded rice. The investigation consisted of four experiments viz., Experiment Ia - Concurrent growing of green manure crops in dry seeded rice, Experiment Ib - Residual effect of concurrent growing of green manure crops in dry seeded rice, Experiment IIa - Concurrent growing of daincha in wet seeded rice and Experiment IIb - Residual effect of concurrent growing of daincha in wet seeded rice. The experiment on concurrent growing of green manure crops in dry seeded rice consisted of two green manure crops (horse gram and cowpea), three methods of incorporation (Incorporation by cono weeder, desiccation by 2,4 - D spray @1.0 kg ha-1 and allowing for self decomposition) and two levels of nitrogen (100 and 75% of recommended N) and a control without green manure crops . Among the two green manure crops, cowpea was the best in supplying the required quantity of green matter with 25 per cent savings of N fertilizer and a substantial reduction in weed incidence. All the three methods of incorporation were found to be equally effective. Hence in places where there is a difficulty in self decomposition, cowpea can be effectively incorporated by conoweeder or by spraying 2, 4-D. The cowpea variety used in this study was a short duration bush type variety facilitating additional pod yield from cowpea before it was incorporated. Concurrent growing of cowpea along with dry seeded rice is a viable system as it resulted in increased productivity, profitability and sustainability dry seeded rice. In the experiment to study the residual effect of concurrent growing of green manure crops in dry seeded rice, the main plots of dry seeded rice crop during the 1st crop season were divided into two sub plots and applied 100 and 75 per cent N to the subplots. The results revealed that concurrent growing of green manure crops were effective in increasing the yield and sustaining soil fertility status compared to pure crop of rice receiving 5 t ha-1 of FYM and 100 per cent of the recommended nitrogen. But there was no savings of N fertilizer to the succeeding transplanted rice crop as the highest yield of succeeding rice was achieved only when it received 100 per cent of the recommended N. The profitability of the rice- rice cropping system was the highest with concurrent growing of cowpea in dry seeded rice. The experiment on concurrent growing of daincha in wet seeded rice consisted of two stages of incorporation of daincha (20 DAS and 30DAS), three methods of incorporation (Incorporation by cono weeder, desiccation by 2, 4 - D spray @1.0kg ha-1 and Desiccation by Chlorimuron ethyl+ met sulfuron methyl spray @ 4.0 g ha-1 met sulfuron methyl spray @ 5 g ha-1) and two levels of nitrogen (100 and 75% of recommended N) and a control without daincha. Results indicated that concurrent growing of daincha can be successfully practiced in wet seeded rice with improved productivity. Incorporation of 30 days old daincha employing any of the three methods of incorporation was equally effective in increasing the productivity and profitability of wet seeded rice. Incorporation of daincha at 30 DAS could add about 14 t ha-1 of green matter with minimum investment and resulted in 70 per cent weed suppression. Concurrent growing of daincha receiving both 100 and 75 per cent of recommended N produced significantly higher yield than pure crop of rice receiving 5 t ha-1 of FYM and 100 per cent of the recommended nitrogen. Hence there was a saving of 25 per cent N without affecting the yield. The highest yield was obtained when 100 per cent of recommended N was applied to the system. The treatments for the experiment to study the residual effect of concurrent growing of daincha in wet seeded rice were similar to that of dry seeded rice. The results showed that concurrent growing of daincha and its incorporation at 30 DAS was effective in increasing the yield of succeeding rice and sustaining soil fertility status compared to pure crop of rice receiving 5 t ha-1 of FYM and 100 per cent of the recommended nitrogen. The highest yield of succeeding rice was achieved only when it received 100 per cent of the recommended N hence there was no savings of N fertilizer to the succeeding transplanted rice crop. Concurrent growing of daincha in wet seeded rice increased the profitability of the rice- rice cropping system. Concurrent growing of green manure crops in dry and wet seeded rice is a management alternative to reduce the production cost and to increase the yield of rice and is a practical model for sustainable rice production.
