Sensibility of coffee plants micorrized to herbicides

Abstract

The objective of this work was to evaluate the effects of herbicides applied in post-emergence of Arabic coffee plants inoculated and non-inoculated with arbuscular mycorrhizal fungi. The experiment was conducted in a factorial arrangement 2 x 6, being seedlings of Arabic coffee (Catuaí IAC 99 cv) inoculated and non-inoculated with mycorrhizal fungi (Factor 1), and five herbicides (chlorimuron-ethyl, oxyfluorfen, fluazifop-p-butil, fomesafen, [fluazifop-p-butil + fomesafen]) and a control treatment (Factor 2), with four replications. The seedlings inoculated with mycorrhizal fungi (Rhizophagus clarus and Gigaspora margarita) were produced in polyethylene bags and transplanted to 20 dm³ pots when it was in five pairs leaves stage. In seven pairs leaves stage the plants were submitted to the herbicide applications. After 45 days were measured: percentage of intoxication, height, leaf area, root volume, leaves and roots dry matter, leaf nutrient content and root colonization. Noted that chlorimuron-ethyl, oxyfluorfen and [fluazifop-p-butil+fomesafen] resulting in less increment of variables and higher phytotoxicity. The fluazifop-p-butil showed greater selectivity to coffee plants. The inoculated plants obtained higher root colonization than non-inoculated. Considering all parameters, it is concluded that the Arabica coffee cultivar Catuaí Vermelho IAC 99 inoculated with mycorrhizal fungi showed higher tolerance to fluazifop-p-butil. Similarly, also concludes that coffee plants inoculated with FMAs had become more tolerant to the adverse effects of chlorimuron-ethyl, fomesafen, oxyfluorfen and [fluazifop-p-butil + fomesafen].