Climate change has a negative impact on cotton and sesame yields. Intercropping can promote climate resilience through higher plant resource efficiency and natural suppression of insect pests, pathogens, and weeds. So, the two-year field trial was conducted to determine the best date for intercropping sesame and cotton with respect to cotton and sesame agronomic performance and infestation by major pests. Sesame was planted two weeks before cotton sowing, simultaneously with cotton, and two weeks after cotton sowing into cotton planted on April 1, April 15, and May 1. Delayed intercropping of sesame increased cotton yield and yield-related traits at all cotton seeding dates and reduced infestations of insect pests, especially bollworms. Conversely, intercropping sesame two weeks before cotton was sown on May 1 produced the highest sesame agronomic trait values and decreased infestations of insect pests, including the sesame capsule borer. The highest land equivalent ratio (1.21) was obtained by intercropping sesame after two weeks with cotton planted on April 1. However, the lowest land equivalent ratio (1.0) was obtained by intercropping sesame two weeks before cotton in the cotton planted on April 15. On April 1, the relative crowding coefficient for intercropping treatments exhibited greater values than one, while April 15 displayed the lowest value. All of the intercropping treatments of sesame after cotton produced the best total return compared to the sole culture of cotton on the three dates. In summary, intercropping sesame after two weeks with cotton planted on April 1 was the best option for better cotton and sesame productivity, reduced pest pressure, and higher economic returns.
Keywords: Cotton, Insect pests, Land equivalent ratio, Sesame, Total return