Optimization of Planting Date and Density of Cotton Through Crop Mechanistic Model and Field Experimentation in Semi-Arid Conditions

Climate variability and trend affect crop growth, development, and ultimately seed yield. Selection of appropriate planting date and density is essential for improving crop performance under changing climate. A field experiment was conducted under semi-arid climatic conditions to evaluate the performance of cotton crop under different planting dates viz. 22(nd) April, 7(th) May, 22(nd) May and 6(th) June and densities viz 88890, 59260 and 44445 plants/ha. Treatments were arranged by using randomized complete block design with split plot arrangement. The phenological parameters i.e., square initiation, flower initiation, boll formation and boll opening and yield- and yield- components i.e., number of bolls per plant, monopodial branches, sympodial branches, seed cotton yield and seed index were significantly affected by planting dates and densities. Results showed that maximum seed cotton yield (3464 kg ha(-1)) was recorded when cotton was sown on 22(nd) April. However, plant population also affected cotton crop significantly. Maximum seed cotton yield (2751 kg ha(-1)) was recorded for 22.5 cm planting density followed by 15 cm and 30 cm. Furthermore, OZCOT-DSSAT cotton model showed that the simulated phenological parameters with the average error of 9%, 3% and 4% in days to flowering, day to maturity and seed cotton yield, respectively. In sum, simulated data and observed data showed cotton could be planted on 22(nd) April with 59260 plants/ha to achieve maximum productivity.