Photosynthesis, soil temperature and yield of cucumber as affected by colored plastic mulch

Each crop may require a different root-zone temperature to achieve the maximum growth rate and yield. The temperature of the upper soil profile is determined by the soil properties, climate conditions, and site location, and can be either too high or too low for the crop requirements. A proper selection of plastic mulch can be used to modify the root-zone temperature to improve crop growth and yield. Cucumber plants grown in the field were exposed to different soil temperatures in two growing seasons under colored plastic mulches. Field studies were conducted during two growing seasons. Eight colored plastic mulches were tested at each growing season against bare soil. The objective of this study was to determine the effect of plastic mulch on heat accumulation as soil degree-day (DDsoil), photosynthesis rate, and yield of cucumber crop. The experimental design was a randomized complete block with nine treatments (eight colors of plastic mulch plus bare soil as the control) and four replications. The colors of the plastic mulches were: white-on-black, blue, white, black, black embossed, silver-on-black, red, and brown. DDsoil and plant photosynthesis were positively correlated with total yield, suggesting that increases in cucumber yield are due in part to an increase in soil temperature and plant photosynthesis. In conclusion, plants grown under the different colored plastic mulches had similar yields, and most of those plants had higher yields than plants grown in bare soil. We suggest that plastic mulch is useful for farmers of cucumber crops but the specific color of plastic mulch must be determined in each specific region.