Open Access
Comparative efficacy of bromocriptine, cabergoline and thyroxine in inducine oestrus in bitches
(Department of Animal Reproduction, Gynaecology and Obstetrics, College of Veterinary and Animal Sciences, Mannuthy, 2008) Ajitkumar, G; KAU; Sreekumaran, T
Detailed survey on breeding, feeding and management of 1721 dogs belonging to 817 owners was conducted in different parts of Kerala State. Among the dogs surveyed, 518 (30.10%) were male and 1203 (69.90%) were female. Breed-wise details of dogs maintained by individual owners revealed German shepherd dog (20.74%) as the most popular breed of dog followed by Labrador retriever (18.13%), Dachshund (11.39%), Rottweiler (9.12%) and Spitz (5.52%). The percentage of local non-descript dogs was found to be 14.64 only. The prevalence, nature and magnitude of anoestrus among the female dogs were evaluated based on breeding details. Haematological, hormonal, mineral and cholesterol profile of anoestrous bitches were estimated. Data on breeding revealed that 92.93 per cent of bitches were allowed to breed and the remaining 7.07 per cent were kept as virgin throughout their lifetime. The age at first breeding in majority of the bitches (57.85%) was between 1 to 2 years with an average of 16.30 months. The average number of oestrus periods and the number of breeding per year were 2.14 ± 0.24 and 1.47 ± 0.32 respectively. The average duration of proestrual bleeding was found to be 10.87 ± 1.24 days. Most of the bitches (51.97 %) were bred twice in one oestrus and the period of acceptance varied from 4 to 22 days with an average of 8.94 ± 2.18 days. The incidence of failure of conception, abortion, stillbirth and pseudopregnancy were 18.87, 5.72, 15.56 and 13.69 per cent respectively. The neonatal problems encountered in 13.88 per cent of bitches included agalactia / hypogalactia / mammitis (5.29%), cannibalism (2.65%), puppy fading syndrome (2.09%), puerperal tetany (1.98%) and rejection of young one by dam / poor mothering ability (1.87%). Among the bitches surveyed, 134 (11.14%) were identified as in the stage of anoestrus, 65.67 per cent in primary and 34.33 per cent in secondary anoestrus and the average age was 22.68 and 34.34 months respectively. The average duration of secondary anoestrus was 11.71 months. Analysis of breed-wise prevalence revealed that it was high in breeds such as Dachshund (18.18%), Labrador retriever (16.74%), Great Dane (16.67%), Dalmatian (15.38%) and Doberman pinscher (14.00%) and was lowest (2.44%) among local non-descript bitches. Data on body condition revealed that 42 per cent of the anoestrous bitches were with the ideal body score of five, 46 per cent with body score more than five (obese) and 12 per cent with body score less than five (lean). Analysis of haematological profile of anoestrous bitches revealed normochromic normocytic anaemia. The mean serum progesterone, prolactin and thyroxine levels in anoestrous bitches were of 0.57 ± 0.03 ng/ml, 0.75 ± 0.05 ng/ml and 1.80 ± 0.06 µg/dl respectively. The mean serum calcium and phosphorus levels in anoestrous bitches were 8.94 ± 0.24 and 3.48 ± 0.12 mg per cent respectively. The mean serum iron, copper, cobalt, zinc, manganese and cholesterol levels were found to be within the normal range. Oestrus induction trials were carried out in forty anoestrous bitches and the data obtained were compared with that of control bitches. Out of 10 animals treated in each group, five (50%) in Group I (bromocriptine @ 50 μg/kg. body weight), nine (90%) in Group II (cabergoline @ 5 μg/kg. body weight), eight (80%) in Group III (thyroxine @10 μg/kg. body weight) and seven (70%) in Group IV (thyroxine @ 5 μg/kg. body weight) evinced proestrual bleeding. The mean treatment onset to proestrus in Groups I, II, III and IV was 28 ± 3.39, 13.44 ± 3.12, 24.50 ± 3.18 and 33 ± 2.21 days respectively. The average duration of proestrus in the treatment groups was 9.80 ± 0.86, 10.11 ± 0.68, 11.25 ± 0.88 and 10.71 ± 0.68 days respectively as against 9.70 ± 0.42 days in the control group. The average duration of oestrus in the four treatment groups and the control group was 7.60 ± 0.24, 8 ± 0.29, 8.5 ± 0.63, 7.85 ± 0.46 and 8 ± 0.39 days respectively. Fifty per cent of the animals treated with bromocriptine and 10 per cent of the animals treated with cabergoline exhibited nausea and vomiting as side effects, whereas none of the animals treated with thyroxine exhibited side effects. The mean serum progesterone and prolactin levels during anoestrus, on the first day of proestrus and on the day of first breeding did not differ significantly within and between the treatment groups and the control group. The mean serum thyroxine level during anoestrus and on the first day of proestrus did not differ significantly within and between the treatment and the control groups, whereas on the day of first breeding the mean thyroxine level recorded statistically significant difference between the treatment and control groups, the lowest being 1.56 ± 0.18 μg/dl in Group I and the highest being 2.10 ± 0.13 μg/dl in Group IV. Animals treated with levothyroxine (Group III & IV) exhibited a slight increase in the mean level of serum thyroxine on the first day of bleeding as well as on the day of first breeding, but the values were found to be within the normal limits. The haemoglobin level and total erythrocyte count were found to be increased on the first day of proestrus and on the day of first breeding in animals of Group III and IV. The mean serum phosphorus level on the first day of proestrus and on the day of first breeding in the treatment groups were found to continue at low levels as in the anoestrous stage. The mean serum copper level on the first day of proestrus exhibited statistically significant difference between the treatment and control groups. The mean serum level of calcium, iron, cobalt, zinc and manganese during anoestrus, on the first day of proestrus and on the day of first breeding did not reveal statistically significant difference between groups. The overall conception rate in the treatment groups were 40, 70, 50 and 40 per cent respectively as against 70 per cent in the control group. The average gestation length and litter size did not differ significantly between the treatment and control groups.
