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Open Access
Management of foot rot of black pepper (Piper nigrum L.) with mycoinoculant enriched vermicompost
(Department of Plant Pathology, College of Agriculture, Vellayani, 2002) Divya, S; Sasikumar Nair
The study, "Management of foot rot of black pepper (Piper nigrum L.) with mycoinoculant enriched vermicompost" was done at the Department of Plant Pathology, College of Agriculture, Veliayani to explore the possibility of using vermicornpost as a carrier material for mass production of biocontrol agents and to test its efficacy in controlling the disease. The talc based inoculum of Trichoderma harzianum and soil based granular inoculum of Glomus Jasciculatum were mass produced in vermicompost either alone or in combination with farmyard manure or neem cake in the ratio 1 : 1 and 5 : 1 respectively and the efficacy was compared with the standard carrier material of FYM + neem cake (10 : 1). The population of T. harzianum 15 DAI was maximum in the treatment combination of VC + NC (5 : 1). However, the influence of these carrier materials on percentage of mycorrhizal infection 50 DAI was not statistically significant. Vermicompost as a carrier material for biocontrol agents was further tested in pepper var. Karimunda inoculated with P. capsici. Carrier materials as such had no significant influence on disease control. Reduction in foliar infection, disease index, stem infection and percentage mortality was observed in treatments with biocontrol agents. Disease control was maximum with the treatments involving T. harzianum while plant growth promotion was maximum with G. Jasciculatum. The physiological changes in pepper plants after inoculation with P. capsici and biocontrol agents were studied. The phenol and OD phenol content was more in pathogen inoculated plants. The defence related enzymes peroxidase, polyphenol oxidase and phenylalanine ammonia lyase were enhanced with pathogen inoculation as well as with the application of biocontrol agents. SDS-PAGE analysis of proteins with samples extracted from plants one day after inoculation of pathogen showed the presence of two novel proteins with molecular . weights of 78 kDa and 28 kDa in diseased samples which were absent in treatments without pathogen and also in plants treated with COC.
Open Access
Information education and communication (iec) for iodine defficiency disorders (idd) control
(Department of Home Science, College of Agriculture, Vellayani, 2000) Vishma, C A; Rajani, M
Open Access
Availability indices for stressed nutrients for coconut (Cocos nucifera L) in an ultisol
(Department of Soil Science and Agricultural Chemistry, College of Horticulture, Vellanikkara, 2003) Priya, P; KAU; Sureshkumar, P
The present study was conducted with an objective to analyse the soil-plant system, the levels and interactions of nutrient ions in soil, soil solution and plant thereby / finding out the contributing factors to yield. The importance of the term relative intensity lies in the fact that the contribution of mineral elements to growth and yield of plants depend much on the relative amount of one element with respect to the others rather than the absolute content of individual elements. To study the ionic interactions and to unravel the role of Net Ionic Equilibrium based on Ratio Law on soil plant system, a sample of fifty phenotypically identical palms varying in yield from 14.4 to 84.4 nuts palm" year"! grown under an Ultisol were selected. Index leaf samples were collected during pre and post monsoon seasons from 25 palms each from high yielding and low yielding groups. Soil samples were also collected from the basins of these palms during the same seasons at 30 cm (surface) arid 60 cm (subsurface) depths. Soil solutions at saturation point were extracted from the surface samples by centrifugation technique. These leaf, soil and solution samples were analysed / . for different nutrient ions, and the NIE ratios in these three phases were worked out with respect to K and Na. The soil samples were acidic in nature and the variation in rhizosphere pH must have definitely influenced the solubility as well as absorption of different nutrient ions. In the case of available nutrients, the micro nutrients showed significant direct relation with yield both for high and low yielding populations. This might be due to their restricted availability due to aerobic oxidised condition where Fe and Mn might have been precipitated and got into unavailable forms. The BaCh exchangeable ions and the CEC derived from summing up of these exchangeable ions influenced yield directly. Exchangeable K had got a significant dominance in deciding the NIE ratio in soil, solution and in index leaves. Exchangeable K controlled the soil solution concentration of K which in turn controlled the NIE ratio in solution and the ratios in plant. Exchangeable K directly controlled the plant K content and plant K was positively and significantly correlated with the NIE ratios in plant and these ratios were positively and significantly correlated with yield. The negative significant correlation of exchangeable K with plant Mn and Zn revealed the antagonistic effect of exchangeable K in restricting the absorption of Mn and Zn by plants. Among the ionic concentrations in soil solution, Fe was positively and significantly correlated with yield in both the seasons. Soil solution concentrations of Ca and Mg were antagonistically and significantly related with plant Mn content. Potassium content and the NIE ratio in index leaves were found to have a significant direct relation with yield in the pre-monsoon season. Potassium, Ca and Mg were the dominant cations in plant deciding the total cation concentration in index leaves. The NIE ratios between the exchangeable ions, the ions in soil solution and the ions in index leaf samples were mutually, .positively and significantly correlated among themselves. This lead to the conclusion that there exists a constancy in the relative proportion of nutrient ions in the entire soil-plant system which followed Ratio Law. The study lead to the conclusion that the soil test values of the individual ions alone or the plant content of individual ions alone can't give a clear picture of optimum nutrient requirements for the plant. The relative concentration of K in soil through the ~ concentration in soil solution was found to govern the relative concentration in plant which in turn influenced the yield.
