848 EXPERIMENT STATION RECORD. [Vol.36 



yield due to Bordeaux spraying. Bordeaux mixture gave the best control of 

 flea beetles of any of the mixtures applied. Sulphur dust mixtures were some- 

 what beneficial, but their effectiveness as compared with Bordeaux mixture has 

 not been definitely established. The state of cultivation and the fertility of the 

 field are considered to have an intimate relation to the benefit to be derived 

 from spraying. 



Report of potato scab experiments, 1915, H. C. Lint (New Jersey Stas. Rpt. 

 1915, pp. 375-381, fig. 1). — In continuation of previous accounts of the use of 

 sulphur for the prevention of potato scab (E. S. R., 34, p. 155), the author 

 gives the results of further tests to determine the value of sulphur in connec- 

 tion with the control of this disease. 



Experiments carried on in a number of localities indicate that in some cases 

 broadcasting the sulphur is more effective than mixing it with fertilizers. In 

 one instance the mixture of sulphur with fertilizers caused considerable injury 

 to the tubers. In another experiment an increased yield was obtained where 

 sulphur was employed. Sulphur was again found to be more effective in com- 

 bination with potassium chlorid than with potassium sulphate and with acid 

 phosphate than with steamed bone. 



In connection with seed treatment with formaldehyde and corrosive subli- 

 mate, sulphur was found more effective in controlling scab when used with 

 treated than with nontreated seed. A study of the effect of sulphur applica- 

 tions on succeeding crops showed that no permanent injury to hay crops re- 

 sulted, and a beneficial effect was observed on potato crops grown on the same 

 land. Two successive applications of 300 lbs. appear to be more effective than 

 one of 600 lbs., and as effective as one of 600 lbs. followed by 300 lbs. 



Physiological studies of Bacillus radicicola of soy bean (Soja max) and of 

 factors influencing nodule production, J. K. Wilson (Neiv York Cornell Sta. 

 Bui. 386 (1917), pp. 367-413, figs. i5).— The experiments described in this bul- 

 letin were undertaken to study the physiology of the causal organism of nodule 

 formation on soy beans and the factors influencing nodule development, the 

 work being carried on in the greenhouse and laboratory. The data obtained are 

 considered to apply to this organism only, although in many respects they agree 

 with those obtained by other investigators working with other strains of B. 

 radicicola. 



It was found that nodule formation can be checked or stimulated depending 

 on the presence or absence of certain salts and the amount of moisture present. 

 Among the compounds found to stimulate nodule formation are the chlorids, 

 phosphates, calcium-containing compounds, and certain organic carbon-contain- 

 ing compounds, while nitrates, ammonia-containing or ammonia-produ9ing com- 

 pounds, and sulphates reduced nodule production. In the experiments, an in- 

 crease in moisture content from 35 to 45 per cent more than doubled the pro- 

 duction of nodules, while with an increase from 45 to 55 per cent, it was nearly 

 doubled. The composition of the soil solution is considered an important factor 

 in controlling nodule production. 



It is thought that the failure of pure culture work may possibly be explained 

 by the application as fertilizers of inhibiting substances. 



A bibliography is appended. 



A squash disease caused by Choanephora cucurbitanim, F. A. Wolf {U. S. 

 Dept. Agr., Jour. Agr. Research, 8 {1917), No. 9, pp. 319-328, pis. 3). — In an 

 investigation carried on at the North Carolina Experiment Station, the author 

 found summer squashes attacked by a phycomycetous fungus, G. cucurbitarum. 

 A study has been made of the development of the disease and the morphology 

 of the causal organism, the results of which are given in some detail. 



