砂梨品种等级果下降原因的研究Ⅱ采果前叶片矿质养分含量对果个大小及产量的影响

Studies on Decreasing Causes of Standard Fruit Ratio of Sand Pear (Pyrus pyrifolia Nakai) Cultivars Ⅱ Influence of Mineral Nutrient Concentrations in Leaves at Preharvest on Mature Fruit Size and Yield

本试验以晚三吉、湘南和土任锦三个砂梨品种（ＰｙｒｕｓｐｙｒｉｆｏｌｉａＮａｋａｉ）的成年树为试材，研究其果实成熟采收前叶片氮、磷、钾含量与果个大小及产量的关系。结果表明：梨果成熟期叶片氨、磷含量与产量及单果重相关不显著；叶片含钾量在一定范围内与产量呈极显著负回归，湘南、晚三吉和土佐锦三个品种的回归方程分别为：Ｙ１＝８１．８１－７０．０２ｘ１，ｙ２＝１４２．８９－１２５．９７ｘ２，ｙ３＝９９．１９－１１４．６０ｘ３；叶片含钾量在一定范围内与单果重呈极显著正相关，三个品种的回归方程分别为：ｙ４＝２１．９３＋２４３．５２ｘ１，ｙ５＝－７５．８９＋２８４．４７ｘ２，和ｙ６＝－１０１．２４＋４３７．７５ｘ３。

The relationships between the concentrations of N,P and K in Leaves, which were collected atthe same time of fruit harvest, and fruit size, as well as and yield were studied in mature Sand Pear cultivars Xiang-nan, Okusankichi and ThZuojin. The results showed that concentrationsof N, P in leaves at harvest time hadno correlation with the fruit size and fruit yields. The Concentration of potassium had a very significant nesativecorrelation with tbe fruit yields per tree. The relationship between them of tbe tbree cultivars "Xiangun", "Oku-sankichi" and "Tuzuojin" conld be described respectively by y1=81. 8l-70. 02x1, y2=142.89-125.97x2, andy3=99. 19-114.60x3. The Concentrations of potassium had a very s1gn1flcant direct corrlation with the mean sin-gle fruit weight in a certain range. The correlatin equations of the three cultivars "Xiangnan", "Okusankichi" and"Tuzuojin" were y4=21. 93+243.52x1, y5=- 75. 89+284.47x2, y6=- 101. 24+ 437.75x3.