PEAR GROWING IN CALIFORNIA. 



357 



il Pyrus variolosa This species is one of the 

 most promising types in our collection. The 

 tree is a beautiful, vigorous, upright grower. 

 It makes a good union with our cultivated 

 varieties and should prove valuable as a stock 

 for topworking. This species, while not 

 immune to blight, is very resistant. During 

 the summer of 1915 a large number of inocula- 

 tions were made into the tips of young 

 branches, and these usually would blight back 

 for a distance of three to five inches. During 

 1916, a very favorable season for pear blight, 

 the disease would extend down young branches 

 as much as twelve to eighteen inches, and in 

 one case as much as two feet. Seventy-seven 

 inoculations were made into the trunks of two- 

 year-old trees. All but seven of them failed to 

 develop the disease. In the successful infec- 

 tions, only small superficial cankers were 

 produced. In these cankers a new cambium 

 would readily form, and the entire wound 

 would heal over perfectly in a short time. 



"The origin of this species or type is still 

 a matter of dispute. . It has been confused 

 with Pyrus pashia of northern India, from 

 which species it is very distinct. Pyrus 

 variolosa produces medium-sized, pear-shaped 



fruits, which have a persistent calyx. It is possible that this is not a 

 distinct species, but a hybrid. If this should prove to be the case it 

 probably will not come true to type from seeds. This matter will be 

 determined by a study of the seedlings of this type. If this does not 

 come true to type from seeds, the seedlings will be of little value for 

 a root stock. If this should prove to be the case, it will, nevertheless, 

 be of value as a stock for topworking, when propagated by budding 

 or grafting on some other root system. 



" Pyrus ovoidea, Rehder This ranks second only to Pyrus ussuriensis 

 in blight resistance. During 1915 we were unable to get the disease to 

 develop more than four inches even in vigorous-growing shoots of the 

 species. During the very favorable season of 1916 vigorous shoots would 

 blight down as much as fifteen inches. As soon as it reached the hard 

 wood of the previous season it would stop. All the inoculations into one 

 and two-year-old trunks have failed to develop the disease. 



"The trees are vigorous growers, and produce medium-sized fruit, 

 which is egg-shaped, and has a persistent calyx. This species is a native 

 of northern China, and was formerly known as Pyrus simonii." 



Not only is it desirable to secure a root that possesses a high degree 

 of resistance or immunity to blight, but also a trunk which will not 

 develop the disease to any extent. While the Kieffer is more resistant 

 than others of our well-known varieties it often blights badly. In 



FIG. 153. Leaf of Pyrus 

 variolosa. 



139 



