The Inland Mendocino Cooperative Weed Management Area (IMCWMA) is hosting a series of meetings in October and November to raise awareness and increase participation in invasive weed management. Each meeting will feature an invited speaker and conclude with a poster session including refreshments and opportunities to obtain more information about weed management from a number of experts.

Speaker: John Harper, University of California Cooperative Extension, Ukiah

Abstract: Vineyard floor vegetation is primarily controlled by chemical and mechanical methods. Both methods are problematic as herbicide applications can potentially impair water quality and mechanical control (mowing and cultivation) can often be delayed by rains. The cultural practice of grazing sheep in vineyards to control floor vegetation has been used, but cannot be employed after new buds emerge in early spring. We present new results on a method to train sheep to have a dietary aversion to grape leaves by orally dosing sheep with lithium chloride (LiCl) following grape leaf consumption. LiCl causes a temporary illness and a negative association with grape leaves, allowing sheep to graze vineyards past budbreak.

Photo caption: sheep trained for aversion to grape leaves grazing in test vineyard.