防止采前落果　元帅系、津轻系等采前落果严重的苹果园 ,在采收前 4 0天和 2 0天 ,各喷布 1次 2 0ｍｇ/Ｌ萘乙酸 ,可明显减少采前落果 ;也可在采收前 3 0天 ,喷布 4 0ｍｇ/Ｌ萘乙酸 1次。在枣果采收前 3 0天喷布 60ｍｇ/Ｌ萘乙酸 ,采前落果率可降到 1 0 %以下。在巨峰葡萄果 Prevent the premature fall fruit Marshal Department, Tsugaru Department and other serious apple orchard before the harvest, in the harvest 40 days and 20 days, each spraying 1 2mg / L naphthalene acetic acid, can significantly reduce the harvest before falling fruit; Also available 30 days before harvest, spraying 40mg / L naphthalene acetic acid once. In jujube fruit 30 days before harvest spraying 60mg / L naphthalene acetic acid, fruit drop before harvest rate can be reduced to 10% or less. In the Kyoho grape fruit