Browsing by Author "Sheeba Rebecca Isaac"

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Carbon dioxide evolution and yield responses in tomato (Solanum lycopersicum L.) under organic nutrition
(Department of Agronomy, College of Agriculture, Vellayani, 2023-01-16) Pallavi, K N; Sheeba Rebecca Isaac
The research work entitled “Carbon dioxide evolution and yield responses in tomato (Solanum lycopersicum L.) under organic nutrition” was conducted at College of Agriculture, Vellayani during 2020 to 2022 with the objectives, to assess the carbon dioxide (CO2) evolution from different organic sources and to evaluate the response of tomato to CO2 evolved under organic nutrition. The study was conducted as two experiments, i) laboratory incubation and ii) field experiment in trenches (elevated CO2) and under open field condition (ambient CO2). The incubation experiment was carried out in Department of Agronomy, College of Agriculture, Vellayani during January to March 2022 in Completely Randomized Design (CRD) with twelve treatments in three replications. The treatments included were T1 : farmyard manure (FYM), T2 : vermicompost, T3 : poultry manure, T4 : glyricidia leaves, T5 : coir pith compost, T6 : goat manure, T7 : groundnut cake, T8 : neem cake, T9 : rice husk biochar, T10 : rice straw, T11 : chemical fertilizer (3:1.6:1 ratio of N, P2O5, K2O respectively) and T12 : soil. The data recorded were subjected to statistical analysis using GRAPES software. Characterisation of the organic manures revealed that groundnut cake had superior N, P and K contents and rice straw had the lowest contents. The narrowest C : N ratio (11.63:1) was recorded in FYM and the widest, in rice straw (90.90:1) and rice husk biochar (68.25:1). Microbial counts were significantly higher in poultry manure and glyricidia leaves and lower in coir pith compost (bacteria) and rice husk biochar (fungi and actinomycetes). Assessment of CO2 evolution showed a gradual increase in the initial stages with the peak at the eighth week of incubation, and later,declined. The highest evolution (344.43 mg of CO2 100 g-1 soil) was recorded in poultry manure treatment followed by glyricidia leaves and significantly lower in chemical fertilizer and soil alone. Carbon dioxide evolution from the media declined in the order, poultry manure > glyricidia leaves > rice straw > vermicompost > goat manure > FYM > groundnut cake > coir pith compost > neem cake > rice husk biochar > soil alone > chemical fertilizer. The release from organic sources was 14.40 to 47.30 per cent more than that from chemical fertilizers and the highest was from poultry manure, 40.90 per cent higher than from soil. The C degradation rate constant (0.062) was the highest in rice husk biochar and the lowest in vermicompost (0.031). The field experiment was laid out in CRD with six treatments replicated thrice during November 2021 to March 2022 at the Instructional Farm, College of Agriculture, Vellayani. The treatments comprised T1: FYM, T2: vermicompost, T3 : poultry manure, T4 : FYM + 138 glyricidia leaves, T5 : vermicompost + poultry manure and T6 : integrated nutrient management (INM). Tomato variety Manuprabha was raised at 60 cm x 60 cm spacing in the open and in trenches. The NPK recommendation followed was 75:40:25 kg ha-1 and all cultural practices followed were as per the package recommendations (KAU, 2016). The data recorded were subjected to statistical analysis using GRAPES software and the treatments with no values were excluded from statistical analysis. In the open condition, plants were taller with superior number of branches, leaf area and rooting depth and the highest photosynthetic rate in INM (T6) and the lowest in the combination of vermicompost + poultry manure (T5). Flowering was early in INM (26.7 days) with more number of fruits per plant (32.3), fruit weight (63.49 g) and fruit yield (2215 g plant -1 ). Among the organic sources, FYM was found to be superior. Fruits contributed maximum (73.46 – 84.18 %) to total biomass. Quality attributes viz., sucrose, ascorbic acid and lycopene content were significantly the highest in INM and the lowest in T5, whereas, catalase activity and nutrient uptake were significantly higher in T5 treatment. Post experiment soil analysis elicited non significant variations in soil pH, but organic C was significantly the highest in FYM treatment . Available NPK status and microbial counts revealed the high fertility status in vermicompost + poultry manure application. Carbon dioxide evolution increased up to the 4 th and 5th week and decreased thereafter. The total CO2 release was the highest in T5 (37,124 mg kg-1 soil) and the least in T1 (35,004 mg kg-1 soil). The trend in CO2 release was T5>T4>T3>T6>T2>T1. Integrated nutrient management was found to be the most profitable practice with a net return of ₹ 9396.82 per 40 m2 and B:C of 3.15 ratio. Growth attributes viz., plant height and number of branches were significantly higher in the treatment FYM + glyricidia leaves in trenches, while leaf area and root parameters were higher in INM, on par with FYM + glyricidia leaves and sole application of FYM. Chlorophyll content and photosynthetic rate recorded were the highest in INM. Tomato plants in trenches showed poor fruit set and yields. Among the nutrient management treatments, flowering was the earliest in sole FYM application and INM (31.3 and 31.7 days respectively). Stigma protrusion and severe flower drop caused poor fruit set in trenches and hence hand pollination was carried out. However, the treatments T3, T4 and T5 failed to set fruits. The average fruit numbers recorded were 2.7 in T1, 1.7 in T2 and 2.00 