Title: Biorational Management of Cotton Flea Beetle (Podagrica puncticollis Weise) and Cotton Thrips (Caliothrips impurus (PR.)) in Cotton Crop, Gezira State, Sudan
Authors: A. M. A. Rudwan, A.E.M. Hassan, M. T. Y. Elamin, E. Y. M. Ahmed and A.B. Dafaallah
Volume: 8
Issue: 9
Pages: 171-181
Publication Date: 2024/09/28
Abstract:
Cotton is grown in Sudan as a rainfed crop, as well as grown by permanent irrigation. One of the major constraints of cotton production in Sudan is the insect pests. These pests include cotton flea beetle (Podagrica puncticollis Weise) and cotton thrips (Caliothrips impurus (PR.)). This research aims to reduce the cotton production cost and mitigating the environmental pollution through managing the cotton flea beetle (Podagrica puncticollis Weise) and cotton thrips (Caliothrips impurus (PR.)), via biorational management at Gezira State, Sudan. Two experiments were conducted at the Experimental Farm of the Faculty of Agricultural Sciences, University of Gezira, Wad Medani, Sudan during season 2013/14 and 2014/15. In each season a factorial experiment was conducted with three cotton varieties, two sowing dates, and two spacings. The varieties were Senni 1 verity, Brazili (LL) verity, and Hamid local variety. The sowing dates were the third week of June and July, whereas the spacings were 25 and 50 cm intra-row. Treatments were arranged in a completely randomized block design with three replicates. The insect pests were recorded either for their presence or their damage inflicted on cotton plants. Insect predators were monitored as eggs, larvae and adults of Chrysoperala sp., Cheilomens spp. and Exochomus spp. Data were transformed as needed and subjected to analysis of variance (ANOVA) procedure. The cotton flea beetle damage started to appear during August and September, and decreased during October and November in seasons 2013/14 and 2014/15.There were significant (P ? 0.05) interaction effects between variety, sowing date, and spacing on the damage of the beetle during the seasons. The damage of the beetle was significantly higher on Hamid local verity (3.8 - 14.8%) on the two sowing dates on the two spacings compared with Senni 1 verity (0-6.3%) and Brazili verity (LL) (0.5-6.8%). The damage of the beetle was higher at late sown (2.5-6%) compared with early sown (0-4.3%). There were no significant differences in the between the narrow spacing and wide spacing. The cotton thrips damage started to appear during on October and decreased on November and December in season 2014/15. There were no significant (P ? 0.05) interaction effects between variety, sowing date, and spacing were significant interaction effects between variety, sowing date, and spacing on the damage of the thrips. The damage of the cotton thrips was significantly higher on Hamid local verity (21.8 - 25%) on the two sowing dates on the two spacings compared with Senni 1 verity (0.5-2.8%) and Brazili (LL) verity (0.5-5.8%). There were no significant differences in the seasonal average damage of the thrips between the early sown and late sown. However, the thrips damage was higher in the late sown compared with the early sown. Also, there were no significant differences in the seasonal average damage of the thrips between the narrow spacing and wide spacing. Senni 1 and Brazili (LL) varieties harbored low number of Chrysopa spp., Cheilomens spp. and Exochomus nigromaculatus compared to the Hamid variety. Hamid variety sown late significantly harbored a low number of the insect predators compared to Hamid variety that was sown early. Cotton flea beetle and cotton thrips were checked during September to October to the end of the season without insecticide use. Insect pests and natural enemies reflected density dependent pattern. The interaction between the variety, sowing date and spacing has positive effect on the insect control.