350 



PEAR GROWING IN CALIFORNIA. 



should not stop with the removal of the blighted bark only, ))ut should 

 be continued well into the healthy bark in order that all the germs may 

 be removed. 



The fight against blight is by no means confined to the tops of the 

 trees; in fact, if the roots were not also affected by the disease, its 

 control would be a comparativelj^ easy matter. Blighted roots are 

 common in practically every orchard where blight occurs. It may enter 

 the roots in different ways. Careless plowing, whereby portions of bark 

 are removed from the crowns of the trees, creates a fine starting point 

 for infection. Sprouts allowed to grow from the roots about the crowns 

 blight readily and carry the disease to the roots. Such sprouts are 

 very common in cases where the French root (Pyrus communis) is used. 

 Figs. 148 and 149 are good illustrations of crown and root work in 

 blight control. The excavation about this tree was large enough so that 

 a man could very conveniently work within. By means of a small 

 hatchet and bark-scraping tools the bark was removed from most of the 

 crown and from the major portions of some of the larger roots. This 

 work is not only laborious but very expensive and many an orchardist 

 would hesitate about putting in so much time and expending so much 

 money on one tree. The owner of the orchard where these pictures were 

 taken has had much experience in blight control work and he considers 

 that it pays to have a man spend a day or more working on one tree if 

 by doing so he can save it to produce 

 regular crops as they do even when 

 badly mutilated as in the pictures 

 shown. 



A constant fight is necessary in 

 some of the larger California pear 

 orchards and men are hired who do 

 nothing else throughout the season 

 except blight control work. Such men 

 should not only have a more or less 

 technical knowledge of the disease, 

 but should also know every detail in 

 connection with the practical phases 

 of eradication or control. Constant 

 work with the disease soon enables one 

 to detect its presence even though it 

 may be inconspicuously located. The 

 need of reliable men who take an 

 interest in their work is apparent, and 

 some of the more progressive pear 

 growers hire experts who supervise 

 the work of blight control. 



Pig. 148. View of the crown of 

 same pear tree shown in Fig. 149, 

 taken from another side. 



Disinfection of Tools and Cuts. 



Failure to realize the importance of the disinfection of tools and 

 cuts means at least partial failure in the fight against blight. There 

 must be a recognition of the fact that the disease is due to exceed- 

 ingly minute bacterial organisms which are easily and surely trans- 

 ferred from one cut to another in the process of removing blighted 



132 



