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CO RRECTIilG l I AGHESIUII DEFICIENC Y 



The use of magnesium sulfate spray applications on magnesium deficient 

 apple trees at Hassachusetts State Collelge this past season has shown that this 

 method may be a practical and effective treatment. Four special sprays v;ere 

 applied to young trees in an orchard showing considerable foliage scorch and 

 leaf fall in 1941 and 1942. Applications were made at approximately pink, 

 calyx, first and second cover. The sprays contained 16 pounds of Epson salts 

 per 100 gallons of water and were applied as special applications. Incident- 

 ally, it is probably safe (although we have no definite data) to add the Epsom 

 salts to the regular spray mixture thus largely eliminating any extra applica- 

 tion cost for the magnesium. Compared with the check or unsprayed trees, those 

 sprayed showed much less foliage scorch this fall. Of the 146 sprayed trees, 

 65% shov/ed no deficiency symptoms, compared to only 20yo for the sane nuinber of 

 unsprayed trees. Beneficial effects of magnesium spray applications have also 

 been reported from New York and llaine. 



Soil applications of magnesium canpounds have likewise showii promising 

 results at Axiherst. Both Seawater liagnesia and Epsom salts applied at the rate 

 of 5 pounds per small tree in the fall of 1942 were beneficial in reducing 

 scorch prevalence and severity in 1943, These results are not in line v/ith 

 experience elsev^here, where benefits have not been apparent for some years fol- 

 lowing soil treatments. However, the trees at Amherst are young (just beginning 

 to fruit) and are growing under a heavy mulch system of culture. It is probable 

 that both of these factors have a favorable influence on the intake of magnesium 

 from compounds applied to the soil. Tests in an older orchard gave nt indica- 

 tion of benefit from the soil applications. 



In orchards showing serious magnesium deficiency, the application of 

 magnesium in sprays seems to be a logical procedure. For instance, v/ith trees 

 requiring 20 gallons of spray for adequate coverage, 12.8 pounds of Epsom salts 

 would be provided per tree in the 4 applications described above. Thus, in 

 addition to the imraediat-? corrective effect of a foliage application, the amount 

 of magnesium applied (and most of it gets to the ground sooner or later) is equal 

 to or even greater than that in the suggested soil treatment. 



Further experimental work is planned, but in the meantime growers should 

 be doing something to correct serious magnesium deficiency conditions. V/here 

 soils are very acid (and many orchard soils are), magnesium limestone should be 

 applied and vrorked in, if possible. 



Lawrence Southvirick 



WANTED - APPLES OF OID VARIETIES. An exhibit of apple varieties which 

 were common 50 years ago will be staged at the 50th Anniversary of the ^i.f.G.A. 

 to be celebrated at Horticultural Hall in Worcester, January 5 and 6. if vou 

 have a dozen specimens of one or more interesting old varieties available for 

 tnis exhibit, please comunicate with S. Lothrop Davenport, chairman of the ex- 

 hibit comr.uttee. North Grafton, Mass. Among the varieties needed are these: 

 Hubbardston, Porter, Blue Pearmain. Mother. Black Gilliflower, Ben Davis, etc. 



