50 MASS. EXPERIMENT STATION BULLETIN 398 



Tree Characters of Fruit Varieties. (J. K. Shaw, A. P. French, O. C. Roberts, 

 and L. Southwick.) The usual examination of commercial nurseries for trueness 

 to name was made in the summer of 1942. While occasional new mixtures were 

 found in inspected nurseries, the number of misnamed trees was small compared 

 with earlier years. As the work was extended mixtures were found in cherries, 

 pears, and plums. Increased attention is being given to peaches and thousands 

 of misnamed peach varieties are being eliminated although it is not possible to 

 give this as complete a service as other tree fruits. The only way to be sure 

 that peach varieties are invariably true to name is by the maintenance of a scion 

 orchard, known to be correctly named, as a source of renewal of budding stock. 



Comparison of Cultivation and Sod in a Bearing Orchard. (J. K. Shaw.) 

 Of the cultivated plots, one is now under the mulching system and is reported 

 under the following project. Another which had ho fertilizer from 1921 to 1927, 

 but has since received nitrate of soda at the rate of 300 pounds per acre, has 

 developed symptoms of both potash and magnesium deficiency. If potash is 

 applied to correct this deficienc\- a magnesium deficiency will appear on soils not 

 well supplied with this element. Where nitrate of soda alone is used over a period 

 of years a potash deficiency appears on our soils under cultivation after about 10 

 to 15 years. 



One of the sod plots of 10 trees which had been fertilized with nitrogen alone 

 has received a N-P-K fertilizer and another similar plot a N-K fertilizer for the 

 past four years. These plots now show a difference in yield, with the N-K plot 

 yielding best. Both plots have increased fields over the period when nitrogen 

 alone was applied thus dispelling, at least to this extent, the general contention 

 that only nitrogen was necessary as an orchard fertilizer. 



Comparison of Cultivation and Heavy Mulching of Apples. (J. K. Shaw.) 

 The plot of nine Wealthy trees which had been mulched for 20 years continues to 

 show superiority over the similar adjoining plot which has been under cultivation 

 and cover crop, although no additional mulch has been applied for the past four 

 years. There is still a thick layer of decaying mulch through which grasses, 

 mostly quack grass, grow luxuriantly. General observations suggest that when 

 a young orchard is planted immediately following the reinoval of old trees, much 

 attention should be given to building up the soil which has been exhausted of 

 organic matter and nutrients, because it is concei^•able that old trees may be able 

 to maintain themselves quite well on a soil so deficient that newly planted trees 

 are unable to establish themselves and special fertilization should be provided. 



The two plots in the 14-year-old Mcintosh clonal stock orchard near by were 

 mulched as last A'ear and the yield was significantly greater than that of adjacent 

 trees in a Ladino clover sod. No fertilizer has been applied since mulching began; 

 while the trees in the clover have received moderate applications of nitrogen and 

 potash. The foliage on the mulched plots was of a deeper green color and per- 

 sisted longer in the fall than on the adjacent trees. No signs of a nitrogen de- 

 pression have appeared on these mulched plots following the application of liberal 

 amounts of higher carbohydrate material. 



The Effect of Orchard Mulches on the Plant Nutrients in the Soil. (J. K. Shaw 

 in cooperation with the Chemistry Department.) This project was continued by a 

 second application of hay mulch under the mulched trees and collecting soil samp- 

 les for analysis as last year. Grass growing up through the mulch of glass wool 

 was suppressed. No differences in the behavior of the trees was observed. The 

 objective is the study of the behavior of nutrients in the soil. Further comments 

 may be found among the Chemistry projects. 



