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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
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
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.
Open Access
Integrated nutrient management in hedge lucerne (Desmanthus virgatus(L.)willed) under rainfed condition
(Department of Agronomy, College of Agriculture, Vellayani, 2001) Kavitha, G V; KAU; Lakshmi, S
A field experiment was conducted at the Instructional Farm, College of Agriculture, Vellayani, Thiruvananthapuram, Kerala State to find out an integrated nutrient management technique for Desmanthus virgatus (L.) Willd. under rainfed condition. The influence of chemical fertilizers and biofertilizers on growth parameters, fodder yield, quality of produce, uptake of nutrients, chemical properties of soil and economics was investigated. Three levels of nitrogen (0, 15, 30 kg N ha"), three levels of potassium (0, 20, 40 kg ha") and biofertilizers (Rhizobium, AMF and Rhizobium + AMF) were combined to form twenty seven treatment combinations. The experiment was laid out in split plot design with three replications. Results of the experiment revealed that the chemical fertilizers as well as bioinoculants had significant positive influence on improving the fodder production potential of Desmanthus virgatus. Application of inorganic fertilizers and eo- inoculation of hedge lucerne with Rhizobium and AMF significantly increased the growth parameters namely plant height, length of branches, number of branches and leaf: stem ratio. Highest dose of chemical fertilizers and dual inoculation with biofertilizers registered maximum green fodder yield in all four harvests. Similar results were obtained in the case of dry fodder yield also. Quality parameters of the forage significantly improved as a result of dual inoculation with biofertilizers. Maximum crude protein content was realized with application of highest dose of nitrogen and potassium. The nutrient uptake showed a significant increase with increase in doses of chemical fertilizers. Dual inoculation of biofertilizers significantly increased the uptake of nitrogen, phosphorus and potassium. Combined application of biofertilizers improved the nitrogen and phosphorus status of the soil after the experiment. Highest dose of nitrogen gave the highest soil nitrogen content. Similarly highest dose of potassium recorded highest soil potassium content after the experiment. The physical and economic optimum dose of nitrogen for Desmanthus virgatus was 32 kg ha-I and 31 kg ha-I respectively while that of potassium was 22 kg ha-I, The use of chemical fertilizers and dual inoculation with biofertilizers recorded highest net returns and benefit: cost ratio, emphasizing the need for an integrated approach in nutrient management.
Open Access
Nutrient management for basmati rice (oryza sativa L) in wetlands
(Department of Agronomy, College of Agriculture, Vellayani, 2002) Sindu, M S; KAU; Annamma, George
A field experiment was conducted at the Instructional Farm, College of Agriculture, Vellayani from September 2001 to January 2002 to derive an optimum package for nutrient management for basmati rice in wetland condition. The experiment was laid out in factorial RBD with three replications. The treatments consisted of three levels of N (60, 90 and 120 kg N ha"), two sources of N (SI: SO per cent N as FYM and SO per cent N as chemical fertilizer and S2 : SO per cent N as vermicompost and SO per cent N as chemical fertilizer), two NPK ratios (2 : 1 : 1 and 2 : 1 : I.S) and an absolute control thereby forming 13 treatment combinations. Results of the experiment revealed that the effect of both N levels and NPK ratios had significant influence on most of the biometric and yield attributing characters and yield of basmati rice. Nitrogen @ 120 kg ha-I and NPK ratio of 2 : 1 : I.S were found significantly superior to lower levels. Eventhough the effect of sources of N was significant on plant height and dry matter production, the effect was not visible on the yield attributing characters and yield of the crop. A significant linear increase in grain yield was recorded upto 90 kg N ha-I , and thereafter the increase in grain yield was marginal. But the straw yield increased linearly with increase in N level and was also significantly influenced by the sources of nitrogen. NPK ratio of 2 : 1 : I.S recorded higher grain and straw yield. Nitrogen @ 120 kg ha-I and NPK ratio of 2 : I : I.S produced the highest grain protein content. The cooking time of grains increased with increase in N level. Nitrogen @ 120 kg ha-I and NPK ratio of 2 : I : I.S recorded the highest uptake of nutrients. Use of vermicompost for substituting 50 per 1'9 cent N resulted in the highest uptake of Nand P while the effect on K uptake was not significant. An increase in N application resulted in an increase in available N and P status of the soil after the experiment. Nitrogen @ 120 kg ha ", use of vermicompost for substituting 50 per cent Nand NPK ratio of 2 : 1 : 1.5 registered significantly superior available K status in the soil. The maximum NUE in terms of agronomic efficiency and apparent recovery was observed at 90 kg N ha-! and thereafter it decreased with the increase in N level. Application ofNPK in 2 :. 1 : 1.5 ratio also resulted in higher NUE. Sources of N were significant only with respect to apparent recovery and substituting 50 per cent N with vermicompost registered superior value. The physical optimum dose of N for grain yield and agronomic efficiency were worked out to be 109.24 and 94.67 kg N ha-! respectively. Straw yield exhibited a linear response to applied nitrogen. An increase in N level increased the disease incidence while a significant reduction in disease incidence was observed with the NPK ratio of 2 : 1 : 1.5 over 2 : 1 : 1. The highest net returns and BCR were recorded when FYM was used to substitute 50 per cent of nitrogen. Increase in N levels upto 90 kg ha-! and application of NPK in' 2 : 1 : 1.5 ratio was found profitable. So a fertilizer dose of 90 : 45 : 67.5 kg NPK ha-! with 50 per cent N as FYM and 50 per cent N as chemical fertilizer can be recommended for maximizing the yield and returns of basmati rice in wetlands.
