Does the substrate affect the germination of soybean seeds treated with phytosanitary products?

Abstract

The use of an appropriate method that accurately expresses physiological seed quality and minimizes possible phytotoxicity by chemical products in laboratory testing with soybean seeds is relevant. The objective of this work was to evaluate the influence and infer the method adequacy for the representative evaluation of physiological quality of soybean seeds treated with phytosanitary products. Two experiments were carried out in a completely randomized design, with trial 1 in a 9×5 factorial scheme involving nine seed treatments, including fungicides and insecticides, and solutions with five osmotic potentials (0, -0.25, -0.5, -0.75 and -1.0 MPa) for wetting a paper substrate in a germination experiment, with evaluation of the normal seedlings at five and eight days after sowing. The second experiment consisted of a 9×7 factorial, with nine seed treatments and seven methods for germination evaluation at 5 days (between paper - BP, between sand - BS, between paper with water restriction - BPWR, between paper with preconditioning - BPC, sand between paper - SBP and vermiculite between paper - VBP). Treatments with insecticides affect seedling germination and evaluation, with greater phytotoxicity in relation to fungicides. Methods with readily available water led to greater phytotoxicity than methods with low water availability. For soybean germination evaluation of seeds treated with phytosanitary products, the BPC, SBP and VBP methods were optimal.