WHY IRRIGATION FOR STRAWBERRIES? 



Dominic A. Marini 

 Southeast Regional Fruit and Vegetable Specialist 



Irrigation is an important management tool for growers inter- 

 ested in obtaining consistent high yields of quality strawberries. 

 Strawberries can be a very productive and profitable crop with po- 

 tential yields as high as 18,000 quarts per acre. However, to ob- 

 tain such yields, careful attention to all cultural practices is 

 required, including maintaining an adequate moisture supply; Ample 

 moisture is essential for optimum fruit size and high yields, and 

 there are periods during every season when irrigation is necessary 

 on both the non-bearing and bearing bed. Economic studies have 

 shown that returns from irrigation are higher with strawberries 

 than with other crops. 



Strawberries are shallow-rooted, with the greatest concentra- 

 tion of roots in the top 4 to 6 inches of soil and most of the 

 plant's moisture is obtained from the top 12 inches. The plants 

 require about one inch of water per week for optimum growth, from 

 the time plants are set until the crop is harvested. 



Moisture is needed when the plants are set so that they can 

 become established quickly, make rapid growth, and start produc- 

 ing runners early. It is necessary to enhance rooting of runners 

 and to produce large plants with multiple crowns. Moisture is crit- 

 ical during August and September when fruit buds for the following 

 year's crop develop within the crown. In the bearing year, 

 adequate moisture is essential for maximum fruit set and to produce 

 large berries. If a bearing bed is to be carried over for another 

 year, moisture is necessary after mowing or renovating. 



Irrigation is useful in other phases of strawberry production 

 management besides supplementing rainfall. Frost protection is one 

 of these. Hardly a spring goes by when strawberry crops do not suf- 

 fer some frost losses. Some blossoms are killed outright, while 

 others produce small, deformed, worthless fruit or "nubbins." Most 

 frost damage occurs to open blossoms, but unopened buds can be dam- 

 aged by low temperatures before bloom or before emerging from the 

 crown. 



Most investigators report that strawberry crops can be protec- 

 ted from temperatures as low as 22°F, while a recent article in 

 American Fruit Grower states that irrigation saved a high percen- 

 tage of the bloom at 1 5 ° F . 



Growers report using irrigation on as many as 18 nights during 

 a season for frost protection. As little as 50 gallons per acre 

 per minute or 1/10 inch per hour will provide frost protection. 

 Irrigation should start at 33 or 34°F before freezing begins and 

 should continue until the ice has melted and the temperature has 



