Effect of "Nidogiri method" pruning after harvesting for recovering vigor and increasing flower clusters on grapevine [Vitis] in early heating green house

In green house, if we continue early heating which starts before last ten days in January, grapevine will fall tree vigor and decrease flower clusters. In this report, we examined effect of "Nidogiri-method", pruning after harvesting and making new shoot, to solve these problems. 1) After treatment of "Nidogiri", new shoots grew rapidly, and became good branch at the time of defoliation. The new root quantity increased and the shoot-root ratio declined. Several effects of pruning were observed in the following year; i) sprouting was good, ii) growth of shoot was good, iii) clusters increased and enlarged, iv) ripening time forwarded, v) yield increased by 10-20%. 2) Optical time of treatment, in case of field temperature, was middle to end of June when minimum temperature was over 15 degrees C. Maintaining temperature over 15-18 degrees C in the plastic house, we got equal effects when we treated just after harvest on May. 3) We examined the effect of "Nidogiri" on four varieties, and got good results on "Delaware" and "King Dela" in sprouting, shoot growth, cluster and grape quality, "Kyoho" in sprouting and cluster, while in case of "Ruby Okuyama", growth and development of treating trees was inferior to nontreated trees. 4) The effect of "Nidogiri" was limited in one year. Trees which treated for two years tended to recover tree vigor. 5) To investigate the cause which "Nidogiri" makes growth well, we observed a nourishment change in the dormant shoot. As for the carbohydrate content, both the treated tree and the non-treated tree can have headed in the peak during November in the last ten days, but as for the peak value, the treated tree had higher carbohydrate content than non-treated tree. Content of sucrose since December deceased in non-treated tree, but increased in treated trees