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Open Access
Evaluation of multi x bi bivoltine hybrids of silkworm
(1998) Rajeni, Narayanan; KAU; Ranjith, A M
In a study undertaken to evaluate the region and season specific multi x bi and bivoltine hybrids of silkworm Bombyx mori, for commercial exploitation in Kerala, six hybrids of silkworm were reared using K-2 and S-36 mulberry varieties under Vellanikkara condition. The crosses used were PM x NB18, PM X NB4D2 and their reciprocals, NB4D2 x NB18 and its reciprocal and PM as check. The evaluation was carried out based on characters like leaf consumption, larval duration and weight, cocoon and shell weights, shell ratio percentage, average filament length, denier, reelability and renditta. The climatic factors were also correlated with major economic characters of silkworm. The present study confirms the superiority of bivoItine silkworm hybrids like NB4D2 x NBI8 and NB18 x NB4D2 justifying their wide acceptance in states other than Kerala. It is evident that if rearing is done in a systematic way, by strictly adhering to the brushing period in correlation with the seasons and if the use of high quality mulberry varieties is advocated these crosses will yield good returns in Veil ani kkara. Though the various economic parameters reflected a variable trend, ultimately when the average filament length/g cocoon, shell ratio percentage and cocoon weight were considered, the bivoltine hybrids performed superior to the others.
Open Access
Bio farming in vegetables : effect of bio fertilizers in amaranth
(Department of Agronomy, College of Agriculture, Vellayani, 1998) Niranjana, N S; KAU; Meerabai, M
An experiment was conducted at the Instruction farm attached to the College of Agriculture, Vellayani, during April - Sept 1996 with objectives of finding out the impact of biofertilizers Arospirillum , AMF and dual inoculation under varying and varied levels of fertilizer on amaranthus. Study also aimed to note the economics of the integrated approach and to identify the best economic combinations which improve yield and quality of amaranth varieties Arun and Kannara local. The study had three controls and two number of replications. The results of the study revealed that yield attributing characters like no: of harvests, yield harvest", marketable yield and dry weight were highest in plots applied with dual inoculation of Azospirillum and AMF with 75 per cent dose of p.op. Azospirillum with 50 per cent POP also gave good results. Both these treatments were on par and was better than our state recommendation. Growth characters viz: Seedling growth rate, plant height, number of leaves per plant, number of branches per plant, LAI were highest. for Azospirillum inoculation at early stages. While AMF inoculation gave notable results at later stages. Physiological parameters namely Biomass, NAR, Root dry weight were significantly improved with dual inoculation and higher dose of chemical fertilizer. Leaf dry weight, RGR and CGR responded most to inoculation with Azospirillum at early stages, while at later stage AMF performed well. Kannara local was superior to 148 Arun at early stages. But Arun performed superior to Kannara local with the progress of time. Stem dry weight was significantly influenced by application of AMF. Vermicompost gave high biomass till 45 DAT. Quality of amaranth improved when biofertilizer was given with higher dose of chemical fertilizer in almost all parameters discussed. Dual inoculation with 75 per cent POP gave maximum content of total mineral and moisture. Ascorbic acid content was highest for the treatment dual inoculation with 25 per cent POP. AMF with 75 per cent POP recorded high protein content, the same bioagent with 50 per cent POP gave lowest content of oxalates. Less fiber flush of amaranth w.as got from plots given Azospirillum + 75 per cent POP. Uptake of major nutrients namely Nand P was influenced by inoculation of Azospirillum along with higher dose of chemical and AMF with lower inorganics respectively. Major nutrient status in the soil after the experiment was more in case N,P,K for dual inoculation, Arospirillum and AMF respectively. Irrespective of biofertilizer higher dose of inorganic gave greater residual amount of nutrients. Dual inoculation with 75 per cent dose and Azospirillum along with 50 per cent dose gave maximum l?:C ratio and net returns. Vermicompost recorded minimum disease score. Lower levels of chemical fertilizers recorded less infection.
