2013 ASHS Annual Conference

Two studies were conducted to compare the performance of freeze protection methods for strawberry (Fragaria x ananassa) growth and yields. Treatments consisted of: a) 4.5 gal/min sprinkler heads (control); b) 3.5 gal/min sprinkler heads; c) heavy row covers on the crop canopy (0.9 oz/yd²); d) heavy row covers on 1.5-ft high minitunnel hoops; e) light row covers on the crop canopy (0.6 oz/yd²); and f) light row covers on 1.5-ft high minitunnel hoops. Row covers were placed on the crop between 12 and 3 pm on the afternoon of the forecast freezing night, while sprinklers were turned on when air temperature at 4-ft above the surface reached 34 ° and they were turned off when ice on strawberry leaves melted. There were 18 freezing and near freezing nights (≤ 34 °F) at the experimental site during the two seasons. The minimum air temperatures in non-irrigated areas during the two seasons were 21 and 27 °F, respectively. In covered plots, the minimum temperature directly above the crop canopy was 34 °F, regardless of the cover weight and the use of hoops to raise the covers above the canopy. Approximately 39 acre-inch/acre were needed in the control plots. Using nonirrigation alternatives for freeze protection resulted in the highest early and total marketable fruit weights, where total yields in plots treated with these alternatives ranged between 15.1 and 15.4 ton/acre while there was approximately a 20% fruit weight decline when sprinkler irrigation was utilized, regardless of the output volume.