| Boron deficiency
dramatically influences yield. Leaves toward the end of the shoot
show a spotty yellowing. Affected leaves tend to be undersized and
cupped. Affected clusters may totally abort or develop a few small
berries, often with many small, green shot berries.
This condition results because ovules on affected flowers are poorly
fertilized.
Petiole tests
can confirm this deficiency. Soil or foliar boron applications may
correct the deficiency. Excess boron fertilization may result in
toxicity to vines. |