Open Access
Nodulation Behaviour Of Acacia Mangium Wikd.In Response TO Rhizobium Inoculation
(Department of Tree Physiology and breeding, College of forestry,Vellanikkara, 1998) Dhaneshkumar, P; KAU; Ashokan, P K
An investigation was carried out during April 1996 to December 1997 at the College of Forestry, Kerala Agricultural University, Vellanikkara to study the nodulation characteristics of Acacia mangium Willd. plantation and to isolate and compare the efficiency of rhizobia from different agroclimatic regions of Kerala. The efficiency of these rhizobial isolates under varying conditions of soil fertility and acidity were also evaluated. Survey conducted throughout the state showed rhizobial association and nodulation in all mangium plantations. The soil of these plantations were acidic with pH values ranging from 4.9 to 6.2. Experiments conducted to study the rhizobial characteristics indicated that, the fast growers (Rhizobium spp.) as well as the slow growers tBradyrhizobium spp.) are involved in nodulation of A. mangium in Kerala. The efficiencies of different rhizobial isolates were studied in polypots using sterilized and unsterilized soil - sand mixture. Two other polypot experiments were conducted to study the response of the rhizboial isolates to liming and Nand P application. The experiments were laid out in C.R.D with three replications. Seedlings raised in unsterilized soil performed better as compared to seedlings in sterilized soil. However, the response to inoculation was more prominent in sterilized soil. In sterilized soil, seedlings inoculated with Rhizobium isolates from mangium ;MRh-3 (Mananthavadi), MRh- 2(Perambra), MRh-13 (Trivandrum), MRh-6 (Vellanikkara) and MRh-lO (Mavelikkara) and commercial mangium culture (" Agroforester - Group A") showed superiority in nodulation and growth characteristics while the isolates from A. auriculijonnis and commercial culture of A. auriculijonnis, ("Agroforester - Group C") were not much effective. Seedling - response to inoculation varied with rhizobial isolates, and mangium showed its specificity in Rhiozbium requirement for nitrogen fixation. The application of lime adversely affected nodulation capacity of the rhizobial isolates of mangium from Kerala, indicating the adaptations of these isolates to acidic soils. The nodulation efficiency of commercial culture "Agroforester - Group A" was improved by lime application, indicating that this strain is adapted to soils of higher pH. The nodulation and nitrogen fixing efficiency of the isolates were improved by supplementating fertilized N and P. The need for a starter dose of Nand P for effective nodulation and efficient Ny-fixation in mangium seedlings. MRh-6 (Vellanikkara) performed poorly in unfertilized soil, but showed superiority when applied with N and P fertilizers, indicating the sensitivity of this isolate to site conditions. As the rhizobial isolates from different agroclimatic regions of Kerala responded differently under varying soil pH and doses of Nand P, inoculation of selected strains of rhizobia depending on site conditions may be needed for successful establishment of mangium seedlings.
