36 
Colorado Experiment Station 
the only place that the latter showed up was in the irription 
furrows An examination of this field early in July, 1919, showed 
only about 10 per cent, as much milkweed as had been present 
the previous year. The crop of wheat, which had just bpn re- 
moved was excellent and the milkweed had been so checked by 
shading that the grain was cut above the top of the milkweed 
plants, consequently there was none of the poisonous plant in the 
straw The field was- again plowed in August, 1919, and m bep 
tember, and again plajnted to wheat. Probably the best couree to 
follow in this case would be to fallow again m 1920 after tp re- 
moval of the grain and in 1921 to sow hpvily to allalfa, the ob- 
ject being to get in a crop as soon as possible that will completely 
take the ground. 
EEADICATION ON ROCKY HILLSIDES 
The most difficult problem from the eradication standpoint is 
presented by the occurrence of the whorled milkweed on the rocky 
hillsides below irrigation ditches. This condition is reprerented 
in Figure 27. The hillside shown is between Paonia and Hotch- 
Fip:. 27 — Milkw2ed on hillside below ditch on driveway 
between Paonia and Hotchkiss. 
kiss in Delta County on a main stock driveway. This condition is 
prevalent for twelve or fourteen miles in this particular locality. 
The formation is as shown in Fig. 28. The ditch here shown is at 
