tits 
Effects of Crops on 
n growth of tobacco plants in pots. At 
left, effect of tops of potatoes. Pot i] 
iem to depress growth, while the tops a 
,s were obtained with tops and roots of 
imparative effects of tops and roots of hairy vetch on growth of tobacco in the field. Row in 
jenteris a control to which no vetch material was added. Row to left of center received tops 
>f fresh vetch plants, and row to right of center received roots of vetch plants applied to the soil 
ibout seven weeks before transplanting the tobacco. A beneficial action is shown by the tops 
