Organic Outdoor Tomatoes Regional screening and breeding in Germany Many thanks to the Rut- and Klaus-Bahlsen Foundation, the German Federal Organic Farming Scheme and our colleagues on farm and in garden! Results After two years of screening the share of commer- cial varieties was 9.1%, and 31.8% were obtained from genebanks. 59.1% of the most interesting va- rieties originated from NGOs and individual seed savers. During four years of screening and regional tests the top ten varieties were identified. Included are wild-, cocktail-, salad-, processing-, and beef- steak-tomatoes (see pictures). The high heritability of Phytophthora-infections on leaves and fruits, and for yield (74-96%) confirmed the suitability of the experimental design (Table 1). For all traits the varieties were the most important variance component. Site specific adaptation, i.e. variety x location interaction, was of minor impor- tance or absent. For fruit infections variety x year interactions were stronger than variety x location interactions. Introduction Tomatoes are the most important vegetable in Germany, but more than 90% of the consumption are imported. One of the major obstacles for increased production is the breakdown of outdoor tomato production. Increasing infections with late blight (Phyto- phthora infestans) have almost eliminated commercial cropping and seriously impaired private production. The aim of the project during the years was 1) to evaluate and recommend suitable open pollinated varieties for organic outdoor production and 2) develop a regional breeding program within organic horticulture. Materials and methods Regional evaluation was based on 3500 accessions. In close contact with genebanks, NGOs, seed trade, and private seed savers, 92 varieties were selected for comparative trials at three farms in central and northwestern Germany. The number of varieties was reduced during 2003 to Some additional varieties with superior performance in a screening at one farm were included. Two replications with two plants (2006: 3 x 2) were grown per location. Layout and maintenance of the plots favoured Phytophthora- infections. Each year a group of varieties was tested at 25 to 35 locations. Backyard and market gardens, botanical and other public gardens, and research institutions participated. Suitable varieties identified in the screening were used to make crosses to combine the important traits earlyness, field resistance against late blight, high yield, and good fruit quality. The most advanced crosses were included in the screening Bernd Horneburg and Heiko C. Becker Department of Crop Sciences, Georg-August-University, Von Siebold Str. 8, D Göttingen, Germany, As an example for the regional breeding program a wide cross between the wild tomato Golden Currant (fruit weight 6 g) and the sa- lad tomato Matina is shown below. The relative value for late blight infections (mean of , Matina = 100) for Golden Currant was 56 for leaf infections, and 50 for fruit infections. Wild tomatoes yield poorly when grown at a stake. One typical way of production is shown below to the left. The important traits field resistance against late blight and long harvest period of the wild tomato were suc- cessfully incorporated in the F5- and F6-generations (Table 2) and resulted in the highest yield in the screening Rote Murmel Golden Currant Cerise rot Matina CelsiorCerise gelbPaprikaförmige Outlook The methodology for a regional breeding program is developed and needs to be put into practice! We would appreciate co-operation with other regions facing similar problems. X → Golden Currant x Matina F5 Golden Currant CelsiorResi Cerise gelb DeBerao Rote Zora Paprikaförmige