Open Access
Nutrient Status of the soil and plant as influenced by spacing and continued manuring in Coconut
(Department of Agronomy, College of Agriculture, Vellayani, 1998) Pratheep, M S; KAU; Purushothaman Nair, N
A study was conducted during 1995-96 at Coconut Research Station, Balaramapuram of Kerala Agricultural University to asses the nutrient status of . the soil and plant in West Coast Tall coconuts planted at three different spacings and manured with three levels of macro nutrients. The treatments were three spacings (5 m x 5 m, 7.5 m x 7.5 m and 10 m x 10 m) and three fertilizer levels (control i.e., zero NPK, the lower level i.e., 340 g N + 225 g P205 + 450 g K20 per palm per year and the higher level i.e., 680 g N + 450 g P205 + 900 g K20 per palm per year). The basic experiment was started in 1964 and being continued. The data collected during the study (1995-96) was statistically analysed and the results are presented here under. Closer spacing increased height of palms. The spacings of7.5 m x 7.5 m was statistically superior since it gave the highest nut yield per palm per year. Manuring increased height of palms, girth and leaf production. At the highest level of NPK closer spacing of 5 m x 5 m could give the highest yield per unit area. Female flower production was higher under 7.5 m x 7.5 m spacing. Fertilizer application also increased flower production. Fruit setting was not influenced by palm density and fertilizer application significantly increased fruit setting. Number of nuts per bunch was higher at the spacing of 7.5 m x 7.5 m and progressively increased with manuring. The weight and volume of unhusked nut was the lowest at the closest spacing and in unfertilized palms. There was increase in weight of husk with increase in spacing. Similarly there was an increase in the ratio of weight of husk to unhusked nut with increasing spacing. Maximum thickness and weight of kernal was recorded at the spacing of 7.5 m x 7.5 m. Copra out turn was more at the spacing of 7.5 m x 7.5 m. In manured palms there was a higher copra out turn per hectare contributed by the higher yield. The oil content of copra was negatively correlated with per palm yield. Available NPK of soil decrease with wider spacing. The soil nutrient status increased with application of macronutrients and the accumulation of fertilizer was more in the upper layer of 0 to 25 cm. There was decline in NPK status with increase in depth. The Ca and Mg content of soil decreased with increase in spacing up to 7.5 m x 7.5 m. Both Ca and Mg content of soil decreased with increase in macro nutrient application. Ca content of soil decreased with increase in depth. However, the decrease of Mg content was seen only up to 50 cm depth. Available micro nutrients (Fe, Cu, Mn and Zn) decreased with increase in spacing and application of fertilizers. Available Fe, Cu and Mn content of soil decreased with increase in depth. Nand P content of leaf of coconut increased with wider spacing. However K content decreased with spacing. All the three macro nutrients increased with increase in fertilizer application. Ca and Mg content of leaf also increased with increase in spacing and fertilizer application. By fertilizer application Fe, Mn and Cu content of leaf increased whereas Zn and Na decreased.
Open Access
Gaps In The Adoption Of Plant Protection Practices By Commercial Vegetables growers Of Thrissur District
(Department of Agricultural Extension, College of Horticulture,Vellanikkara, 1998) Manoj, M; KAU; Joy Mathew
It is commonly observed that there is a wide gap between the technology generated in research stations and its actual use by the clientale. It is with this view in mind that the present study was undertaken to identify the gaps in the adoption of plant protection practices by commercial vegetable growers in Thrissur District. The relationship between personal, situational and psychological characteristics of commercial vegetable farmers and their adoption was also studied. The constraints in the adoption process were also subjected to analysis. The study was conducted in Thrissur district. The sample consisted of 150 farmers from the three selected panchayats for the study. Data were collected using pretested and well structured interview schedule and suitable statistical techniques were employed in the analysis of the data. A prime aspect observed during the course of this study was the non- availability of simple and more compatible plant protection technology thus forcing the farmers to accept the failures of applying complex plant protection technology. Lack of adequate and effective linkage between various extension o agencies and research institutions in transfer of technology has led to the confinement of the improved plant protection technology within the research institutions. This has resulted in the non-availability of many an improved technology to the farmers thereby resulted in an unwaranted gap in the adoption of improved plant protection practices by commercial vegetable farmers. The results of multiple regression analysis indicated that cosmopoliteness, information source utilisation and scientific orientation as the important variables tDJ explaining maximum variation in the extent of adoption and level of knowledge about improved plant protection practices by commercial vegetable farmers. The important constraints perceived by the farmers were increased cost of plant protection chemicals, difficulty in preparation/application of pp chemicals, difficulty in the selection of alternate chemicals, inadequacy of capital, non- availability of labour and lack of knowledge about technology. The results point vividly to the prime need for strengthening the extension education efforts of the field functionaries to reduce the gap with respect to the adoption of improved plant protection practices by commercial vegetable farmers.
