Função de resposta hídrica da abobrinha italiana em diferentes coberturas do solo

Abstract

The use of soil mulch using legumes and grasses is a practice that brings benefits to vegetables crops . The objective of this study was to evaluate the effect of three different soil coverage’s (millet, crotalaria and without cover) submitted to five different irrigation slides (40, 60, 80, 100, 120% in relation to 100% ETc) under the agronomic performance of Curcubita pepo cv. Italian. The experiment was carried out in two stages, the first one being the planting of cover crops, millet and crotalaria, where before flowering they were cut, crushed and arranged in tarpaulins for drying, and then distributed in the plots of the experimental area. In the second stage, the pits for Italian cv. sowing, where the installations of the drip irrigation system and the assembly of decomposition test of the vegetal residues were made. For development of the decomposition rate assay, polyethylene bags containing 50 g of crushed millet and crotalaria were placed in the rows between the pits. The agronomic performance evaluations were performed using five destructive analyzes at intervals of 21 days each after planting. Plant height, stem diameter, leaf area, number of male and female flowers, dry mass of stem, root, leaf area and flowers. The nondestructive analyzes were performed in the field, among them, the daily count of male and female flowers the growth of the fruits and during the fruit harvest were measured the length, fresh mass, bulb diameter and peduncle. To evaluate the decomposition rate of the plant residues, three bags of each treatment were collected at intervals of 7, 15, 21, 30, 45, 60, 90 and 120 days after planting, the material was dried in an oven and then measured its dry mass. For plant residues of millet and crotalaria, the decomposition was due to the irrigation depths evaluated and the time, described by simple exponential model. It was obtained a higher decomposition rate for vegetable residues of crotalaria, and greater mass accumulation of straw to cover millet. Regarding the evaluations of agronomic performance of the crop, it presented better results for the treatments with greater 120% blades and coverage with millet, obtaining a production of 16 t / ha.