Grapevine Decline in Pennsylvania and New York
Grape growers in Pennsylvania and New York have become increasingly aware of grapevine decline. Vine decline reduces yields and the availability of high quality fruit from old vines. Growers also have to pay for replacement plants and the labor required for replanting - in addition to losing income during re-establishment. Young and old vines of all cultivars can be affected.
Vine decline may be caused by insects, drought stress, overcropping, nutrient deficiencies, winter injury, herbicide damage, air pollutants, and viral, bacterial, and fungal diseases. These factors may all contribute to vine decline.
Declining vines may exhibit any of the following symptoms:
- Yield reduction over successive cropping years
- Reduction in canopy growth
- Uneven growth and development of vines & clusters
- Sudden vine collapse in mid- to late summer during high temperatures and drought stress
- High susceptibility to water stress, poor fertility, or to over-cropping
- High proportion of transplant failure
- Plants express disease inconsistently from year to year
- Cane stunting or dieback