Evaluation of Exogenous Salicylic Acid Application on White Mould Disease (Sclerotinia sclerotiorum) and Photosynthetic Pigments in Lettuce (Lactuca sativa L.)

Abstract

The aim of this study was to investigate the effectiveness of salicylic acid (SA) treatment against white mould disease (Sclerotinia sclerotiorum) (SS) disease in lettuce (Lactuca sativa L.) plant. In this study, two lettuce cultivars (Melina and Fuzila) were used and four treatments were applied to the plants (control, SS, SA, and +SA+SS treatments). Weight (g), the number of marketable leaf per plant, the number of non-marketable leaf per plant, leaf ratio (%), relative water content (%), chlorophyll parameters (chlorophyll a, b and total chlorophyll (mg 100g-1), colour parameters (L, a and b) and disease severity (%) were determined. According to the results, SA treatment increased the weight (563.65 g plant-1 for cv. Melina and 574.67 g plant-1 for cv. Fuzila) and number of marketable leaves (26.83 leaf per plant for cv. Melina and 31.33 leaf per plant for cv. Fuzila) whereas it decreased the number of non-marketable leaves (8.66 leaf per plant for cv. Melina and 6.67 leaf per plant for cv. Fuzila) in both cultivars. Besides, it was found that SA treatment reduced disease severity by 19% and 14% for cv. Melina and cv. Fuzila, respectively. Total chlorophyll contents ranged from 0.421 mg 100g-1 to 0.484 mg 100g-1 for Melina and 0.467 mg 100g-1 to 0.593 mg 100g-1 for Fuzila cvs. These results demonstrated that there was an increasing tendency due to SA applications for the total chlorophyll content in all cultivars. Consequently, it has been determined that SA treatment is effective and can be used against white mold disease in lettuce plants.

Keywords

• disease severity
• lactuca sativa l.
• marketable yield
• salicylic acid
• sclerotiorum sclerotinia
• quality