01872naa a2200205 a 450000100080000000500110000800800410001902000150006010000170007524500760009226000090016852011860017765300210136365300200138465300180140470000140142270000170143670000190145377301940147210879972013-01-30 2012 bl uuuu u00u1 u #d a90660591921 aPETRI, J. L. aEffect of thidiazuron (TDZ) in the fruiting of apple tree 'royal gala'. c2012 aIn the South of Brazil, fruit production may be limited by reason of low fruit set, caused by the climatic conditions during the blooming time. In these situations, the use of growth regulators can improve fruit set, and consequently minimize the yield variation. The experiments were carried out in a commercial orchard located Santa Catarina, Brazil, during the 2011/2012 season. TDZ concentrations and period of application were tested and production parameters and mineral content of the fruit were evaluated. The fruit set was affected by TDZ concentration and time of application. The treatment TDZ 25 mg L-1 showed the highest values of fruit set with 53.2% while the untreated trees only 8.7%. The best time of application was in the E2 stage with 33.3% fruit set. The production (kg tree-1) and number of fruit per tree were both affected by concentration and time of application. The lowest fruit production was obtained in untreated trees (16.7 kg tree-1) while the best result was obtained in the treatment TDZ 25 mg L-1 + TDZ 25 mg L-1 (60.9 kg tree-1). TDZ influenced the fruit shape, decreased the red color and had little effect on the mineral content of the fruit. aGrowth regulator aMalus domestica aSize of fruit1 aCOUTO, M.1 aLEITE, G. B.1 aSCHVEITZER, B. tIn: INTERNATIONAL SYMPOSIUM ON ORCHARD SYSTEMS, 10., 2012, Stellenbosch, South Africa. Abstracts... Stellenbosch, South Africa: International Society for Horticultural Science, 2012. p. 39.