Evaluation of Colored Plastic Film Mulches for Broccoli Production in Georgia

Summary

Plastic film mulches have been found to increase yield and quality in broccoli. The effect of mulches was more significant in the spring than in the fall season.

Situation

Plastic film mulches are often associated with increases in plant growth and yield of many vegetables crops, such as, tomato, pepper, watermelon, and cucumber, among others. Studies in tomato, for example, have shown that color of the plastic mulch can drastically affect plant growth and yield. No studies, however, have reported on the effect of plastic film mulches on broccoli.

Response

Studies were initiated with the objectives of determining the effects of colored plastic mulches on root zone temperature and broccoli plant growth and yield. The goals were to provide information that would allow Georgia growers to better select the type and color of plastic mulch to use that would result in maximum broccoli yield and quality.

Impact

Colored plastic film mulches affected root zone temperature and the accumulation of soil degree days. Mean daily root zone temperature (RZT), maximal daily RZT and degree day accumulation in the soil were highest in dark-colored mulches (blue, black, red, and gray) and lowest in light-colored mulches (silver and white), while minimal daily RZT was highest in silver mulch and lowest in white mulch. Silver mulch showed the smallest diurnal fluctuations in RZT among plastic mulches, with the highest RZT during the night and among the lowest in the afternoon. Colored plastic mulches also affected broccoli plant growth and yield, although the effect of mulches was more dramatic in the spring than in the fall seasons. Broccoli yield was linearly related to both the vegetative top dry weight and root dry weight of mature plants. Broccoli yield was little affected at mean RZT of < 21 ºC but increased with increasing mean RZTs above 21 ºC up to 25 ºC. Thus, broccoli plant growth and yield responded more favorably to dark colored mulches than to light colored mulches, suggesting that broccoli benefited from increased soil warming. No high RZT stress effects on broccoli plant growth or yield were observed in this study. Thus, this study suggests that plastic film mulches, particularly the dark-colored mulches, may be an option for spring broccoli production in Georgia.

State Issue

Agricultural Profitability and Sustainability

Details

• Year: 2009
• Geographic Scope: International
• County: Tift
• Program Areas:
  • Agriculture & Natural Resources