Open Access
Agricultural expert system - a participatory assessment
(Department of Agricultural extension, College of Horticulture, Vellanikkara, 2008) Helen, S; KAU; Kaleel, F M H
Cyber Extension includes effective use of Information and Communication Technology, national and international information networks, Internet, Expert Systems, Multimedia Learning Systems and Computer based training systems to improve information access to the farmers, extension personnel and scientists. The dissemination of the technologies could be enhanced by using expert systems and other artificial intelligence technologies (Hadi et al., 2006). An expert system is a computer-based program that uses knowledge, facts and different reasoning techniques to solve problems that normally require the abilities of human experts. The expert systems are based on the concept of artificial intelligence in which the experience and knowledge of human experts are captured in the form of IF-THEN rules and facts, to solve the field problems (Rao, 2003). ‘Diagnos-4’, was a computer-assisted software developed by Kerala Agricultural University during 2004. This package would support the agricultural extension workers and literate farmers for decision-making and help them in suggesting suitable control measures of the major pests and diseases of important nine crops of Kerala (Ganesan, 2002). It will be modified and released shortly for the benefit of all the stakeholders involved in agricultural development. Before introducing the system among users, it is appropriate to explore the possibilities of functioning of AES under the existing extension system so that suitable modifications can be made to make it more user friendly. Development of AES, ‘Diagnos-4’ was the pioneering and ambitious programme of Kerala Agricultural University. The personnel involved in technology dissemination and technology users need much information on plant protection measures. Hence ‘Diagnos-4’ was selected purposively. The research was conducted among the prospective users in two phases viz; exploratory design among researchers who were in the research institutes engaged in AES development and in TOT, all over India and experimental design among extension personnel and farmers from Palakkad District of Kerala. Mean scores, percentage analysis, Kendall’s Coefficient of Concordance, t-test for two samples assuming equal variances and Binary Logistic Regression were the statistical tools used in this study. Twenty AES were identified during this study, developed by various agricultural research institutions in India. Many of the systems were restricted only to limited groups of users and they were yet to be popularized among the ultimate users. It was found that extension personnel and farmers possessed low level of knowledge especially in the areas of plant protection aspects of crops and they were in need of information on the same. Hence there is a lot of scope for the application of AES among extension personnel and farmers on plant protection aspects of crops that help the users to clarify their doubts, confirm their knowledge and provide real time information to the technology users. Prospective users in the transfer of technology stream were very much satisfied about the future prospects of AES based on its better performance, settings in the AES, mode of presentation, practicability and serviceability of the system. The areas that needed modifications were: retrievability of information, relevancy of information and information content. Release of Malayalam Version with more emphasis on easy retrievability of information, needs the immediate attention of the researchers. All the categories of respondents perceived that AES had got ‘more potential’ in the transfer of technology in terms of disseminating information to the users. The combination of AES and human expertise showed better performance and higher Information Efficiency Index (IEI) among the extension personnel and farmers. Majority of the extension personnel rated AES with high IEI. Whereas majority of the farmers rated AES with low IEI. Extension personnel and farmers assessed that the overall percentage of solution offered by AES in the plant protection of rice, coconut and banana was almost on par with the solutions given by human experts and in combination, it served better. It is better to introduce the AES designed separately for extension personnel and farmers. It is also necessary to release the software among the prospective users after a comprehensive orientation in using the AES. Maximum potential of AES can be explored by making the users as the partners in the AES development process to ensure user friendliness of Agricultural Expert System.
