Browsing by Author "Mary Shyna , J."

Filter results by typing the first few letters
Now showing 1 - 1 of 1
  • No Thumbnail Available
    Item
    Evaluation of STCR based targeted yield equations for cowpea (Vigna unguiculata L) in southernlaterites
    (Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani, 2023-04-27) Mary Shyna , J.; Visveswaran ,S
    The study entitled ‘Evaluation of STCR based targeted yield equations for cowpea (Vigna unguiculata L.) in southern laterites’ was conducted at the Department of Soil Science and Agricultural Chemistry, College of Agriculture, Vellayani during 2020-2021. The targeted yield equation developed by AICRP on STCR during 2018 for cowpea was test verified for southern laterites (AEU 8) in this study. A farmer’s field in Kalliyoor gram panchayath, Thiruvananthapuram was selected for the experiment. The variety used in the study was Anaswara and the design followed was RBD. The experiment consisted of five treatments viz., POP-KAU with organic manure management (T1), POP-KAU on the basis of soil test (T2), STCR recommendation for a targeted yield of 15 tonnes (T3), STCR recommendation for a targeted yield of 16.5 tonnes (T4) and STCR recommendation for a targeted yield of 18 tonnes (T5). The targeted yield equation followed in this study is as follows; FN = 3.88 T – 0.098 SN – 0.02 ON FP2O5 = 4.34 T – 0.619 SP – 0.01 OP FK2O = 16.53 T – 0.489 SK – 0.08 OK Here, FN, FP2O5, and FK2O are nitrogen, phosphorus and potassium contributions from the fertilizers respectively. SN, SP and SK are nitrogen, phosphorus and potassium contributions from the soil respectively. Similarly, ON, OP and OK are nitrogen, phosphorus and potassium contributions from the organic sources respectively. T in the equation represents the targeted yield. Different soil and plant parameters were analysed to study the performance of the crop under each treatment. This includes initial and post harvest physico-chemical characteristics of the soil, biometric observations, nutrient content of pod and stover, yield parameters and dry matter production. The biometric observations viz., average length of the pod, average weight of the pod, the number of pods per plant and the number of seeds per pod were found to be the maximum in T5. Also the number of days to first flowering and the number of days to 50% flowering was the least in this treatment. All the three yield targets in STCR treatments were achieved. The maximum yield was observed in T5 and the minimum in T1. In the case of the weight of the stover, the highest value was shown by T5 and the lowest by T1. Dry matter production of the above ground portion also showed the same trend. For the particle density, bulk density and porosity of the post harvest soil, there was no significant difference found among the treatments. The pH and OC content of the soil showed slight increase after the harvest. The maximum N, P and K content was found in T5 and the minimum in T1. The highest dehydrogenase activity was observed in T1 and the lowest was observed in T5. The nutrient status of the stover and the pod was analysed. In both stover and pod samples, the treatments T5 and T1 showed the highest and the lowest N, P and K contents respectively. The chlorophyll content in the leaf samples showed significant difference among all the treatments where the highest chlorophyll content was recorded in T5 and the lowest was observed in T1. The pesticide residue analysis done for the presence of quinalphos in soil showed the maximum value in T2 and the minimum in T4. The pesticide residue level for quinalphos in the harvested pods was below the detectable level. Correlation studies were carried out to find the correlation between yield and other different parameters. A significant negative correlation with yield was found for the number of days for first flowering and the number of days for 50% flowering. There was significant positive correlation between the average length of the pod, the average weight of the pod, the number of pods per plant and the number of seeds per pod with yield. Similarly, the weight of the stover showed a significant positive correlation with yield. In the case of N, P and K contents in soil, stover and pod samples, there was a significant positive correlation with yield. The analysis of nutrient status of the plant parts showed that, higher nutrient contents was observed in plants which were grown under treatment having higher amount of fertilizer doses. This shows a direct proportion of fertilizer applied and the nutrients absorbed. The micro nutrient status of the samples did not show significant difference among the treatments. The treatment T5 was economically superior to the other treatments as it has the maximum B: C ratio. Therefore, it can be concluded that STCR- IPNS based targeted yield equations for cowpea can be extended to AEU 8 for successful cultivation. This ensures the maximum utilization of the fertilizers and the maximum profit to the farmer without disturbing the soil quality.