Changes of root zone temperature, growth and productivity of broccoli cultivated with coloured plastic mulches

Abstract: The main aim is to find out the influence of using coloured plastic mulches (blue, white, green, red, black and white on black) compared with a mulch-free treatment on the root zone temperature, growth and productivity of broccoli. The results indicated that the highest and lowest mean root zone temperatures were recorded the in the dark-coloured mulches (blue, green, red and white on black) and in the light-coloured mulches (white), respectively, in both the winter and spring seasons. The average shoot length, leaf number and root volume of the broccoli for all the treatments was higher in the spring season compared with those of the winter season. The highest marketable head fresh weight values were 449.6 and 451.0 g found in the black mulch, while the lowest values were 391.4 and 397.5 g found in the winter and spring seasons for the red mulch, respectively. The N, P, K, Ca and Mg concentrations in the broccoli heads ranged from 2.0 to 2.8%, 0.9 to 1.0%, 2.7 to 3.6%, 1.9 to 5.9% and 0.5 to 0.89%, respectively, for all the treatments.