Acta Hortic. 1271. ISHS 2020. DOI 10.17660/ActaHortic.2020.1271.61 XXX IHC – Proc. III Int. Symp. on Innovation and New Technologies in Protected Cultivation Eds.: F. Boyaci et al. 447 The effects of solarization and grafting on pepper (Capsicum annuum L.) production in greenhouse I. Çelik a , M. Turgut, R. Ozalp, B. Sayin and M.A. Celikyurt Bati Akdeniz Agricultural Research Institute, Antalya, Turkey. Abstract Effects of solarization and grafting on pepper (Capsicum annuum L. ‘Kusak’ F1) production were investigated in a greenhouse of Bati Akdeniz Agricultural Research Institute located in Antalya. Trial was set up according to split plot design with 3 replicates. Main plots were assigned to solarization with or without chemicals: solarization (S), solarization+metham sodium (S+Ms), solarization + condor (S+Cr), solarization + basamid (S+Bs) and control (C) without solarization and chemicals. Sub plots were assigned to grafting treatments including non-grafted ‘Kuşak’ F1 or grafted ‘Kuşak’ F1/ ‘Atlanta’ F1, ‘Kuşak’ F1/AG 9306, ‘Kuşak’ F1/BATEM-PR, ‘Kuşak’ F1/‘Snoker’ F1 and ‘Kuşak’ F1/‘Troser’ F1. Observations were taken for the properties such as plant length, fruit weight, early yield and total yield in trial plots. In conclusion; grafting was not a good option to grow pepper on different rootstocks; however, solarization plus condor always provided better quality and higher yields in pepper production regardless of the rootstock used. Keywords: grafting, MeBr alternatives, pepper, rootstocks INTRODUCTION Pepper is an important vegetable in the world with a production amount of 34.497.462 t. Turkey is ranked third in the world after China and Mexico (Anonymous, 2016). Most of the production (704 293 t) comes from protected cultivation located especially in Antalya, Mersin, Muğla and Hatay provinces (Anonymous, 2017). Protected pepper production in Turkey ranks fourth after tomato (3.829.931 t), cucumber (1.121.625 t) and watermelon (791.277 t). Pepper has been effected by the most prevalent and damaging soil-borne pathogens resulting in severe yield and quality losses. Phythium spp., Rhizoctonia spp., Fusarium spp., Alternaria spp., Sclerotinia spp., and Phytophthora capsici are the most important soil borne pathogens in pepper production areas (Anonymous, 2009). There are many disease agents in pepper production under greenhouse conditions, but the ones that cause economic loss include Fusarium stem rot (Fusarium solani), pepper root and collar rot (Phytophthora capsici L.) (Anonymous, 2009). There are some cultural practices such as the use of a resistant cultivar, grafting and chemical treatments to decrease crop losses caused by these diseases. Methyl bromide (MeBr) was a chemical used for controlling the soil-borne disease, because it was a strong fumigant diffusing easily and effectively. It had been used to control these soil-borne pathogens for almost 60 years in many countries of the world (MBTOC, 2007). In Turkey, for over 30 years, MeBr had been efficiently applied to the soil in protected cultivation to control various fungi, bacteria, insects, mites, nematodes and rodents as well as many weeds (Yilmaz et al., 2008). In 2007, it’s use was banned. Several alternatives to MeBr have been identified as: chemical, non-chemical and combined alternatives. The non-chemical alternatives include solarization, steam application, resistant cultivars (hybrids), soilless culture, bio-fumigation and grafting. Chemical alternatives that are extensively used include: metham sodium, dazomet and 1,3- dichloropropene. Chemical and non-chemical alternatives can be applied together for better efficiency. Grafting has been used against soil-borne pathogens in vegetables since 1920 in Japan a E-mail: celik_ibrahim@yahoo.com