86 MASS. EXPERIMENT STATION BULLETIN 355 



The Genetic Composition of Peaches. (J. S. Bailey and A. P. French.) In 

 the spring of 1938 an orchard of 288 selfed seedlings of Oriole was set in a low, 

 cold situation to let nature eliminate the less hard>' ones. It is hoped to obtain a 

 few seedlings of outstanding hardiness for use as new varieties or breeding stock. 

 At the same time a block of 240 selfed Elberta trees was planted to increase this 

 population. 



Some breeding was done in the spring of 1938 but little more will be done until 

 the present orchard land becomes available for replanting. 



On August 2, 1938, the "X disease" of peaches was observed in Massachusetts 

 for the first time by E. M. Stoddard of the Connecticut Agricultural Experiment 

 Station. A few days later it was found in both the college and station peach 

 orchards. Diseased chokecherries, which are always associated with diseased 

 peaches, were found near the orchards and a campaign started to eliminate them. 



The tropical hurricane damaged a number of trees both in the college and 

 station orchards. Some of the trees in the college orchard were set up and wired 

 in place. The small trees in the two seedling orchards set in 1938 were set up. 

 Blown -over trees in the other seedling orchards will be removed or severely 

 pruned and left so that one or two more crops can be obtained. Since this storm 

 blew ofif all fruit remaining on the trees at that time, no data could be obtained 

 on seedlings ripening after the 21st of September. This may have upset some of 

 the genetic ratios of fruit characters. 



An extraordinary case of inheritance of foliar glands has been observed in the 

 Gold Drop peach. The glands of this variety are neither typically globose nor 

 typically reniform. They might be described as "indeterminate". Gold Drop 

 when self pollinated gave 25 percent of the seedlings with globose glands and 75 

 percent with glands like the parent. When one of these globose gland type seed- 

 lings was crossed with Elberta, a pure reniform gland type, the offspring all had 

 glands of the "indeterminate" type. 



The inheritance of blossom size appears to follow a simple Mendelian formula. 

 Champion when selfed, gave 128 seedlings with large flowers, 268 with medium, 

 and 129 with small flowers, an excellent fit for a 1:2:1 ratio. Some other combina- 

 tions gave peculiar ratios which have not as yet been explained. 



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

 Certain changes in the fertilizer treatments of several plots were made in the 

 spring of 1938 to see if any changes in trends will appear in the behavior of the 

 trees. Plot 2, a sod plot which has had only nitrate of soda, received a complete 

 fertilizer, and plot 4 received potash in addition to nitrogen previously applied. 

 On most plots the amount of nitrogen was somewhat reduced. To plot 3, which 

 has never been fertilized, waste hay at the rate of about two tons per acre was 

 applied. This will be worked into the soil in the spring in an effort to build up 

 organic matter which has been reduced by 17 years of cultivation with very poor 

 cover crops. 



Several of the trees in this orchard suffered from the hurricane but all have been 

 replaced with the hope that they will not suffer severely from the injury. The 

 yields were rather low due to a poor set of fruit and possibly loss from the hurri- 

 cane, though all dropped apples were added to obtain the total yield. It still 

 appears that potash in addition to nitrogen is needed in this orchard, but evidence 

 of the need of added phosphorus is not yet clear. 



Comparison of Clover Sod and Grass in a Sod Mulch Orchard. (J. K. Shaw.) 

 The sawdust mulch applied to this orchard has failed to suppress the grass but has 

 resulted in no evident injury to the trees. It appears that much more than the 

 four-inch layer applied is necessary to make a covering that will function effec- 

 tively. Cost of transportation has prevented the addition of more sawdust. 