in T6. The largest fruits (12.85 g) and per plant yield (63.03 g) were recorded in T1. Vegetative biomass contributed the maximum (85.68 – 100 %) to total biomass. Among the treatments, INM recorded superior fruit quality and plant nutrient uptake. Soil analysis after the experiment 139 revealed significantly higher organic C in FYM application and combination of vermicompost and poultry manure, higher soil NPK status and microbial population. The total CO2 release was the highest in vermicompost + poultry manure treatment (71,247 mg kg-1 soil) and the lowest in FYM (60,895 mg kg-1 soil). The trend in CO2 release was T5>T4>T3>T6>T2>T1. Air and soil temperatures were comparatively higher in T5 and relative humidity was 100 per cent in all treatments throughout the experiment. Economic analysis revealed negative net returns and very negligible B:C ratios. Comparing the effect of nutrient sources on tomato grown in open field and elevated CO2 condition (t test), it was unveiled that the tomato plants grown in trenches recorded taller plants and higher leaf area and improved physiological attributes except stomatal conductance. Fruit and vegetative biomass were the major drivers for the total biomass production in open and trenches respectively. Fruit set and yield were higher in open but, quality attributes were higher in fruits set in trenches than in open. Based on the results of the study it could be concluded that addition of organic sources in soil increased the CO2 evolution and it was the highest from poultry manure. Carbon degradation declined in the order, FYM > vermicompost > poultry manure > soil alone > coir pith compost > goat manure > rice straw > glyricidia leaves > neem cake > chemical fertilizer > groundnut cake > rice husk biochar. In the open, the influence of the nutrient sources was more prominent and high economic yields in tomato were realized in INM (75:40:25 kg NPK ha-1 along with FYM @ 20 t ha-1 ). Among the organic nutrition treatments, T1, FYM (@ 2.65 t ha-1 along with alternative application of vermicompost @ 1 t ha-1 and supernatant solution of fermented neem cake @1 kg 10 L-1 at 10 days interval up to 2 MAP) was superior in terms of yield and B:C ratio. In the trenches, CO2 evolution significantly influenced the vegetative growth and fruit setting. Fruit setting was poor and yields were realized with artificial pollination in FYM, vermicompost and INM, and the yield per plant was comparatively higher in organic nutrient management with FYM.
Conservation tillage and nano nitrogen nutrition in Chinese potato (Plectranthus rotundifolius (poir.) spreng.)
(Department of Agronomy, College of Agriculture, Vellayani, 2024-04-27) Gopika, K T; Sheeba Rebecca Isaac
The study entitled "Conservation tillage and nano nitrogen nutrition in Chinese potato [Plectranthus rotundifolius (Poir.) Spreng]" was conducted at College of Agriculture, Vellayani during 2021-2023. The objective of the study was to assess the impact of conservation tillage and nano nitrogen nutrition on the growth, tuber yield and quality in Chinese potato, and carbon build up in the soil. The field experiment was executed during December 2022 to May 2023 at College of Agriculture, Vellayani. The experiment was laid out in split plot design with three methods of tillage [c1: Conventional tillage, c2: Reduced tillage (RT)+ surface incorporation of green manure (GM) cowpea and c3: RT+ surface retention of GM cowpea] as main plot treatments, and four N management practices [n1: 100% recommended dose of nitrogen (RDN) + nano urea, n2: 75% RDN+ nano urea, n3: 50% RDN+ nano urea and n4: 100% recommended dose of fertilizers (RDF)] as sub plot treatments, in three replications. In RT treatments, fodder cowpea variety Aiswarya was raised as green manure crop @ 20 kg seeds ha-1 and incorporated/ surface retained as mulch at flowering stage (45 DAS). Secondary ploughing in c2 and c3 plots was confined to the row zone alone. Cuttings of Chinese potato variety Suphala were planted at a spacing of 30 cm x 15 cm in all the plots. The NPK recommendation followed was 60: 60: 100 kg ha-1 (KAU, 2016). Nano urea (@ 0.4%) was sprayed 20 and 40 days after planting (DAP) as per treatments fixed. Other cultural operations were done in accordance with the KAU package recommendation for the crop. The treatment, c2 resulted in significantly taller plants at 90 and 120 DAP, higher number of branches per plant at 120 DAP and superior leaf area per plant at 30, 60 and 120 DAP. Among the subplot treatments, the significantly taller plants at 30 and 60 DAP, plant spread at 30, 60 and 90 DAP and number of branches at 30 DAP were recorded in n3. The treatment n1 recorded the highest leaf area at all the growth stages. Among the interactions, plants in c2n3 were significantly taller at 30 and 60 DAP, with the highest plant spread and leaf area at all stages of observation. The yield attributes and yield, number of tubers per plant (21.59), average tuber weight (12.13g) and marketable tuber yield (130.67 g per plant) were significantly the highest in c2. Tuber yield (16.20 t ha-1) was significantly higher in c3 and comparable with c2. In N management, n3 (50% RDN + nano urea) resulted in highest number of tubers and yield, and were the lowest in n4. Among the c x n interactions, c2n3 produced the highest tuber yield (17.74 t ha-1). Significantly higher chlorophyll contents were observed in c2 and was on par with c3. The chlorophyll content in n1 and n3 remained similar at 30 DAP and at 60 DAP, n1 was superior. The treatment combination c2n3 recorded the highest chlorophyll content at 60 DAP. Crop growth rate computed until 90 DAP, were significantly