Improved management of walnut quality factors under grower control : Literature review prepared for the Australian Walnut Industry Association

Improved management of walnut quality factors under grower control. This paper presents a review of the literature on the ability of growers to manage and improve walnut quality. Initially the background is set by looking at the general production process for walnuts, the Australian industry, the range of walnut products available and the specific issues they may have for quality. The review then looks at the areas of safety that need to be managed by growers, particularly contamination by agricultural chemicals, microbes, toxins and spoilage products. What constitutes quality for the various players and how to accurately define these measures are considered. The review covers all the factors within the grower’s control that could affect quality and what the consequences of good or poor management might be on walnut quality. These factors include orchard establishment, water use, PGR use, vegetative growth, fertility, pests and disease, environment control and nut management. The management of nuts must start in the orchard and then proceed through harvest, cleaning, drying, storing, processing and transport. Finally a model for validation of a high walnut quality management system by growers is presented along with an extensive literature list.