32 OREGON WALNUTS 



Some branches will be shortened to eight or twelve inches, while 

 with others it will be advisable to let them grow from twelve 

 to twenty inches, according to the balance of the tree. It will 

 be necessary each year to thin out a few of the undesirable 

 branches that form bad angles, or have a tendency to grow 

 inward. 



After the trees come to bearing, about the only pruning 

 necessary will be to thin out the trees where they tend to become 

 too dense, and occasionally suppress some few of the leaders 

 that tend to become too rangy. It will also be found advisable 

 during the first few years to shorten back or remove some of the 

 branches that droop to the extent of interfering with tillage. 

 The great tendency of the walnut is to droop, and no matter 

 how well the trees are trained, one will always have to remove a 

 certain number of drooping branches. 



Pruning should be done preferably after the danger of 

 serious freezing is over and before the sap starts to flowing 

 strongly in the spring. For western Oregon, February is gen- 

 erally a very suitable month for walnut pruning. 



Diseases. 



There are a number of diseases that attack the English wal- 

 nut. The most serious of these is the walnut blight, known 

 scientifically as Bacteriosis. This is a bacterial disease and is 

 probably carried by insects. Its first appearance is noted in 

 early spring. On the leaves it starts in the form of black spots 

 which enlarge and generally cause some malformation of the 

 leaves, those attacked often bending towards the area affected. 

 Black patches will appear on the outer bark, often causing a 

 drying up of the young twigs and fruit spurs, killing them back 

 to the main branches. The damage to the tree, however, at 

 least in Oregon, is, as a rule, not serious ; especially is this true 

 of the better French strains. The greater damage comes from 

 the attack on the nuts. Small, black, irregular spots which 

 spread quite rapidly appear on the surface of the nut. When 

 these appear soon after the young nuts are formed, they will 

 generally cause a large dropping of the fruit. Those nuts 

 which do not drop often have their meats ruined by black decay. 