Open Access
Development of protocol for quality control of commercial organic manures and their evaluation
(Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2008) Gowri Priya; KAU; Harikrishnan Nair, K
The research project entitled “Development of protocol for quality control of commercial organic manures and their evaluation” was conducted at College of Agriculture, Vellayani during 2006-2008, with the objectives of quality evaluation of the major commercial organic manures in Kerala, development of a quality protocol for assessing quality and detecting adulteration in commercial organic manures, studying the mineralization pattern of major nutrients in selected manures and their comparative effect on crop performance. Forty four commercial organic manure products and their raw materials were collected from the manufacturers allover Kerala and their physical, chemical and biochemical characters were analysed. Standard compost manures viz., standard vermicompost, standard coirpith compost and standard city waste compost were prepared at the Instructional Farm, College of Agriculture, Vellayani and their physical, chemical and biochemical characters were analysed. The raw materials viz. bone meal, leather meal and neem cake were mixed in different proportions and the characters of the resulting organic meal mixtures were estimated. Based on these data, a protocol was developed to predict the nitrogen, phosphorus and potassium contents of the organic manures prepared by mixing bone meal, leather meal and neem cake in any ratio. A storage experiment was conducted to study the changes in quality aspects of organic manures during a period of one year. The quality parameters of market samples and the corresponding factory samples of COMs were compared. An incubation experiment was conducted to study the nutrient mineralization pattern of organic manures. A field experiment was carried out to evaluate the performance of selected organic manures using amaranthus variety Arun as test crop. The results of the investigation revealed that none among the forty four commercial organic manures conformed completely to the quality standards specified by the Fertilizer (Control) Amendment Order, 2006, of the Government of India. The colour of COMs varied depending on their raw materials (ingredients) and the odour of COMs varied depending on raw materials and the state of decomposition. The total nitrogen contents of COMs varied from 0.7 per cent to 7.87 per cent. Majority of the COMs had total nitrogen contents between 2.8 per cent and 5.85 per cent. The C/N ratio of COMs varied from 2.86 to 43.18 and only one product viz. SN 4 (Neem cake marketed by TIFFCO Fertilizers & Chemicals) had a ratio more than 20:1. All the COMs contained satisfactory level of total organic carbon. The total phosphorus content varied from 0.12 per cent to 4.57 per cent and the total potassium content in COMs varied from 0.12 per cent to 7.87 per cent. Only eighteen of the COMs had pH in the neutral range and with respect to EC, only three COMs were good for use having EC values less than 4 dS m-1. Based on heavy metal contents, the COMs P.L.meal (PL Agro Technologies Ltd.), Skymeal (Vembanad Chemicals & Fertilizers) and Haritha Super (The Gramakarshaka Fertilizer Company Pvt Ltd.) were found unsuitable for long term application to soil. The standard compost manures did not conform to the specifications of moisture content and bulk density as per Fertilizer (Control) Amendment Order, 2006. The total nitrogen content of SVC was 1.4 per cent, SCC 0.7 per cent and SCWC 2.1 per cent. All the three SCMs recorded C/N ratios below 20. SVC and SCWC had satisfactory levels of total P while SCC was poor in total P. The three SCMs did not contain enough total K to conform to the minimum limit prescribed by the Fertilizer (Control) Amendment Order, 2006. The pH of SVC and SCWC were within the neutral range of 6.5- 7.5, while SCC was more acidic with pH of 3.93. The electrical conductivity of the SCMs ranged from 0.33 to 3.4dS m-1. The total organic carbon contents of SCMs were above 30 per cent. SCMs had heavy metal contents below the maximum limits prescribed by the Fertilizer (Control) Amendment Order, 2006. The analysis of raw materials revealed that leather meal was a good source of nitrogen, bone meal and pressmud were good sources of phosphorus and pressmud was the best source for potassium. The mathematical models developed for predicting the N, P and K contents of any mixture of bone meal, leather meal and neem cake were: N estimated= 3.62088 BM+ 6.58962 LM+ 1.74407 NC+ 4.74391 (BM)x(LM) + 7.8398 (BM) x (NC) – 9.87862 (LM)x(NC), where BM is the proportion of bone meal in the mixture, LM is the proportion of leather meal in the manure and NC is the proportion of neem cake in the mixture. P estimated= 8.41214 BM+ 0.37157 LM+ 0.41953 NC- 2.73548 (BM) x (LM) + 10.15749 (BM) x (NC) – 8.72905 (LM) x (NC) K estimated= 0.38543 BM+ 0.01872 LM+ 1.19747 NC+ -0.04393 (BM) x (LM) + 2.98573 (BM) x (NC) – 5.64704 (LM) x (NC) The model could be used for finding out adulteration of organic manures with inorganic fertilizers to boost their nutrient contents. Different ratios of bone meal, leather meal and neem cake were worked out to prepare organic manures with different levels of N, P and K. The results of the storage study showed that the organic carbon content of organic manures decreased from the initial value during the storage period of one year. The changes in nitrogen, phosphorus, potassium and sodium contents of organic manures showed varying patterns during storage. Comparison of quality of market and factory samples of COMs revealed that the organic carbon and nitrogen content of all the market samples were significantly less than their corresponding factory samples while P and K contents showed varying patterns. The mineralization patterns of major nutrients from the organic manures in incubation experiment indicated that in general, the available nitrogen and phosphorus contents in soils treated with organic manures increased upto 30-45days after incubation and decreased thereafter. The mineralization pattern of potassium from organic manures in soil showed pronounced variation. The treatment with Karshaka Agromeal Grade I (SN 26) recorded higher contents of N, P and K. In the field experiment the highest yield in the first crop was in the treatment with NPK fertilizers + Karshaka Agromeal Grade I. The control treatment with no fertilizers and manures recorded the lowest yield. The application of organic manures was found to improve the quality aspects of the crop. The highest content of available N in soil after harvest of first crop was recorded in T10 (NPK fertilizers + SVC) and lowest available N content was observed in T4. The available phosphorus content after harvest of first crop was highest in T7 (NPK fertilizers + Golden meal) and the lowest value of available P2O5 was observed in T6 (NPK fertilizers +Skymeal). The available potassium content after harvest of first crop was highest in T10 and the lowest content of available potassium was obtained from T14. Application of organic manures was found to raise the pH of the soil in treatment plots. The electrical conductivity of soil was significantly influenced by the different treatments. The highest yield, total dry matter production, total marketable yield and total yield per plant of the second crop was recorded in T7 (NPK fertilizers +Golden meal) and the lowest was in T14. The highest B: C ratio of 1.31 was recorded in T4 and the lowest value was recorded in T14 (absolute control) which had a B:C ratio of 0.90.
