Uneven Ripening on Grape
Return to Abiotic Disorders
Uneven ripening is evident when some berries within a cluster fail to color-up and ripen. Over-cropping, nutrient deficiency, excessive canopy shading, or overexposure due to excessive leaf and/or shoot removal, disease, insect, or herbicide injury may induce uneven ripening. Hybrid cultivars derived from V. labrusca parentage are more prone to uneven ripening in hot climates; the cultivar ‘Concord’ is particularly sensitive.
Uneven ripening in 'Concord' grape.
(Photo: John Strang, University of Kentucky)
Management:
- Follow proper cultural techniques: prune and manage canopy to prevent heavy shading, crop thin to balance vine growth, monitor nutrient levels through foliar analysis, avoid excess nitrogen, control disease and pests, manage weed growth (especially tall or climbing weeds), and avoid herbicide injury.
- Plant ‘Concord’ type cultivars (such as ‘Sunbelt’) that are less prone to this disorder.