【摘要】 土施和叶面喷施PP333每株有效成分1mg或1.5mg,都明显地减少了砂培条件下杜梨实生苗的营养生长,缩短了节间长度,减少了地上部鲜重和干重、总叶片鲜重、总叶面积和总叶片数,增加了根冠鲜重和干重比。土施还抑制了主根生长,增加了吸收根的粗度、吸收根和侧根占根总鲜重的比例。处理后10天,即表现出明显的抑制作用,有效期约30～45天,有效期的长短与施入量有关,施用量较多,有效期较长。 在田间条件下用PP333处理7年生鸭梨树,春季叶面喷施125ppm或250ppm三次,明显地减少了当年春梢的延长生长,缩短了节间长度,但对当年二次梢和翌年春梢、二次梢生长无明显影响。秋季和早春土施每cm~2主干横截面积77.5mg或155mg有效成分,对当年春梢影响较小,但强烈地抑制了当年二次梢和翌年春梢、二次梢的生长。土施和叶面喷施都明显地增加了翌年的开花数量和产量。土施影响了果实形状,使果柄处的突起消失,同时减弱了果柄的肉质化。更多还原

【Abstract】 1. Pyrus betulaefolia Bge.Seedlings 45 days after germination were grown in quartz sand and treated by soil application or foliar spray of PP333 ( ( 2RS, 3RS ) -1 -( 4 -chlorophenyl ) - 4 , 4 -dimethyl- 2 - ( 1H- 1,2,4 -triazol- 1 -yl ) pen-tan-3ol ) ,at the rate of 1.0 or 1.5 mg ai per plant. Both methods sig-nificantly reduced plant height, internode length, fresh and dry weight of shoots and leaves, and leaf area. No effect was observed on leaf num-ber per plant. Both methods markedly increased root-top ratio. There was no significant differences between the treated and non-treated plants in the fresh and dry weight of the roots, fresh weight of lateral and feeding roots, stem girth, average area and fresh weight per leaf.Soil app-lication markedly inhibited tap root growth but increased the thickness of feeding roots and the proportion of lateral roots and feeding roots in the total weight of the root system. Growth of the seedlings was signifi-cantly inhibited 10 days after treatment, but resumed 30 to 45 days after treatment. This indicated that the effect of this chemical lasted for 20 to 35 days, the length of the effective period being dependent on the dosage applied, the higher the dosage, the longer the period. 2. ’Yali’Soil application at the rate of 38.8, 77.5 and 155 mg ai per cm2 trunk cross section area was made either under the branch drip or as a collar drench to 7-year-old trees in the fall of 1984 and in the early spring of 1985 respectively. Foliar spray at the rate of 62.5, 125 or 250 ppm was made 2 weeks after full bloom and repeated J.O and 25 days after the first spray. In the year of application, both soil application and foliar Spray markedly inhibited the shoot growth, but the effective period of time was different between the two methods: Foliar spray signifi-cantly reduced the spring shoot growth and internode length, but no effect was observed on secondary shoot growth. On the contrary,soil app-lication either in the fall or in the spring had relatively small effect on the spring shoot growth, while markedly inhibited the secondary shoot growth. In the year following application, there was no significant inhi-bitive effect of foliar spray both on the spring and secondary shoot growth, but soil application still markedly reduced the spring shoot length and internode length and inhibited the secondary shoot growth. Both soil application and foliar spray significantly increased the amounts of return bloom and yield.Two years’ data showed that there was no significant effect of both methods on fruit set. individual fruit weight, length-diameter ratio, length and thickness of the pedicel, an’d total soluble solids of the fruit juice. However, the sweelling at the stem end of the fruit which is a typical characteristic of this cultivar, disappeared with the treatment of soil application. Furthermore, the usually fleshy basal part of the pedicel became lignified.更多还原