higher in c2 and during 90-120 DAP, in c3. It remained the highest in n1 upto 60 DAP and thereafter, n3 and n2 recorded the higher values. Leaf Area Index was higher in c2 but on par with c3. The highest LAI was recorded in c2n1 at all growth stages. No significant variations were found in days to start of senescence and biomass partitioning at the start of senescence due to tillage methods and interactions. Biomass accumulation followed the order tuber > stem > leaf, in all treatments. In tubers, significantly the highest biomass (66.4%) was recorded in n3. Nutrient uptake was higher for N and K in c2 and P uptake, in c3. With respect to N management, significantly higher N uptake was computed in n1 while P and K uptake were the highest in n3. Among interactions c2n3 was superior. Quality of tubers in terms of vitamin C and protein contents remained on par in c3 and c2 and among N management treatments, superior vitamin C content was observed in n3, and protein in n1. Starch content was the highest in n1 on par with n2. Among the treatment combinations, the highest starch and protein contents were observed in c2n1, and vitamin C in c2n3. The methods of tillage, N management and their interaction showed varied effects on soil nutrient status and were more pronounced for P, S and Zn. Conservation tillage methods (c2 and c3) elicited significant variations in soil C status. The highest TOC (11.80 g kg-1) and labile C (4.94 g kg-1) were recorded in c2 while non labile C (7.64 g kg-1) was the highest in c3. The C stock (5093 g m-2) was the highest in c3 and among interactions, c2n3 recorded the highest TOC. Soil microbial population and dehydrogenase activity were the highest in c2 and among c x n interactions, the combinations including c2 was superior. Economic analysis revealed c2n3 as the most profitable treatment combination for Chinese potato cultivation. The net income and BCR computed were ₹429657 ha-1 and 2.54 respectively. Based on the results of the study, in Chinese potato, the practice of raising GM cowpea sown @ 20 kg seeds ha-1, incorporation of biomass at flowering, planting stem cuttings in reduced tilled beds and nutrient management with 30 kg N (50% RDN), 60 kg P2O5, 100 kg K2O ha-1 + nano urea foliar spray (0.4%) at 20 DAP and 40 DAP, can be recommended as the most suitable conservation agriculture strategy. The C stock in soil was found to improve with conservation tillage practices.
Conservation tillage and nano nitrogen nutrition in Chinese potato (Plectranthus rotundifolius (poir.) spreng.)
(Department of Agronomy, College of Agriculture, Vellayani, 2024-04-27) Gopika, K T; Sheeba Rebecca Isaac
The study entitled "Conservation tillage and nano nitrogen nutrition in Chinese potato [Plectranthus rotundifolius (Poir.) Spreng]" was conducted at College of Agriculture, Vellayani during 2021-2023. The objective of the study was to assess the impact of conservation tillage and nano nitrogen nutrition on the growth, tuber yield and quality in Chinese potato, and carbon build up in the soil. The field experiment was executed during December 2022 to May 2023 at College of Agriculture, Vellayani. The experiment was laid out in split plot design with three methods of tillage [c1: Conventional tillage, c2: Reduced tillage (RT)+ surface incorporation of green manure (GM) cowpea and c3: RT+ surface retention of GM cowpea] as main plot treatments, and four N management practices [n1: 100% recommended dose of nitrogen (RDN) + nano urea, n2: 75% RDN+ nano urea, n3: 50% RDN+ nano urea and n4: 100% recommended dose of fertilizers (RDF)] as sub plot treatments, in three replications. In RT treatments, fodder cowpea variety Aiswarya was raised as green manure crop @ 20 kg seeds ha-1 and incorporated/ surface retained as mulch at flowering stage (45 DAS). Secondary ploughing in c2 and c3 plots was confined to the row zone alone. Cuttings of Chinese potato variety Suphala were planted at a spacing of 30 cm x 15 cm in all the plots. The NPK recommendation followed was 60: 60: 100 kg ha-1 (KAU, 2016). Nano urea (@ 0.4%) was sprayed 20 and 40 days after planting (DAP) as per treatments fixed. Other cultural operations were done in accordance with the KAU package recommendation for the crop. The treatment, c2 resulted in significantly taller plants at 90 and 120 DAP, higher number of branches per plant at 120 DAP and superior leaf area per plant at 30, 60 and 120 DAP. Among the subplot treatments, the significantly taller plants at 30 and 60 DAP, plant spread at 30, 60 and 90 DAP and number of branches at 30 DAP were recorded in n3. The treatment n1 recorded the highest leaf area at all the growth stages. Among the interactions, plants in c2n3 were significantly taller at 30 and 60 DAP, with the highest plant spread and leaf area at all stages of observation. The yield attributes and yield, number of tubers per plant (21.59), average tuber weight (12.13g) and marketable tuber yield (130.67 g per plant) were significantly the highest in c2. Tuber yield (16.20 t ha-1) was significantly higher in c3 and comparable with c2. In N management, n3 (50% RDN + nano urea) resulted in highest number of tubers and yield, and were the lowest in n4. Among the c x n interactions, c2n3 produced the highest tuber yield (17.74 t ha-1). Significantly higher chlorophyll contents were observed in c2 and was on par with c3. The chlorophyll content in n1 and n3 remained similar at 30 DAP and at 60 DAP, n1 was superior. The treatment combination c2n3 recorded the highest chlorophyll content at 60 DAP. Crop growth rate computed until 90 DAP, were significantly higher in c2 and during 90-120 DAP, in c3. It remained the highest