Nodulação e desenvolvimento de plantas oriundas de sementes de soja com altos teores de molibdênio

Abstract

Molybdenum is supplied to plants mainly through seed treatment, although the use of seeds enriched with Mo is a possible alternative. In the present study nodulation and development of soybean plants derived from seeds of plants that received leaf application of different rates of Mo was evaluated. The Mo was supplied through of leaf applications during the maturation process, in a single or divided application, made between the R5.2 and R5.4 stages, in two trials, in Lavras, MG and Ituiutaba, MG. Later these seeds were sown in pots, kept in a greenhouse and the plants were evaluated at the R1 stage. The molybdenum (39% Mo) treatments were: 1 application of 1000g. ha-1; 1 application of 800g.ha-1; 1 application of 600g.ha-1; 1 application of 400g.ha-1; 2 applications of 500g.ha-1; 2 applications of 400g.ha-1; 2 applications of 300g.ha-1; 2 applications of 200g.ha-1; check (without Mo) and check + Mo through seed treatment. The assays were made in a randomized complete block design, with four replications. The following were evaluated: the Mo contents in the seed, plant height, plant canopy and root dry matter, nodules and nodule dry matter per plant and leaf nitrogen content. The Mo content in the seed increased with the rate applied in plants whether in a single or divided application. The direct treatments of seeds with the Mo solution decreased the number of nodules per plant. The Mo accumulation in soybean seeds did not damage the nodulation and did not interfere in the plant development. Plants derived from enriched seeds or seeds treated with Mo have greater N accumulation in the leaves.