EFFECT OF PROHEXADIONE-CALCIUM (REGALIS) ON DIFFERENTIATION OF FLOWER BUDS AND FRUIT SET IN PEAR VAR. PASSE CRASSANE

Summer pruning and Prohexadione-Ca were the strategies that produced the next shortest shoot length; however, summer pruning registered the lowest return bloom and accumulated yield. Prohexadione-Ca did not have any significant negative effect on either return bloom or yield. Prohexadione-calcium (Regalis) as a shoot growth retardant that inhibits gibberellins biosynthesis has been used to improve the differentiation of flower buds and fruit set in Pear var. Passe Crassane. The aim of this study was to evaluate the efficacy of applying Regalis by foliar applications in Passé Crassane pear orchards to reduce tree vigor or shoot growth and to control the alternate fruit production. Three different dosages were tested: 50ppm, 100ppm 150ppm. Regalis treatments ranging from 50 to 150 ppm were compared with control, without treatments. The first treatment was applied 7days after petal fall and the others every 10 days after the first treatment. Three different dosages were tested: 50ppm, 100ppm 150ppm. Regalis treatments ranging from 50 to 150 ppm were compared with control, without treatments. The first treatment was applied 7days after petal fall and the others every 10 days after the first treatment. The data was collected at the full bloom time and two weeks, at the time of fruit set. The flower number and the fruit number was significantly difference after the treatment of 150 ppm and 100ppm than the application of 50ppm and without treatment. The average fruit weight was greater than other treatments and than non treated-trees. Variability in soluble solids concentration (SSC,0Brix) was not significantly different between different treatment (50ppm, 100ppm and 150ppm)