by Layne Wade, Technical Service Manager, Arysta LifeScience

Often times, rainfall will bring more than a rainbow to a grape grower’s vineyard. It can also bring fungal organisms like Botrytis cinera, the causal agent of Gray mold and the leading cause of berry and fruit rot. The end result is extensive losses to crop yield and fruit quality.

Wet conditions in the early season can cause flower cluster and shoot infections, which can lead to an increase in late-season inoculum levels. The pathogen can overwinter on grape clusters from the previous year, but it is also commonly present on other decaying organic matter in vineyards during the growing season.

Infections on grapes can begin on the plant’s leaves, stems and bud axils, but when berries mature and ‘gain sugar’ they are increasingly susceptible to infection, with the peak of this susceptibility occurring post-veraison. As the berries ripen, fruit flies can help spread Botrytis spores to uninfected clusters and from plant to plant. The fungal infection colonizes the surface of berry tissue and invades the top layers of epidermis cells. The invasion can cause epidermal cracks, where fungal growth produces mycelium and spores, resulting in a gray, velvety appearance of the infected grapes.

To combat disease pressure, researchers recommend proper removal of leaves from around grape clusters during the growing season to lessen the accumulation of humidity and aid in protecting them with effective fungicides.

Keeping Botrytis in check at harvest time often requires a season-long approach and rotations with effective materials such as PH-D® and ELEVATE® Fungicides. The two fungicides, from Arysta LifeScience, provide effective disease control while preserving grape growers’ fungicide options for years to come.

PH-D is a broad-spectrum, Group 19 fungicide with a 0-day pre-harvest interval in grapes. It can be applied in grapes up to six times per year, when climatic conditions exist for the development of Botrytis and other disease infections such as Powdery mildew.

ELEVATE is a protectant fungicide that binds with the waxy layer of the grape and disrupts the Botrytis life cycle from spore germination to the beginning of mycelial growth and colonization. ELEVATE is the only member of the FRAC group 17 fungicide class and, when used in a tank mix or rotation with other fungicides, delivers dependable and economical Bunch rot control.

To learn more about the Arysta LifeScience portfolio of crop protection products, contact your crop protection retailer, visit www.arysta-na.com or call 886-761-9397.

_{Always read and follow label directions. ELEVATE and PH-D are registered trademarks of an Arysta LifeScience Group Company. Arysta LifeScience and the Arysta LifeScience logo are registered trademarks of Arysta LifeScience Corporation. © 2018 Arysta LifeScience Group Company. SPC-17108}