274 POMOLOGY 



ter injury in some sections. Frequently high wind velocity 

 will accompany low temperatures and if the soil is not well 

 protected by a covering of snow or of vegetation, it will 

 diy out to the point at which root injury is extensive. The 

 twigs and buds may also be injured to a greater extent under 

 such conditions, and it is connnonly supposed that their 

 tissues are directly dried out by the action of the wind. It 

 is more probable, however, that these tissues experience a 

 drying to death due to the water supply being shut off by 

 the freezing of the roots. 



ORCHARD PRACTICES 



244. Cultivation.^ — As indicated above, the chief factor 

 in hardiness of fruit-trees is their maturity before going into 

 winter condition. Therefore, in sections in which winter 

 injury is likely to occur, the orchard practices should be 

 such as to obtain a good growth and yet allow the wood and 

 buds to mature before winter. In a cultivated orchard the 

 tillage should stop by the first or middle of July in most dis- 

 tricts (except when it is an advantage to delay the rest- 

 period). A cover-crop should also be sown at the time of 

 the last cultivation as it has a twofold function in relation 

 to winter injury, (1) by sei^ving to withdraw any excess mois- 

 ture in the soil and hence aid in maturity of the trees; and (2) 

 by acting as a mulch to prevent such deep freezing, and al- 

 ternate freezing and thawing as would occur if the land were 

 bare. Emerson ^ and others note the effects of various 

 cover-crops on depth of freezing in orchards. They show 

 that in a season of snowfall corn or cane is a good crop for 

 the orchard as it holds the snow to good advantage, while 

 in a season of no snow such crops as mat down well will af- 

 ford the greatest protection. 



1 Neb. Agr. Exp. Sta. Bull. 92. 1906. 



