Crop Geometry and Nitrogen Levels Influence on Growth, Yield and Economics of Compact Cotton (Gossypium hirsutum L.) in Rainfed Vertisols

Abstract

Aims: To study the effect of crop geometry and nitrogen levels on compact cotton genotype in rainfed vertisols condition.
 Study Design: The experiment was laid out in a randomized block design with a factorial concept with 3 levels of crop geometry and four levels of nitrogen with 12 treatment combinations and replicated thrice.
 Place and Duration of Study: A field experiment was conducted on vertisols under rainfed conditions at Regional Agricultural Research Station Lam, Guntur during the year 2018 – 2019.
 Methodology: The treatments consisted of three crop geometries S1 – 60 cm × 10 cm, S2- 75 cm × 10 cm, S3- 90 cm × 45 cm in combination with four nitrogen levels N1- 45kg N ha-1, N2- 90kg N ha-1, N3- 135 kg N ha-1, N4- 180 kg ha-1.
 Results: Closer crop geometry of 60 cm × 10 cm recorded taller plants and maximum dry matter accumulation, functional leaves per square meter, leaf area index, maximum chlorophyll content, number of bolls per square meter and seed cotton yield per ha-1, net returns and returns per rupee. However, the number of sympodial branches per plant and sympodial length was highest with wider crop geometry of 90 cm × 45 cm. All the growth and yield parameters recorded were maximum with the application of 180Kg N ha-1 than all the other levels of nitrogen tested.
 Conclusion: Overall, the results showed that the Crop geometry of 60cm × 10 cm with application of 135 kg N ha-1 was found to be optimum to realize of maximum seed cotton yield and net returns.