-3- 



75 bushels per acre. Of course, in ten years when the more vigorous trees 

 have begun to bear, the story will be different. But Golden Delicious on 

 Mailing IX will delight the back yard fruit grower if he can control the 

 curculio and naggot. With Duchoss the story is quite different. Mailing XVI, 

 which is a standard stock for most varieties, brought Duchess into bearing 

 earlier than the very dwarfing stock DC. These are indications of some of 

 the coraplexities in the clonal stock problem. j. k. Shav/ 



IJAGilESIUI-I DBFICIEilC Y 



llsntion has been made of the raagnesi'om deficiency in our Experiment 

 Station orchards. There is little doubt that many of our trees suffer from a 

 lack" of magnesium. They look fine until some time in July or early August 

 when, rather suddenly, the leaves may shov/ some yellow chlorosis, dead areas 

 appear and the older scorched leaves may fall while those near the tip of the 

 shoots often remain green and healthy. 'vTe have been v;orking with quick tests 

 to determine what trees are dangerously low in magnesium as v;ell as in other 

 mineral elements. This work has been alternately encouraging and discouraging. 

 Just now we feel that we have a procedure that will show if a tree is deficient 

 in magnesium. Tests from orchards out in the state shov/ some that seem to be 

 suffering from this deficiency. If your orchard showed burned and falling 

 leaves in August and September, it should be looked into. Magnesium ff.rtilizer 

 experiments in a Three Rivers orchard and at the Station have been started and 

 further experiments are planned. j. ].;. shaw 



POSSIBLE REMEDIES FOR LIAGIJES lUIi DSFICIENCY 



Several inquiries have come in regarding the procedure to follow in 

 correcting magnesium shortage in apple orchards. There is increasing evidence 

 that quite a number of orchards in this state nay be suffering from this 

 trouble. Unfortunately, an easy and certain solution of the problem cannot 

 be given at the present tLme. 



In Canada serious magnesium deficiencies in apple orchards have been 

 recognized and studied for about four years. Several treatments have been 

 tried and most of these have been found inadequate to effect quick and complete 

 recovery of affected trees. This seems peculiar since annual crops respond 

 very readily. In a letter from Dr. H. Hill who has carried on most of this 

 magnesiura work, there is some very interesting information. In areas where 

 the deficiency is most severe, the soil is very acid - below pH 5.0. This 

 SQsms to be the case in Massachusetts also. Dr. Hill recommends applying 

 dolomitic limestone on such soils, although he says that several years may 

 elapse before there is any benefit from the magnesium. Surface applications 

 made in 1939 have given no signs of control. For quicker and perhaps only 

 temporary results, magnesium sulfate (Epsom Salt) has been recoiiUiended, Ap- 

 plications of 12 pounds per tree in the spring of 1939 controlled the trouble 

 only after about two years. In 1941, the trees v/ere back to normal. It would 

 seem that probably this is one of the best methods of alleviating magnosiiun 

 deficiency fairly quickly in apples. However, when soils are acid, magnesium 

 limestone should be given to correct th'; pH and thus help to affect a more 

 permanent cure. 