Open Access
Diversity of small mammals in the Parambikulam wildlife sanctury
(Department of Wild Life Sciences, College of Forestry, Vellanikkara, 2003) Lekshmi, R; KAU; Ambika Varma, B
A detailed study was conducted in the Parambikulam Wildlife Sanctuary during 1999-200 I to prepare an inventory and to estimate the abundance of small mammal fauna in diverse ecological habitats of the Parambikulam Wildlife Sanctuary. In this study, a total of twenty seven species of small mammals belonging to eight orders were recorded from the Parambikulam Wildlife Sanctuary. Among the eight orders Rodentia was represented maximum with eleven species followed by Carnivora with ten species, remaining orders represented only by a single species. While comparing the rodents trapped from different habitats, natural forest account for more number of species than plantation and vayal. The most common rodent species in the three habitats was Rattus rattus, whereas Golunda ellioti (Indian bush rat) was found only in the moist deciduous natural forest because of the favourable ecological conditions prevailing there. Maximum diversity was more in the natural forest than in plantation and vayal whereas species richness was more in vayal followed by plantation and natural forest. The relative dominance was also high in natural forest than plantation and vayal. Correlation between floral diversity and rodent species indicates that natural forest with more number of plant species possessed high rodent species richness. The ideal conditions prevailing in the natural forest would have helped the survival of rodent species. The lack of ideal conditions in the plantation and vayal would have been the reason for lesser number of rodent species.
Open Access
Molecular characterization of piper species usiing RAPD technique
(Department of Plantation Crops and Spices, College of Horticulture, Vellanikkara, 2002) Murugan, C; KAU; Sujatha, V S
The study on "Molecular characterization of Piper species using RAPD techniques" was conducted in the Department of Plantation Crops and Spices and CPBMB, College of Horticulture, Vellanikkara, Thrissur from December, 1999 to August, 2001. Material included 13 species/accessions of the genus Piper including Piper nigrutn Linn. These were analysed with 20 selected oligomer decamer primers using PCR technique and agarose gel electrophoresis. The selection of ideal DNA isolation technique was done based on observations of purity of bands, quality of the DNA bands and quantity of DNA recovered. The protocol of Edwards et al. (1991) was selected for DNA isolation with additional step of chloroform-isoamyl alcohol treatment. Fifty decamer primers were screened using DNA. of P. nigrum and 20 were selected based on the number of bands produced, reproducibility of the bands and distinctness of the RAPD profile. RAPD profile of the 13 species of Piper were compared for genetic similarity index (using Jaccard's coefficient), with all 20 selected primers separately. Pooled similarity of the twenty primers put together was found out for 9 species which gave amplification for all the 20 selected primers. The results of pooled analysis was subjected to cluster analysis (SAl-IN) and phenetic dcndrogram was constructed employing UPGMA. Four clusters were obtained, comprising of two accessions of P. nigrum In the first, two accessions of P. longum in the second, P. colubrinutn and P. attenuatum forming the third cluster and P. chaba, P. belle and P. arboreum forming the fourth.
