WEEDS AND GRASSES IN ORCHARDS 



351 



is the chief cause for the spread of weed seeds. Much care must be 

 exercised to prevent spreading weeds. 



Losses from Weeds.— There are several sources of loss due to 

 weed growth. (1) They rob the crop of the plant food which it 

 needs; (2) they use the moisture which the crop should use; (3) 

 they crowd and strangle the crop; (4) they often poison soils and 

 make them unsuitable for the crops. 



Fig. 249 



Fia. 250, 



Fia. 249. — Black Mustard: 1, top of plant; 2, seedling; 5, seed small and enlarged. 

 (Minnesota Station.) 

 Fio. 250. — Five-Finger; 1, top of plant; 2, seedling; 3, seedling somewhat older; 4, separate 

 leaf; 5, seed enlarged. (Minnesota Station.) 



It may be said that weeds are beneficial in some respects. They 

 cause the owner to till the soil when otherwise he might neglect 

 it. Some are good for feeding pigs or other stock, prickly lettuce 

 (Fig. 247), pig weeds and others are relished by swine. 



Weeds and Grasses in Orchards. — It has already been shown in 

 this volume that orchards should have a cover crop started about 

 the middle of July or first of August. The purpose of this is to 

 check the wood growth of the trees and cause them to ripen there 



