March 10, 1916] 



SCIENCE 



365 



The Relation of the Seed Stock to the Control of 

 Bean Anthracnose and Bean Blight: J. H. 



MtTNCIE. 



On aeeount of the enormous losses caused "by 

 them, the diseases, anthracnose and blight, have 

 become a serious menace to the bean-growing in- 

 dustry of the "United States. For the season of 

 1915 it is estimated that the loss, to the Michigan 

 bean crop alone, is at least a million bushels and 

 the money loss about two and one half million dol- 

 lars. The control measures, recommended by vari- 

 ous authors, incorporated with our own, have been 

 tried out in our experimental plats. These meas- 

 ures consist of the application of fungicides to the 

 growing plants and treatment of the seed with 

 chemical solutions and hot water. In no case did 

 these measures prove satisfactory in controlling 

 the diseases. Likewise the planting of native 

 seed from some of the western states proved un- 

 satisfactory. It has been found possible to grow 

 Michigan seed beans in western states where the 

 climate is favorable and where these diseases are 

 of no economic importance, and to secure, in this 

 way, seed apparently free from disease. The be- 

 havior of the plants from western-grown Michi- 

 gan seed will be further tested in our experimental 

 plats. Since spraying and seed treatments have 

 failed to control these diseases, we have sought for 

 a palliative, to be employed until some satisfac- 

 tory control measure can be worked out. We have 

 found that by planting a variety of beans of high 

 productivity, the losses due to these diseases can 

 be so decreased that, in ordinary years, they will 

 not be burdensome to the industry. This variety 

 of pea beans is known commercially in Michigan 

 as the Early Wonder. According to Mr. W. W. 

 Tracy, of the U. S. Department of Agriculture, 

 this variety was heard of in western New York, 

 in 1890, as the Little Early Scofield. Seed from 

 a single plant was first grown in Michigan in 

 about 1908. Later, when seed from this variety 

 was put on the market the varietal name was 

 changed to Early Wonder. Early Wonder beans 

 have been observed under field conditions in six of 

 the principal bean-growing counties of this state, 

 during the past three seasons. At least two thou- 

 sand acres of beans of this variety were under ob- 

 servation this season. This variety of beans is 

 well adapted to Michigan conditions, matures 

 early and produces well. On account of this early 

 ripening, the pods harden before the diseases have 

 made serious inroads into the tissue, thus prevent- 

 ing to a great extent the spotting of the seed. 

 Data collected for the past three seasons bring out 



the following points: (1) Early Wonder beans 

 ripen from ten days to two weeks earlier than ordi- 

 nary home-grown varieties. (2) The average 

 yield per acre is twenty bushels. (3) The average 

 pick per bushel is two pounds. (4) The seed is 

 uniform in size, shape and color. (.5) The pods 

 ripen evenly and hang high above the ground. 

 (6) Early Wonder beans produce well, even under 

 severe disease and weather conditions. We are 

 recommending that true Early Wonder beans be 

 planted in Michigan as a palliative measure until 

 some more successful control measure for the 

 anthracnose and blight can be found. 

 Nezv Methods and Apparatus for Determining, 



Qualitatively and Quantitatively, the Effects of 



Sulphur Dioxide on Plants: P. J. O'Gaka. 



A r&um^ of the work done by European and 

 American workers is given. It is shown that the 

 methods of sulphur dioxide analyses have been in 

 error, this error often reaching up to one thou- 

 sand per cent, or more. Furthermore, the type of 

 apparatus used in subjecting plants to an atmos- 

 phere containing sulphur dioxide gas was faulty. 

 In addition it may be stated that the effects of the 

 various environmental factors, such as tempera- 

 ture, humidity and light, were not sufficiently taken 

 into consideration as affecting plants subjected to 

 an atmosphere containing sulphur dioxide. The 

 method's employed in the experimental work which 

 has been carried on by the writer and His assist- 

 ants have been such as to take into account every 

 factor which would influence the effects of sulphur 

 dioxide on ^plants. For the first time it has been 

 possible to measure accurately extremely minute 

 quantities of sulphur dioxide. It has been pos- 

 sible to subject plants to known concentrations of 

 sulphur dioxide and to check these concentrations 

 during the progress of the experiments. During 

 the seasons of 1914 and 1915 twenty-six agricul- 

 tural crops were investigated, the purpose being 

 to determine qualitatively and quantitatively the 

 effects of sulphur dioxide when employed at vari- 

 ous concentrations and at the various periods of 

 growth of the various crops. During the two 

 years during which the experimental work has 

 been carried on fully two thousand experimental 

 plots have been used. The new methods and ap- 

 pliances will be shown by the use of a large num- 

 ber of lantern slides. 

 Concerning Certain Peculiar Tissue-strands in a 



Protomyces Gall on Ambrosia Trifida: Alban 



Stewaet. 



The stems of the great rag-weed, Amhrosia 

 trifida, are sometimes infected by Protomyces 



