10 BULLETIN 756, U. S. DEPARTMENT OF AGRICULTURE. 
and plowed under green in the spring before the trees have started 
their growth. Just what procedure should be followed depends on 
the conditions connected with each orchard. But whatever the con- 
ditions may be, some definite and consistent soil-building policy 
should be adopted in the pecan orchards of the South if rosette is to 
be overcome and healthy productive orchards maintained. The pro- 
gram of work should involve the growing of one crop, preferably a 
legume, which may be returned to the soil. This procedure should 
be accompanied by the gradual deepening of the plow furrows until 
8 or 10 inches of surface soil is turned over annually. 
In this connection it is only necessary to add that intercrops which 
draw heavily on the soil moisture in the spring, such as oats, have a 
very undesirable effect on the trees by checking their growth, and 
they undoubtedly aggravate the disease. Consequently, such crops 
should never be allowed to mature in the orchard, but when used 
should be turned under about the time tree growth is starting. 
THE USE OF FERTILIZERS. 
Definite advice can not be given on the use of commercial fertiliz- 
ers until adequate experimental data are available. Meantime, it 
would appear from the experiments which have been conducted and 
from. the writer’s general knowledge of the situation that the best 
course to follow is to use them on such intercrops as may be planted 
rather than to attempt to produce healthy trees by the direct use of 
such materials. 
In these experiments, heavy applications of stable manure, cotton- 
seed meal and stable manure, and cottonseed meal alone, in connec- 
tion with legumes, have proved highly beneficial to rosetted trees. 
Inasmuch as the supply of stable manure is so limited, the orchardist 
must of necessity place his main dependence for soil improvement 
upon the consistent use of legumes or other crops which may be re- 
turned to the soil, together with the judicious use of commercial fer- 
tilizers to promote the growth of these crops. Legumes have the ad- 
vantage of adding nitrogen to the soil as well as increasing its humus 
content and water-holding capacity and are for that reason to be 
preferred to other intercrops for improving the soil. Whether the 
tops of such soil-building crops are to be turned under, grazed off, or 
cut for hay is largely a matter of economics, and the individual 
grower must determine which is the best course for him to follow. 
While the soil will be improved and the disease overcome more rap- 
idly by turning under the entire crop, it may be and probably would 
be the more profitable course in the South at the present time to uti- 
lize the tops for hay. 
