Plant growth and fruit yield of watermelon as influenced by colored plastic film mulch

ABSTRACT Watermelon [Citrullus lanatus (Thunb.) & Nakai] is widely grown on plastic mulches in the southeast United States, but responses of plants to plastic mulch color are not well understood. The objectives of this study were to determine the effects of colored plastic mulches and changes in root zone temperature (RZT) on fruit yield of watermelon fruit. The mulches (152 cm wide) evaluated were: black, blue, gray, red, silver (metallic), and white. During the first weeks after transplanting, canopy development was more rapid on black, blue, and red than silver and white mulches. As the season progressed and temperatures increased, differences in canopy development among mulch treatments tended to decrease. Watermelon plant growth benefited from soil warming using plastic film mulches, mainly blue, black, and red. There were no differences in fruit yield among different colored mulches, indicating that under the temperature conditions of the present study, the RZTs during fruiting were within optimal range for watermelon which is estimated to be 28.3°C.