Sulfoxaflor Applied via Drip Irrigation Effectively Controls Cotton Aphid (Aphis gossypii Glover)

Abstract

Aphis gossypii Glover is a major pest of cotton and can severely affect cotton yield and lint quality. In this study, the efficacy of sulfoxaflor applied via drip irrigation and foliar spray on controlling cotton aphids was evaluated in 2016 and 2017 in Xinjiang, China. The distribution of sulfoxaflor in cotton roots, stems, leaves, and aphids, as well as its effects on two natural enemies of aphids, were also investigated. Results showed that sulfoxaflor applied through drip irrigation mainly concentrated in leaves and provided effective control of cotton aphids for 40 days, compared to 20 days when applied through foliar spray. Furthermore, drip application resulted in much lower sulfoxaflor concentrations in aphids than foliar spray. As a result, ladybird beetle and lacewing populations were higher in drip applied plants than in foliar sprayed plants. Additionally, the cost of drip irrigation was lower than foliar spray as cotton plants are commonly irrigated via drip irrigation in Xinjiang. Our results showed that application of sulfoxaflor through drip irrigation is an effective way of controlling cotton aphids in Xinjiang due to a prolonged control period, safety to two natural enemies, and lower cost of application.

Sulfoxaflor Residues in Pollen and Nectar of Cotton Applied through Drip Irrigation and Their Potential Exposure to Apis mellifera L.

“…On 5 April 2016 and 24 April 2017, cotton seed (Xinliuzao-42) was sown in a field installed with a drip irrigation system under the film. The experimental field site was similar to our previously reported site [9].…”

“…The application rates were chosen based on previous test results of sulfoxaflor (drip irrigation: sulfoxaflor, 700 g a.i. ha −1 ) in a cotton field in Xinjiang [9]. The detailed calendar of sulfoxaflor treatments is presented Table 1.…”

“…ha −1 or 700 g a.i. ha −1 following the days indicated in Table 1 based on the procedures previously described [9]. Drip controls were the same irrigation regime without any chemicals.…”

“…Chemigation has numerous advantages, including uniform distribution of insecticides and reduction in application times, manpower, and cost [3,[5][6][7]. Increasing reports have shown that insecticides applied via drip irrigation exhibited higher efficacy against crop pests than the conventional foliar spray method [2][3][4]6,[8][9][10].…”

“…Sulfoxaflor is a novel sulfoximine insecticide, which exhibits high degree efficacy against a wide range of sap-feeding insect pests, including many that are resistant to neonicotinoids [17][18][19]. A recent report showed that drip irrigation of sulfoxaflor was more effective in the control of cotton aphid than conventional foliar spray [9]. Although sulfoxaflor and neonicotinoids are chemically distinct, they share a common biological mode of action [20].…”