PEACH GROWING 3 



most resistant condition, cannot withstand the cold and ail are killed. The killing 

 of fruit buds in this way is less frequent than in the other two ways. 



The temperature at which fruit buds are killed is uncertain. In some j-ears, 

 buds have been killed at a temperature of -10"F. In one j-ear buds were reported 

 to have withstood -20°. This difference is probably due partly to the internal 

 condition of the buds, but mostly to the weather conditions preceding the killing 

 temperature. Experience in the college and experiment station orchards indi- 

 cates that in most years -14° or -15° is the danger pomt at which buds are killed 

 regardless of their stage of development. 



Most varieties of peaches form many more fruit buds than can be developed 

 into mature fruits. Probably not more than five percent of the buds develop 

 into mature peaches, so that if ten percent of the buds are uninjured and are 

 well distributed over the tree, there are enough for a good crop. 



Investigation shows that increased hardiness is associated with increased storage 

 of reserve food material (carbohj-drates) in the tree, while decreased hardiness 

 is associated with increased storage of water and nitrogen. Therefore, the best 

 cultural practice is to (1) fertilize early in the sprmg, (2) cultivate thoroughly 

 through the early part of the season and then sow a cover crop, and (3) thin the 

 crop adequately to prevent overbearing. 



This treatment stimulates the tree to make a vigorous growth early in the 

 season and to store up later the maximum amount of reserve food material. But 

 the increased cold resistance gained in this way is slight. The greatest hope for 

 success lies in the careful choice of sites, in the planting of the hardiest of our 

 present varieties, and in the introduction of more hardy varieties. 



In Massachusetts, the wood of peach trees is less likely to be killed by winter 

 cold than aie the fruit buds. However, the wood may be killed in severe winters 

 under much the same conditions as the fruit buds. Hardiness of bud and hardi- 

 ness of wood do not always go together. Elberta, which is one of the tenderest 

 in bud, is one of the hardiest in wood. 



A peach tree will recover from moderate injury to the wood if proper remedial 

 measures are taken. It is best not to prune or fertilize the tree until the extent 

 of the injury can be observed accurately. If the injury is not too severe, the dead 

 parts of the tree should be removed and the remainder given a light detailed prun- 

 ing to stimulate growth. Thorough cultivation and liberal fertilization also help 

 the tree to outgrow the injury. Heavy pruning and fertilization may result in 

 the production of too large a leaf area. Then during a dry period in the summer 

 this excessive leaf area might demand more water than the reduced conducting 

 system could supply, and cause the death of the tree. The winter injured tree 

 should have very careful, and not extreme, treatment while recovering from the 

 injury. 



ESTABLISHING THE PEACH ORCHARD 



Sites and Soils 



The choice of a good site is a very important step in starting a peach orchard. 

 Since winterkilling is one of the greatest obstacles to peach growing in Mass- 

 achusetts, a site should be chosen where this danger is least. 



The ideal site is located on a gentle slope, high enough above the surrounding- 

 land (100 to 125 feet above the general stream level is gooci) so that cold air and 



