Effect of various fertilizers and salicylic acid on induced resistance of citrus against Panonychus citri (McGregor) (Acari; Tetranychidae)

Abstract

Abstract The citrus red mite, Panonychus citri (McGregor), is one of the important pests of citrus trees. The use of non-selective and broad-spectrum insecticides leads to reduce in the natural enemy pressure on this pest and transforms P. citri into the main pest. Thus, there is a great need to replace efficient and sustainable strategies of pest management that conserve natural enemies and has less risk to the environment. In the present study, the induction of resistance was carried out in two-year-old citrus seedlings using a foliar application of amino acid, humic acid, potassium, vermiwash, and Salicylic acid either individually or in combination against P. citri. Our data indicated a lower survival rate, longer immature duration, shorter adult longevity, and lower fecundity due to an increase in the resistance of citrus. In individual treatments, the developmental time of immature stages, survival, and fecundity was significantly smaller in combined treatments, intermediate in individual treatments, and greater in control and vermiwash treatments. Correspondingly, some population growth parameters of P. citri such as net reproductive rate, intrinsic rate of increase, finite rate of increase, and generation time, all were lower when the mites fed on combined treatments, especially on potassium + salicylic acid with the lowest performance. Our results suggest that the induction of resistance in citrus trees with a combination of fertilizer and SA leads to a significant reduction in damage to the citrus red mite.