in n1 upto 60 DAP and thereafter, n3 and n2 recorded the higher values. Leaf Area Index was higher in c2 but on par with c3. The highest LAI was recorded in c2n1 at all growth stages. No significant variations were found in days to start of senescence and biomass partitioning at the start of senescence due to tillage methods and interactions. Biomass accumulation followed the order tuber > stem > leaf, in all treatments. In tubers, significantly the highest biomass (66.4%) was recorded in n3. Nutrient uptake was higher for N and K in c2 and P uptake, in c3. With respect to N management, significantly higher N uptake was computed in n1 while P and K uptake were the highest in n3. Among interactions c2n3 was superior. Quality of tubers in terms of vitamin C and protein contents remained on par in c3 and c2 and among N management treatments, superior vitamin C content was observed in n3, and protein in n1. Starch content was the highest in n1 on par with n2. Among the treatment combinations, the highest starch and protein contents were observed in c2n1, and vitamin C in c2n3. The methods of tillage, N management and their interaction showed varied effects on soil nutrient status and were more pronounced for P, S and Zn. Conservation tillage methods (c2 and c3) elicited significant variations in soil C status. The highest TOC (11.80 g kg-1) and labile C (4.94 g kg-1) were recorded in c2 while non labile C (7.64 g kg-1) was the highest in c3. The C stock (5093 g m-2) was the highest in c3 and among interactions, c2n3 recorded the highest TOC. Soil microbial population and dehydrogenase activity were the highest in c2 and among c x n interactions, the combinations including c2 was superior. Economic analysis revealed c2n3 as the most profitable treatment combination for Chinese potato cultivation. The net income and BCR computed were ₹429657 ha-1 and 2.54 respectively. Based on the results of the study, in Chinese potato, the practice of raising GM cowpea sown @ 20 kg seeds ha-1, incorporation of biomass at flowering, planting stem cuttings in reduced tilled beds and nutrient management with 30 kg N (50% RDN), 60 kg P2O5, 100 kg K2O ha-1 + nano urea foliar spray (0.4%) at 20 DAP and 40 DAP, can be recommended as the most suitable conservation agriculture strategy. The C stock in soil was found to improve with conservation tillage practices.
Influence of green fruit picking and nutrient sources on fruit production in okra (Abelmoschus esculentus (L.) moench)
(Kerala Agricultural University, 1998) Sheeba Rebecca Isaac; Pushpakumari, R; Saraswathy, P
Input optimization for short duration Red gram [Cajanus cajan (L.) Millsp.]
(Department of Agronomy, College of Agriculture,Vellayani, 2021) Anjana Devaraj, G; Sheeba Rebecca Isaac
The study entitled “Input optimization for short duration red gram [Cajanus cajan (L.) Millsp.]” was conducted at College of Agriculture, Vellayani during 2017 - 2020 with the objectives, to assess the suitability of two short duration varieties of red gram, standardize the spacing and nutrient management practices for short duration red gram and to examine the legume effect on succeeding fodder maize crop. The investigation was done as three experiments (i) assessment of the suitability of two short duration varieties and standardization of spacing and nutrient levels (ii) assessment of legume effect on fodder maize and (iii) nutrient scheduling in red gram. The experiment I was laid out in randomized block design (RBD) with three replications during Rabi season (November to March) in 2018 - 2019 and the confirmatory experiment, during 2019 - 2020. The treatments included combinations of varieties [v1: APK 1; v2: Vamban (Rg) 3], spacings [s1: 40 cm x 20 cm; s2: 60 cm x 30 cm] and nutrient levels [ n1: 40:80:40, n2: 30:60:30; n3: 20:40:20 kg NPK ha-1 ]. Half nitrogen (N), potassium (K) and full phosphorus (P) were given basally, remaining as top dressing, 30 days after sowing (DAS). Farmyard manure (FYM) was applied uniformly @ 12. 5 t ha-1 . The varieties, spacings and nutrient levels had significant influence on the growth characters of red gram at the different stages of observation. Variety Vamban (Rg) 3 (v2) recorded significantly taller plants, higher number of branches and root parameters compared to APK1 (v1) during both the years of experimentation. The wider spacing, s2 (60 cm x 30 cm), the highest nutrient level, n1 (40:80:40 kg NPK ha-1 ) and the combination, v2s2n1 resulted in superior values for plant height, number of branches per plant, root volume and root dry weight, while narrow spacing (40 cm x 20 cm) recorded the highest number and weight of nodules per plant. The interactions also exerted significant influence on growth parameters with the interactions involving v2, s2 and n1 recording higher values. The variety APK 1 showed earliness in flowering with significantly higher average pod weight, 100 seed weight, seed yield (1.04 t ha-1 ) and haulm yield (3.70 t ha-1 ). Narrow spacing and the highest nutrient level recorded superior values for average pod weight, seed and haulm yields. The interactions also resulted in significant variations in yield attributes and yield. Pooled analysis of yield data of the two years registered the highest seed yield (1.38 t ha-1 ) in v1s1n1 (APK 1 + 40 cm x 20 cm + 40:80:40 kg NPK ha-1 ). Maximum dry matter production (DMP), crop growth rate (CGR) and seed protein content were recorded in APK 1 and at the highest nutrient level. Among the spacings tried, wider spacing resulted in the highest DMP and seed protein, while CGR was higher in the narrow spacing. The partial factor productivity (PFP) for N, P and K were superior in