- 8 - 



risen above freezing. A single 1/8 or 3/16 inch nozzle per sprink- 

 ler head will deliver enough water to protect the crop. 



Irrigation also can be used to improve the performance of her- 

 bicides and fertilizers. Pre-emergence herbicides kill germinating 

 weed seeds, but in order to do so, they must come in contact with 

 the- seeds. From 1/2 to 1 inch of moisture is necessary within a week 

 after the herbicide application from the surface to move the chemical 

 into the soil to contact the germinating weed seeds. Moisture is 

 also required to dissolve fertilizer applied as sidedressi.ig and move 

 it down into the root zone of the strawberry plants. 



As with other tools, irrigation must be used properly for max- 

 imum benefits. When used to supply moisture, irrigation should be 

 applied before wilting begins, so that plant growth will not be in- 

 terrupted. It should not be over-applied on fruiting beds or soft 

 fruit or fruit rots may result. Overwatering can cause waterlogged 

 soil and root injury, and may also leach nitrogen from the soil. 

 But properly used, irrigation can help to insure consistent high 

 yields of good quality strawberries here in New England, where ade- 

 quate, timely rainfall is so unreliable and losses from spring 

 frosts a likely possibility. 



"ALTERNATE ROW SPRAYING FOR APPLE PESTS" 



R. J. Prokopy, R. G. Hislop, and K. I. Hauschild 

 Department of Entomology 



In the last issue of "Fruit Notes", we discussed the findings 

 of our 1976 studies on mite predators in Massachusetts apple 

 orchards. We presented information suggesting that some Massachusetts 

 growers having substantial numbers of mite predators needed to use 

 fewer miticide sprays than other growers having few mite predators. 

 Usage of certain insecticide and/or fungicide materials was apparently 

 harmful to the predators in some orchards. We suggested that growers 

 could reduce miticide usage by employing only those insecticides and 

 fungicides to which the mite predators seemed partially or fully 

 tolerant or resistant. 



In this article, we discuss our 1976 findings on another poten- 

 tially useful method for reducing the amount of pesticide in 

 Massachusetts orchards: alternate middle of row spraying. 



The alternate middle row spray treatment involves spraying alter- 

 nate halves of each tree on alternate spray dates instead of both 

 halves on all spray dates. For example, in applying the first cover 

 spray, the sprayer would be driven up the middle between tree rows A 

 and B and return down the middle between rows C and D, skipping the 

 middle between rows B and C. For the second cover spray, the sprayer 

 would be driven up the middle between rows B and C, down the middle 

 between rows D and F, and so forth. If this pattern were followed 



