A Study On The Absorption And Distribution Of Sulphur On Different Varieties Of Potato

The absorption and distribution of sulphur(S) in potato of different varieties, Zihuabai, Shepod and Desiree, was systematically studied in field experiment. The results show:1 The content of sulphur in leaves is the highest at earlier growth stage. The range is 0.15%～0.45%. At late growth stage, the content of S in roots is the highest, the range is 0.20%～0.30%, the content of S in tubers is always the lowest in the growth period of potato, the range is only 0.06%～0.20%.2 The amount and rate of absorption at a stage, and the ratio of the amount absorbed at a stage to the total vary wavely with the growth of the potato, and the three varities show the similar vary pattern. In the stage of tuberization to tuber-expanding, leaves, stalks and tubers grow quickly, the absorbed rate and amount of S at this stage is higher than other stages. The amount of S absorbed is 6.70～9.69㎏/hm2, the speed absorbed is 0.28～0.40㎏/hm2.d, the percentage absorbed at this stage is 42.79～64.54%. At mature stage, the absorbed rate and amout of S descreased to the lowest of the whole growth. Season for the death of leaves and stalks and the stopping of the tuber growth.3 At earlier growth stage, 62.45%～89.71% of S is distributed in leaves and stalks. After that, the S is gradually transferred from roots, stalks and leaves to tubers, and 72.86%～83.02% of S is in the tubers at harvest.4 Reaching the highest absorbing amount, parts of S in the roots, stalks and leaves of potato transfer to tubers. The transferring quantity of S shows leaves>stalks>roots.5 The amout of S shows very significantly positive correlation with the dry matter weight and amount of N, P, K.6 When the yield of potato is 20457～29850㎏/hm2, producing 500㎏ tubers need absorb 0.28～0.37㎏ S. The production efficiency of S is 1362.9～1778.2㎏/㎏.7 Increasing the quantity of sulphur-fertilizer can raise the yield of potato, content of chlorophy, leaf's area, content of Vc, dissolving sugar content and the protein content, and decrease the starch and the reducing sugar content.