i 6 
The Colorado Experiment Station. 
irrigation, and with the method of watering commonly used, it is 
often impossible to, touch these soils with the cultivator from the 
first watering in early summer until the following spring. 
It is often the case that shallow furrows and a large head of 
water are used and the result is a flooding of the whole surface. 
When dry enough to work again, the soil has run together and the 
surface is so hard that it is impossible to cultivate it, and the grower 
resorts to frequent watering to keep the orchard going. In these 
soils the water settles slowly and a smaller head run in deeper 
ditches would no doubt prove more satisfactory. 
I think growers with these heavy adobe soils should also re¬ 
sort to the planting of cover crops to improve soil texture 
They could gradually be brought into shape where they 
could be more easily handled after irrigation. Growers, as a rule, 
pay too little attention to the sub-soil. Too often, the rule follow¬ 
ed is, if you can kick up dust on the surface, irrigate. The ap¬ 
pearance of the tree indicates to a great extent its needs, but after 
all, it is an examination of the sub-soil which, most surely deter¬ 
mines whether the orchard needs water or not. 
General rules which it might be well for growers tc follow in 
applying water are as follows : 
The more sandy the soil, the greater the number of ditches, 
the shorter the run in both time and distance. 
The longer the ditches, the larger the head. 
The stiffer the soil, the fewer and deeper the ditches, the long¬ 
er the run in time and distance, and the smaller the head. 
PROBLEMS FOR THE ENSUING YEAR. 
Some of the problems for the coming year as brought out by 
this season’s work are as follows: 
Pear Blight and its control, giving especial attention to tne 
form known as blossom blight in apples. 
Peach mildew and the effects of lime-sulfur wash as a winter 
spray in comparison with Bordeaux mixture. 
Grape mildew (Uncinula spiralis) and its control and the ef¬ 
fect of winter and summer spraying. 
Observations on grape growing in general with reference to 
watering, pruning, packing and shipping. 
Further study of the root-rots of apples to determine, if pos¬ 
sible, the causes and remedies. 