the combination v1s1n1 in both years. Individual effects of the variety APK 1, narrow spacing and the highest nutrient level recorded maximum nutrient uptake and in the combinations of APK 1 or Vamban (Rg) 3 with 40 cm x 20 cm and 40:80:40 kg NPK ha-1 . Available soil N and microbial counts assessed after the experiment were the highest after APK 1. Wider spacing and the highest NPK level recorded maximum soil available nutrient status, while microbial counts, at narrow spacing. Soil nutrient balance sheet computed for N was positive during both years. The balance sheet for P was positive for all the treatment combinations involving wider spacing during the first year. During the second year, all treatments showed positive balance for P except v1s1n1, v1s1n2, v1s2n2 and v2s2n3. Nutrient balance for K was positive in treatments v1s1n1, v1s2n1 and v2s1n1 during the both years. Pooled mean of the economics of cultivation during the two years revealed maximum net returns per hectare (₹ 88621/-) and B:C ratio (2.03) in v1s1n1 (APK 1 + 40 cm x 20 cm + 40:80:40 kg NPK ha-1 ). The legume effect of red gram on fodder maize was assessed during Kharif season, June to August 2019. Crop residues (root + shoot + fallen leaves) of red gram were incorporated in situ and allowed to decompose for two months. The maximum quantity of residues (4.83 tha-1 ) was generated in the treatment combination T7, Vamban (Rg) 3 + 40 cm x 20 cm + 40:80:40 kg NPK ha-1 imposed in red gram, which was on par with T1, the combination, APK 1 + 40 cm x 20 cm + 40:80:40 kg NPK ha-1 (4.75 tha-1 ). There were no marked variations in the biochemical characters of residues, while C: N ratio was significantly narrower in T1 (18.2: 1) and T7 (18.9:1). Residue incorporation improved the soil chemical properties and at 60 days after residue incorporation (DAI), maximum soil pH and C pool (total organic carbon and labile carbon) were estimated in treatment T7, and recalcitrant organic carbon, in T1. Soil available N, P status and dehydrogenase activity were higher in T1, and available K, in T7 at 60DAI. Fodder maize seeds (variety, African tall) were sown during the third week of June in the residue incorporated plots. Green and dry fodder yields (33.61 and 11.37 t ha-1 respectively) were the highest in the treatment T7 which was on par with T1 (32.85 and 11.08 t ha-1 respectively). Soil available NPK status were found to decline from the initial status with fodder maize cultivation. The nutrient scheduling experiment was conducted during Rabi season, 2019 - 2020, in RBD with nine treatments and three replications. The variety APK 1, spacing 40 cm x 20 cm and nutrient level 40:80:40 kg NPK ha-1 found superior in Experiment I were adopted. The integrated nutrient management (INM) practices evaluated were T1: 100 % NPK as chemical fertilizers, T2: 100 % N + 50 % P + 100 % K + P solubiliser, T3: 100 % N + 100 % P + 50 % K + K solubiliser, T4: 100 % N + 50 % P + 50 % K + P solubiliser + K solubiliser, T5: T1 (50 % N foliar), T6: T2 (50 % N foliar), T7 : T3 (50 % N foliar), T8 : T4 (50 % N foliar) and T9 : Absolute control: No fertilizers. The entire dose of N was given as soil application in T1 to T4 and foliar spray of 50 per cent N in T5 to T8 with urea (2 %) at 30 and 45 DAS. Phosphorus and K solubilisers (Bacillus megaterium and Bacillus sporothermodurans respectively) were mixed with powdered FYM in the ratio 1: 50 separately, and 10 g of each mixture was added in soil one week after basal fertilizer application. The INM practice of 100 per cent N + 50 per cent P + 50 per cent K along with P and K solubilisers (T4) recorded significantly taller plants (109.70 cm), maximum number of branches (6.5) at harvest, whereas weight of nodules per plant at flowering (0.59 g) and root parameters were significantly the highest in treatment T8. Average pod weight (0.62 g) and seed yield (1.48 t ha-1 ) were superior in T4 and on par with the combination involving foliar nutrition, T8 (1.46 t ha-1 ). Integration of P and K solubilisers with chemical fertilizers (100 % N and 50 % P and K), registered 50 per cent higher yield than the absolute control. Among the agronomic indices, DMP at 100 DAS (34.18 g plant-1 ), CGR at 80 - 100 DAS (3.44 g m-2 day-1 ) were the highest in T4, and RGR, in T2 followed by T4. Substitution of 50 per cent Pand K with biofertilizers recorded maximum uptake of N, P and K and physiological efficiencies for the nutrients. Computation of nutrient balances with the INM practices adopted revealed the highest positive balance for N in T8, P in T4 and for K in T7. Economic analysis showed the treatment T to record the highest net return per hectare (₹ 94722 /-) and B: C ratio (2.05). Based on the results it could be concluded that the short duration red gram varieties, APK 1 and Vamban (Rg) 3 are suitable for cultivation in the southern laterites of Kerala. The variety APK 1 was superior in terms of yield and profit and can be recommended for planting at a spacing of 40 cm x 20 cm and an NPK dose of 40:80:40 kg ha-1 based on the soil test results. Evaluation of the legume effect of red gram revealed significant increases in soil fertility status with residue incorporation. Among the treatments imposed in red gram, irrespective of the variety, the residual effect realized with red gram planted at 40 cm x 20 cm spacing and fertilized with 40:80:40 kg NPK ha-1 was found to be superior in terms of fodder yield in the succeeding crop of maize. The integrated nutrient management practice that proved profitable in APK 1 involved application of 40:40:20 kg NPK ha-1 as chemical fertilizers along with P and K solubilisers, the entire dose in soil.
