Plastic mulch color and potassium foliar application affect growth and productivity of strawberry (Fragaria X ananassa Duch)

Abstract

The field experiment was conducted to study the effect of plastic mulch color (red, red over black and black) and potassium foliar application (0, 500 and 1000 ppm) on some growth aspects, photosynthetic pigments, minerals, endogenous phytohormones, early and total fruit yield and fruit quality of strawberry plants (Fragaria x ananassa) cv. Festival during 2009/2010 and 2010/2011 seasons. Results indicated that 1000 ppm potassium foliar application or red and red over black mulches gave significantly the highest values of the plant growth (plant length, number of crowns and leaves, fresh and dry weights, and total leaf area per plant), photosynthetic pigments, NPK, total sugars, total free amino acids and crude protein concentrations in leaves, gibberellins, auxins and cytokinins in strawberry shoots (but the lowest abscisic acid), yield and fruit quality (vitamin C, total soluble solids titratable acidity and anthocyanin). The interactions indicated that the best values of all tested characters were obtained by 1000 ppm foliar K application with red or red over black plastic mulch. Hence, it could be recommended that red and red over black mulches with foliar application of potassium at 1000 ppm can be used to increase the final yield and fruit quality of strawberry plants.