Effects of duration of coverage with spunbonded polyester rowcovers on growth and yield of bell pepper (Capsicum annuum L.)

Waterer, D. 2003. Effects of duration of coverage with spunbonded polyester rowcovers on growth and yield of bell pepper (Capsicum annuum L.). Can. J. Plant Sci. 83: 387-391. Transparent rowcovers installed at transplanting and removed as growing conditions improve are commonly employed to promote development of warm-season vegetable crops. In regions with a brief and cool growing season, short-stature warm-season crops such as peppers could potentially benefit from being kept under the rowcovers for extended periods after transplanting. This study examined the influence of duration of coverage with spunbonded polyester rowcovers on vegetative growth, fruit yields and degree of fruit maturity of bell peppers over the 1999, 2000 and 2001 cropping seasons in Saskatchewan, Canada. Eight-week-old transplants of several cultivars of pepper were covered for 6 wk or 10 wk after transplanting or for the duration of the growing season. All growth and yield responses to the duration of coverage were consistent across the cultivars tested. In 1999, extending the period of coverage reduced aboveground vegetative growth of the crop, otherwise vegetative growth was not influenced by the duration of coverage. During the relatively cool 2000 cropping season, the duration of coverage had no effect on fruit yields or the proportion of the fruit that matured to red prior to frost. By contrast, in the warmer 1999 and 2001 cropping seasons, fruit yields declined as the duration of coverage increased. Excessively high temperatures interfere with fruit set in peppers. These results suggest that the risk of exposing the crop to excessively high temperatures may be increased by extending the period of coverage into the warmer periods of the growing season. Extending the period of coverage beyond the standard 6 wk also required additional labor and occasionally exacerbated problems with weeds and insect pests.