Delaying flowering in short-day strawberry transplants with photoselective nets

Authors: Takeda, Fumiomi; Glenn, David; Callahan, Ann; Slovin, Janet

Submitted to: International Journal of Fruit Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/16/2010
Publication Date: 6/8/2010
Citation: Takeda, F., Glenn, D.M., Callahan, A.M., Slovin, J.P. 2010. Delaying flowering in short-day strawberry transplants with photoselective nets. International Journal of Fruit Science. 10:134-142.

Interpretive Summary: The strawberry has long been an important fruit crop in the Eastern United States, but in the last ten years, production acreage has decreased and the once thriving field nursery business has disappeared. The labor for removing flowers on nursery plants by hand costs about $500 per acre. We conducted studies to determine whether photoselective shade nets over plants can reduce or delay flowering. The 'Strawberry Festival' transplants for the study were produced from runner tips that were harvested in early July and plugged into small rooting containers. Starting August 1, transplants were either placed under red or blue colored shading net for four weeks or left uncovered (control). The control plants started flowering in late September, and more than 90 percent of unshaded plants had bloomed by November. Flowering in plants that were red & blue shaded did not occur until early January. The results of this study showed that a simple change in greenhouse management can delay bloom by several months, reducing production costs and increasing grower profits.

Technical Abstract: The effect of growing transplants under photoselective netting on subsequent field performance of strawberry plants was tested. In August, 'Strawberry Festival' strawberry plug plants were grown under red or blue ChromatiNet and without shade netting (control) in a glasshouse. Fall flowering response was determined in an annual plasticulture system in the field. The control plants began flowering in late September, and by late November, more than 90 percent of unshaded plants bloomed. These plants produced fruit from October to early January. Flowering in plants that were grown under red- or blue-colored shade netting did not occur until early January. The results of this study suggested photoselective shade netting over strawberry plug plants in August provides an opportunity for manipulating the flowering time in short-day strawberries. Delayed flowering is a desired physiological response, because it can potentially eliminate the need for detaching flowers manually in strawberry nursery fields and is useful for targeting fruit harvest in February or the Valentine's Day.