Influence of double cropping on growth and yield of dry beans with colored plastic mulches
There are numerous studies of the use of plastic mulches in vegetable production, but there is little documentation of their use with dry beans (Phaseolus vulgaris L.) in single and double cropping. The objective of this study was to grow dry beans over two consecutive growing seasons using the same plastic mulch of different colors and examine the influence of soil temperature on growth and yield. The experiment was conducted in Saltillo, Coahuila, Mexico, in the spring and summer of 2008. The treatments included four colored plastic mulches: white-on-black, black, silver-on-black, aluminum-on-black, and bare soil as a control. The experimental design was a randomized complete block with four replicates. The percentage of photosynthetically active radiation (PAR) reflected from the plastic tended to be highest with the white-on-black mulch and lowest with the black mulch. Mean soil temperature under the plastic mulch decreased with the increasing percentage of reflected PAR. Mean soil temperature exhibited a relationship of 98% and 99% to yield in the first and second growing season, respectively. Photosynthetically active radiation had a relationship of 98% and 86% to yield in the first and second growing season, respectively. The effect of the colored plastic mulch on yield was significant (p < 0.05) in the first growing season but not in the second, where plastic mulch and bare soil treatments had similar yields, indicating that plastic mulches do not always increase yield.