Abstract
Vein-yellowing of leaves has often appeared at the basal part of shoots of the Campbell′s Early vines grown under wetting conditions during the rainy season in Kagawa prefecture, resulting in a serious damage for its production. To clarify the metabolic mechanism of this foliage disorder, the content of mineral nutrients was compared between the vein-yellowed leaves and the normally developed ones collected from other healthy vineyards.
1.The vein-yellowed leaves contained less N and P, and more Cu than the normal leaves. Particularly, the upward and downward trends of the element content were marked with N in petiole and vein and with P and Cu in mesophyll.
2. In the vineyards where leaves have shed in every rainy season, the N and P contents decreased and the Cu content increased in the leaves at the basal part of bearing shoots with their growth. This suggests that the vein-yellowing symptom is closely related to the Cu content of leaves which is affected through the change in soluble Cu content of soil.
3. When pot-cultured vines were submerged at the root zone, rootlets turned black and died before long. In the leaf analysis at the basal part of shoots, the vines treated with excess water showed less N, P and K and more Mn, Fe and Cu contents than the non-treated vines. However, no marked difference of the mineral nutrient contents was observed with the leaf at the top part of shoots between both the treated and non-treated vines.
