2018 ASHS Annual Conference

Determining irrigation requirements for Brussels sprout production under rowcover is essential to maximize yield and improve water use efficiency (WUE). The response of spring planted Brussels sprouts to two plastic mulches (black and white) in combination with spun bonded rowcover and no rowcover was investigated at the Eastern Shore Agricultural Research and Extension Center of Virginia Tech on a Bojac sandy loam soil. The objective of this study was to determine the difference in water requirement and WUE under rowcovers compared to open field conditions. Plants were irrigated based on soil moisture and an irrigation event was initiated at 50% deficit of the plant available water. The amount of water applied (irrigation time) was estimated to bring soil moisture in the root zone to field capacity. In addition, temperature, humidity, wind speed, and solar radiation were measured in the canopy to estimate and compare evapotranspiration under rowcovers with the open field. Rowcovers increased air temperature in the growing season, but reduced solar radiation and wind, so evapotranspiration was less under rowcovers in comparison to the open field. Lower evapotranspiration was associated with less irrigation under the rowcovers compared to the open field. Rowcovers increased plant growth, stem length, number of sprouts, and total yield. In conclusion, rowcovers increased Brussels sprout production and WUE, which may justify their use to improve the sustainability of vegetable production in water limited areas.