Open Access
Contributing factors and problems associated with overweight among rural and urban school children
(College of Agriculture, Vellayani, 2008) Ambily, G Uniithan; KAU; Syamakumari, S
We live in an energy sparing society today. Changes in diet coupled with increasingly inactive life styles have sparked off overweight and obesity in several countries of the world including India and Kerala. Overweight is associated with the onset of major chronic diseases leading to complications and also psychosocial problems in children and adults. The greater concern is that the risks of overweight during childhood will persist into adolescence and adulthood. Hence close monitoring of overweight prevalence in children and adolescents and taking timely preventive measures will be an effective approach in dealing with the problem of obesity. The study entitled “Contributing factors and problems associated with overweight among rural and urban school children” was undertaken with the major objective to assess the contributing factors and related problems due to overweight among rural and urban school going children and to find out the impact of diet counselling. A total of 3886 children from the selected schools were screened for overweight and obesity using standard overweight/obesity indicators. The sample selected for the study comprised of a total of 840 school going children of which 720 belonged to the experimental group of overweight children and 120 belongs to the control group of normal weight children. The sample was selected from 10-15 years of age group with equal number of boys and girls from each of the six age groups selected from rural and urban areas of Thiruvananthapuram District. A comprehensive analysis of socio economic and demographic features, time utilization, activity pattern and dietary profile of the subjects were carried out to find out the contributing factors behind the development of overweight and obesity in school going children. A probe into the health, physical, academic, psychosocial and behavioural adjustment problems was also undertaken to get a picturesque and exhaustive information on the problems associated with overweight and obesity. A systematic and in-depth appraisal to understand the dietary adequacy, macronutrient intake, energy balance and impact of diet counselling and health education was also carried out on the micro sample of 120 children selected from the macro sample of 840 overweight and normal weight children. The data collected was statistically analysed to determine the significant difference between the overweight and normal weight children in the areas studied and also to give the relationship or association of the variables selected for the study. The major findings of the study are: From the total of 3886 children screened, the overall prevalence of childhood obesity was found to be 4.99 per cent, 17.73 per cent was overweight when only 58.67 per cent was normal weight, 16.16 per cent was under weight with a BMI less than 15, and 2.44 were severely malnourished with BMI less than 13. An interesting observation made was that the overall prevalence of overweight and underweight was comparable at 16 to18 percent. The study thus proved that even though the indicators of over nutrition like overweight and obesity are rising disturbingly, undernutrition is still a problem even in Kerala. Region wise comparison of anthropometric measurements revealed that there was significant difference at 1 per cent level in body weight, BMI, body fat, waist circumference, waist:hip ratio and MUAC of overweight and normal weight children. The sample as a whole form two homogeneous groups with most of the overweight children hailing from middle income and upper middle income whereas majority of the normal weight children were from lower middle income and middle income showing that income is a contributing factor for overweight and obesity. Majority of the children in both groups were from nuclear families with one or two siblings and with parents having good education and employment status. A greater majority of overweight children were living in own houses. The dietary habits and preferences of the sample studied were in par with earlier studies done in this field with significant difference between overweight and normal weight children. Results revealed that snacking habits seen in overweight children could also be a contributing factor of obesity. The study also revealed that majority of the sample in both groups were non –vegetarians. The intake of cereals, meat group, snacks, hotel/canteen foods, and sweets were higher in overweight children. Similarly, the intake of macronutrients like carbohydrate, fat and protein were also significantly higher in overweight children. The activities and time utilization pattern of the overweight and normal weight subjects were noted to have a significant contribution to their weight condition. The sedentary activities were significantly higher and heavy activities were significantly lower in overweight children confirming the proved fact that the lesser the energy spent, more is the gain in weight. The evaluation of the energy balance computed from energy intake and energy expenditure revealed the following. The difference in energy intake and the positive energy balance was found to be significantly higher in overweight children compared to that of normal weight children indicating the need for maintaining an energy balance consistently for weight maintenance. The knowledge, attitude and practices of the children were assessed in the areas of nutrition, diet related diseases, physical activity and weight reduction. The difference was found to be significant between overweight and normal weight groups in all the three areas with normal weight having higher scores indicating better knowledge, right attitude and correct practices. When the problems associated with overweight and obesity were assessed, overweight children were noted to have more problems associated with puberty like early menarche, problems with menstrual bleeding in girls while