Use of the green manure in the onin bulb production in irrigated system

Abstract

Bulb development is affected by water availability, temperature, photoperiod, plant and physiological age of the plant and nitrogen supply. For the production of commercial bulbs, irrigation and nutrient management must be adequate. Green manure is a strategy that can contribute to making mineral nutrients available in the soil. The objective of this work was to evaluate the effect of different species of green manure on the transverse and longitudinal diameter of the bulb of onion hybrids in an irrigated system. The experiment was carried out at the Federal University of Grande Dourados, in Dourados - MS, whose soil is classified as a dystrophic Red Latosol, with a very clayey texture and the region's climate as Aw type, with dry winter, average annual precipitation of 1500 mm and average temperature of 22 ºC. The experimental design was randomized blocks, with split plots, four replications, five cultivation systems - Witness (spontaneous vegetation); onion cultivation in succession to millet (Pennisetum glaucum); onion cultivation in succession to Jack Bean (Canavalia ensiformis); onion cultivation in succession to velvet bean (Mucuna aterrina); onion cultivation in succession to Crotalaria (Crotalaria juncea) - and two hybrid onion cultivars (Andromeda F1 and Aquarius F1). The experimental unit consisted of a 5.4 x 1.0 m plat, three rows of onion cultivation, with spacing of 0.30 m between lines and 0.10 m between plants, with the onion seedlings transplanted under the vegetable residue. of green manure species, corresponding to each plot. The irrigation system was by drip, with an irrigation line for each cultivation line. Irrigation management was carried out using the electronic device “HidroFarm”, which takes into account the water status of the soil. At 114 DAT, the onion was harvested manually, and the plants were kept in the curing process for 15 days. The longitudinal and the transverse diameter of the bulb were evaluated. It is concluded that the use of the species of velvet bean, crotalaria and Jack bean provides greater values of transverse diameter of the bulb, while the millet and crotalaria provides greater values of longitudinal diameter. The Andromeda hybrid presents superior productive performance with a higher value of longitudinal diameter of the bulb under local growing conditions.