1994 Volume 63 Issue 3 Pages 515-521
The contribution of lateral and primary leaves to the growth and quality of 'Kyoho' (Vitis vinifera × V. labrusca) berries was investigated. The total leaf area on each bearing shoot was adjusted to ca. 1500 cm2 by removing primary or lateral leaves at veraison so that the percentage of lateral leaf area (LL) beyond or distal to the cluster was : ca. 100 (100 - LL), 70 (70 - LL), 30 (30 - LL), and 0 (0 - LL) of the ca. 1000 cm2.
The net photosynthetic rate (Pn) of the primary and lateral leaves on treated and intact shoots were determined.
1. The berries on 100- and 70 - LL shoots ripened faster than they did on 30- and 0 - LL shoots. Berries on 100- and 70 - LL shoots accumulated total soluble solids (TSS) and anthocyanin faster than they did on 30- and 0 - LL shoots. Contrarily, titratable acidity of the berries on 100- and 70 - LL shoots decreased more rapidly than they did on 30- and 0 - LL shoots.
2. During the ripening stage of the berry, the Pn of lateral leaves was faster than that of primary leaves. The Pn of basal primary leaves was significantly slower which may be responsible for the retarded ripening of berries on 0 - LL shoot.
3. No significant difference was found in the leaf structure or the mineral nutrient content between primary and lateral leaves when measured before the veraison.