Vine Lines: Petiole Sampling To Monitor Grapevine Nutrient Status

摘要

FARMING is all about timing. Some of the things we need to do are time-flexible like pruning, while others are time-sensitive like applying a spray for powdery or downy mildew. Missing a spray to control mildew can leave you with a problem for the rest of the season. Monitoring the nutrient status in vines is also a "time-sensitive" activity. The best way to find out what fertilizers you might need to apply is to analyze "petiole" (leaf stem) samples at bloom time and again at verai-son (berry softening). Bloom time is important because insufficient levels of micronutrients at bloom can have a season-long effect on fruit quality. Veraison is important since at this time there is a major change occurring within the vine (the beginning of fruit ripening). This involves the uptake and remobili-zation of macronutrients (potassium in particular).