456 



EXPERIMENT STATION RECORD. 



upon the uninjured surface of immature plums, they were without 

 effect on the plant although the fruit was kept moist under a bell jar to 

 aid in the infection. When sown on the uninjured surface of green 

 peaches, a slight growth resulted, and when the inoculation of the peach 

 was effected by punctures, the fungus produced spots quits abundantly. 

 It is stated that the disease may be held in check by early and repeated 

 applications of Bordeaux mixture. 



Formalin for prevention of potato scab, J. C. Arthur {Indiana 

 Sta. Bui. 65, pp. 19-36, pis. 2). — Preliminary tests of formalin, made in 

 a greenhouse by soaking potatoes for 2 hours in solutions of the strengths 

 of 1 : 800, 1 : 400, 1 : 200, 1 : 120, and 1 : 40 resulted in no injurious effect 

 upon the germination of the tubers and indicated that formalin is a 

 successful fungicide for scab. 



Three field tests were made with formalin solutions of various strengths. 

 In two cases the tubers planted were badly scabbed and in a third case 

 they were apparently free from scab. In one case formalin was com- 

 pared with corrosive sublimate treatment. The tubers in one test were 

 treated 1 hour and in the others 2 hours. In all cases the potatoes were 

 grown in soil which had been cropped with potatoes continuously for 

 the 7 preceding years and contained scab germs. The soil was light, 

 shallow, and well drained. No fertilizers were used. The rainfall in 

 July was much above the normal. A summary of the results of the 3 

 tests is shown in the following table: 



Percentage of injury to crop from scab ; seed tubers treated with corrosive sublimate and 



formalin and untreated. 



Formalin treatment for potato scab under farm conditions was tried 

 by farmers in 4 localities. All reported favorable results. The 

 injury from scab at the station was much greater in the portions of the 

 held containing most soil moisture. Tables are given showing in detail 

 the results of the tests at the station. Experiments showing that for- 

 malin is not dangerously poisonous are noted. The author's method of 

 estimating the injury from scab is prescribed. A bibliography of liter- 

 ature on the germicidal, therapeutic, and physiological action of formalin 

 is given. The author believes that formalin is equal to corrosive sub- 

 limate as a treatment for potato scab, and recommends a solution of the 

 approximate strength of 1:300. The directions given are to soak 

 tubers 2 hours in a solution of i pt. formalin in 15 gal. of water. 



Damping off, G.F.Atkinson (Xew York Cornell Sta. Rpt. /S9~>, pp. 313-340, pis. 6, 

 fig. /).— Reprint of Bulletin 94 of the station (E. S. R., 1, p. 220). 



