The purpose of this work was to evaluate the effect of Quinmerac, comparatively with 2, 4-D and potassium nitrate, in the productivity of 'Clemenules' tangerines (Citrus reticulata Blanco), through the increase of the percentage of fruits with larger size for the fresh market, and also to determine possible undesirable effects on the fruits quality and presence of fitotoxicity by two successive years of applications on the same trees. During 1998/99 and 1999/00, the experiments were carried out in two plots of 'Clemenules' tangerines of seven years old of implanted, budded on trifoliate orange (Poncirus trifoliata Raf.) one, and on the second one citrange 'Troyer' (P. trifoliata x Citrus sinensis Osbeck), in Mburucuyá, Corrientes, in a typical Psammacuent soil. The treatments used were: control without application; Quinmerac (10%), 10 mg.L-1; Quinmerac (10%), 15 mg.L-1; 2, 4-D (31%), 20 mg.L-1 (1998/99) and potassium nitrate (14%N, 39% K), 2.5 g.L-1 (1999/2000). The products were sprayed on the trees, with a volume of 2.5 L.tree-1. Biweekly the plants were observed to detect fitotoxicity symptoms. At the harvest time, the yield was determined, and the fruits classified by size in two categories; the external rind quality by its aspect and the internal quality by the juice percentage, Brix degrees, acidity and ratio. The treatments with Quinmerac and potassium nitrate increased between 10 and 15% the proportion of fruits with size adequate for fresh market. There were no effects on the total production, fruits quality, or fitotoxicity.
Quinmerac; 2, 4-D; potassium nitrate; Citrus reticulata
