Evaluation of the effect of magnesium in combination with organic manures on the growth and yield attributes and yield of cotton (Gossypium hirsutum L.) inTypic Ustropept

Cotton is India's most significant commercial crop and has a significant role in the agricultural economics of the nation. A field experiment was conducted in a farmer’s field located in Achchandavilthan village of Srivillipudhur block, Virudhunager District, from 28-Aug 2019 to Jan, 2020 to evaluate the response of cotton to foliar and soil application of magnesium combination with organic manures on the growth and yield attributes and yield of cotton in magnesium deficient soil. The soil was categorized as “Moderately deep clay Typic Ustropept, and medium N, P and high K content, in a randomized block design with fifteen treatments and three replications. The results revealed that the application of MgSO4 at a rate of 50 kg ha-1 along with 250 kg vermicompost for 30 days (1:5 ratio) at critical stages of crop growth along with the Soil Test Crop Response (STCR) based N,P2O5 and K2O RDF registered the maximum plant height at all three stages (40,70 and harvest) of crop growth (94.7, 122.3 and 222.2 cm), number of monopodial branches plant-1 (33.4), number of sympodial branches plant-1(73.1), numbers of boll plant-1 (48.3), boll weight (3.9 g), and seed cotton yield (26.2 q ha-1). This was followed by treatment (T9) MgSO4 at a rate of 50 kg ha-1 incubated with 500 kg FYM for 30 days (1:10 ratio) along with STCR) based N,P2O5 and K2O RDF and the lowest treatment receiving the recommended dose of N, P2O5 and K2O alone (80:40:40 kg ha1). It was revealed that natural chelated fertilizer prepared from MgSO4 incubated with organic manures for 30 days significantly improved the growth and yield of cotton.