The system for regulation of cotton bollworm population on tobacco in crop rotation of organic agriculture

Abstract

The results of development of the control system over the population of cotton bollworm Helicoverpa armigera Hbn are presented to protect seed plantings of tobacco with the use of plant isolation. The studies were conducted in the Krasnodar Territory on a tobacco variety Yubileiny novy 142. The regulation of the cotton bollworm population on tobacco seed plantings was carried out by the method of mass capture of male pests with pheromone traps in order to change the gender balance. This was done together with the application of a biopreparation and sowing of a trap crop (corn) to attract and catch butterfl ies at an earlier stage. At a high degree of bollworm population (4–10 specimens / tobacco infl orescence) on non-isolated plants, insecticides based on baculovirus of nuclear polyhedrosis of cotton bollworm FermoVirin XC (in the doze 1.0– 4.0 g/ha) and Helicovex (0.05–0.2 l/ha) were used three times with an interval of 7 days in combination with “male vacuum”. Biological effi ciency was 38– 77 and 62–84% in reducing the number of bollworm larvae, 41–75 and 60–79% in decreasing the damage, respectively. The decrease in the number of bollworm larvae on isolated plants reached 36– 70 and 58–79%, the decrease in damage – 39–69 and 60–72%, respectively. Treatment of seed plots with virus insecticides allowed to save from 22 to 43 kg of the biological yield of tobacco seeds per 1 ha on non-isolated plants and from 21 to 51 kg on isolated plants. With a low number of hatching larvae (14 specimens / 100 plants), a single use of the preparations Bitoxibacillin (Bacillus thuringiensis var. Thuringiensis) and Lepidocide (Bacillus thuringiensis var. Kurstaki) reduced the amount of phytophage by 47–75 and 48–64%, respectively. The system is recommended for use on other crops damaged by cotton bollworm, including in organic farming technologies.