I20 



Journal of Agricultural Research 



Vol. XII, No. 3 



Table V. — Percentage, according to size, of Grimes apples affected with bitter-pit. 



October i8, IQ16 



The large apples were much more susceptible to bitter-pit than the 

 small ones, but evidently size can not be taken as a measure of sus- 

 ceptibility, since the small apples on the heavily irrigated plats often 

 developed more disease than the large ones on the lightly irrigated ones. 

 (Table V; fig. 6.) A study of the table shows, however, that the same 

 soil conditions that favored bitter-pit also tended to increase the size 

 of the fruit, the plats standing in practically the same order as to 

 percentage of apples larger than 3X inches as they do in percentage of 

 bitter-pit. 



EXPERIMENTS ON JONATHAN APPLES IN 1915 



Irrigation experiments were made on Jonathan apples similar to those 

 already reported on Grimes. The work was carried out in an orchard 

 at Wenatchee, Wash. The soil was a rich gravelly loam, with a con- 

 siderable percentage of clay, underlain at a depth of i6 inches with 

 a layer of medium fine gravel. For several years previous to the 

 beginning of the experiments the orchard had been heavily manured with 

 slaughterhouse refuse, and during the time of the experiments it was 

 kept in alfalfa. The trees were 6 years old, and there were 5 trees in 

 each plat. The experiments were begun in 191 5. Breaks in the irri- 

 gation canals at various times and a rainstorm on July 26 made it impos- 

 sible to secure much contrast in the different plats before the first of 

 August. All the trees but those of plat i were extremely dry the latter 

 part of June and the first half of July. A further report of this condition 

 is given later in this paper under the head "Drouthspot." There was 

 a shortage of water several times in August, plat 5 suffering severely 

 from drouth at this time and finally losing more than 75 per cent of its 

 foliage and considerable of its fruit (PI. 4, B). Plat 3 suffered from 

 drouth the latter part of August, but no defoliation occurred. Plat 2 

 was practically as wet as plat i during the latter part of July and first of 

 August, but became quite dry about the middle of August. The moisture 

 conditions for the season are given in figure 7. 



