کنترل جنسیت گل در مراحل مختلف رشد و نمو طالبی (Cucumis melo var. reticualus L.) با کاربرد اتفون

To investigate the effect of ethephon on control of male flowers in melon, a split plot experiment, with randomized complete blocks design and three replications, was conducted in Agricultural and Natural Resources Research Center of Varamin, Iran, during 2005-2006. The main factor included three levels of plant growth stage (3-leaf, 6-leaf and early reproductive stage) and sub-plots included four ethephon levels (0, 100, 200 and 300 mg/L). The appearance time of female flowers, number of male and female flowers (7 and 14 days after application of ethephon), total yield and female/male flowers ratio were evaluated. Results showed that plant response to increasing concentration of ethephon depends on plant growth stage. By using the ethephon concentrations of 100, 200 and 300 mg/L, the emergence of female flowers was delayed 6, 13 and 15 days, respectively, in comparison to control. The highest yield (26430 kg/ha) was obtained with spraying of 200 mg/L ethephon in trifoliate plants. In this case, the ratio of female to male flowers was highest (81.5%). A high dose of ethephon (over 200 mg/L) was associated with reduced yield and ratio of female to male flowers, at all stages of plant growth, especially in reproductive growth stage. The results this research showed that the beneficial effects of ethephon application is possible only if the right time is chosen with respect to plant growth.