5.1.19
STUDIES ON THE EFFECTS OF SOIL SOLARIZATION AND SOME TRICHODERMA SPP. APPLICATIONS TO CONTROL SOILBORNE DISEASES IN PROTECTED VEGETABLE CROPS IN THE EASTERN MEDITERRANEAN AND TURKEY

S YUCEL1, H PALA1, S CALI1 and A ERKILIC2

1Plant Protection Research Institute, PO Box 21, 01321 Adana, Turkey; 2Agricultural Faculty, Department of Plant Protection, 01330 Adana, Turkey

Background and objectives
About 17.5 million tons of vegetable crops are produced in 66.551 ha in Turkey, and 26% of the production belongs to the Mediterranean region. Protected vegetable crops are the major part of vegetable production, with 89% in this region. Soilborne diseases cause great damage when the same crops are grown for long periods in the same greenhouses. Chemical control measures against soilborne diseases have technical, environmental and economical restrictions. In recent years, soil solarization treatments using heat disinfection effects to eliminate (or at least reduce) soil pathogens have become popular. With this treatment, soil becomes microbiologically clean and antagonist populations can easily be increased [1].

Materials and methods
In this study, solarization was applied for 8 weeks (11 July-11 Sep, 1997) in a greenhouse soil infected with Fusarium spp. and Rhizoctonia solani, then Trichoderma harzianum (Trichoderma-2000, Mycontrol) was added to the soil and cucumber seedlings were planted. At the end of the vegetation period the effects of solarization, alone and combined with T. harzianum, were evaluated on the cucumber plants.

Results and conclusions
The percentage of cucumber root-rot disease was found to be 27.3% for solarization application, 24.3% for T. harzianum application after solarization, and 47.8% for control plots. Although no significant difference was found between solarization and T. harzianum application, similar trials are being conducted for pepper plants as a second crop.

References
1. Katan J, 1987. Soil solarization. In Chet I, ed., lnnovative Approaches to Plant Disease Control. Wiley, New York, pp. 77-106.