Arya, A P
Performance of grain cowpea (Vigna unguiculata (L.) Walp.) in response to conservation tillage in the summer rice fallows of Onattukara sandy plains - Vellayani Department of Agronomy, College of Agriculture 2025 - xi,143p.
MSc
The study entitled “Performance of grain cowpea (Vigna unguiculata (L.) Walp.) in response to conservation tillage in the summer rice fallows of Onattukara Sandy Plains” was undertaken at College of Agriculture, Vellayani, during 2022 2024 with an objective to assess the response of grain cowpea varieties under conservation tillage and to work out the economics of cultivation. The field experiment was carried out at Onattukara Regional Agricultural Research Station, Kayamkulam under Onattukara Sandy Plains (AEU-3)’ from February to April 2024. The experiment was laid out in split plot design with four replications. The main plot treatments were three tillage options (T) viz., T₁ - Zero tillage + herbicides (pre plant application of glufosinate ammonium @ 0.375 kg ha 1 fb imazethapyr @ 50 g ha-1 at 15 DAS), T₂ - Minimum tillage + herbicide (imazethapyr @ 50 g ha-1 at 15 DAS) and T3- Conventional tillage. Sub plot treatments were three varieties viz., (V), Krishnamony (V₁), Hridya (V₂) and PGCP 6 (V3). The crop was managed according to the Package of Practices of KAU (2016) except land preparation and weed management. Under the treatment T1, the crop was sown in the residues of the previous crop without any prior soil tillage leaving the paddy stubbles as such. Under the treatment T2, the crop was sown after giving a shallow tillage which retained the paddy stubbles as mulch in the field. Hand weeding was done at 15 DAS in T3, conventional tillage. Cowpea seed was sown by dibbling at a spacing of 25 cm X 15 cm and recommended dose of nutrient @ 20:30:10 kg NPK ha-1 was applied as per KAU POP recommendations (KAU, 2016). The tillage options significantly influenced the growth attributes like plant height, number of primary branches per plant, and number of leaves per plant at 15 DAS, 30 DAS, 45 DAS and at harvest. Zero tillage + herbicides had higher values for all these parameters. Among the varieties, PGCP-6 resulted in taller plants at all stages of observation and higher number of leaves per plant at 45 DAS and at 140 harvest and primary branches per plant at harvest, whiHridya had more number of leaves and primary branches. The plants grown under zero-tillage + herbicides produced higher dry matter at 15 DAS, 30 DAS, 45 DAS and at harvest (0.31 g per plant, 4.58 g per plant, 22.19 g per plant and 29.84 g per plant, respectively). The variety PGCP-6 accumulated more dry matter at 30 DAS, 45 DAS and at harvest (5.34 g per plant, 26.84 g per plant and 37.17 g per plant, respectively) compared to other varieties. However, the interaction between tillage options and varieties was significant only at 30 DAS and the treatment t1v3 (PGCP-6 grown under zero-tillage) had higher dry matter accumulation (5.73 g per plant) than others. Number of pods per plant and hundred seed weight were significantly influenced by tillage options. The zero tillage + herbicides resulted in significantly higher number of pods per plant (18.24), hundred seed weight (8.70 g), pod yield per plant (17.86 g), seed yield per plant (9.50 g), haulm yield per plant (25.34 g), seed yield ha-1 (950 kg) and haulm yield ha-1 (3868 kg). Among the varieties, PGCP-6 resulted in the highest value for all yield parameters and yield viz., number of seeds per pod (15.18), pod length (17.26 cm), pod weight (2 g), and hundred seed weight (12.65 g). The pod yield per plant (17.39 g), seed yield per plant (9.94 g) haulm yield per plant (37.12 g), seed yield ha-1 (1254 kg), and haulm yield ha-1 (5666 kg) were also higher for the variety PGCP-6. Zero tillage + herbicides resulted in 13.5 per cent higher yield than conventional tillage. However, the interactions between tillage options and varieties were not significant for yield and yield attributes. Tillage options had a significant influence on rooting depth, root dry weight, and root volume and conventional tillage resulted in superior values. Zero tillage + herbicides resulted in lower values for these parameters. The variety PGCP-6 exhibited higher values for all root parameters studied. The nodule parameters like the total number of nodules per plant, nodule fresh weight, and effective nodules per plant were significantly influenced by tillage options at 30 DAS and zero tillage + herbicides showed higher values. Among the 141 varieties, PGCP-6 had higher values for