Revista Brasileira De Herbicidas 2018; 17(4): 1-12
Efficacy and selectivity of metribuzin and diuron in pre-transplanting of tomato crop under with different cover crops species
The tomato plant is an oleraceous that has low tolerance to most of the herbicides used, which limits the use of chemical products in integrated weed management. By this fact, this study was conducted for evaluating the efficacy and selectivity of the metribuzin and diuron, both applied before transplanting the tomato crop, upon different cover crops. Seeds of tomato cv. IPA 6 were planted in trays and transplanted to pots at the stage of two leaves. The species used were: exposed soil (control), Urochloa ruziziensis (0.30 t ha-1), Pennisetum glaucum (0.42 t ha-1) and weed community (0.39 t ha-1), being of herbicide application. The phytotoxicity, efficacy and plant height were evaluated at 7, 14, 21, 28 and 35 days after application (DAA), and in the last evaluation day it was also measured the dry mass of leaves, stem and roots. Regarding the selectivity, the metribuzin provided low phytointoxication in the seedlings, with no effects in the biomass. Despite the efficacy, diuron was not selective to tomato, causing high phytotoxification rates (65 to 100%). It was concluded that the treatment covered with U. ruziziensis, P. glaucum and weed community supplemented the both herbicides action, but only metribuzin was selective when applied in tomato pre-transplanting.
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