Open Access
Standardisation of seed processing techniques in chilli (Capsicum annuumL.)
(Department of Olericulture, College of Horticulture, Vellanikkara, 1998) Liji, P V; KAU; Meagle Joseph, P
Studies on seed quality aspects of chilli var. Jwalasakhi and Ujwala were undertaken in the Department of Olericulture, College of Horticulture, Vellanikkara during 1997-98 to fix the optimum fruit maturity stage and to standardise the best seed processing and storage methods for maintaining viability and getting maximum seed quality. Physiological maturity studies in variety Jwalasakhi indicated that fruits reached maximum size by 30 d.a.a. The fresh weight of fruits was maximum at 35 d.a.a. and it was on par with the fresh weight fruits at 30 and 40 d.a.a. So, vegetable harvest of this fruits can be extended from 30 to 40 d.a.a. In the case of variety Ujwala, both fruit length and fresh weight of fruits was maximum at 40 d.a.a. seeds of 45 days maturity recorded the highest 1000 seed weight in variety Jwalasakhi and it was at 40 d.a.a. in variety Ujwala. Seed germination studies revealed that seeds of 45 day maturity recorded the highest germination percentage. After six months storage seeds of 45 days maturity recorded the maximum germination percentage. In general, speed of germination, vigour index and seedling dry weight were maximum for seeds of 45-50 days maturity and it is the optimum stage for harvesting fruits for seed extraction. Seed quality was found to be influenced by different combinations of seed extraction and fruit drying methods. Sundrying of fruits avoiding the peak hours and hand extraction of seeds retained high viability and vigour of seeds during storage. Fruit drying in mechanical drier was deleterious to the seed quality. Both machine and hand extracted seeds of fruits-dried in mechanical drier recorded the lowest mean germination percentage, speed of germination, vigour and seedling dry weight. High value for electrical conductivity of seed leachate was recorded for the seeds from fruits dried using mechanical drier. The results of the seed storage studies indicated that seed germ inability of both varieties was greater in seeds stored in paper bags and this might be due to the escape of excess moisture released in seeds, during storage. Seed viability and storability are largely dependent on the storage conditions and the air conditioned storage of seeds recorded at the maximum germination percentage, speed of germination, seedling dry weight in both chilli varieties and it was lowest for the seeds stored under ambient conditions. From this study it can be concluded that physiological maturity of seeds in chilli var. Jwalasakhi and Ujwala is attained at 45-50 d.a.a. Hand extraction of seeds and sundrying of well ripe fruits avoiding the peak hours maintained germination and seedling vigour during storage. Air conditioned storage and paper containers were best for maintaining the seed quality upto six months.
Open Access
Yield maximisation of banana through organic and inorganic manuring
(Department of Agronomy, College of Agriculture, Vellayani, 1998) Baiju, B R; KAU; Shahul Hameed, S M
. An experiment was conducted at the Instructional farm attached to College of Agriculture, Vellayani during January 1995 to November 1995 with the objective of finding out the different sources of organic and inorganic nutrients for increasing the productivity of Nendran banana, the effect of post shooting application of urea and growth regulators on the bunch weight and to work out the benefit cost ratio by the integrated use of organic and inorganic fertilizers. Four levels of manures and three levels of post shooting treatments were tried in RBD with 3 replications. The results of the study revealed that application of poultry manure at the rate of five kg plant-1 increased total crop duration. Farm yard manure at the rate of 10 kg plant-1 and 2,4-D 10 ppm spray recorded maximum height at all stages. Bunch yield was maximum of (11.39 kg) with poultry manure at 5 kg plant-1, Highest bunch weight was recorded by 2,4-D 10 ppm spray and total number of fingers with urea 1 per cent spray. Among the ripe fruit characters, highest pulp / peel ratio was with poultry manure at the rate of five kg plant-1 even though higher finger weight, pulp weight and lower peel weight were recorded with poultry manure at the rate of five kg plant-1. Application of urea one per cent spray increased weight of finger. Among the quality attributes, higher values for TSS were noticed with level M1. Lowest value for acidity was observed for five kg poultry manure and tying urea 15 g. Total sugar was high with 10 kg farm yard manure and 2,4-D 10 ppm spray and non reducing sugar was high with level farm yard manure at 10 kg plant-1. Sugar-acid ratio was low for vermicompost at the rate of five kg plant-1. Sensory evaluation revealed that all treatments produced fruits with similar taste, flavour and colour. N content of index leaf showed significant variation at harvest with maximum value recorded with neem cake at the rate of five kg plant-1. P content of leaf was maximum with level neem cake five kg plant-1 and minimum with level farm yard manure 10 kg plant-1. The K content of leaf was maximum with neem cake level five kg plant-1 among manurial treatment. When the economics of production was worked out, it was observed that a combination of farm yard manure at 10 kg plant-1 and 2,4-D 10 ppm spray (M1P1) recorded the highest benefit cost ratio. The highest net profit of Rs. 1,49,045 was realised per hectare in farm yard manure at 10 kg plant-1 and 2,4-D 10 ppm spray. The present study revealed that application of poultry manure at five kg plant-1 and 2,4-D 10 ppm spray was beneficial for better growth, yield and quality of fruit in 'Nendran' banana.
