Although harvest is approaching for many grape growers on the West Coast, Botrytis bunch rot remains a high threat to vineyards throughout the end of the season. Botrytis bunch rot (also known as vulgar rot, or noble rot when referring to its effect on wine) can be devastating to grape yields. In addition to protecting current grape vines, growers also have to be mindful of next year's fruit due to the possibility of overwintering fungus.
Botrytis bunch rot overwinters as sclerotia, which are hard, resistant structures sometimes referred to as "berry mummies." Following rain or irrigation, sclerotia germinate and produce spores that travel by air currents or rain showers. Most often, fungal spores require free water for a specific period of time before they can germinate.
Late-season infections, including Botrytis, are most severe when temperatures range from 58 °F to 82 °F, relative humidity exceeds 92 percent and free moisture is present on the fruit surface.
Stopping the problem in its tracks is critical to avoid overwintering disease. In addition to proactive practices such as pruning and providing adequate air circulation to grapes during the growing season, UPL recommends using a fungicide such as PH-D® or ELEVATE® up to harvest to protect vines from the potential effects of overwintering Botrytis bunch rot.
ELEVATE Fungicide (FRAC group 17) provides locally systemic activity and is excellent at controlling Botrytis bunch rot and powdery mildew. ELEVATE can provide post-infection activity when applied early in the disease life cycle and has been shown to enhance the efficacy of other fungicides when used in a powdery mildew spray program. With a zero-day pre-harvest interval, you can use ELEVATE up to the day of harvest.
PH-D Fungicide (FRAC group 19) is a broad-spectrum fungicide that offers a high degree of Botrytis and powdery mildew control in grapes. Its benefits of a zero-day pre-harvest interval and 4-hour REI make it an excellent option for disease management sprays close to harvest. PH-D is the only product in FRAC group 19, making it an important resistance management tool.
What is happening in your vineyard will affect not only this year's harvest but next year's vines. Say no to overwintering disease. With UPL, you can count on dependable disease control and a staff dedicated to keeping your vineyard protected all season long. To learn more about the UPL portfolio of crop protection products, contact your local UPL sales representative or visit www.upl-ltd.com/us.