عنوان مقاله [English]
نویسندگان [English]چکیده [English]
This study was conducted to evaluate the responses of two greenhouse tomato cultivars to nutrient solutions' electrical conductivity (EC). Two cluster type greenhouse tomato cultivars (Razan and Ergon) were grown in perlite in a glasshouse hydroponic system. The grown plants were daily fed with either constant EC nutrient solutions (ECs 2, 3 ds m-1) or nutrient solutions of alternatively changing ECs of 1.5, 2, and 3 ds m-1. The basis for EC change in the alternatively changing ECs treatment was the rate of evaportanspiration rate during the day. The results indicated that variable EC treatment could improve total soluble solids (TSS) in tomato fruit while the other quality factors (firmness, pH, titratable acidity and ascorbic acid) were not affected by nutrient solutions. The yield in variable EC treatment being equal to that in commonly used solution (EC=3 ds m-1) improved the economic profitability of mineral usage in hydroponics greenhouse tomatoe production systems. There were differences obsereved between the two cultivars in yield and quality characteristics. Ergon yielded higher, while Razan carried a higher TSS content.