Use of Plastic Mulch for Successive Crops

ABSTRACT Using plastic mulch for multiple (successive) crops spreads the installation and removal costs of plastic mulch and drip irrigation tubing over two or more crops, thus reducing the cost per crop. When using plastic mulch for a summer crop, white rather than black is preferred to reflect light and reduce soil temperature. Painting black mulch white allows the reuse of black mulch from a winter/spring crop. A study was conducted to determine the effect of the amount of white interior latex paint used to coat black plastic mulch on production of yellow summer squash (Cucurbitapepo var. melopepo (L.) Alef.). Ratios of 1:1, 1:2, and 1:4 (paint:water) were applied in a band on top of the bed at broadcast equivalent rates (BER) of 225, 450, and 900 l/ha (24, 48, and 96 gal/a). Spring 2000, fall 2000, and summer 2001 plantings of ‘Lemon Drop’ squash were seeded through the painted mulch. Rate of paint per acre had little effect on yield results. Regardless of paint: water ratio or application rate of the dilute mix, yields were equivalent in most cases to the yields from white mulch plots. A second study evaluated the long-term durability of 0.025 mm and 0.032 mm (1.00 mil and 1.25 mil) black plastic mulch. Differences in ultimate tensile force between mulch thicknesses were small. No reduction in ultimate tensile force measured to cause failure in mulch was noted after nine months in the field. During cooler fall months, ultimate tensile force increased while ductility decreased. There were no observable differences in ease of removal of the two thicknesses after 6 months or 11 months. Both thicknesses tore easily during removal.