Morphological and physiological response of sugarcane under abiotic stress to neonicotinoid insecticides

Neonicotinoids are systemic insecticides that can have biostimulant effect in various cultures. The aim of this study was to evaluate if neonicotinoids have stimulant effects on the growth and tolerance of sugarcane to drought stress. The experiment was performed in pots, in a fully randomized design, laid out in a 2 × 4 factorial scheme, with five replicates, with two irrigation schemes, irrigated and with water deficit, and three neonicotinoid insecticides: imidacloprid, thiamethoxam, and clothianidin and a witness. Neonicotinoids had beneficial effects on the initial growth of sugarcane, increasing the total weight of plants, resulting in greater plant height, and higher mass of root system, especially, which clothianidin increased production of 42 % of the stem mass, and 20 % of the root mass, resulting in a 37 % increase in the total mass relative to the non-stressed plant controls, 121 days after planting. Thiamethoxam and clothianidin were the most efficient to minimize the effects of drought stress, attested by the lower accumulation of proline, and improvement in the photochemistry and photosynthesis activity of the drought stressed plants.