This study investigated the effective harvest of ‘Kyoho’ grapevines by examining their characteristics including bud development, necrosis types and flower primordium formation. The size of the axillary bud did not show any difference in the 5th node or more, but it was smaller because it was closer to the base in the 4th node or less. In the 1st node, the rates of main bud necrosis (MBN), accessory bud necrosis (ABN), and whole bud necrosis (WBN) were high, and the rate of flower primordium formation was low, but there was no significant difference in the other nodes. Therefore, it was expected that using other nodes than the 1st node would be advantageous to secure production. Because the growth progresses after sprouting, the main bud necrosis rate increases, showing a very low flower primordium formation rate in March of the following year. Therefore, a method is needed to increase the storage nutrients in the winter and the rate of flower primordium formation after March. This study found that the thickness of the shoots should be less than 8.5 mm between the 3rd and 4th nodes, and the length should be less than 60 cm for nodes up to the 10th node.
Figures & Tables
Fig. 1. The necrosis types of lateral bud observed by the photograph of stereomicroscope in ‘Kyoho’ grapevine. (A) Normal, normal bud, (B) MBN, main bud necrosis, (C) ABN, accessory bud necrosis, (D) WBN, whole bud necrosis. AB, accessory bud; Fp, flower primordium; Lp, leaf primordium; MB, main bud; N, node; WWT, white wool tip.