Open Access
Management of phytophthora disease of black pepper (piper nigrum L. walp) using plant growth promoting microbial inoculants
(Department of Plant Pathology, College of Agriculture, Mannuthy, 2003) Beena Nair, S; KAU; Anith, K N
The study, "Management of Phytophthora disease of black pepper (Piper nigrum L. Walp) using plant growth promoting microbial inoculants" was conducted at the Department of Plant Pathology, College of Agriculture, Vellayani to investigate the effect of plant growth promoting rhizobacterial strains belonging to fluorescent pseudomonads and Bacillus spp. and the root endophytic fungus, Piriformospora indica on the suppression of nursery wilt of black pepper incited by Phytophthora capsici. Two strains of fluorescent pseudomonads viz., Pseudomonas putida strain 89B61 and P. jluorescens strain RCL3R4, two strains of Bacillus viz., BY -1 and BY -2 and P. indica were included in the study to explore their potential in plant growth promotion and disease suppression. P. capsici inoculated control, uninoculated healthy control, chemical control (0.20 per cent COC drenched at 15 days intervals) and combined application of Trichoderma harzianum and an AMF, Glomus fasciculatum were maintained for comparison. In the dual culture assay, conducted in vitro for preliminary screening, though P. indica exhibited a slight mycelial growth inhibition initially, the pathogen later overgrew the antagonist. Among the bacteria, fluorescent pseudomonad strains exhibited better mycelial growth inhibition 'on both PDA and Carrot Agar. The influence of different biocontrol agents on growth promotion of the black pepper cuttings was not statistically significant. However, the fluorescent pseudomonad, P. putida strain 89B61 exhibited maximum growth promotion. In the experiment conducted to test the potential of vanous plant growth promoting microbial inoculants in suppressing nursery wilt, the plants treated with spore suspension of P. indica exhibited the highest wilt percentage of 93.22 per cent which was more than that in the inoculated control (37.48). The plants treated with the fluorescent pseudomonad, P. jluorescens strain RCL3R4 recorded a wilt percentage of 6.70. All other treatments were highly effective and checked the infection completely. The Bacillus strain, BY -2 exhibited better disease suppression in vivo. The fluorescent pseudomonad, P. putida strain 89B61 also showed disease suppression in vivo, which indicated that it has the dual function of plant growth promotion and disease suppression.
Open Access
Bionomics and ecological management of coconut eriophyid mite
(Department of Agricultural Entomology, College of Horticulture, Vellanikkara, 2001) Vidya, CV; KAU; Ranjith, A M
The bionomics and ecological management of coconut eriophyid mite, Aceria guerreronis (Keifer) was studied under the Department of Entomology, College of Horticulture, Vellanikkara. The preference of mites to bunches of different maturity, symptoms of damage, population dynamics, relationship of mite population with weather factors and the distribution pattern of mites based on plant morphology were considered for the study. Some ecological management practices were also tried along with this. The experiment was laid out as completely randomised design. Mites were absent in male and female flowers and also on buttons of first bunch. Initiation of infestation starts from buttons of second bunch and population increases further and maximum population is noticed in buttons of third and fourth bunches and thereafter it decreases. This is because after fourth bunch, the meristematic tissue becomes necrotic due to feeding of mites and hence mites cannot feed further easily. Traces of population were noticed even on nuts of ninth bunch. Predatory mites were also seen along with eriophyid mites even though they are very negligible. Symptoms of damage were seen outside from second bunch onwards. The symptom initially appears as whitish streak or triangular patch and it increases further in length and breadth and becomes brownish and later necrotic. In some cases, cracks, cuts and gummosis can be seen on the husk. The relationship between surface damage and mite population was worked out. Maximum mite population was noticed when the surface damage was 1-3 and 3-6 cm2 before and after the removal of perianth respectively and the percentage of damage was 1-3 per cent. Mite population was found to vary with different weather parameters. Minimum temperature of current week, current, -1 and -2 fortnights and maximum temperature of -2 fortnight were positively related with mite population. Morning humidity is also positively related with mite population. Mite population was negatively related with wind speed of zero current, current, -I and -2 fortnights. There is no direct relation between mite population and rainfall, number of rainy days, evening humidity and sunshine hours. Mite infestation was irrespective of the height of the palm, crown shape and perianth arrangement. The intensity of infestation varies between each inner tepals. Maximum infestation was under fourth tepal followed by fifth and sixth tepa\. The preference of mites to different portions under each tepal also varies with maximum entry through the 'outer edge' of fourth tepal followed by 'outer edge' of fifth tepal, 'middle' portion of sixth tepal, 'middle' portion of fifth and fourth tepal, and 'inner edge' of sixth and fifth tepa\. Infestation was found to be less in round shaped nuts compared to oval and oblong nuts. Maximum incidence was in green coloured nuts followed by greenish yellow and orange coloured nuts. There was no reduction in mite damage by different water regimes (rainfed, channel and drip irrigated) fertilizer regimes (0.34:0.17:0.68 kg NPK/palm, 0.5:0.32:1.2 kg NPKlpalm and 0.25:0.32:1.2 kg NPKlpalm) micronutrients (MgS04, ZnS04, MnS04, Borax and Micronutrient mixture) and crown cleaning (once and twice in an year).
