420 REPORT OF OFFICE OF EXPERIMENT STATIONS. 



In pot experiments, lie found that when cert am plants like oats, 

 blue grass, mustard, or potatoes were used as cover crops for seedling 

 peaches the trees ripened their wood long before there w as sufficient 

 frost to injure the foliage. When, however, such plants as crimson 

 clover, peas, and beans w'ere used as cover crops the leaves remained 

 on the trees green and luxuriant vmtil killed hj severe frost November 

 1. These leguminous plants proved a perfect failure so far as ripening 

 the wood and preparing the trees for winter were concerned. An 

 examination of the root growth in the pots showed that the root 

 systems of the trees and the plants in the case of the nonleguminous 

 group were not at all intimate, but in the case of the clover and the 

 peaches the roots were so intermingled that the}^ matted together 

 and could not be easily separated. From a practical standpoint, 

 therefore, where the object of the cover crop is to hasten the maturity 

 of the tree, cereals would probably prove much more effective than 

 legumes, especially crimson clover. These results suggest a line of 

 w^ork with cover crops that might prove very useful to peach growers. 



At the Nebraska Station'' the use of cover crops induced the peach 

 trees to ripen up from a few weeks to two months earlier than trees 

 given continuous cultivation throughout the season. At that station 

 and in other Western States it is A^ery desirable that the ground be 

 well filled with moisture when freezing weather comes on, as the trees 

 continue to evaporate moisture throughout the winter. On this 

 account it is desirable to use a cover crop that will be killed b}' the 

 first severe frosts of the fall, otherwise its contimuMl growth woidd 

 result in drying out the soil, so that moisture available for the tree 

 during the winter would be reduced below the danger limit. The 

 crop should also be such as will stand up well during the winter to 

 catch and hold the snow in order thus to prevent deep freezing of the 

 ground and to retain as much moisture as possible. ^lillet has proved 

 exceptionally well suited as a cover crop at that station for these 

 various reasons. 



In experiments in mulching at the California Station'' the apjdi- 

 cation of a nudch of fresh barnyard manure early in the season served 

 better for conserving moisture than did a mulch of cultivated earth. 



WINTER IRRIGATION. 



A. J. McClatchie found that better results are secured with peaches 

 and apricots in the irrigated regions of southern Arizona" if the 

 orchard is irrigated in winter when water is a])un(lant and the trees 

 dormant than if tiie water is applied only during the growing season. 

 Peaches and apricots made branch growths of 3 to 6 feet per season 



oNebra.ska Sla. I'.ul. 7!». ''(."iilifornia Sta. Kpt. lS<».j. p. 401. 



<: Arizona Sta. Bui. .37. 



