MSc

The study entitled "Soil and nutrient management for suppression of Fusarium wilt disease of yard long bean (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt)" was conducted at Instructional Farm, College of Agriculture, Vellayani during February to May 2017 with the objective to assess the impact of liming practices, organic manure addition and nutrient management on the suppression of Fusarium wilt disease of yard long bean.
The experiment was laid out in RBD with thirteen treatments and three replications. The treatments were T1-soil test based POP (control), T2-T1 + foliar fertilization of 19:19:19 (0.5%), KNO3 (0.3%), MgSO4 (1%) and borax (0.5%) at fortnightly interval, T3- organic package(cow dung 20 t ha-1 as basal followed by additional dose of 1.5 t ha-1 poultry manure + 50 kg ha-1 rock phosphate as 4 equal splits at fortnightly intervals),T4 – fortified organic fertilizer (4 t ha -1 as basal, followed by 5 top dressings @ 50g/plant at fortnightly intervals),T5-IDM package (seed treatment with carbendazim @ 2g/kg seed+ burning of pits prior to sowing + soil incorporation if Trichoderma enriched neem cake organic manure mixture @ 1 kg/pit at twinning stage + mancozeb and carbendazim (0.3%) at 20, 40 and 50 DAS), T 6-T2 + lime 250 kg ha-1 + T5-IDM package (Seed treatment with carbendazim @2 g/ kg seed +burning of pit sprior ro sowing+soil incorporation of Trichoderma enriched neem cake organic manur emixture @ 1 kg/pit at twinning stage +mancozeb and carbendazim (0.3%) at 20,40 and 50 DAS), T6-T2+lime 250 kg ha -1 + cow dung 20 t ha-1, T7-T2 + lime 250 kg ha -1 +Trichoderma enriched cow dung 20 t ha-1, T8-T2 + lime as per LR (basal)+ cow dung 20 t ha -1, t9-t2+ lime as per LR (basal)+Trichoderma enriched cow dung 20t ha-1, T10-T2+ lime as per LR (2 equal splits- basal and at flowering )+cow dung 20 t ha-1, T11-T2+ lime as per LR (2equal splists _ basal and at flowering) +Trichoderma enriched cow dung 20 t ha -1, T12-T2+ dolomite 400 kg ha-1+ cow dung 20 t ha-1, T12-T2 + dolomdite 400 kg ha -1 + Trichoderma enriched cow dung 20 t ha-1.
The results revealed that the growth attributes of the crop were significantly influenced by the treatments. The minimum number of days for flowering was observed in T8 and T9 (32 days) and the maximum cop duration of 95.33 days was observed in the treatment T 10. The treatment T11 recorded the highest leaf area index of 0.42. The yield and yield attibutes namely pod length (51.10 cm), pod weight (19.69g), number of pods per plant (65), yield per plant (1286.35 g) yield per plot (12.86 t ha-1), total dry matter production (2.72 t ha-1)and harvest index (0.62) were the highest in treatment T11. The highest soil PH was observed in the treatment T10 (6.74) which received lime as per lime requirement in 2 equal splits at basal and at flowering stage which was on par with T11 (6.69) and T8 (6.54). The EC and organic carbon status of soil were not significantly influenced by the treatments.
There was a significant influence of the treatments on the available N and P status of soil at harvest of the crop with T11 (304.12 kg ha-1) and T9 (80.23 kg ha-1) recording the highest values respectively. The highest available Ca was registered by T11 (304.12 mg kg -1) while the lowest value was noticed in T2 (229.53mg kg-1). The highest available Mg was observed in T13 (206.05 mg kg -1) which received dolomite @ 400 kg ha-1. The treatments improved the available S status of soil with T11 (5.43 mg kg -1) recording the highest value. The available Fe and Mn were significantly reduced in the treatments receiving lime. The incorporation of various liming materials and organic manures significantly increased the available Zn and Cu, while the available B status was unaffected.
Analysis of index tissue concentration of nutrients indicated significantly higher content of N (2.65%) and P (0.37 %) in T11. The content of secondary nutrients Ca, Mg and S were significantly influenced by the treatments with T10, T12 and T13 recording the highest values of 3.66% 1.34% and 0.27 % respectively. The content of Zn and B were also significantly increased with T9 (28.46 mg kg -1) and T11 (32.32 mg kg-1) recording the highest values respectively. All the treatments receiving lime @ LR along with foliar fertilization improved the uptake of N, P, K, Ca, Mg, S, Zn, Cu and B.
The highest disease incidence of 55.51% and disease index of 45.84% were obtained in the control treatment T1 which was on par with T2, T3 and T4. The treatment T11 resulted in zero disease incidence and disease index which was on par with the IDM package treatment (T5). Analysis of economics of production in various treatments revealed that the higher BCR was obtained in the treatment T11 (2.58) which was on par with T10 (2.54).
From the study it can be concluded that increased growth and yield of yard long bean through the suppression of Fusarium wilt disease can be achieved by the basal application of Trichoderma enriched cow dung @ 20 t ha -1 as organic manure, lime @ LR in 2 splits at basal and flowering stage as soil amendment and soil test based dose of fertilizers as soil application along with foliar fertilization of 19:19:19 (0.5%), KNO3(0.3%), MgSO4 (1%) and borax (0.5%) at fortnightly interval as nutrient source.