Open Access
Spatial and temporal variations in the development of agriculture in Kerala
(Department of Agricultural Statistics, College of Horticulture, Vellanikkara, 2002) Allahad, Mishra; KAU; Ajitha, T K
Agricultural scenario of Kerala is unique as compared to other states of India. The present study entitled "Spatial and temporal variations in the development of agriculture in Kerala" was undertaken mainly with an objective of constructing composite indices to quantify the development of agriculture based on suitable indicator variables for each district or region of Kerala. The significance of the districtwise and temporal disparities in agricultural development have been studied. The agricultural growth with respect to acreage and gross production of major crops • is also estimated using different growth curves. The time series data from 1970-71 to 1997-98 collected from State Planning Board and Directorate of Economics and Statistics, Government of Kerala, Trivandrum were used for the study. As all the districts were not present before 1985-86 state was divided into several regions. Districts wise analysis was carried out from 1985-86 to 1997-98, whereas region wise analysis was carried out from 1970-71 to 1997-98. For measuring the diversification level of districts or regions five indices viz., Herfindahl Index, Entropy Index, Modified Entropy Index, Composite Entropy Index and Ogive Index were computed. All the quantitative indices were constructed by using the total cropped area of seven major crops of Kerala. It was found that in most of the periods the diversification in cropping pattern was mainly towards plantation crops. The most diversified district was Kollam, where the cropping pattern had equal importance to all the major crops. Based on the real situation, out of the five measures of diversification Composite Entropy Index was found to be better suited. It was also noticed that as time progressed the diversification level among the districts or regions decreased. The Compound growth rates of both production and acreage were computed and it was found that rubber recorded the highest C.G.R. The food crops viz., rice and tapioca showed negative C.G.R whereas cash crops viz., coconut and pepper showed positive C.G.R for both production and acreage. Productivity index were constructed for each district taking into consideration the variety of crops and their relative importance in a particular district. The results revealed that different districts behaved differently with respect to the rate of growth of productivity. Development is a multidimensional process, so instead of analysing a single variable, composite index or development index for different districts or regions were computed by using several indicators, which contributed to the development of agriculture. In the present study three methods were used to compute the development index based on seven indicators. In the first approach i.e. Taxonomic approach during 1985-86, 1990-91 and 1995-96 Emakulam occupied the first place in agriculture development. However, Wayanad and Kasargode were the two least agriculturally developed districts during the above said periods. It was also observed that there was hardly any change in the level of development of agriculture over different periods of study. In Taxonomic approach each variable was considered to have equal contribution towards the development of agriculture. However, it is unlikely to happen so. With this fact, the Taxonomic approach was modified in Modified Taxonomic approach by giving separate weightage to the indicators based on the score given by experts. In the present study separate weightage did not have any significant impact on the classification of districts or regions on their agricultural development status. Obviously the selected variables might be highly correlated. Characteristics in biological experiment are highly correlated. In the present study Principal Component analysis was used to overcome this problem. The first component of both district wise and region wise analysis contributed around 99.5 per cent of total variation. Therefore, without loosing any information supplied by the seven variables, the first component score was taken as the composite index of development. Hence in the present context Principal Component analysis could be considered as the best method, as no approximation is involved. It could be considered as a more comprehensive method. The Potential targets for the under developed districts or regions are also estimated to assess the position of those districts or regions compared to the model • districts or regions. Accordingly suitable development programmes can be launched or special care can be taken to allocate resources optimally on per capita basis to reduce spatial disparities in development.