early/late voice change and appearance of facial hair and secondary sex characteristics were seen in boys. The health and physical problems, though not very prominent in both weight groups, the percentage of overweight children having health and physical problems were higher. Similarly, the psycho social and behavioural adjustment and academic problems in overweight children were significantly higher than normal weight children. On assessment of the impact of diet counselling, a significant difference at 1 per cent level was observed in the before and after values of weight, BMI and body fat of overweight children. Overweight children who received diet counselling and health education showed significant reduction in weight, BMI and body fat when compared to that of control group. The study revealed that family history of obesity, high financial status, and dietary factors like faulty dietary habits and excessive intake of energy dense foods along with increased sedentary life style and significant reduction in physical activity or energy expenditure form the major contributing factors towards the development of overweight and obesity. Overweight and obese children are also found to have significantly higher pubertal problems, health, physical, academic, psychosocial and behavioural adjustment problems than normal weight children. However the study proved that, with proper dietary and behavioural interventions along with constant help, support, encouragement and motivation from all the family members and health care professionals, overweight children can definitely regain and maintain their ideal body weights and lead a normal healthy way of life. The control of this epidemic is a challenge and requires strong social and political will in addition to medical management. The results obtained suggest the intervening role of socio-economic and demographic environment, knowledge, attitude and food habits, life style pattern, work load and psychosocial adjustments on the dietary profile of overweight children. This prompts for further researches to improve the nutrition related knowledge of children and to inculcate the importance of leading a healthy life style which incorporate ample physical activity with decreased work load and tension. Urgent measures to improve the food habits of school going children are also recommended. Parents are the key players when developing interventional programmes in children. Therefore interventional programmes should be planned in such way that will create awareness in parents about the importance of weight reduction in leading a healthy life with lesser physical, psychosocial and health problems through proper diet and adequate physical activity.
Open Access
Species diversity of the orchard fruit fly complex and the biorational management of the mango fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae)
(College of Horticulture, Vellanikkara, 2008) Thiyagarajan, P; KAU; Jim, Thomas
The mango fruit fly, Bactrocera dorsalis (Hendel), is one of the serious pest of orchard systems, causing severe economic damage in fruit crops. Because of the enigmatic behavioural adaptations of the fruit fly species in different host fruits, the conventional pest management practices often provide unsatisfactory results. More over, the use of chemical interventions result in the usual set backs of insecticide resistance, pest resurgence, destruction of natural enemies and pollinators, pesticide residue in the harvested produce and related environmental and health hazards. Hence, there is an impetus for research and development on sustainable and eco friendly fruit fly management technology in orchard crop systems. In this context, the study on “Species diversity of the orchard fruit fly complex, and the biorational management of the mango fruit fly, Bactrocera dorsalis (Hendel) (Diptera : Tephritidae)” was carried out in the Department of Agricultural Entomology, College of Horticulture at Vellanikkara and farmers field during 2005-07. Investigations were undertaken to study the population dynamics of orchard fruit fly complex in different host fruits and to correlate its seasonal occurrence with the weather parameters, to evaluate the different types of lure material for fruit fly monitoring and management by various lure application techniques, to evaluate the emergence pattern, location of alightment on host trees, optimum height of trapping and distribution of fruit fly, to evaluate different food lures under cage experimentation and finally, to evolve an eco-friendly and biorational pest management strategy against B. dorsalis in mango orchards. The population of orchard fruit flies responding to methyl eugenol was monitored at weekly intervals from August 2005 to July 2006 at three locations in the KAU orchards in Vellanikkara and Mannuthy campuses and found that the highest peak of population was observed during the second week of March and the lowest during the third week of December. As different orchard fruits are serving as hosts for the B. dorsalis complex such as sapota, lovi lovi, citrus, fig, guava, carambola and jack, their population attained several peaks as and when different fruits were available in plenty in their respective fruiting seasons. Correlations between fruit fly catch (in mango) in ME traps and the weather parameters at Vellanikkara revealed that the maximum and minimum temperatures showed a significant positive correlation with the fruit fly population. Among other host fruits, rainfall showed a positive correlation with the fruit fly population in sapota. In Lovi lovi, maximum and minimum temperatures as well as relative humidity showed a positive correlation with the fruit fly population. In jack maximum and minimum temperatures increased the catch of fruit fly numbers. In guava, fig and carambola, all the weather parameters showed a non significant correlation with fly population. The population of mango fruit flies and other species responding to methyl eugenol traps were monitored at monthly intervals from August 2005 to July 2006 at Vellanikkara. Four species of fruit