192 NEBRASKA STATE HORTICULTURAL SOCIETY 



The branches that should be removed are mainly those that Inter- 

 fere with other branches. An even distribution of branches is desir- 

 able with fruit spurs scattered well over each branch. A mistake often 

 made is by trying to accomplish the main part of the work from the 

 ground. The main limbs are stripped too well toward their terminals 

 where thick bunches of branches occur. Better start in the tops and 

 work downward thinning the branches of each limb even though 

 some of these main limbs are removed before the job is completed. 

 In selecting between two limbs that are crowding the most desirable 

 should be retained, keeping in mind conveniences in spraying, thinning 

 and harvesting as well as the relation of this limb to the amount of 

 sunlight and air admitted. Other things being eriual the lower one 

 should usually be retained. The general tendency at the present is 

 to grow low headed trees. Low headed trees are much more conven- 

 ient to spray and to harvest the fruit from and are more resistant 

 against winds and storms. The lower limbs should be barely high 

 enough to clear the ground when loaded with fruit. The weight of 

 the fruit gradually brings them downward and to offset this they must 

 be pruned annually to buds and twigs pointing upward. 



FIRE BLIGHT OF APPLE TREES. 



E. C. Stackiiian, Assistant Plant Pathologist, University Farm 



St. Paul, Minn. 



There is a great deal of twig and branch blight of apples this 

 year. The most striking characteristics are the browning of the leaves 

 and blackening of twigs. The dead leaves do not fall, but remain 

 on the tree, thus showing very clearly the position of diseased branches. 

 Upon close examination the blighted twigs or branches are seen to be 

 very distinctly blackened. Not only the smaler branches may be 

 affected, but also large limbs and, in some cases, even the trunks. 



Trees showing such symptoms as those described are usually affect- 

 ed with fire blight, so called because in severe cases whole trees may 

 appear to have been scorched. The disease is caused by a bacterium 

 and is very contagious. Usually the microbe is carried to the tree by 

 insects w^hich visit the flowers. When it is deposited on a flower it 

 multiplies very rapidly and the blossom is blackened and killed, this 

 phase of the disease being known as blossom blight. 



The infection may extend along under the bark, killing and black- 

 ening the twig, and often progressing into the branches. It may also 

 get into the trunk, either through' pruning wounds or through shoots 

 growing out from the trunk. It may then cause the socalled body 

 blight. 



Infection- takes place not only through the flowers, but also 

 through tender shoots, water spouts, suckers, or spurs. For this reason, 

 in orchards where the blight has gained a foothold, nothing should be 

 done which would encourage rapid growth. Unfortunately the same 



