Effcet of PP₃₃₃on Growth and Fruiting for 8 Spceies of Economie Trees.

Key words: 
• pp333 /
• plant growth retardants /
• fruit tress /
• economic plants /
• growth /
• fruit set /
• effect

Abstract: PP333 at different concentrations was used in 8 economie species of treessuch as peach,plum,chestnut and ginkgo in different ways. Results showed that PP333, to various extents,had some retardant effect on elongation of new growth and enlargement of leaf area in these 8 species,especially in peach followed by plum,pear and chestnut trees.In chestnut,the effect was very obvious on new growth in the 2nd year of treatment.Floral bud formation was accelerated in peach and plum with the treatment of PP333,so was fruit set in adult peach trees,which was opposite to what was observed in young peach trees.In addition,appearance,disappearance and duration of retardant effect of PP333 Proceeded at the different time among species。ComPensating growth usualy followed disappearance of the retardant effect at the time of early growth。For some species,PP333 came to effect only by increasing concentration or by increasing time of treatment。