flies viz., B. dorsalis, B. caryeae, B. correcta and B. zonata were identified and the average monthly catches were 1436.41, 77.83, 27.25, 19.33 flies/trap respectively. The species diversity index worked out revealed that the mango fruit fly, B. dorsalis is the most dominant species as compared to the other three species. Sex ratio studies revealed that B. dorsalis population in ripe mango, bread fruit, rose apple and fig was more rather male biased with 1:0.99, 1:0.89, 1:0.97, 1:0.94 respectively, while, there was a slight female dominance (1:1.06) in guava. The optimum height for the ME bottle traps for fruit fly monitoring and management in mango was determined to be at two metre above the ground level during both rainy and non rainy periods in mango. The optimum height for the lure swab treatment on mango and bread fruit trees was found to be again at two metre height with more number of entrapped flies while, in sapota, it was only at 1.5 metre height. Among the four directions of attractional and behavioural orientations to the lure swabs, the western and southern sides of the tree trunks were having the higher number of fly catches as got stuck. The emergence rate of mango fruit flies from the soil was recorded to be higher from the middle zone at a distance of 2-3 meters radial distance from the tree base. The peak time of adult fly emergence from the soil litter was found to be between 6 am to 10 am. The time of attraction in the Spathiphyllum plants acting as a trap plant for fruit fly attraction to its spadix was found to be between 7 to 8 am. The studies on the behavioral alightment and hiding place of the adult flies on the mango tree revealed that they prefer to colonize on the under side of the leaves in the lower canopy during the season. The flies were also observed to frequent more on the proximal end of the maturing fruits especially borne in the lower branches of the tree canopy. The fruit fly attraction to different food lures when tested under cage experimentation proved that the flies were attracted more towards the fruit macerates of banana varieties viz., Poovan and Robusta and also to other host fruits namely Prior variety of mango followed by rose apple. The maximum response of fruit flies to ME traps as evidenced by the male catch was determined between 4-6 pm and 6-8 am under shaded tree canopy during the mango season. The studies on the population levels of mango fruit fly in ten different locations from Thrissur (Kerala) to Sadayanpallam (Tamil Nadu) over a distance of 75 km with the ME traps revealed that the trend of population increase from flowering to harvest across the region was almost similar and there was no probability of any suspected migration. Among mango varieties observed, the Prior and Alphonso were found to be having the maximum fruit fly infestation. Neelam, Moovandan and Chandrakaran were the least susceptible ones. Among the other host fruits, rose apple and guava had recorded higher infestations as high as 100 per cent and 30 per cent respectively. The results on the sticky trap experiments in mango and sapota orchard revealed that a vertically hanging yellow poly pack board of size 30 x 20 cm was having the maximum number of entrapped fruit flies. The newer application technique with sticky lure swabs on the tree trunks with gelatin based formulations in combination with ME and ME- banana macerate proved efficient in both trapping the adult flies and consequent reduction in fruit damage. Three field experiments undertaken to evaluate the efficacy of selected biorational techniques against mango fruit fly in variety Prior and Alphonso in the College orchard at Vellanikkara, revealed that the methyl eugenol bottle trap and methyl eugeonl + banana lure swab formulation on the tree trunk recorded the lowest fruit damage as compared to other treatments. Post harvest loss by the latent damage incited by the already oviposited eggs on the pre ripened fruit before harvest could be successfully prevented by the hot brine (0.5%) dip treatment of the fruits at 55°C for 15 minutes which afforded 100 per cent protection by the fly maggots during post harvest storage. Studies on the natural enemies of B. dorsalis complex in mango, resulted in the identification of one larval pupal parasitoid namely Biosteres arisanus (Sonan), which was having only 2.76 per cent natural parasitism on the maggots with in the fruits as evidenced by the ecloded adult parasitoid under the laboratory conditions. The mango fruit fly, Bactrocera dorsalis (Hendel), is one of the serious pest of orchard systems, causing severe economic damage in fruit crops. Because of the enigmatic behavioural adaptations of the fruit fly species in different host fruits, the conventional pest management practices often provide unsatisfactory results. More over, the use of chemical interventions result in the usual set backs of insecticide resistance, pest resurgence, destruction of natural enemies and pollinators, pesticide residue in the harvested produce and related environmental and health hazards. Hence, there is an impetus for research and development on sustainable and eco friendly fruit fly management technology in orchard crop systems. In this context, the study on “Species diversity of the orchard fruit fly complex, and the biorational management of the mango fruit fly, Bactrocera dorsalis (Hendel) (Diptera : Tephritidae)” was carried out in the Department of Agricultural Entomology, College of Horticulture at Vellanikkara and farmers field during 2005-07. Investigations were undertaken to study the population dynamics of orchard fruit fly complex in different host fruits and to correlate its seasonal occurrence with the weather parameters, to evaluate the different types of lure material for fruit fly monitoring and management by various lure application techniques, to evaluate the emergence pattern, location of alightment on host trees, optimum height of trapping and distribution of fruit fly, to evaluate different food lures under cage experimentation and finally, to evolve an eco-friendly and biorational