Open Access
Vermicompost as a potential organic source and partial substitute for inorganic fertilizers in sweet potato (Ipomoea batatas (L.) Lam.)
(Department of Soil Science and Agricultural Chemistry,College of Agriculture, Vellayani, 1998) Suresh Kumar, S N; KAU; Ushakumari, K
An investigation entitled "Verrnicompost as a potential organic source and partial substitute for inorganic fertilizers in sweet potato (Ipomoea batatus (L) Lam)" was carried out at the Instructional Farm, College of Agriculture, Vellayani during the period December 1995 to April 1996. The main objectives of the study were to study the efficiency of vermicompost as an organic manure, the extent to which inorganic fertilizers can be substituted when vermicompost was used as an organic source and the feasibility of reducing the dose of vermicompost. The experiment was laid out III randomised block design with seven treatments and four replications. The treatments consists of package of practices recommendations of Kerala Agricultural University for sweet potato (cattle manure + inorganic fertilizers) and vermicompost as organic source with graded doses of inorganic fertilizers. The growth parameters like vine length and number of branches did not show any significant variation. However highest vine length and number of branches are noticed in treatment which received vermicompost as a sole source of nutrient. Significant difference was observed in vine yield and highest vine yield was obtained when vermicompost was given as a sole source of nutrients. Yield attributing characters like length and girth of tubers and number of tubers did not show any significant variation. With respect to mean tuber weight and tuber bulking rate, the treatment differed significantly and maximum effect was observed when vermicompost was applied along with half the recommended dose of inorganic fertilizers. Significant treatment effect could be observed in total tuber yield and marketable tuber yield. Vermicornpost with half or 3/4th NPK produced highest yield. From this it could be deduced that by using vermicompost as organic manure in sweet potato, it is possible to bring down the usage of chemical fertilizers. Half or 3/4th dose of vermicompost along with recommended dose of inorganic fertilizers was equally effective as that of package of practices recommendations of Kerala Agricultural University (cattle manure + recommended inorganic fertilizers) in yield and yield attributes of sweet potato. The nitrogen and phosphorus content in the leaves and vmes did not show any significant difference by applying various treatments. But in tubers the nitrogen content was maximum when 1/2 inorganic fertilizers + organic manure as vermicompost was applied. The phosphorus accumulation in tuber was maximum in the combination of full inorganic fertilizers + organic manure as cattle manure was given. The treatment combination of full inorganic fertilizers + organic manure as vermicompost resulted m maximum accumulation of phosphorus in leaves, vines and tubers. Regarding calcium, magnesium and iron contents of leaves, vines and tubers there was no significant difference among various treatments. The application of full inorganic fertilizers + organic manure as vermicompost produced maximum manganese concentration in leaf and tuber. The starch content of tubers showed a decreasing trend with the reduction in the quantity of inorganic fertilizers. But by reducing inorganic fertilizer levels, the reducing sugar percentage increased. The crude protein, crude fibre and carotene contents showed the same trend as that of reducing sugar. The plant uptake of nitrogen, phosphorus and potassium was maximum when 112 inorganic fertilizers + organic manure as vermicompost was applied. The organic carbon level after the crop showed significant difference among various treatments. The maximum organic carbon percentage was noticed when nitrogen as vermicompost + organic manure as vermicompost was given. The growth characters like vine yield, number of branches were negatively correlated with yield. The yield components like number of tubers per plant, tuber weight, uptake of nitrogen, phosphorus and potassium showed positive correlations with yield. The economics worked out show that the highest net profit was obtained when 1/2 inorganic fertilizers + organic manure as vermicompost was given. The cost of cultivation while applying this treatment was minimum and it showed a B C ratio of 2.53.
