276 MASS. EXPERIMENT STATION BULLETIN 271 



.seems to liave dcnion.strated the .superiority of iieavy iniiich over cultivation, 

 botli being without added fertilizer. It is planned to make some change in 

 the test as it has been proved that a program of cultivation without fer- 

 tilizer will not maintain jiroduction on this soil. 



The Effects of Fertilizer Limitation on Fruit Plants. (J. K. Shaw). 

 The fruit i)lants (apple, peach, grape, raspberry) that have been on this 

 experimental field were removed in the spring of 1930. The fertilizer 

 treatment was continued, and a crop of buckwheat grown and not re- 

 moved. It is planned to reset the field in the spring of 1931 to own- 

 rooted trees. These field plots with their long-continued fertilizer treat- 

 ments serve as a source of soil for certain pot experiments. 



Role of Potash and Lime in Fruit Tree Nutrition. (J. K. Shaw). A set 

 of pot cultures similar to those of last year but with different fertilizer 

 treatments were grown. Applied nitrates increased growth only to a small 

 degree. Magnesium-free calcium carbonate was as effective without as 

 with added magnesium sulfate. It seems clear that this soil having a pll 

 value of about 4.75 is too acid for the best growth of fruit plants. 



Effect of Potash and Lime on Apple Trees. (J. K. Shaw). This pro- 

 ject has been carried on without change. Determinations made at several 

 times during the summer showed that soil nitrates were present on plots 

 receiving no nitrogen-carrying fertilizer and also on some of the plots 

 receiving nitrogen, though most such plots showed rather small concen- 

 trations at times. No nitrates were present on white clover areas on the 

 phosphorus-potash-lime plot. 



Study of Varieties of Tree Fruits. (J. K. Sliaw and O. C. Roberts). 

 The station continues to add new and promising varieties of fruits to its 

 test orchards. All the more prominent "bud sports" of apples are under 

 observation. There was an excellent crop on the new peach varieties 

 received from the New Jersey Experiment Station. Most of these are 

 promising and merit a trial b,v Massachusetts growers. There seem to 

 be among them varieties that are worthy to replace most of the varieties 

 now commonly grown with the exception of Elberta. The Ideal peach 

 of New Zealand, received from the United States Department of Agri- 

 culture, gave a heavy crop of attractive peaches that seemed promising 

 for home canning. The Newburgh raspberry, originated at the New York 

 Experiment Station, gives promise of being a desirable mosaic-resistant 

 variety. The Macoun apple seems to be a variety that shoidd be tested 

 generally in Massachusetts orchards. 



Fruit Bud Formation in the Strawberry. (K. .\. Van Meter). This pro- 

 ject was carried out as outlined in the last reixirt and a new bed, with 

 some modifications of treatment, set for fruiting in 1931. This bed in- 

 cludes, fertilizer treatments as follows: 



1. No nitrogen 



2. August 15, nitrate of soda 



3. August 15, sulfate of amnu)nia 

 1. August 15, urea 



5. September 15, nitrate of soda 



6. September 15, sulfate of ammonia 



7. September 15, calurea 



8. October 1, sulfate of ammonia 



9. October 15, sulfate of ammonia 



