HORTICULTURE 35 



danger of injury. Using a short whiffle-tree either with leather ends 

 or having the ends covered with burlap protects the trees from bark- 

 ing. 



All the soil possible should be turned and that which cannot be 

 reached with the plow conveniently, should be stirred with the cul- 

 tivator later on. At times when the cover crop leaves but little vege- 

 table matter on the soil in the spring, or when it is well decayed by 

 time for beginning cultivation, the cut-away or disc harrow may be 

 substituted for the plow. Plowing or discing is best followed by har- 

 rowing. The number of times the orchard should be harrowed de- 

 pends somewhat upon local conditions. After putting the soil in* 

 good tilth following the plowing, the orchard should be harrowed 

 at least every two weeks. The object to be attained in this cultiva- 

 tion is to keep a good dust mulch on the surface to conserve the mois- 

 ture, and incidentally to keep down the weeds. 



Harrowing should follow each rain as soon as the soil is suffi- 

 ciently dry to work. Not only does this help conserve the moisture 

 from the rain, but if the dust mulch which has been destroyed is not 

 replaced, not only that which has recently fallen, but also additional 

 amounts previously held in the soil will be speedily lost. Cultivation 

 is valuable during periods of drought. Many growers believe that 

 because no rain has fallen since the last cultivation, that it is a waste 

 of time to harrow again. Repeated moisture determinations made 

 during a period of drought of frequently cultivated and uncultivated 

 soils but in all other respects similar show that the cultivated areas 

 retained much more moisture than the uncultivated. 



Cultivation of the orchard soil is not only valuable as a means 

 of conserving moisture, but it hastens the availability of food ma- 

 terials in the soil and provides for good aeration, both of which are 

 of so great importance. "Remember that cultivation is essentially 

 manure." This quotation from the late Dr. Kedzie is indicative of 

 the value of cultivation a.s a factor in the availability of plant food. 



When to Sow Cover Crops. The time at which cultivation shall 

 cease and the cover crop be sown is very largely a matter of judg- 

 ment. It depends almost entirely upon what soil moisture conditions 

 are during the latter part of July, and what they are likely to be dur- 

 ing the remainder of the season. One of the chief objects of the 

 cover crop is to assist in controlling the moisture content of the soil 

 during late summer and early fall. If there are large amounts of 

 moisture in the soil during this period, there is danger of new wood 

 development continuing so long that it goes into winter only par- 

 tially matured, and is very likely to winter kill. On the other hand 

 reducing the quantity of moisture in the soil tends to hasten ma- 

 turity and avoid unfavorable conditions. 



It will be seen then that in a season in which there is heavy 

 rainfall or probability of heavy rainfall during August and Septem- 

 ber, that a rapidly growing cover crop becomes an effective means of 

 reducing the moisture content of the soil. In seasons of drought, the 

 cover crop will make proportionately less growth and not prove in- 

 jurious to the trees. In wet seasons the cover crop should be sown 



