SPRAY BURN
Identification
- Superficial or deeper scarring on berries
- Yellow then brown areas on leaves where material contacts leaves
Often Confused With
Phomopis – necrotic spots on leaves surrounded by ring of yellow tissue
Sun burn – no foliar symptoms
Ozone injury – no fruit injury
Anthracnose - on fruit there is a light centre with a dark raised edge
Scouting Notes
Cultivars can differ widely in their sensitivities to various chemicals. There are also many factors that can influence the occurrence and severity of phytotoxicity. These include weather conditions before, during and immediately after application, plant growth stage, vine stress, combinations of products used, and residue from prior products.
Management Notes
In general, no fungicide, miticide, foliar nutrient or insecticide should be applied once the ambient temperature exceeds 30 ºC.
Be aware of chemical incompatibilities of foliar nutrients with pesticides, adjuvants or product carriers (for example soluble bags).
Do not tank mix products if there is a caution statement regarding tank mixing on either product label.
Some varieties are sensitive to specific fungicides or insecticides or chemical combinations.The table lists only specific warnings about phytotoxicity found on labels of fungicides and insecticides commonly used on grapes. Phytotoxicity may occur where adjuvants used for one component of a tank mix may allow another component to penetrate vine tissues though the original product was not intended to and now results in crop injury.
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