Open Access
Response of tomato to varying levels of fertigation
(Department of Agronomy, College of Horticulture, Vellanikkara, 2002) Rajaseelan Kingsly, D; KAU; Jaikumaran, U
A field experiment was conducted during 2000-2001 at the Agricultural Research Station, Mannuthy, Thrissur to find out growth and yield as well as water use and nutrient relations of tomato, as influenced by different levels of fertigation i.e. continuous nutrition through drip irrigation. The experiment consisted of combinations of three levels of irrigation (0.3,0.6 and 0.9 PE) through drip system and three levels of fertilizer (100, 50 and 150% recommended dose) supplied through drip irrigation. The fertilizer nutrients were supplied in progressive increments for sixty days and the fertigated treatments were mulched using black HDPE sheet. A control treatment, which received 20 mm surface irrigation through furrow method once in three days along with normal soil application of fertilizer without mulch cover was also included to compare with fertigation treatments. The experiment was laid out at randomised block design with three replications. The tomato CV Shakthi was tried in the experiment. The results revealed that the growth parameters viz., plant height, Leaf Area Index (LAI) and ~eaf Area Duration (LAD) were higher in the fertigated treatments than in the control crop. The respective values were 50.48 cm, 5.60 and 113.4 in case offertigated crops and 48.52 cm, 5.46 and 110.9 for the control crop, when observed at final growth stage. The control crop had a significant rooting pattern with higher vertical length (26.8 cm), lateral length (15 cm) and root dry weight of (8.2 g) than the fertigated treatments which had the respective values of 18.65 cm, 11.00 cm and 3.9 g. The ferigated crop produced maximum fruit set of 56.5 per cent and 36 numbers of fruits plant" with mean yield of 31.51 t ha-I. The respective values for the control crop were 42.6 per cent, 22 and 19.31 t ha" only. The treatment which received 150 per cent fertilizer dose with 0.6 PE irrigation gave a maximum yield of37.3 t ha-I which was 93 per cent more than the control crop. This level of production was comparable with that of the crop receiving 100 or 150 per cent recommended dose of fertilizers with irrigation at 0.9 PE through drip. The TSS content was not influenced by different treatments, but higher acidic fruits were produced by the control crop. The fertigated crops in general contained more nutrients in their biomass compared to control crop. The highest NPK content in plant was recorded at 60 DAP and at the stage these nutrient contents were 4.9,0.285 and 3.13 per cent in case offertigated crops and the respective values in control crop were 4.0, 0.245 and 3.07 per cent. The fruit cracking and bacterial wilt incidence were not affected by various treatments. But 72 per cent of control crop suffered by leaf curl virus disease but only 40 per cent, in case of fertigated plants. The mean soil temperature upto 30 cm depth increased "<-;- under mulched conditions over control treatment during morning (7.;3<) 1ST) and 'L.C;;- evening (2.:Mt 1ST) by 3.3°C and 2.6°C respectively. While control crop received 700 mm of water, the crop irrigated through the drip at 0.9, 0.6, 0.3 PE received 506, 358 and 210 mm of water. Field water use efficiency was the highest in the treatment which received 100% fertilizer with 0.3 PE irrigation (14.62 kg fruit per m-3 of water). As the irrigation levels reduced and fertilizer application increased FWUE was increased. The moisture content of the soil was more at 15 cm depth both at 15 and 30 cm radial distances, in all irrigation levels. The economic analysis indicated that the crop under recommended dose of fertilizer with 0.9 PE irrigation gave a maximum BC ratio of 1.92 followed by the crop raised under 150 per cent fertilizer dose with 0.6 PE irrigation (1.91). The saving of water through respective treatments, when compared to control enabled 0.38 and 0.95 ha to be additionally brought under irrigated tomato, if respective treatments were employed. The investigation led to the conclusion that fertigation is a sound technology and produceshigh yields in tomato. If water is not a limiting factor, adopt irrigation at 0.9 PE using 100 per cent recommended dose of fertilizer and if water availability is - constrained, adopt irrigation at 0.6 PE using 150 per cent recommended dose of fertilizer to reap rich harvest.

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