| Four chemical thinners with three concentrations each were used to observe their thinning effect on 'FlordaSun' and 'EarliGrande' peach cultivars under climatic conditions of Islamabad, Pakistan in 1995. These peach cultivars were found successful for growing in that area after an evaluation trial conducted from 1988 through 1993. The experiments were conducted at the National Agricultural Research Center, Islamabad, Pakistan. The chemicals included NAA (5, 10, 15 ppm), BA (25, 50, 75 ppm), Accel (25, 50, 75 ppm) and GA{dollar}sb3{dollar} (5, 10, 15 ppm). These chemical have been evaluated in thinning peaches in various climates and locations. The thinning response was variable. NAA at 10 ppm, Accel at 25 ppm and GA{dollar}sb3{dollar} at 5 ppm reduced fruit set on 'FlordaSun' peaches compared to the control. NAA at 5, 10 and 15 ppm decreased the fruit set in 'EarliGrande' peaches. All concentrations of BA, Accel and GA{dollar}sb3{dollar} except GA{dollar}sb3{dollar} at 15 ppm reduced the fruit set in 'EarliGrande' peaches. NAA at 10 and 15 ppm increased fruit weight of 'FlordaSun' peaches. BA had no effect on fruit weight. BA at 25, 50 and 75 ppm and GA{dollar}sb3{dollar} at 15 ppm and all concentrations of Accel decreased fruit firmness compared to the control while, other quality parameters like SSC, pH, fruit length, fruit diameter, were consistently affected by growth regulators on 'EarliGrande' peaches. There were not many outstanding findings obtained from this study, but by learning the techniques and methodology from this trial it is hoped that work on these lines will be continued in future on major fruit crops of Pakistan like citrus and mango along with stone and pome fruit where fruit size, overbearing, alternate bearing and fruit set is a problem. |