Leaf litter recycling in homestead agroforestry systems
(Department of Agronomy, College of Agriculture, Vellayani, 2017) Harishma, S J; Sheeba Rebecca Isaac
Litter decomposition and nutrient dynamics of selected multipurpose trees in homesteads
(Department of Agronomy, College of Agriculture, Vellayani, 2001) Sheeba Rebecca Isaac; Achuthan Nair, M
Nutrient optimization for grain cowpea (vigna unguiculata (L.) walp.) in high phosphorus soils
(Department of Agronomy College of Agriculture, Vellayani, 2018) Anjaly, V; Sheeba Rebecca Isaac
Nutrient recycling of selected tree leaf litters in homesteads
(Department of Agronomy, College of Agriculture, Vellayani, 2019) Reshma Das; Sheeba Rebecca Isaac
Productivity of spinach beet as influenced by varieties and nutrient doses
(Department of Agronomy, College of Agriculture, Vellayani, 2017) Vinod Alur; Sheeba Rebecca Isaac
The investigation entitled “Productivity of spinach beet as influenced by varieties and nutrient doses” was carried out at College of Agriculture, Vellayani, Thiruvananthapuram to assess the suitability of five varieties of spinach beet under protected and open conditions, to standardize the nutrient doses and to work out the economics. The experiment was laid out in split plot design in the Instructional Farm, College of Agriculture Vellayani at 8.50 N latitude, 76.9 0 E longitude, under protected and open conditions as two separate experiments during August- November 2015 and 2016 respectively. The treatments included five varieties (V1: All Green; V2: Pusa Bharathi; V3: Punjab Green; V4: Indam Kolkatta; V5: Trendy) in main plots and three nutrient levels ( N1: 40:20:40 kg NPK ha-1; N2: 60:30:60 kg NPK ha-1; N3: 80:40:80 kg NPK ha-1) in sub plots with four replications. The soil belonged to the order oxisol. The results of the experiment under protected condition revealed that among the five varieties tested, Punjab Green was found superior in terms of the number of leaves, leaf area index (LAI) and yield. The maximum leaf yield recorded by Punjab Green was 4.78 kg m-2 followed by All Green (4.56 kg m-2). Plant height, total number of leaves plant-1 and LAI were significantly higher at N3 (80:40:80 kg ha-1)compared to the lower doses. The same NPK level recorded the highest yield of 4.70 kg m-2 which was significantly superior to the other levels. The interaction effects were significant with v1n3 recording maximum leaf yield (5.06 kg m-2) followed by v3n3 (5.01 kg m-2). Nutrient uptake (NPK), protein and Fe contents were the highest in Punjab Green which was significantly superior to the other varieties, while vitamin C was the highest in Pusa Bharathi. Spinach beet fertilized with 80:40:80 kg NPK ha-1 showed significantly higher values for NPK uptake, Ca content and vitamin C. Soil pH was found to increase with higher levels of nutrients and organic carbon content decreased from the initial values. Available NPK status in soil were found to increase with the increased NPK application. The var. Punjab Green showed maximum net returns ( 881.59from 10m2) and benefit-cost ratio (1.44) and among nutrient levels, nutrient dose of 80:40:80 kg NPK ha-1 was found to be the most economical (net returns from 10 m2 - 835.54, B:C ratio- 1.42). Taking into account the interaction effects, the varieties All Green and Punjab Green at 80:40:80 kg NPK ha-1 could be recommended for cultivation under protected conditions. In open field condition, the var.All Green recorded significantly taller plants with the highest number of leaves, LAI and leaf yield. Among the different nutrient levels, N3 (80:40:80 kg NPK ha-1) was found to be significantly superior in yield attributes and leaf yield in spinach beet. The interaction of Pusa Bharathi and 80: 40: 80 kg NPK ha-1 registered significantly higher yield (4.14 kg m-2) followed by All Green at 80 :40 : 80 kg NPK ha-1 (4.02kg m-2). Nutrient uptake, vitamin A, C, protein and Ca contents were significantly high in the var. All Green and inthe nutrient dose of 80 :40:80 kg NPK ha-1. Interaction effect of the above combination (v1n3) also recorded higher values for the plant nutrient contents. Available N, P and K contents in soil significantly increased with increase in NPK levels. Economic analysis revealed that the interaction v2n3 (Pusa Bharathi and 80 :40 : 80 kg NPK ha-1) was most profitable ( net returns 495.39 from 10 m-2 and B:C ratio 1.25) followed by v1n3( net returns 418.36 from 10 m-2 and B:C ratio 1.21). The variety Punjab Green and All Green were the most suitable varieties for cultivation in polyhouse while All Green and Pusa Bharathi could be recommended for cultivation in the open. The Ca, protein chlorophyll content and NPK uptake were the highest in Punjab Green and All Green in the polyhouse and open respectively. The NPK dose of 80:40:80 kg NPK ha-1was found to be the suitable nutrient dose under both conditions irrespective of the variety. Taking into account the economics of cultivation, the combinations, All Green + 80:40:80 kg NPK ha-1 was the most profitable in the polyhouse while Pusa Bharathi + 80:40:80 kg NPKha-1, for cultivation in the open.
