Combination effects between gamma radiation and spraying equipment for three cotton boll pests controlling

Abstract

Pneumatic knapsack motor sprayer (Cifarilli) and Hand-held Hydraulic sprayer (Matabi) were used as two sprayer equipment for assessment the spraying efficacy. Nine compounds related to bio-agent groups were used; one of them (orange oil) was exposed to gamma radiation doses of 160, 320 & 640 Gy for potentiating purpose with B. thuringiensis mixture. The treatments were Bacillus thuringiensis (Kurstaki), Orange oil, B. thuringiensis + orange oil, B. thuringiensis + orange oil 160 Gy, B. thuringiensis + orange oil 320 Gy, B. thuringiensis + orange oil 640 Gy, azadirachtin, azadirachtin + orange oil and emamectin benzoate. The treatments aforementioned were evaluated with the two spraying equipment used against three pests of cotton bolls that were pink bollworm, Pectinophora gossypiella (Saund); spiny bollworm, Earias insulana (Boisd.) and Cotton seed bug, Oxycarenus hyalinipennis (Costa) population and infestation reduction percentages. Pneumatic knapsack motor sprayer (Cifarilli) was higher than Hand-held Hydraulic sprayer (Matabi) in success the control of the three pests in population and infestation reductions of three pests used. Moreover, B. thuringiensis + orange oil 640 Gy was considered the best gamma radiation treatment that caused reduction percentages in population and infestations against three pests used but lower than emamectin benzoate efficacy. Meanwhile, B. thuringiensis or orange oil had the least value when used singly for three pests controlling. In addition, the compounds used especially B. thuringiensis + orange oil 640 Gy enhanced the most cotton crop parameters acts in seed numbers, lint and seed weights during the two cotton seasons 2018 & 2019. So, gamma radiation can potentiate the orange oil when mixed with B. thuringiensis to become the most effective compounds as companion with Pneumatic knapsack motor sprayer (Cifarilli) uses against the three pests mentioned and cotton crop parameters compared with the same compounds without exposing to gamma radiation. It could be recommended to use the treatments with Low Volume spraying equipment to cause a satisfactory coverage on cotton plants. Its spectrum droplets were ranging between 124-178 mm with sufficient number ranging from 35-200 N/cm². Also, performance rate of Pneumatic Knapsack motor sprayer (Cifarilli) (20 L./Fed.) was 12 Fed./day; while, It was 3.46 Fed./day for Hand-held Hydraulic sprayer (Matabi) (56 L./fed.). Moreover, Low Volume spraying reducing the time lost in the process filling of machines with the spray solution to get homogenous spray coverage and saving the spray lost on the ground.