14 BULLETIN 1104, U. S. DEPARTMENT OF AGRICULTURE. 



foothill and inland orchards have relatively a somewhat higher 

 temperature, more sunshine, and lower humidity. 



For several years fruit has been gathered from orchards located 

 well up on the hills, above the fog belt, and also from several dif- 

 ferent orchards down on the floor of the valley. The fruit from 

 these different orchards has been handled in the same way, stored 

 under similar conditions, and inspected in the spring to determine 

 the distribution of orchards producing fruit which tends to brown 

 internally during storage. This fruit has been compared with 

 Yellow Newtown apples from Virginia and from the Yakima and 

 Wenatchee districts of Washington. 



Some internal browning has been found to occur in Yellow New- 

 town apples from' all these fruit-growing sections as well as from 

 all parts of the Pajaro Valley apple district. From the sections 

 outside the Pajaro district, however, and in the hill orchards in 

 that district, internal browning has been found only to such a 

 small extent as to be of little importance in a commercial way. 

 Only in fruit from the orchards on the floor of the valley, in the 

 summer fog belt and growing in soil of very high fertility, has this 

 trouble been particularly serious. These observations are based on 

 the inspection of hundreds of boxes of fruit extending over several 

 years. The detailed records of these inspections are much too 

 voluminous to be included in this bulletin. 



RELATION OF INTERNAL BROWNING TO SOIL FERTILITY AND FERTILIZERS. 



In order to determine whether internal browning is related to 

 any soil deficiency either of an organic or of an inorganic con- 

 stituent, a series of fertilizer plats was laid out in 1917 and initial 

 applications were made. Three plats were established, trees outside 

 the plats receiving no fertilizer treatment serving as a check. Each 

 plat contained 15 trees. 



Plat 1, known as the nitrogen plat, received 10 pounds of am- 

 monium sulphate per tree in 1917. As the trees were very large 

 and no appreciable response could be detected from this treatment, 

 the quantity was increased to 20 pounds in 1918. In 1919 sodium 

 nitrate was used instead of the ammonium sulphate, and in 1920 

 20 pounds of ammonium sulphate were again added. 



Plat 2, the manure plat, was started in the spring of 1917. Soil 

 was removed from around the trees in an area equal to about the 

 spread of the branches, and about a ton of barnyard manure was 

 applied at the base of each tree. In addition, 20 pounds of steamed 

 bone meal, containing about 20 per cent of phosphoric acid and 

 4 per cent of nitrogen, were added for each tree. Thus, each tree 

 in the plat was very heavily fertilized with phosphoric acid, nitro- 

 gen, and organic matter, while considerable potash was available 

 in the manure. No subsequent applications of fertilizer were made. 



