Relationship between cotton planting date and two bollworms associated with their natural enemies

Abstract

Abstract Background Cotton is the most widespread, profitable non-food crop in the world. Egypt is one of the greatest countries in producing cotton (Gossypium hirsutum L.) in the world. Many pests attacked cotton which reduced the quality and quantity of the cotton yield such as pink bollworm (Pectinophora gossypiella) (Lepidoptera: Gelechiidae) and the spiny bollworm (Earias insulana) (Lepidoptera: Noctuidae). Results The insect infestation increased significantly by delaying planting date. The fewest numbers of pests attacked cotton recorded in the earliest planting date (March 23rd) with highest weight of cotton yield. The results showed that the mean rates of infestation with pink bollworm were (2.11, 3.5, 2.33 individuals/boll) for March 23rd, April 17th and May 6th, respectively, while the mean rates of infestation with bollworm were (1.60, 2.79, 1.67 individuals/boll) for March 23rd, April 17th and May 6th, respectively. Conclusion It was concluded that planting cotton as early as on March 23rd reduces the rate of infestation of E. insulana and P. gossypiella and increases the population of its natural enemies as well. Then, it is resulting a significant increase in the quality and quantity of the yield of cotton.