Feb. x, i9ii 



Onion Smudge 



711 



(3) badly diseased. The result of this classification is given in Table III, 

 and samples from the dried and the undried lots are shown in Plate 85, 

 A, B. 



Experiment 2. — On August 30, 191 7, several bushels of white onion 

 sets were secured from a field where the crop had been harvested on 

 August 16 and placed in stacks of shallow crates. The weather had 

 been clear during this intervening period, and good natural conditions 

 for curing had prevailed. Smudge was prevalent on the outer scales of 

 the sets at this time. In order to test the effect of exposure to moist 

 weather on the progress of the disease, a portion of this lot in the crates 

 was sprinkled with water daily for one week, approximating roughly what 

 often occurs when a rainy period comes during harvest. After one 

 week a part of the moistened lot was placed in a kiln drier, where the 

 temperature was held at ioo° to 120 F., until the bulbs were thor- 

 oughly dried. The remainder of this lot was allowed to dry naturally 

 under cover. All the sets were then stored in a standard onion storage 

 house. Samples taken from a moistened and an unmoistened crate on 

 October 10 are shown in Plate 85, C, D. Marked increase in the amount 

 of smudge was very noticeable within a few days after moistening was 

 begun. On January 14, 191 7, the amount of smudge was estimated by 

 classifying several hundred bulbs from each of the three lots into either 

 of two classes, namely, (1) those free from smudge or only slightly 

 diseased and (2) those so badly diseased as to impair their market 

 quality. The results are given in Table IV. 



Table IV. — Effect of varied conditions at harvest on the amount of smudge on stored onion 



sets 



Treatment. 



Condition at end of 

 storage period. 



Percent- 

 age free 

 from 

 smudge 



or 

 slightly 

 diseased. 



Percent- 

 age badly 

 diseased. 



Best natural curing 



Exposed to moist conditions after harvest 



Artificially dried after exposure to moist conditions 



25119°— 21 4 



42 



93 



48 



