PEAR DISEASES 



1641 



stood, however, that the above practice 

 would not be at all advisable in most 

 Pacific coast districts, where there is a 

 shortage of soil moisture. There are 

 localities, however, where it may on some 

 occasions become necessary to make use 

 of cover crops in this way. The use of 

 cover crops on the Pacific coast should be 

 for a wholly different purpose, namely, 

 to add fertility to the soil as well as to 

 change its physical condition; in fact, 

 the use of cover crops may be considered 

 to serve the same purpose as stable 

 manure in making the soil more easily 

 tilled and rendering it in better condi- 

 tion for giving up plant food. Cover 

 crops of vetch or field peas, of course, 

 add nitrogen to the soil, and, from this 

 standpoint, it is perhaps better that these 

 leguminous plants should be used in pref- 

 erence to rye, or any of the grains or 

 grasses. On some soils such cover crops 

 as rye or wheat do not give the best re- 

 sults, especially on the sticky soils. It 

 usually takes a great deal of labor to 

 produce a good soil mulch after turning 

 under a crop of rye. 



The rule in the pear orchards of the 

 Eastern states has been to keep the trees 

 in a half-starved condition for fear blight 

 would destroy them. Orchard treatment 

 of this kind naturally renders the fruit 

 less luscious and with a distinctly poorer 

 flavor than fruit grown under good cul- 

 tivation. While I would advise a good 

 deal of caution in producing a too vig- 

 orous or sappy tree, when there is se- 

 rious danger of destruction by blight, I 

 would not advise the pear and apple 

 growers of the Pacific coast to starve or 

 under-cultivate or under-prune their 

 trees; but I do mean to say that they 

 should practice moderation in all these 

 things. This is especially true in dis- 

 tricts where the blight is new to them, 

 and where they are not thoroughly ac- 

 quainted with the methods of eradicating 

 it from their orchards and keeping it 

 under control. Pear blight is so different 

 from all other orchard diseases, which 

 respond so readily to spray treatments, 

 that it has been the general rule for 

 whole communities, and even states, to 



lose all their orchards before being 

 brought to a realization of the necessity 

 for studying the disease carefully and 

 obeying to the letter the instructions for 

 combating it. 



Losses from Blight 



Mention has been made of the enor- 

 mous losses in the pear districts of the 

 San Joaquin valley, California. In the 

 short space of three years, from 1900 to 

 1904, almost half a million pear trees 

 were lost by blight. Practically no at- 

 tempt was made to check the disease, 

 and one of the greatest industries of the 

 San Joaquin valley vanished like a 

 dream, even before the people realized 

 what had befallen them. As in other 

 localities, east and south, the growers 

 had a self-sufiicient and self-satisfied feel- 

 ing that blight could never hurt them. 

 They had grown pears for a quarter of a 

 century and more, and such a thing as 

 blight entering their valley was just as 

 impossible as anything one might im- 

 agine. 



In all that time, thunder, lightning, 

 excessive heat, cold, etc., had caused not 

 the slightest injury. However, as soon 

 as blight came, all the factors mentioned 

 above seemed to explain their predica- 

 ment fully; they needed no help and 

 spurned assistance. This is the story, in 

 a few words, a story which might be told 

 of many other localities which had suf- 

 fered the same calamity. 



In 1904 the blight invaded the pear 

 district of the Sacramento valley, and 

 although some little work was done in 

 the matter of eradicating it, the efforts 

 were weak and ineffective. Prominent 

 men in the state became alarmed and 

 the pathologists of the United States De- 

 partment of Agriculture were called to 

 the Coast, In the fall of 1904 Professor 

 M. B. Waite made his first visit to Cali- 

 fornia and inaugurated a plan of cam- 

 paign for eradicating it, or at least keep- 

 ing it under control. The Government 

 pathologists did not come to the Pacific 

 coast until they were called. Such influ- 

 ential men as Ex-Governor Pardee and 

 prominent Southern Pacific officials ap- 



