2i8 Journal of Agricultural Research voi. xviii. no. 4 



influence; of orchard conditions 



It is generally admitted that the susceptibility of apples to scald prob- 

 ably varies with orchard conditions, but little experimental data has ever 

 been published on the subject. In the fall of 191 8 apples were secured 

 from various soil and orchard conditions at Wenatchee, Wash., for com- 

 parative storage tests on this point. In one test, Grimes apples from 

 lightly irrigated trees growing in heavy clay soil were compared with 

 similar apples from lightly irrigated trees on alluvial sand receiving a 

 spring application of 10 pounds of sodium nitrate per tree. The apples 

 were stored in the usual box packages in commercial cold storage. They 

 were removed to a temperature of 15° C. (59° F.) on February 6 and notes 

 taken February 15. The apples from the heavy clay soil had 35 per cent 

 of scald and those from the heavily fertilized sandy soil 60 per cent of 

 scald. 



Experiments were conducted also with apples from a Grimes orchard 

 in which irrigation experiments were being made. The orchard was in 

 alfalfa and the soil of the various plots was quite uniform. The con- 

 trasts in irrigation were started the first of July and maintained for the 

 rest of the season. With the heavily irrigated plot the soil moisture was 

 kept at approximately 50 per cent of saturation, and with the lightly 

 irrigated one at approximately 20 per cent of saturation, while with the 

 third plot the soil moisture was kept at approximately 20 per cent from 

 July I to August 15, and then at approximately 50 per cent the remainder 

 of the season. The methods of irrigation, soil sampling, etc., were the 

 same as those reported in an earlier paper (4) and will not be repeated here. 

 The apples were picked on September 18, when mature but not overripe, 

 and placed in storage the following day. They were removed from storage 

 February 5 and were held at a temperature of 15° C. (59° F.) for one 

 week before notes were taken. In experiment A one box of apples from 

 each plot was used under each storage condition. In experiment B sepa- 

 rate records were made for the apples of different sizes. There were 

 from I to 6 pecks of each size under each storage condition. The results 

 are given in Table III. 



The apples from the plot receiving light irrigation early and heavy irri- 

 gation late developed about twice as much scald as those from the plot 

 receiving heavy irrigation continuously and three to four times as much 

 as those from the lightly irrigated plot. 



It is particularly interesting to note that the increased amount of scald 

 on the heavily irrigated apples was not due to their larger size, since the 

 increase was as great on the small apples as on the large ones. It has 

 been observed in an earlier publication (5) that large apples often scald 

 worse than small ones. The foregoing results indicate that in the present 

 case size is a secondary factor, the real cause of the increased scald being 



