- 4 - 



Even among the MM group are clones that do not have a single 

 mother plant that indexes virus free on certain indicators. The same 

 is true of many of the so-called super strains of our well advertised 

 varieties. There are latent virus diseases present in apple varieties 

 as well as in certain apple rootstock clones. But before one condemns 

 the use of certain rootstock clones, one has to prove that the latent 

 virus actually affects growth, bearing, and the end product, namely 

 the fruit. 



Virus diseases that do harm, of course, should be eliminated - 

 I am referring here to those with visible symptoms either on the tree 

 or the fruit. As long as we do not know what effect the latent virus 

 present in the rootstock has upon the variety, we should not condemn 

 the use of the rootstock. 



We have used EM VII and others in the EM group for more than 

 30 years successfully and shall continue to do so. As far as we know 

 now, the latent virus present in EM VII has not affected in any way 

 the varieties we have grown on this rootstock. 



I see no advantage in the use of rootstocks free of latent virus 

 if we have to grow on them varieties that carry also a virus in a 

 latent stage. 



It will take a number of years to prove or disprove that the 

 latent virus present in EM VII is harmful and affects the performance 

 of the trees. As long as this is unknown, growers should not be 

 alarmed about it," 



-- William J. Lord 

 / I I I I I I I I I 



POMOLOGICAL PARAGRAPH 



Soil Versus Leaf Analyses 



"Fertilizers for Fruit Crops" was the title of an article by A.L. Kenworthy 

 in the 91st Annual Report of the Michigan State Horticultural Society. In his 

 article he mentions that experience has shown that there is a very poor relation- 

 ship between soil tests and actual needs of fruit trees. Leaf analysis is the 

 most reliable diagnostic method. Leaf analysis combined with a thorough knowledge 

 of the crop considered will provide the most reliable method of determining 

 fertilizer needs for fruit crops. 



-- William J. Lord 

 / I I I I I I I I I 



