Comparing Solarization Soil Treatment with Methyl-bromide Soil Fumigation on Strawberries

Abstract

There is a great deal of interest in the possibility of developing suitable materials or procedures for use in strawberries and other crops in place of methylbromide as a soil fumigant. One such has been soil heating resulting from the bed application of transparent polyethylene. This requires high mid-summer soil temperatures with relatively high soil humidity. We present the results of a solarization experiment. Bed soil temperature were measured regularly at a depth of 12 cm through the 9 weeks of differential treatments. The soil temperature differences were highly significant, averaging ≈7°C higher than the non-solarized treatments. Weed control is one of the results of high interest. The number of weeds were counted twice. The number in the solar plots were not significantly different from the number counted for the methyl-bromide-fumigated plots. Vegetative vigor (asexual response) was also an important measurement. This was measured in two ways: first, the number of runners, and second, the measurement of plant size. The results were identical. The solarized plots and fumigated plots were identical in plant size and identical in runner production, and both were significantly different from the non-solarized and non-fumigated plots. Similar results were obtained for the sexual responses, yield, and fruit size. Solarization should be tested sufficiently in detail as a possible procedure to replace some methyl-bromide fumigation. The biggest problem may be difficulty getting the temperature high enough to be adequately effective.