Monitoring Spread of Grape Phylloxera by Color Infrared Aerial Photography and Ground Investigation

Abstract

In 1977, phylloxera was discovered in five year old own-rooted Cabernet Sauvignon vines. Interpretation of aerial photos taken annually 1978-81 shows that phylloxera is readily distinguishable from other grapevine maladies, and that the annual rate of increase averages 255%. Projecting annual increases at this rate, all vines will be dead or unproductive in the eighth year following phylloxera discovery. However, because of the geometric increase in infestation, production may still be economical through the fifth to seventh year. Annual aerial detection and projection of the increase rate will enable vineyard managers to determine the optimum time to replant infested vineyards with vines grafted onto phylloxera resistant rootstocks.