EFFECT OF PACLOBUTRAZOL SPRAYS ON SHOOT GROWTH, YIELD AND FRUIT QUALITY OF MEIT GHAMER PEACH CULTIVAR

摘要

The present study was ducted during two successive seaons 2002 and 2003 on peach cv. 'Meit Ghamer' to investigate the influences of various concentrations (0, 50, 500, 750, 1000, 1500 ppm) of paclobutrazol spraying after three weeks from full bloom,on shoot growth, yield, maturity and fruit quality, beside leaf characters and their NPK contents. The results indicated that, spraying paclobutrazol highly significant decreased shoot extension at all concentrations, the severity of shoot growth suppression was influenced by spray concentration, the highest concentration recorded the lowest values of shoot length during the growing seasons. The reduced shoot growth rate in the paclobutrazol sprays, from before the time of stone hardening, resulted in larger fruits, with a consequent increase in yield and earlier maturity of the fruits. The highest yield/tree (48.33 and 45.67 kg/tree) was recorded with paclobutrazol spray at 750ppm in the first and second seasons respectively, while the lowest yield/tree (38.33 ; 36.33 and 36.67 ; 37.33 kg/tree) were obtained from paclobutrazol spray at 1500ppm or control during the tow seasons of study, respectively. Spraying paclobutrazol at 750ppm achieved the highly significant highest values (127.33and 121.67 g); (123,33 and 118.33 cm); (6.39 and 6.13 cm) and (76.00 and 71.67 %) of fruit weigh, volume, diameter and skin color, respectively during the two seasons. Moreover, pacloputrazol spraying at all concentrations increased fruit content of anthocyanin and TSS but reduced Acidity in fruit juice. The results also showed that, leaf area and dry weight were reduced by paclobutrazol spraying, the decreasing was linearly with paclobutrazol concentration. No clear effect on nitrogen, but decreased phosphorus and potassium leaf content as affected by paclobutrazol spraying in both seasons of study.