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insufficient information concerning whether poison ivy foliage is expanded enough 

 before fruit forms to obtain sufficient absorption of Amitrole for effective top 

 and root kill. More data were also needed to determine the limitations of 

 Amitrole in regard to the timing of post-harvest application. 



Amitrole has label approval for use to control poison ivy in non-bearing 

 apple orchards. Apply at the rate of 4 pounds (50 per cent formulation weedazol 

 or amino triazole) per 100 gallons of water when the ivy is in full leaf. 



Ammate still has no clearance for poison ivy control under trees. 2,4,5-T 

 Is effective against poison ivy but its use has resulted in severe damage to 

 trees at times. 



WHATEVER APPROVED HERBICIDE IS USED, READ THE LABEL AND FOLLOW DIRECTIONS'. 



---William J. Lord 



i I i I I I I I I I I I I I I I ! I 



CHEMICAL THINNING FOR 1962 



Most growers would agree that the probable need for chemical thinning 

 Mcintosh, following the very heavy 1961 crop, will be much less this year. We 

 anticipate a lighter bloom, except in occasional Mcintosh blocks where serious 

 loss of crop by frost occurred last spring. As far as other varieties are con- 

 cerned, the situation will be quite variable from orchard to orchard depending 

 on the bloom weather at blossom time, frost injury, etc. 



During the past two years we have had an opportunity to compare the insecti- 

 cide Sevin (1-Naphthyl N-methylcarbonate or NMC) as a post-bloom thinner of 

 apples with our older treatments of NAA (naphthalene acetic acid) and NAD 

 (naphthylacetamtde) . So far Sevin has appeared to be an excellent thinner of 

 Mcintosh and less injurious to foliage than any other material we have ever tried 

 for this purpose. The only variety it has failed to thin somewhat in our tests 

 has been Golden Delicious. However, very heavy setting varieties like Early 

 Mcintosh may not be thinned adequately by this mild thinner. Sevin can be used 

 on such hard to thin varieties at petal-fall time, though, and then followed by 

 an application of NAA or NAD a week to 10 days later. Remember, Sevin can thin 

 apples up to about 30 days after bloom or about 25 days after petal-fall. The 

 use of this insecticide for insect control on blocks within this period on trees 

 which do not need thinning may result in a serious, needless loss in crop size. 

 Sevin appears to thin a light or moderate set proportionately as much as a heavy 

 set. 



The action of Sevin on the growth rate of persisting apples differs somewhat 

 from that of NAA type materials. NAA when applied for chemical thinning purposes 

 seems to have a slight temporary (about 10 days) growth-inhibiting action on the 

 persisting fruit. This action doesn't cause a complete cessation of fruit growth 

 for a time but merely reduces the rate of growth. The action was great enough in 

 one test on Golden Delicious to reduce the ultimate size of the fruit at harvest 

 by about one-eighth of an inch. Sevin does not appear to have any growth 



