Improving spray retention to enhance the efficacy of foliar-applied disease- and pest-management products in field and row crops

The deposition and retention of foliar-applied plant disease-management products and other pesticide's in relation to spray application parameters have rarely been characterized. Most of the research in this area has been conducted on herbicides; however, extrapolation from herbicides to other pesticides, whose activity is generally more site specific, is not always possible. Complex interactions among spray parameters, product formulation, and the morphology and architecture of the target plant call affect distribution, retention, and efficacy of foliar-applied products. This review describes the factors that affect retention and performance of disease-management products oil field and horticultural crops, with special emphasis oil plant tissues with a vertical orientation (e.g., petioles of celery, Apium graveolens var. dulce, and heads of wheat. Triticum aestivum). Disease development oil these vertical tissues call have a major impact on yield and quality (e.g., fusarium head blight on cereals), but spray coverage and retention are often too low to reduce infection Success. Because of the complex interactions among spray parameters. product, and host, the optimum management strategy for a particular host-pathogen combination may be specific to that combination or even to a specific pesticide. More research in this area is required before generalizations will be possible. However, we Conclude that the efficacy of foliar-applied disease-management products and other pesticides can be enhanced by optimizing spray application parameters-particularly nozzle orientation and droplet size.