در خاك آهكي )Fragazia ananassa( اثرهاي كاربرد آهن و اسيد سولفوريك بر برخي ويژگي هاي رشدي و عملكرد توت فرنگي

EFFECTS OF IRON AND SULFURIC ACID ON VEGETATIVE AND REPRODUCTIVE CHARACTERISTICS OF STRAWBERRY (FRAGARIA ANANASSA DUCH.) IN CALCAREOUS SOIL

Iron chlorosis is one of the important limiting factors for production of strawberry (Fragaria ananassa Duch.) in calcareous soils. Low solubility of Fe compounds in soil is usually the cause of chlorosis. Sulfuric acid (H2SC)4) has been applied to such soils in order to correct the chlorosis of field crops but research reports for horticultural crops is scarce. This study was, therefore, conducted to investigate the effect of H2SC)4 application on growth and Fe uptake of strawberry ʹArmoreʹ grown on a calcareous soil. The experiment was a 4x4 factorial with complete randomized design with 4 rates of H2SO4 (0, 10, 20 and 30 g of H2SO4 Kg-1 soil) and 4 rates of Fe (0, 5, 10 and 15 mg Fe kg-1 soil as Fe-EDDHA) in four replications.Vegetative and reproductive growth, pH and also electrical conductivity (EC) of treated soil were studied. Soil pH decreased and EC increased as the rate of H2S04 application increased. The effect of H2S04 and Fe on the weight of the secondary fruits were more pronounced. Application of H2S04 up to 20 g kg -1 soil, increased the weight of the primary fruit but the weight decreased at the higher rates of H2S04 presumably due to increase in soil EC. The highest weight of the primary and secondary fruit and total yield per plant were obtained at 30 g H2S04 plus 10 mg Fe kg-1 soil. This is beleived to be due to the effect of Fe which alleviated the suppressing effect of high EC. Application of 15 mg Fe kg-1 soil, however, did not prevent the suppressing effect of high EC. This may be attributed to the antagonistic effect of Fe on other nutrients. Application of H2S04 increased leaf area and chlorophyll content of the leaves. The highest chlorophyll content was obtained at 20 g H2S04 kg-1 soil. Decrease in leaf area and occurreance of leaf scorching due to high EC were observed at higher rates of H2S04.