Open Access
Genetic evaluation of F2 generation of intervarietal crosses in greengram (vigna radiata (L.) wilczek
(Department of Plant Breeding and Genetics, College of Agriculture, Vellayani, 2001) Leenamol, M A; KAU; Kamalam, N
A research programme was carried out at the Department of Plant Breeding and Genetics, College of Agriculture, Vellayani during 2000-2001 with the objective of assessing the potential of F2 progenies of greengram in terms of variability and correlation with respect to yield, yield attributes and shade tolerance. Fifteen F 2 progenies derived from intervarietal crosses were evaluated under the partial shade of coconut garden adopting a randomised block design with three replications. Data collected for seventeen characters were subjected to statistical analysis. Coefficient of variation, heritability, genetic advance, correlation and path coefficients were estimated. The 15 F 2 progenies revealed significant difference for all the characters. However, measurement of periodical shade intensity did not show significant difference among the plots indicating the prevalence of uniform shade. Phenotypic and genotypic coefficient of variation were high for grain yield, leaf area index, number of pods per plant, photosynthetic efficiency, harvest index and 100 seed weight. High heritability coupled with high genetic advance was observed for harvest index, grain yield, number of pods per plant, 100 seed weight and photosynthetic efficiency. Correlation studies indicated that the characters leaf area index, . photosynthetic efficiency, number of seeds per pod, 100 seed weight and harvest index exhibited significant positive correlation with grain yield whereas days to 50 per cent flowering and days to maturity recorded significant negative correlation. Among yield components, photosynthetic efficiency and harvest index exhibited significant positive correlation with number of seeds per pod and 100 seed weight. Photosynthetic efficiency exhibited the highest positive direct effect on grain yield followed by harvest index. Negative direct effect on grain yield was recorded for number of seeds per pod, days to maturity and days to 50 per cent flowering. It can be concluded from the present study that under partially shaded condition, photosynthetic efficiency and harvest index are the most important yield components which can serve as selection criteria for better yield in greengram. Accordingly the genotypes T 7 (Ganga 4 x Pusa Baisakhi), T 5 (LGG 460 x Philippines), T I (IIPRM 3 x Philippines), T 2 (Ganga 4 x Philippines) and TI4 (RMG 353 x CO-2) and Tlo (LGG 460 x Pusa Baisakhi) may be selected for further work.
Open Access
Effect of nutrient inter-relations on productivity of rice in lateritic soils
(Department of Agronomy, College of Horticulture, Vellanikkara, 2002) Sindhu, P V; KAU; Meera Menon, V
The effect of nutrient inter-relations on productivity of rice in latritic soils was investigated during the first crop season (Virippu) Or 1999-2000 at the Agricultural Research station, Mannuthy. The objective of the study was to arrive at the minimum level combination of applied elements for maximum productivity based on the interaction pattern between applied and native elements so as to develop a sustainable management system. Jyothi was used as the Fest variety to analyse the pattern of interacting influences of P, K, Ca and S at two levels each, among themselves as well as on the native elements. The results showed that treatments had significant beneficial influence on yield expression, causing 90 and 10% increases in yield over absolute control and the presently recommended package of practices. This indicated the necessity of including Ca and S in the nutrient management system. Decline in chlorophyll content and high levels of cell sap pH, together with excess contents of Fe and Zn appear to act as the supressors of yield expression. The latter influences are inherent in soil and are actually the net product of the balance between positive and negative effects of nutrients. A significant finding was that application of any element by itself was not a guarantee for its uptake, and was subject to the effect of other elements, and similarly, had direct or indirect influences on other elements. The positive influence of K and Ca at the maximum tillering and S at the panicle initiation stage, and negative influence of Fe and Mn at the panicle initiation stage pointed out to the need for phasic management of nutrients. The only element inhibiting Fe uptake had been Si, suggesting that the reversal of the process of laterisation holds the key to higher yields. Discriminatory transfer of individual elements between leaf blade and leaf sheath appeared to be an important regulatory factor in deciding yield expression. Highest yield resulted when blade-sheath ratio was maximum tillering and panicle initiation declined in respect of Ca, Fe and Mn and increased in respect of K and S. the study resulted in development of the broad base of a management technology for high productivity and sustainability. The components included keeping N at the present reconunended level, reducing P by 50%, increasing K by 100% and top dressing N using s containing fertilizers as well as moderate basal dressing with Ca.

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