Sink efficiency of red gram [Cajanus cajan (L.) Millsp.] as influenced by pottasium and growth regulators
(Department of Agronomy, College of Agriculture, Vellayani, 2022-02-25) Madiki Aashiq; Sheeba Rebecca Isaac
The research work entitled “Sink efficiency of red gram [Cajanus cajan (L.) Millsp.] as influenced by potassium and growth regulators” was conducted at College of Agriculture, Vellayani, during 2019-2021. The main objectives were to assess the effect of potassium nutrition and growth regulators on growth, seed yield and dry matter partitioning in red gram and to work out the economics. The field experiment was laid out in randomized block design with 12 combinations of two factors, potassium and growth regulators, as treatments and a control, in three replications, during January - May 2021. The factors included were four levels of potassium (a1 - 0.5 % K2SO4, a2 - 1.0 % K2SO4, a3 - 0.25 % KNO3, a4 - 0.5 % KNO3) and three growth regulators (b1– gibberellic acid (GA3) 75 mg kg-1, b2 - brassinosteroid (BR) 0.1 mg kg-1, b3 - humic acid (HA) 100 mg kg-1). The variety used for the study was APK 1 and the nutrient dose adopted was 40:80:40 kg NPK ha-1. The treatments of foliar spray were given twice, potassium fertilizers, at flower bud and pod formation stages and growth regulators, 30 days after sowing (DAS) and at flower bud stage. The control plot was maintained without foliar application. The results of the study revealed that the plants were significantly the tallest at 60 and 90 DAS (94.59 and 148.87 cm respectively) in a4 (0.5 per cent KNO3). At flowering, the superior number of branches (8.73), leaf area (1662.76 cm2) and the highest root volume and rooting depth were recorded in a4. The number of root nodules was found maximum in a2. Foliar application of GA3 (b1) resulted in significantly taller plants at 60 and 90 DAS, and at flowering, the significantly superior number of branches, leaf area, root volume and the highest rooting depth and root-shoot ratio. The variation in the number of root nodules with the growth regulators was non-significant. Growth attributes were the highest in the interaction, a4b1 (0.5 % KNO3 x GA3), while the nodule number and weight, at flowering were maximum in a1b2 (0.5 % K2SO4 x BR). Treatment effects were significantly superior to control for all parameters, except the number and weight of nodules, which remained comparable. Crop growth rate (CGR) during 30-60 DAS, 60-90 DAS and 90 DAS- harvest, and leaf area index (LAI) were significantly the highest in a4, and among the growth regulators, in b1. The interaction effects were also significantly higher in the a4b1 combination. The individual effects of potassium and growth regulators revealed maximum dry matter partitioning to the shoots followed by that to pods and roots. Among the combinations, the partitioning to the pods was comparatively higher in a4b1 (45.06 %). The treatments were significantly superior to the control with respect to CGR, LAI and dry matter partitioning towards pods and roots, while that to shoots was significantly higher in the control. Chlorophyll and relative leaf water content in leaves at flowering remained comparable, whereas the soluble protein content in leaves was the maximum in a4b1. Foliar nutrition of potassium did not elicit marked variations in the number of days taken to 50 per cent flowering, while yield attributes remained significantly the highest with 0.5 per cent KNO3 application. Seed (1081.33 kg ha-1) and haulm (4837.27 kg ha-1) yields were significantly superior in a4. Among growth regulators, BR induced earliness in flowering (57.6 days) and the yield attributes were significantly the highest in b1. Foliar application of GA3 recorded the maximum seed yield (1100.13 kg ha-1) and haulm yield (4780.82 kg ha-1), the latter was on par with b2 (BR). The interaction effects also revealed significantly the highest values for yield attributes and yield in a4b1. Comparing the treatments with the control, treatment effects were markedly higher. Potassium nitrate influenced the crude protein content in seed favorably and the effect of treatments was significantly superior to the control. NPK uptake was the highest in a4, and among the growth regulators, the maximum uptake of P and K were recorded in b1. Among interactions, the nutrient uptake was significantly higher in a4b1, and in comparision with the control, the treatment effects were superior. The post-harvest analysis of soil did not show any significant variation in pH and organic carbon content, whereas available nutrient status varied significantly and was the lowest in the treatment combination, a4b1. Maximum net income (₹ 85723 ha-1) and benefit cost ratio (2.51) were realized in the treatment combination a4b1, and the net income was 46.4 per cent higher than that in control. Based on the above findings it can be concluded that foliar application of KNO3 and GA3 enhanced growth, sink efficiency and seed yield in red gram. Considering the economics, foliar nutrition with KNO3 (0.5 %) at flower bud and pod formation stages and GA3 (75 mg kg-1), 30 DAS and at flower bud stage, along with the nutrient dose of 40: 80: 40 kg NPK ha-1 can be recommended for cultivation of red gram.