the nodule parameters. The tillage option x variety interaction was significant and the variety PGCP-6 under zero tillage + herbicides had higher values for the nodule parameters. The effect of tillage options and varieties on weed density and weed dry matter was significant. At 15 DAS and 45 DAS, zero tillage + herbicides resulted in lowest weed density and weed dry weight. At 30 DAS conventional tillage recorded lower weed density and dry weight compared to other tillage options. Among the varieties, the weed incidence was lesser in PGCP-6. There was no significant interaction between tillage and varieties. The NPK uptake by plant was significantly affected by the treatments. The nutrient uptake was higher in zero tillage + herbicides. The variety PGCP-6 resulted in higher NPK uptake compared to other varieties. No significant interaction was observed between tillage options and varieties. At 15 DAS and 45 DAS, NPK removal by weeds was higher in conventional tillage. However, at 30 DAS, zero tillage + herbicides resulted in higher NPK removal by weeds. Among the varieties, nutrient removal by weeds was lesser in PGCP-6. At 45 DAS, dehydrogenase enzyme activity was higher in zero + herbicides and was on par with minimum tillage + herbicide. Among the varieties V2 (Hridya) and V3 (PGCP-6) recorded comparable values for soil dehydrogenase enzyme activity. At 30 DAS, urease enzyme activity was higher in zero tillage + herbicides. Among the tillage options, zero tillage + herbicides resulted in the highest net income (₹35653 ha-1) and benefit-cost ratio (1.70). Among the varieties, PGCP 6 registered higher net income (₹60027 ha-1) and benefit cost ratio (2.14). Considering the growth and yield as well as net income and benefit cost ratio, the grain cowpea variety PGCP-6 can be cultivated under zero tillage with herbicides (preplant application of glufosinate ammonium @ 0.375 kg ha-1 and post emergant herbicide imazethapyr @ 50 g ha-1 at 15 DAS) in the summer rice fallows of Onattukara Sandy Plains. It was found to be the most cost effective technology 142 for managing the weeds, a major production constraint in the in the summer rice fallows of Onattukara.
Agronomy
Cowpea
Vigna unguiculata (L.) Walp.
Tillage
Summer rice
Onattukara sandy plains
630 / ARY/PE PG
Performance of grain cowpea (Vigna unguiculata (L.) Walp.) in response to conservation tillage in the summer rice fallows of Onattukara sandy plains - Vellayani Department of Agronomy, College of Agriculture 2025 - xi,143p.
MSc
The study entitled “Performance of grain cowpea (Vigna unguiculata (L.) Walp.) in response to conservation tillage in the summer rice fallows of Onattukara Sandy Plains” was undertaken at College of Agriculture, Vellayani, during 2022 2024 with an objective to assess the response of grain cowpea varieties under conservation tillage and to work out the economics of cultivation. The field experiment was carried out at Onattukara Regional Agricultural Research Station, Kayamkulam under Onattukara Sandy Plains (AEU-3)’ from February to April 2024. The experiment was laid out in split plot design with four replications. The main plot treatments were three tillage options (T) viz., T₁ - Zero tillage + herbicides (pre plant application of glufosinate ammonium @ 0.375 kg ha 1 fb imazethapyr @ 50 g ha-1 at 15 DAS), T₂ - Minimum tillage + herbicide (imazethapyr @ 50 g ha-1 at 15 DAS) and T3- Conventional tillage. Sub plot treatments were three varieties viz., (V), Krishnamony (V₁), Hridya (V₂) and PGCP 6 (V3). The crop was managed according to the Package of Practices of KAU (2016) except land preparation and weed management. Under the treatment T1, the crop was sown in the residues of the previous crop without any prior soil tillage leaving the paddy stubbles as such. Under the treatment T2, the crop was sown after giving a shallow tillage which retained the paddy stubbles as mulch in the field. Hand weeding was done at 15 DAS in T3, conventional tillage. Cowpea seed was sown by dibbling at a spacing of 25 cm X 15 cm and recommended dose of nutrient @ 20:30:10 kg NPK ha-1 was applied as per KAU POP recommendations (KAU, 2016). The tillage options significantly influenced the growth attributes like plant height, number of primary branches per plant, and number of leaves per plant at 15 DAS, 30 DAS, 45 DAS and at harvest. Zero tillage + herbicides had higher values for all these parameters. Among the varieties, PGCP-6 resulted in taller plants at all stages of observation and higher number of leaves per plant at 45 DAS and at 140 harvest