HORTICULTURE. 1007 



June all the trees in this orchard died of dronglit during one of the wettest seasons 

 on record in Nebraska. 



In the study of the effect of cover crops on fall development and winter injury of 

 young peach trees, 2 orchards of 48 trees each were set, one orchard on bottom land 

 and the other on upland. Both orchards were given clean cultivation up to about 

 the middle of July each year, then each orchard was divided and one-third seeded 

 to oats, one-third to millet, and the remaining third given clean cultivation through- 

 out the fall. In 1901 all the trees on the upland stopped growth early in the fall 

 and no great difference was noticeable in the maturity of the wood of the trees in the 

 different plats. On the bottom lands the trees on the cover crop plats stopped grow- 

 ing about the middle of August, but growth was continued on the cultivated plat 

 until much later. The following spring it was found that many of the trees on the 

 bottom lands had been badly injured, half the trees on the late cultivated plats being 

 dead and the remainder seriously injured. On the cover-crop plats about half the trees 

 were badly injured, while the remainder were unhurt. Not a single tree was dead. 

 Aliout i more trees were injured where oats were seeded than where millet had been" 

 used. None of the trees on the uplands was seriously injured by the winter's cold, 

 though on the late cultivated plat nearly all the trees showed considerable brown 

 ciiloration beneath the ))ark. The results secured in 1902 are not yet complete. 

 They show, however, a better ripening of the wood on the cover-crop plats than on 

 tlie cultivated plats. 



In the third experiment 7 boxes, each 2 ft. square and 18 in. deep, 'were filled with 

 loam soil of varied water conhmt. In each box 25 apple and 10 cherry seedlings 

 were planted. Six of the boxes were set outdoors about the middle of December. 

 I lay was placed between and around the boxes and covered with soil. One box of 

 trees was stored in a cool, dry cave. Of those left outdoors one box was covered with 

 a mulch of straw 4 in. deep, one was protected with a covering of snow about 4 in. 

 deep whenever snow fell, and the remaining boxes were left without any covering, 

 snow being swept off when it came. The following February, when the boxes Avere 

 examined, none of the cherry roots had been injured enough to prevent their grow- 

 ing, and there was practically no difference in the degree of injury in the different 

 Ijoxes. The apple roots, however, were considerably injured, the greatest injury 

 occurring in the drier soils. 



Out of 25 apple trees set in the unprotected box containing 10.4 per cent of moisture, 

 20 trees were dead and 5 injured. In the unprotected box containing 15.2 per cent 

 of moisture, 19 trees were dead and 6 injured. In the box with a moisture content 

 of 19.8 per cent, 3 were dead, 10 injured, and 12 uninjured. In an un])rotected box 

 containing 25.6 per cent of soil moisture, 8 trees were dead, 4 injure<l, and 18 unin- 

 jured. The box covered with the straw mulch contained 16 per cent of soil moisture, 

 and none of the trees were dead in this box and but 7 injured. In the box covered 

 occasionally with snow, and containing 15.8 per cent of moisture, 7 were dead and 8 

 injured. Not a tree was injured in the box stored in a cool, dry cave, though it con- 

 tained but 10 per cent of soil moisture. This is believed to show that the winter 

 injury to apple roots is not alone due to dryness of the soil, but to cold and dryness 

 combined. The mulch was advantageous in preventing the alternate freezing and 

 thawing which took place in bare soils. A record is given showing the depth of 

 frost in bare ground and ground covered with a millet cover crop. 



In conclusion, the author states that a cover crop is one of the best means for pro- 

 tecting the roots of trees from winter injury. Likewise any method of culture that 

 leaves the ground moist in fall has an advantage over methods that leave the ground 

 dry. In the station experiments the soil under cover crops that have been killed by 

 early frosts has been as moist on the approach of winter as soils given clean cultiva- 

 tion throughout the fall. For the young orchard, thorough cultivation in early sum- 

 mer, followed by a cover crop in the fall, is advocated. 



