Juan C. Díaz-Pérez and John Silvoy
Department of Horticulture, Coastal Plain Experiment Station,
University of Georgia, Tifton, Georgia, U.S.A., 31793-0748

Abstract. The objective of this study was to determine the effects of colored plastic mulches on the yield of broccoli (‘Packman’) grown in the spring and fall seasons. The plastic mulches were black, blue, gray on black, silver on black, and white on black, and bare soil. Root-zone temperature (RZT) was measured by determining soil temperature midway between the plants at 10 cm below the mulch and the soil surface. Mean RZT in the fall (18.2 C) was about 6 C lower than in the spring (24.3 C). In the fall, mean RZT was highest under black mulch and lowest under white mulch and bare soil, while in the spring mean RZT was highest under gray and blue mulches and lowest in bare soil. Both total and marketable yields were higher in the spring than in the fall. During the fall, top biomass and total and marketable yields yields were no significantly different among mulch treatments. During the spring, top biomass was highest on black mulch and lowest on bare soil and blue mulch, and both total and marketable yields were highest on black mulch and lowest on white mulch and bare soil. Both marketable and total yields increased with increasing values of mean RZT. Within the range of RZTs of this study, no evidence was found of detrimental effects of high RZTs on broccoli yields. In conclusion, soil warming associated with the use of plastic mulches increased broccoli yields.

PDF Order Form
Secure Server Order Form