The aim to evaluate the effect of diuron, sulfentrazone in ametryn herbicides and mycorrhizal association in quantum efficiency of photosystem II of 'Imperial' pineapple nursery. The split-split plot scheme was used, taking in plot the 2 x 4 factorial, being the factors two types of nursery pineapple: inoculated with P. indica and without inoculation and four doses of herbicides: 0, 1.5, 3.0 and 6.0 L ha-1 for ametryn, 0, 1.6, 3.2, 6.4 L ha-1 for diuron and 0, 0.4, 0.8 and 1.6 L ha-1 for sulfametrazone and the sub-plot evaluation times, distributed in a completely randomized design with three replications. Herbicides were applied to the substrate before planting of pineapple nursery. Inoculation with the fungus P. indica it was made at the time of planting. The evaluation of quantum efficiency was taken as the ratio chlorophyll a fluorescence (Fv/Fm), determined at 60, 90 and 120 days after planting of the nursery pineapple, determining the initial fluorescence, maximal and variable. Data were submitted to analysis of variance and regression. Herbicide ametryn did not affect the photosystem II efficiency of pineapple nursery associated with the fungus P. indica. Inoculation with the fungus P. indica increased the photosystem II efficiency. The diuron and sulfentrazone herbicides application at high doses decreased in photosystem II efficiency of 'Imperial' pineapple nursery without inoculation with the fungus P. indica.
Ananas comosus; mycorrhizal association; chlorophyll fluorescence
