not have more open lenticels in 1939 than that from some of the other 

 lots; so the large number of infections cannot be explained on that 

 basis. The fruit from the Wiley Heights orchard was poorly shaped in 

 both 1939 and 1940, but it was considerably larger in 1939. In 1939 

 these apples were highly susceptible to infection when dipped in a 

 suspension of spores , but when they were not inoculated no decay 

 developed (fig. 3). These results can be explained on the presump- 

 tion that the natural spore load carried by the fruit was very light. 



Table 6. — Relation of orchard source to the susceptibility of Delicious apples inocu- 

 lated with blue mold 



[Fruit harvested Oct. 2, 1939, and Sept. 25, 1940; total decay for March 18, 1940, and March 14, 1941, respec- 

 tively. All fruit, except as indicated, dipped in a spore suspension, packed, and stored at 32° immediately 

 after washing. All temperatures in ° F.] 





Infections 1 in fruit from indicated orchard 



Time of washing 



Tieton 



Lower 

 Naches 



Naches 

 Heights 



Selah 

 Heights 



Wiley 

 Heights 





Len- 

 ticel 



Other 



Len- 



ticel 



Other 



Len- 

 ticel 



Other 



Len- 

 ticel 



Other 



Len- 

 ticel 



Other 



19S9 2 



Num- 

 ber 

 15 

 12 

 1 

 6 

 

 



Num- 

 ber 

 28 

 44 

 11 

 13 

 4 

 7 



Num- 

 ber 

 19 

 8 

 9 

 23 

 10 

 12 



Num- 

 ber 

 26 

 34 

 11 

 19 

 8 

 10 



Num- 

 ber 

 14 

 18 

 5 

 38 

 12 

 16 



Num- 

 ber 

 34 

 39 

 22 

 35 

 17 

 24 



Num- 

 ber 

 22 

 16 

 6 



35 

 9 

 8 



Num- 

 ber 

 37 

 41 

 14 

 27 

 10 

 12 



Num- 

 ber 

 54 

 43 

 15 

 75 

 19 

 22 



Num- 

 ber 

 46 



Day after harvest 3 _ 



45 



After 3 days in warehouse 



After 2 weeks at 32° . 



26 

 38 



After 6 weeks at 32° 



20 



After 10 weeks at 32° 



20 









5.7 



17.8 



13.5 



18.0 



17.2 



28.5 



16.0 



23.5 



38.0 



32.5 







mo* 



Day after harvest _ _ . . _ _ . . _ . 



8 

 8 

 5 

 3 



10 

 12 

 10 

 1 



25 

 14 

 27 

 21 



15 

 11 

 19 

 14 



26 

 8 

 26 

 17 



19 

 14 

 17 

 17 



26 

 16 

 24 

 16 



20 

 14 

 14 

 12 



10 

 2 

 2 



1 



10 



After 3 days in warehouse 



After 2 weeks at 32° 



10 

 14 



After 6 weeks at 32° 



5 









6.0 



8.3 



21.8 



14.8 



19.3 



16.8 



20. 5 



15.0 



3.8 



9.8 







i Total found in 150 fruits; in 1939, 3 lots of 50 fruits each were used; in 1940, 4 lots of 50 fruits each were 

 used, and the results were reduced to a 150-fruit basis. 



2 From each orchard are included 1 unwashed lot, 1 lot washed first with sodium silicate (80 pounds to 100 

 gallons) at 100° F. and then with 1.5-percent hydrochloric acid at 80°, and 1 lot washed first with sodium 

 silicate solution at 110° and then with hydrochloric acid at 100°. 



3 Held at 32° for 2 weeks before being inoculated and packed. 



4 From each orchard are included 1 unwashed lot, 1 lot washed with sodium silicate (80 pounds to 100 gal- 

 lons) at 80°, 1 lot washed with 1.5-percent hydrochloric acid at 80°, and 1 lot v/ashed first with sodium 

 silicate at 100° and then with hydrochloric acid at 80°. 



The fruit from the Lower Naches, Naches Heights, and Selah 

 Heights orchards developed a moderate amount of lenticel infection 

 during both seasons, whereas the Tieton apples consistently showed a 

 high degree of resistance. The apples from all of these ranches were 

 fairly well shaped, but the fruit from the Tieton orchard tended to be 

 somewhat smaller than that from the others. Although Baker and 

 Heald (2) were unable to correlate fruit size with susceptibility to 

 lenticel infection, the work of Rose (23) and the experience of commer- 

 cial fruit handlers indicate that large apples of a given variety generally 

 develop more decay than small ones. The increased susceptibility 

 of large fruit may possibly be due to the fact that its greater weight and 

 coarser texture make it more subject to bruising and abrasion. Al- 

 though maturity has a pronounced effect on lenticel infection (2, 3), 

 it apparently was not a factor in this experiment as all of the fruit was 

 harvested on the same day from orchards within a 5-mile radius and 

 at approximately the same altitude. 



15 



