【摘要】 <正> 缺硼是我国苹果生产上最常见的营养障害之一,各主要苹果产区都有缺硼果园。我们对果园土壤硼营养的状况,还了解得很不够。在土壤溶液中,硼可能是以硼酸形态存在,而植物所摄取的硼或许也是末离解的硼酸形态。由于很难测定土壤溶液中硼的浓度,所以土壤有效硼的浓度通常以热水溶性硼的数量来表示,一般认为当土壤热水溶性硼浓度低于0.5ppm时,果园即表现缺硼。此时施用硼肥即能显出肥效。但是,实际上,硼肥的效果与果树营养状况以及土壤性质有很大关系,在砂质、有机质低和酸性土壤中,较易于出现缺硼现象,而这样的土壤上能更好地显示硼肥的效果。更多还原

【Abstract】 A series of boron application experiments were carried out on the Golden Delie(?) ous apple trees in the Mt. Liangshan region of Sichuan Province since 1980. The date showed that:(1) The effectiveness of boron application depended upon two factors: the initial boron level of the tree and the methods of application used. Foliar application of 0.4% boron at the full bloom stage increased leaf boron contents about 2 to 6 ppm, when the boron status of the tree was in potential deficient level, its leaf boron ranged from 22 to 27 ppm, could be easily controlled by this treatment. Soil application of boron 125 g per tree in early spring increased leaf boron content 11 to 16 ppm, which could control most of the severe boron deficient status when the initial leaf boron were below 19 ppm.(2) Treatments with soil application of boron revealed residual effects on the improvement of fruit number and crop yield while no residual effect was found in the treatment of foliar spray.更多还原