Manage of crop load to improve fruit quality in plums

Abstract The crop load of European plums must be adjusted to achieve high quality with adequate size and skin color in order to attend market requirements. The present study had the objective to investigate the effects of chemical and mechanical thinning, applied isolated and in combination of both, at different phenological stages of Katinka plum growing in Southern Germany. The following thinners were tested: mechanical thinning, chemical thinning with Ammoniumthiosulfate - ATS, Ethephon, Prohexadione-Calcium and Gibberellin. Mechanical thinning treatment isolated or associated with ATS. Significantly increased fruit drop and reduced the yield. It also, increased fruit size and fruit weight when compared to the control plants. Also Ethephon increased fruit drop and fruit size when compared to the control plants. Among to other chemical treatments, no positive effects were observed for fruit thinning when compared to the control plants.

摘要：欧洲李（European plums）的挂果负载量需进行调控，以培育出果形规整、果皮色泽优良的高品质果实，从而契合市场需求。本研究以德国南部种植的Katinka李为试材，探究化学疏果、机械疏果单独施用及二者联用于不同物候期的应用效果。本次测试的疏果方式与药剂包括：机械疏果、硫代硫酸铵（Ammoniumthiosulfate，简称ATS）化学疏果、乙烯利（Ethephon）、调环酸钙（Prohexadione-Calcium）及赤霉素（Gibberellin），其中机械疏果可单独施用或与ATS联用。与对照组相比，机械疏果处理可显著提升落果率、降低产量，同时增大果实尺寸与单果重；乙烯利处理相较对照组同样可提升落果率与果实尺寸。其余化学疏果处理相较对照组未观测到正向疏果效果。