give one, two or three weeks scab protection, as desired, by adjus- 

 ting the amount of fungicide in the spray tank and applying at 400 

 gals, per acre. This is still in the experimental stage, but he 

 believes that 1 quart to 100 gallons dilute (one gallon Difolatan 

 per acre) may give one week of protection, two quarts per 100 (2 

 gallons/A) may give two weeks protection, and 3 quarts per 100 (3 

 gallons/A) may give three weeks protection. He is not yet ready 

 to make recommendations. 



*************** 



USE OF ETHEPHON (ETHREL*) TO INITIATE FLOWER 

 BUD DEVELOPMENT ON APPLE TREES 



W.J. Lord and Duane Greene 

 Department of Plant and Soil Sciences 



Growers are interested in ethephon's ability to promote spur 

 development and flower-bud formation on young apple trees. To in- 

 duce this response, the label gives the following directions: 



"To increase flower-bud development in both spur and non-spur 

 type young non-bearing trees, apply a foliar spray of Ethrel 1 or 

 2 weeks after peak bloom period (as determined by bearing trees in 

 the area). On young trees just beginning to initiate a few flowers, 

 treat 4 to 5 weeks after full bloom to minimize over- thinning and 

 misshapen fruit (calyx end pinched) . Reduced vegetative growth and 

 increased bud development during the season of application should 

 increase flowering the following spring. Trees should be large 

 enough to support a set of apples before they are treated to initi- 

 ate flower buds. 



I. Spur-Type Trees: Mix 1-1/3 pints of Ethrel* in 100 gallons 

 on water (5 pints in 300 gallons). Spray trees thoroughly 

 and uniformly to the point of runoff. 



II. Non-Spur Type Trees: Mix 3-1/3 pints of Ethrel* in 100 

 gallons of water (10 pints in 300 gallons) . Spray trees 

 thoroughly and uniformly to the point of runoff. This 

 rate may completely defruit trees. 



Treat when air temperatures are between 60"F and 90°F." 



Our studies show that concentrations much less than those sug- 

 gested on the label will reduce fruit set drastically when applied 

 anytime from full bloom to the completion of June drop. Therefore, 

 we will continue to suggest that ethephon not be used on young 

 bearing trees if fruit thinning is undesirable. 



*Trade name 



