373 The Effect of the Type of Seedling and of the Planting Scheme on Productivity and Quality of Tomatilo (Physalis peruviana L.) grown under Bulgarian Conditions N. Panayotov and S. Tsorlianis Agricultural University of Plovdiv 12 Mendeleev Str. Plovdiv 4000 Bulgaria Keywords: tomatilo, planting scheme, seedlings, yield, quality, Physalis peruviana L. Abstract The main purpose of this investigation was to study the effect of different types of seedlings and planting schemes on the morphological development, yield and quality of fruit of tomatilo, grown under Bulgarian conditions. The experiments were carried out with plants from Physalis peruviana L., grown with pricked and non-pricked seedlings, planted in different spaces between plants in the rows – 40, 50, 60 and 70 cm, and between the rows – 70 cm. The highest yield was established in the treatment 50 x 70 cm – 965.7 kg/dka and 752.6 kg/dka for pricked and non- pricked transplants, respectively. INTRODUCTION Tomatilo is a rarely grown and comparatively new vegetable crop in Bulgaria. However, its delicious taste and the suitable conditions in our country for growing it give opportunities to enrich the diversity of vegetable crops and the abundance of the market. Hewett et al. (1993) reported about spreading of the cultivation and about the increased significance of this crop. Dascalov et al. (1961) and Genkov et al. (1974) suggested wide ranges for the possible spaces within the rows for its growing in Bulgaria  50 to 70 cm, without pointing the best. Ayala (1994) indicated that the planting scheme of tomatilo is of the greatest significance for a high yield. Detailed investigations in different aspects of agri  technology of tomatilo related with the yield and quality of the fruit were carried out by Maheha et al. (1989) and Montalvo (1996). The purpose of this investigation was to study the effect of different types of seedlings and planting schemes on the morphological development, yield and quality of fruit of tomatilo, grown under the Bulgarian conditions. MATERIALS AND METHODS The experiments were carried out in 1997  1999 in the experimental field of the Department of Horticulture at the Agricultural University of Plovdiv, Bulgaria, with local varieties. The first group of plants was sown in spaces 10 x 10 cm on 10 February and was pricked out (by putting the seedlings in pots at larger spaces) in the two-leave stage and the second group was sown on 15 March without pricking out. Sowing was done with 1.5 g/m 2 . Transplanting was carried out on 10 May by the following schemes: 1.70 x 40 cm, 2800 cm 2 , 3571 plants/dka; 3. 70 x 60 cm, 4200 cm 2 , 2380 plants/dka 2.70 x 50 cm, 3500 cm 2 , 2857 plants/dka; 4. 70 x 70 cm, 4900 cm 2 , 2040 plants/dka (dka. is equal to 0.1 ha). The morphological characteristics of 25 transplants and of 25 plants in the beginning of the flowering stage  weight and volume of the root at 30 cm depth; weight, length and diameter of the stem; number and weight of the leaves, were analyzed. Number of fruits per plant, average weight of fruit and total yield were determined. Dry matter (by weight), content of vitamin C according to Mury (Stambolova et al., 1978), sugar content according to Hagedorn  Yensen (Stambolova et al., 1978) and acid content as maleic acid (Stambolova et al., 1978) were also determined (Central Research Laboratory of the Agricultural University of Plovdiv). The variance analysis was made by Proc. 2nd Balkan Symp. on Veg. & Potatoes Eds. G. Paroussi et al. Acta Hort. 579, ISHS 2002