New Approaches for Controlling the European Red Mite, Panonychus ulmi (Koch) in Relation to Population Dynamics on Apple trees

Abstract

: The population dynamics of European red mite Panonychus ulmi (Koch) was affected by considerable factors, during two successive seasons 2020 and 2021, at Abu El-Matamir, EL- Beheira Governorate. Furthermore, the experimental work included two separate trial treatments. The first was directed for estimation the impact of the population dynamics, in addition to control above mentioned pest. While the second was directed to investigate the recent approach of agrochemical mixtures looking for new safe products against P. ulmi . On the first experimental trial, the results indicated three peaks of activity regarding the infestation by P. ulmi. The first peak occurred at the 2 nd week of May, the second peak was at the 2 nd week of August, while the third peak was at the 1 st week of October, during season 2020. Almost the same trend was obtained during season 2021. The reduction percent of infestation was 97.7% season 2020 and 97.9% season 2021, showed that Fenbutatin-oxide was the most potent and active product against the P. ulmi . Followed by Abamectin 90.3% season 2020 and 90.4% season 2021. Both compounds Sulfur and Petroleum oil, were the least effective compounds achieving 60% average reduction. The recent approach to use agrochemicals against of P. ulmi (Abamectin, Chitosan, K. silicate, Petroleum oil and Sulfur) in addition to use the mixtures of half dose of Abamectin plus fixed dose of Petroleum oil, while Abamectin and 3/4 dose of Sulfur used in the application. Full dose of Chitosan and K. silicate were investigated against P. ulmi . The data obtained indicated that (Abamectin + Chitosan) reduce the P. ulmi infection percent by 95.4% and (Abamectin + K. silicate) 94.6% were the most effective tested mixtures. Mixtures (Abamectin + P. oil) and (Abamectin + Sulfur) gave 93.7% and 92.6% infection reduction, respectively. Mixture (Chitosan + Sulfur) and (K. silicate + Sulfur) showed the least effective mixtures 82.9% and 81.8% infection reduction during the course of study2020. The days post-treatment (Abamectin + Chitosan) and (Abamectin + K. silicate) gave the most effective tested mixtures showed 95.2% and 94.1%, respectively. The reduction percent of P. ulmi showed that all mixtures gave considerable effect against of P. ulmi above 80%. Meanwhile, mixtures (Chitosan + Sulfur) and (K. silicate + Sulfur) showed the least effective mixtures 83.3% and 82.1% reduction duringthe course of study 2021, used as alternative for Fenbutatin-oxide for controlling of P. ulmi on apple crop.