and primary branches per plant at harvest, whiHridya had more number of leaves and primary branches. The plants grown under zero-tillage + herbicides produced higher dry matter at 15 DAS, 30 DAS, 45 DAS and at harvest (0.31 g per plant, 4.58 g per plant, 22.19 g per plant and 29.84 g per plant, respectively). The variety PGCP-6 accumulated more dry matter at 30 DAS, 45 DAS and at harvest (5.34 g per plant, 26.84 g per plant and 37.17 g per plant, respectively) compared to other varieties. However, the interaction between tillage options and varieties was significant only at 30 DAS and the treatment t1v3 (PGCP-6 grown under zero-tillage) had higher dry matter accumulation (5.73 g per plant) than others. Number of pods per plant and hundred seed weight were significantly influenced by tillage options. The zero tillage + herbicides resulted in significantly higher number of pods per plant (18.24), hundred seed weight (8.70 g), pod yield per plant (17.86 g), seed yield per plant (9.50 g), haulm yield per plant (25.34 g), seed yield ha-1 (950 kg) and haulm yield ha-1 (3868 kg). Among the varieties, PGCP-6 resulted in the highest value for all yield parameters and yield viz., number of seeds per pod (15.18), pod length (17.26 cm), pod weight (2 g), and hundred seed weight (12.65 g). The pod yield per plant (17.39 g), seed yield per plant (9.94 g) haulm yield per plant (37.12 g), seed yield ha-1 (1254 kg), and haulm yield ha-1 (5666 kg) were also higher for the variety PGCP-6. Zero tillage + herbicides resulted in 13.5 per cent higher yield than conventional tillage. However, the interactions between tillage options and varieties were not significant for yield and yield attributes. Tillage options had a significant influence on rooting depth, root dry weight, and root volume and conventional tillage resulted in superior values. Zero tillage + herbicides resulted in lower values for these parameters. The variety PGCP-6 exhibited higher values for all root parameters studied. The nodule parameters like the total number of nodules per plant, nodule fresh weight, and effective nodules per plant were significantly influenced by tillage options at 30 DAS and zero tillage + herbicides showed higher values. Among the 141 varieties, PGCP-6 had higher values for the nodule parameters. The tillage option x variety interaction was significant and the variety PGCP-6 under zero tillage + herbicides had higher values for the nodule parameters. The effect of tillage options and varieties on weed density and weed dry matter was significant. At 15 DAS and 45 DAS, zero tillage + herbicides resulted in lowest weed density and weed dry weight. At 30 DAS conventional tillage recorded lower weed density and dry weight compared to other tillage options. Among the varieties, the weed incidence was lesser in PGCP-6. There was no significant interaction between tillage and varieties. The NPK uptake by plant was significantly affected by the treatments. The nutrient uptake was higher in zero tillage + herbicides. The variety PGCP-6 resulted in higher NPK uptake compared to other varieties. No significant interaction was observed between tillage options and varieties. At 15 DAS and 45 DAS, NPK removal by weeds was higher in conventional tillage. However, at 30 DAS, zero tillage + herbicides resulted in higher NPK removal by weeds. Among the varieties, nutrient removal by weeds was lesser in PGCP-6. At 45 DAS, dehydrogenase enzyme activity was higher in zero + herbicides and was on par with minimum tillage + herbicide. Among the varieties V2 (Hridya) and V3 (PGCP-6) recorded comparable values for soil dehydrogenase enzyme activity. At 30 DAS, urease enzyme activity was higher in zero tillage + herbicides. Among the tillage options, zero tillage + herbicides resulted in the highest net income (₹35653 ha-1) and benefit-cost ratio (1.70). Among the varieties, PGCP 6 registered higher net income (₹60027 ha-1) and benefit cost ratio (2.14). Considering the growth and yield as well as net income and benefit cost ratio, the grain cowpea variety PGCP-6 can be cultivated under zero tillage with herbicides (preplant application of glufosinate ammonium @ 0.375 kg ha-1 and post emergant herbicide imazethapyr @ 50 g ha-1 at 15 DAS) in the summer rice fallows of Onattukara Sandy Plains. It was found to be the most cost effective technology 142 for managing the weeds, a major production constraint in the in the summer rice fallows of Onattukara.
Agronomy
Cowpea
Vigna unguiculata (L.) Walp.
Tillage
Summer rice
Onattukara sandy plains
630 / ARY/PE PG