Efeito da aplicação de molibdênio em caupi (Vigna unguiculata (L.) Walp.) em condições de campo

Abstract

Two experiments were carried out at field conditions in the Department de Fitotecnia UFRRJ with the aims of the study the effect of molybdenum in cowpea (Vigna unguiculata (L.) Walp.). The seeds from the cultivar CNCx 409-11F-P2 were used with a plant population of 200.000 plants.ha-1. The first experiment was arranged in a factorial block design with 4 replications, 5 levels of Mo (100, 200, 400, 800 g.ha-1) applied in the leaves and the control, 3 times of application (32 days after germination, flowering period and seed pod filling). During the plant development, 3 harvests were made: 48 and 79 DAG and at the end of plant grown. The parameters analyzed were: number and weight of nodules, shoot and root dry weight and productivity. At the second experiment, the treatments were applied: two levels of pH (5.5 and 6.5); six levels of Mo (20, 40, 80, 160, 1280 g. ha-1) applied in the leaves and the control; 2 ways of Mo application (in the soil and foliar application); with 4 replications. The harvests were made at 62, 73 and 87 DAG and at the end of plant growth. The parameters analyzed were: number and weight of nodules, shoot and root dry weight, productivity and Mo concentration in the seeds. The foliar applications of Mo increase the number of nodules. Occurred a significant variation of weight of nodules shoot and root dry weight in function of the form of Mo application, soil or leaves. The range of Mo concentration in the seeds was between 0,45 and 26,93 g.Mo.semente-1.