Open Access
Cataloguing And Identification Of Promising Ashgourd Ecotypes In Relation TO Season And Maturity
(Department of Olericulture, College of Horticulture,Vellanikkara, 1998) Mini Menon, P; KAU; Salikutty Joseph
An experiment was conducted during 1995-96 in the Department of Olericulture, College of Horticulture, Vellanikkara to catalogue and identify promising ashgourd ecotypes in relation to season and maturity. 1birty ecotypes of ashgourd were studied for their variability. The experiment was laid out in randomised block design with three replications. High heritability along with high genetic gain was observed for the characters primary branches per plant, fruit yield per plant, seeds per fruit and average fruit weight. Yield was positively and significantly correlated with length of main vine, nodes on main vine, primary branches per plant, internodal length, leaves per plant at 30 days after sowing, male flowers per plant, female flowers per plant, per cent of female flowers, average fruit weight, fruits per plant, percent of fruit set, circumference of fruit, length of fruit, seeds per fruit and 100 seed weight. Average fruit weight exhibited the highest positive direct effect on fruit yield per plant. The ecotype BH 21 possessing highest values for characters like length of main vine, number of nodes, number of female flowers, fruit yield per plant and number of seeds per fruit was selected to study the effect of sowing time and periodicity of harvests on yield. This experiment was laid out in split plot design taking months of sowing as main plot treatments and intervals of harvesting as subplot treatments. All biometric characters were significantly influenced by the sowing time. The crop sown in October was superior to other crops with regard to number of nodes, earliest node at which the first female flower was formed and fruit retained, number of female flowers, per cent of female flowers, number of fruits per plant, number of seeds per fruit and fruit yield per plant. In general the crops sown during August, September and October performed better in yield contributing characters when compared to the crops raised during other months of the year. The plants under the harvest interval of 14 days produced the highest number of female flowers and fruits per plant. Average fruit weight, circumference, fruit shape index, flesh thickness and number of fully developed seeds were highest for fruits harvested at full maturity. Though more number of fruits were obtained from plants' under a harvest interval of 14 days the highest yield in terms of total fruit weight was realised from plants harvested at full maturity. The crop was succumbed to the attack of pests and diseases throughout the year. Fruit fly infestation was severe in April, May and June sown crop. Incidence of pumpkin beetle was severe 111 February, March, April and May sown crop. Mosaic was severe 00 crops sown in November, December, January and February. June and July sown crops exhibited downy mildew disease. The better expression of yield contributing characters and lower incidence of pests and diseases tor the crops sown during August, September and October indicated that these months are most ideal for raising a crop of ashgourd. The crop weather relationship revealed that maximum temperature during first and second weeks after anthesis had a significant positive correlation with' yield at full maturity. Minimum temperature and sunshine hours also have a positive correlation though not significant. A negative correlation exist between relative humidity and yield.

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