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the root knot. The occurrence of such diseases is an indication of nature's demand 
for rotation, and we should heed her call by changing the legume we employ in our 
rotation from time to time. Lei the velvet bean, beggar weed, or crimson clover 
take the place of the cowpea occasionally, even though we have the disease-resistant 
Iron cowpea available. 
Another instance where rotation affords an easy remedy for a serious disease is 
found in Texas, where a fun-jus root rot, formerly known as Ozonium, causes much 
injury to cotton, alfalfa, and other plants. This malady is readily controlled by 
rotation with corn, grasses, or other immune crops for three or four years. 
ROTATIONS FOB 0BCB LRDS. 
Peach orchards in Georgia and Florida are frequently troubled by root knot and 
fungus root diseases, and a long-course system of rotation is required. First, before 
planting the orchard two or three years should he given to five the land of root 
knot and put it into good condition by planting oats, velvet beans, corn, and Iron 
cow peas or beggar weed. Then, during the life of the orchard the intercultural and 
cover cn.ps should he those not subject to root knot. Finally, after the orchard is 
taken out, a period of live years should he given to renovate the land and free it 
from root knot and fungus diseases. Root rot from the attacks of fungi is to be 
feared where peaches are replanted too soon. 
ROTATIONS FOR NURSERIES. 
Rotation in the nursery is particularly important in view of the prevalence of root 
knot, crown gall, etc., in nurseries, and the danger to the public of spreading these 
diseases. If possible, fresh land should always he taken for growing nursery stock. 
Three years of the right rotation would he sufficient lor root knot, hut the time 
crown gall will persist in the land has not been determined, and it would he safer if 
rive years were allowed. 
ROTATIONS FOR TRUCK FARMS. 
Where early vegetables are grown for the northern market, it is often of great 
importance that a rotation should be practiced to avoid plant diseases. Particular 
instances are: (1) Potatoes: To avoid scab and stem rot (Rhizoctonia) . Disinfection 
of the seed will not avail when the soil is full of disease germs. (2) Cabbages: To 
avoid black rot and the Fusarium wilt, cabbages should not come oftener than once 
in three years, and a longer period would do well. 
Other truck crops will be benefited in the long run by a regular system of rotation. 
In conclusion, 1 wish to urge a greater interest in th s subject of crop rotations in 
the South not only for controlling plant diseases, but for all the other objects as 
well It is very important that careful experiments he made, and even more impor- 
tant that extensive practical demonstrations he undertaken to show the farmer the 
necessity of the work and the methods of doing it. 
After a brief discussion of the paper, F. F. Stevens (North Carolina) read the fol- 
lowing paper: 
Notes on Cooperative Experiments. 
Cooperative experiments may be divided fundamentally into two classes according 
to the purpose they serve. Their purpose may be first to uncover unknown truths 
and to extend knowledge; second, to demonstrate to practical farmers methods the 
efficiency of which is already known to the scientist. In weighing the efficiency of 
cooperative experiments these two categories should he clearly recognized. The 
value of cooperative experiments for demonstration should not be underestimated. 
Investigators in the pursuit of new truths labor unceasingly to add to the store of 
knowledge, and then too often abandon the newlv discovered facts before pushing 
them on to practical utility. The experiment stations have accumulated volumes of 
information which would lead to immense improvement in methods of farming and 
accrue to the great financial interest of the agricultural community, if the farmers 
could only be brought to realize their value. Results of research are published at 
great expense in bulletin form, yet only to meet too often a fate known to us all. 
The former is conservative. He is prone to follow in the steps of his grandfather, 
and the bombardment of bulletins seldom suffices to turn him from his course. 
One of the greatest needs of the present day is some means that will bring the 
advancement of science within the ken of the farmer in so far as it relates to his 
vocation. With the younger generation the chief hope lies in agricultural education. 