pest management strategy against B. dorsalis in mango orchards. The population of orchard fruit flies responding to methyl eugenol was monitored at weekly intervals from August 2005 to July 2006 at three locations in the KAU orchards in Vellanikkara and Mannuthy campuses and found that the highest peak of population was observed during the second week of March and the lowest during the third week of December. As different orchard fruits are serving as hosts for the B. dorsalis complex such as sapota, lovi lovi, citrus, fig, guava, carambola and jack, their population attained several peaks as and when different fruits were available in plenty in their respective fruiting seasons. Correlations between fruit fly catch (in mango) in ME traps and the weather parameters at Vellanikkara revealed that the maximum and minimum temperatures showed a significant positive correlation with the fruit fly population. Among other host fruits, rainfall showed a positive correlation with the fruit fly population in sapota. In Lovi lovi, maximum and minimum temperatures as well as relative humidity showed a positive correlation with the fruit fly population. In jack maximum and minimum temperatures increased the catch of fruit fly numbers. In guava, fig and carambola, all the weather parameters showed a non significant correlation with fly population. The population of mango fruit flies and other species responding to methyl eugenol traps were monitored at monthly intervals from August 2005 to July 2006 at Vellanikkara. Four species of fruit flies viz., B. dorsalis, B. caryeae, B. correcta and B. zonata were identified and the average monthly catches were 1436.41, 77.83, 27.25, 19.33 flies/trap respectively. The species diversity index worked out revealed that the mango fruit fly, B. dorsalis is the most dominant species as compared to the other three species. Sex ratio studies revealed that B. dorsalis population in ripe mango, bread fruit, rose apple and fig was more rather male biased with 1:0.99, 1:0.89, 1:0.97, 1:0.94 respectively, while, there was a slight female dominance (1:1.06) in guava. The optimum height for the ME bottle traps for fruit fly monitoring and management in mango was determined to be at two metre above the ground level during both rainy and non rainy periods in mango. The optimum height for the lure swab treatment on mango and bread fruit trees was found to be again at two metre height with more number of entrapped flies while, in sapota, it was only at 1.5 metre height. Among the four directions of attractional and behavioural orientations to the lure swabs, the western and southern sides of the tree trunks were having the higher number of fly catches as got stuck. The emergence rate of mango fruit flies from the soil was recorded to be higher from the middle zone at a distance of 2-3 meters radial distance from the tree base. The peak time of adult fly emergence from the soil litter was found to be between 6 am to 10 am. The time of attraction in the Spathiphyllum plants acting as a trap plant for fruit fly attraction to its spadix was found to be between 7 to 8 am. The studies on the behavioral alightment and hiding place of the adult flies on the mango tree revealed that they prefer to colonize on the under side of the leaves in the lower canopy during the season. The flies were also observed to frequent more on the proximal end of the maturing fruits especially borne in the lower branches of the tree canopy. The fruit fly attraction to different food lures when tested under cage experimentation proved that the flies were attracted more towards the fruit macerates of banana varieties viz., Poovan and Robusta and also to other host fruits namely Prior variety of mango followed by rose apple. The maximum response of fruit flies to ME traps as evidenced by the male catch was determined between 4-6 pm and 6-8 am under shaded tree canopy during the mango season. The studies on the population levels of mango fruit fly in ten different locations from Thrissur (Kerala) to Sadayanpallam (Tamil Nadu) over a distance of 75 km with the ME traps revealed that the trend of population increase from flowering to harvest across the region was almost similar and there was no probability of any suspected migration. Among mango varieties observed, the Prior and Alphonso were found to be having the maximum fruit fly infestation. Neelam, Moovandan and Chandrakaran were the least susceptible ones. Among the other host fruits, rose apple and guava had recorded higher infestations as high as 100 per cent and 30 per cent respectively. The results on the sticky trap experiments in mango and sapota orchard revealed that a vertically hanging yellow poly pack board of size 30 x 20 cm was having the maximum number of entrapped fruit flies. The newer application technique with sticky lure swabs on the tree trunks with gelatin based formulations in combination with ME and ME- banana macerate proved efficient in both trapping the adult flies and consequent reduction in fruit damage. Three field experiments undertaken to evaluate the efficacy of selected biorational techniques against mango fruit fly in variety Prior and Alphonso in the College orchard at Vellanikkara, revealed that the methyl eugenol bottle trap and methyl eugeonl + banana lure swab formulation on the tree trunk recorded the lowest fruit damage as compared to other treatments. Post harvest loss by the latent damage incited by the already oviposited eggs on the pre ripened fruit before harvest could be successfully prevented by the hot brine (0.5%) dip treatment of the fruits at 55°C for 15 minutes which afforded 100 per cent protection by the fly maggots during post harvest storage. Studies on the natural enemies of B. dorsalis complex in mango, resulted in the identification of one larval pupal parasitoid namely Biosteres arisanus (Sonan), which was having only 2.76 per cent natural parasitism on the maggots with in the fruits as evidenced by the ecloded adult parasitoid under the laboratory conditions.

Theses

Browse

Thesis Type

Type

Author

Date

Subject

Search Results