-3- 



For Mcintosh it seems quite certain that these thinners applied from 10 

 to 20 days after petal fall are very helpful In promoting flower bud formation 

 for the following year. This Influence may be more Important in some instances 

 than a reduction in fruit set since growers are not anxious to produce Mcintosh 

 in excess of 3 inches in diameter. The risk of overthinning Mcintosh with 

 NA Amide at suggested concentrations ie small. 



At a recent meeting at Rutgers University where chemical thinning was 

 discussed by a large proportion of the research people in this field east of 

 the Mississippi River, there seemed to be considerable agreement that the 

 degree of thinning obtained could not be predicted on the basis of temperature 

 and humidity at the time of spraying. We believe it is still best to avoid 

 cool, cloudy weather and hot weather, however, when using chemical thinners. 

 Many feel that a frost a week or two before spraying, even if it has no 

 influence on fruit set, greatly increases the thinning potential of NAA or 

 NA Amide and a marked reduction in concentration is advisable. We have some 

 data contrary to this view but this may be the exception, so reduce the spray 

 concentration if temperatures of 28°F have been experienced prior to spraying. 



In the Shenandoah-Cumberland area the use of Tween 20 at 1 pint per 100 

 gallons as an additive with low concentrations of NAA is being suggested for 

 some varieties. Our results with Tween 20 are not sufficiently outstanding 

 to justify the general use of this or other additives with chemical thinning 

 sprays. If you have not been able to thin Golden Delicious adequately with 

 NAA, for example, the addition of 4 ounces of Tween 20 per 100 gallons of 

 water to a 10 or 15 ppm NAA spray might be worth a try, but I don't believe 

 many growers have had trouble thinning Gold Delicious with 20 or 30 ppm of 

 NAA alone. 



As you know thinning Red Delicious chemically is a risky business and 

 our results have been quite erratic. Dr. Art Thompson of Maryland is certain 

 that NA Amide is not a desirable material for this variety and suggests 10 

 to 15 ppm (4 to 6 ounces per 100) of NAA at about 15 to 21 days after full 

 bloom (about the same as 10-15 days after petal fall). NA Amide, he believes, 

 increases the tendency toward the development of "pygmy" fruit. On the other 

 hand, we have seen serious overthinning with NAA on Delicious particularly 

 under poor drying conditions. Unless you are having a serious biennial 

 problem with Red Delicious, we advise caution when using NAA on this variety. 

 It may be best to spray a different fraction of a variety like this at 3 or 4 

 day intervals since we have no way of being sure which day will give the most 

 desirable results. This same procedure may be followed for Mcintosh and other 

 fall and winter varieties to reduce the chances of under or overthinning all 

 the trees of a given variety. 



— F. W. Southwick 



I I I I I I I I I I I I I I I I 



EFFECTS OF PESTICIDES ON HONEY BEES 



A, HOW BEES MAY BE POISONED: 



1. Contamination of water , nectar or pollen with pesticides which have 

 stomach poison action on bees. Contaminated water and pollen can kill 



