Banco de sementes viáveis e manejo de plantas daninhas em sistemas de cultivo do tomateiro industrial

Abstract

Industrial tomato production is hampered by weed occurrence, which may reduce productivity through competition, affect the efficiency of products applied to crops and host commercially important diseases and pathogens. Thus, this study aimed to evaluate the occurrence and management of weeds in industrial tomato cropping systems in the Cerrado of Goiás. In Chapter One, the viable seed bank was evaluated in areas with different weed management systems. The evaluation was made in two conventional tillage areas (CT); two with no-till (NT) and four with no-till and reduced soil preparation (RSP). The most frequent weeds were Conyza bonariensis, Cenchrus echinatus, Ipomoea aristolochiaefolia, Leonotis nepetifolia, Spermacoce latifólia, Senna obtusifolia, Nicandra physaloides, Euphorbia heterophylla, Gnaphalium spp., Brachiaria plantaginea, Zea mays, Bidens pilosa, Macroptilium spp., , Solanum lycopersicum (tiguera), Commelina benghalensis and Sida rhombifolia. Among the soil preparation systems, reduced preparation (RSP) resulted in two species with higher germination: Phyllanthus tenellus and Oxaliss pp. Conventional tillage (CT) resulted in six species with the highest plant emergence number – Ageratum conyzoides, Coronopus didymus, Portulaca oleracea, Eragrostis pilosa, Digitaria horizontalis and Solanum americanum. In Chapter Two, different systems of weed management in tomato crops for industrial processing under center-pivot irrigation were evaluated. The applied treatments were combinations between harrowing and chemical management with glyphosate, s-metolachlor, sulfentrazone and metribuzin-based products at different application periods. The variables plant population and ºBrix were not influenced by the treatments. There was statistical difference within the production components: twenty-fruit mass, yield per plant and productivity. Highest productivity was observed in the following treatments: a) harrowing thirty days after transplant (DAT), application of glyphosate (1,080 g ha-1), metribuzin (480 g ha-1) and s-metolaclhor (1,200 g ha-1) on the seventh DAT (83.39 t ha-1); harrowing on the 30th DAT, glyphosate (1,080 g ha-1) and s-metolachlor (1,200 g ha-1) on the seventh DAT (74.75 t ha-1); c) harrowing on the thirtieth DAT, glyphosate (1,080 g ha-1) on the 14th DAT and sulfentrazone (100 g ha-1) on the seventh DAT (73.06 t ha-1); d) harrowing on the 30th DAT, glyphosate (1,080 g ha-1) on the 14th DAT and s-metolachlor (1,200 g ha-1) on the seventh DAT (71.83 t ha-1) and; e) harrowing on the 30 DAT, glyphosate (1,080 g ha-1) and sulfentrazone (100g ha-1) on the seventh DAT (71.75 t ha.-1).With the “no weeding” and “harrowing-only” treatments, there was reduction of 63.82% and 69.29% in fruit productivity, respectively, compared to the weeded sample. The conclusion is that the applications of sulfentrazone (100 g ha-1) or s-metolachlor (1,200 g ha-1) in weed management systems using glyphosate revealed potential alternatives for industrial tomato production in Goiás.