秋施硼肥在苹果植株中的分布与利用动态

Distribution and Utilization of Boron in Apple Trees

对盆栽苹果树施Ｈ３１０ＢＯ３，于主要物候期测定，结果表明，生长季地上部全Ｂ的变化呈双峰曲线，根系仅出现一次高峰；枝条与粗根皮层的全Ｂ量一般比木质部高３～４倍，但从肥料中吸收的Ｂ占全Ｂ量的百分率（Ｂｄｆ％）二者相差无几。地上部新生器官在新梢旺长期Ｂｄｆ％值迅速提高，其后处于高水平的相对稳定期，细根随时间进展不断下降，粗根则缓慢上升。秋施１０Ｂ肥后的第３年花期测定植株不同器官的Ｂｄｆ％值仍可达１２．７％～３３．６％，而土壤仅为４．２％，并且１０Ｂ在植株中的分布发生了变化，一年生枝与粗根含量显著上升，约比翌年同期增加２倍左右，而主干与细根含量显著下降，说明硼肥在树体内具有长效作用，可再利用。

The apple trees (cv. Liaofu/ M. prunifulia Borkh) in pot culture were applied with H 3 10 BO 3 with 93.3% abundance at B 2.0mg·kg -1 soil in the autumn of 1991. The plant and soil were sampled from the spring of 1992 to the spring of 1993. The results showed that, the change of total boron indicated a bimodal curve in aerial part during growing season and an unimodal curve in root. The total boron in cortex of thick root, shoot and trunk was 3～4 times higher than that in xylem, but the percentage of the 10 B absorbed from 10 B fertilizer in total boron (Bdff%) showed no significant difference between them. Bdff% value of new organs above ground rised sharply in shoot rapid growth period, and then it remained at a high level. Bdff% value in fine roots decreased with advance of time, but increased slowly in thick roots . The Bdff% value in different organs in the third year after B applied in autumn was still 12.7%～33.6%, while only 4.2% in soil. More over, distribution of 10 B in plants changed. The 10 B in the one-year-old shoots and thick roots in 1993 was 2 times higher than that at the sametime in 1992. Trunk and fine roots was significantly lower, which indicated that B in plant tissue could be reused, and it had a long effect.