The effect of salinity stress on the population of sucking pests in cotton

Background and Objectives: Cotton fibers, seeds, and stalks are widely used in the textile industry, food and feed products, and paper making. Salinity stress is a significant factor affecting the natural growth and development of cotton, limiting the cultivation of this strategic crop worldwide.
Materials and Methods: To investigate the effect of salinity stress on the population density of important cotton-sucking pests in salinity-tolerant cultivars, a two-year study was conducted using a completely randomized block design. Six salinity-tolerant cotton cultivars (Sahel, Sepid, Sinduz, 43200, Chokurova, and Siland) were evaluated with four replications in Golestan province. Each treatment or cultivar was planted in four plots, each plot consisting of 10 rows, each 11 meters long, with a row spacing of 0.8 meters and plant spacing of 0.2 meters. Data were collected on yield characteristics and population densities of key cotton-sucking pests, including thrips, whitefly, and cotton aphid. The treatments were then compared.
Results: The data analysis showed no statistically significant differences among cultivars in terms of yield traits and cotton thrips pest population density. However, there were statistically significant differences in terms of cotton aphid and cotton boll weevil population densities per leaf at the 0.05% and 0.01% levels. Using Duncan's method, the comparison of aphid and whitefly population densities was significant at the 5% level. The highest population densities of thrips, aphids, and cotton boll weevils were observed in the Chokurova cultivar with an average of 0.5 per plant, the Sinduz cultivar with an average of 7.9 per leaf, and the Sinduz cultivar with an average of 2.6 per leaf, respectively. Conversely, the lowest population densities of cotton thrips, aphids, and whiteflies were found in the Sepid cultivar, with averages of 0.38 per plant, 4.5 per leaf, and 1.2 per leaf, respectively.
Conclusions: Among the salinity-tolerant cultivars selected in this experiment, the Sinduz variety attracted the highest number of pests. However, the Sepid variety demonstrated good growth and yield, high quality, and tolerance to sucking insects. These results suggest that the Sepid variety is a promising candidate for developing and managing cotton cultivation in saline areas.