Standardization of agrotechniques in spinach beet(Beta vulgaris L.var.bengalensis)
(Department of Agronomy, College of Agriculture, Vellayani, 2020) Sruthy, A B; Sheeba Rebecca Isaac
The study entitled “Standardization of agrotechniques in spinach beet (Beta vulgaris L. var. bengalensis)” was carried out at College of Agriculture, Vellayani, to standardize the planting geometry, nutrient management practice and number of harvests for economic yield and quality in spinach beet under rain shelter condition and to assess the effect on soil chemical and biological properties. The experiment was laid out in randomized block design in three replications during October 2019 to January 2020 with the variety All Green. The treatments included two spacings (s1: 20 cm x 10 cm; s2: 30 cm x 10 cm), two nutrient management practices (n1: inorganic sources; n2: organic sources) and three number of harvests (h1: four harvests; h2: five harvests; h3: six harvests). The NPK dose adopted was 80:40: 80 kg ha-1, one fourth N and K, full P were given as basal, remaining N and K, in splits as top dressing, 20 days after sowing (DAS) and after each harvest. The organic sources used were vermicompost, rock phosphate, arbscular mycorhizhal fungi (AMF) and wood ash, and the inorganic sources, urea, rajphos and muriate of potash. The results of the experiment revealed that among the spacings tried, plant height (30, 40, 60 and 70 DAS), leaf area index (LAI) and leaf yield per 10 m2 were higher in the closer spacing, while per plant leaf area, number of leaves harvested and yields were significantly the highest in the wider spacing, s2. Among the nutrient sources, plant height (30, 40 and 60 DAS), leaf area, LAI and leaf yield were significantly higher in inorganic nutrient management. Leaf area, LAI and leaf yields were significantly the highest for the treatment with six harvests (h3) followed by h2 and h1. The interaction effects of S x N and S x H on leaf yields were significant. Among S x N interactions, s1n1 recorded significantly higher leaf yield per 10 m2 (14.07 kg) and among the S x H interactions, s2h3 recorded the highest leaf yield per plant (111.56 g ) whereas s1h3 showed the highest leaf yield per 10 m2 (16.10 kg). The treatment combination s1n1h3 recorded the highest LAI (1.93) and leaf yield per 10 m2 (17.76 kg). Nutrient uptake (N, P and K) were the highest in s2, n1 and h3. Quality parameters (vitamins A and C, protein and chlorophyll content) were comparatively higher in the leaves of third harvest. Vitamin A and C content were highest in n2 while protein and chlorophyll content were higher in n1. S x N x H interaction was significant for the protein content alone. The soil properties did not show significant variations with spacing except available P status, which was higher in s2. Organic C, available N and K status were significantly higher in n2 and declined with the increase in number of harvests, higher contents were recorded in h1. The combination of s1n2h1 registered the highest available K status in soil. Soil microbial counts were significantly higher for n2 and the variations in fungal counts were significant for S x N, S x H and N x H interactions. Economic analysis revealed that gross and net income from 10 m2 and benefit cost ratios were the highest for the combination of closer spacing, inorganic nutrient management and six harvest, s1n1h3, the values being ( 888, 406 and 1.84 respectively). Based on the results, the most suitable combination of agro techniques for economic yield in spinach beet under rain shelter condition include, closer spacing of 20 cm x 10 cm (s1), NPK dose of 80: 40: 80 kg ha-1 through inorganic sources (n1) and six harvests (h3). Considering the quality (vitamin A and C), organic nutrition (n2) proved to be superior and contents were the highest in the leaves of third harvest. The treatment combinations favourably influenced the soil nutrient status and microbial counts, higher values were recorded for organic nutrient management.
Yield, Quality and vigour of bhindi seed as influenced by number of harvests and nutrient sources
(Department of Agronomy, College of Agriculture, Vellayani, 1995) Sheeba Rebecca Isaac; Pushpakumari, R
An experiment was conducted at the College of Agriculture, Vellayani to study the influence of vegetable harvests and nitrogen sources on the seed yield and quality in hbindi. The treatments consisted of combinations of four different number of vegetable harvests (0, 2, 4, 6) and four sources (12 t FYM + 110:37:74 kg N, P2o5 and K2o ha-1, 12 t FYM + 3.6 t poultry manure, 12 t FYM + 11 t vermicompost and 6 t FYM + 110:37:74 kg N, P2o5 and K2o ha-1. The results revealed that growth characters of bhindi crop were not significantly influenced vegetable harvests except for the height 90 DAS. Frequent picking of green fruits in bhidndi improved the bearing capacity of the plant but the mature fruit yield, seed yield and quality were significantly reduced. Highest seed yield was observed with zero vegetable harvest bur was on par with two vegetable harvests. Among the seed characters, germination percentage, 1000 seed weight, 100 seed volume, seed protein and seed moisture content were not significantly influenced by the vegetable harvests while seedling root and shoot length and vigour index values were better for two vegetable harvest treatments. This treatment apart from a good yield of quality seeds, yielded some vegetable also. The effect of the sources of nitrogen on the germination percentage, seedling root and shoot length and vigour index was not significant while mother crop growth parameters, mature fruit yield and seed yield were significantly high when organic manures were used in conjuction with chemical fertilisers. Farm yard manure at 12 or 6 t coupled with chemical fertilisers gave statistically similar results with regard to the seed yield and quality. Considering the economics, better profits could always be realised when FYM was applied along with chemical fertilisers without any vegetable harvest but, for a satisfactory yield of quality seed and some vegetable, this source should be combined with two vegetable harvests.