Integrated Fruit and Vegetable Research, GA

Non-Technical Summary: Some of the primary vegetable crops in Georgia are at risk due to the disease Phytopthora capscici. Management practices are infeffective. Also, postharvest handling of fruits and vegetables can add conserably to their value, however, losses after harvest can reduce profits and inappropriate practices can compromise food safety. The purpose of these studies are to screen breeding materials for peppers and squash to find resistance to P. capscici and to introduce these into acceptable breeding lines. The second purpose is to identify postharvest practices that maximize quality, shelf-life and food safety. <P> Approach: Packing House Efficiency and Effectiveness. Studies will be initiated to study packing line arrangements, sizes and components that result in the highest quality and least loss of product. Drop studies on packing lines, size and color sorting equipment, and sanitation steps will be evaluated using accepted post harvest and engineering techniques. Field Production Impacts on Quality and Storage. Studies will be initiated to evaluate how field production practices interface with storage and quality. Experiments will include various levels of fertility and water management as they relate to storage life and quality. Replicated field studies will include the various nutrient and water management treatments. Time and Motion Studies for Vegetables. Time and motion studies for various harvest and packing house operations will be conducted to determine the amount of labor required for various operations on certain vegetable crops. Refining Good Agricultural Practices. The current practices will be evaluated and work will be initiated in conjunction with Food Science faculty to amend these practices as needed to meet the third-party audit requirements to which many growers must adhere. Testing of cultivars and breeding lines. Pepper plants from resistant lines will be grown along with susceptible check plants at locations which have previously suffered damage from P. capsici. The experiments will be conducted in a randomized complete block design. Percentage of P. capsici infested plants will be assessed at several points during the growing season. Fruit will also be evaluated for the amount of silvering that occurs. Identification of new sources of resistance in Capsicum. Resistance to the foliar blight, stem blight, and root rot disease syndromes should be evaluated separately since they are under independent genetic control (Sy et al., 2005). Resistance to foliar blight will be screened for using the methods of Alcantara and Bosland (1994). Stem inoculation will be according to the methods of Sy et al. (2005) whereby cotton yarn is tied around the stem and inoculated with zoospores. Root rot resistance will be assessed where seedling roots are inoculated with zoospores and then flooded for 2 days. Transfer of new sources of resistance into adapted germplasm. The first step in the breeding process will be to transfer the resistance genes into adapted bell pepper germplasm. This has been done in the past by the traditional breeding processes of recurrent selection (Thabuis et al., 2004). Once the genetic inheritance is known, this information will be used to determine the most efficient method of introducing the resistance into elite germplasm. Identification of resistance sources in the Cucurbitaceae. Given the differing control of resistance in the various plant parts in pepper, a reliable method will have to be developed for each procedure, using the pepper techniques as a starting point. We anticipate screening both adapted and unadapted material in a search for resistant selections.