646 EXPERIMENT STATION RECORD. [Vol.41 



quality of timothy, redtop, Kentucky blue grass, orchard grass, meadow fescue, 

 and white clover seed August 22, 1919, is also briefly noted. 



The identification and control of Colorado weeds, W. W. Robbins and B. 

 BoYACK (Colorado Sta. Bui 251 {1919), pp. 126, flgs. 77).— The principal weeds 

 occurring in the State are described and illustrated and control measures indi- 

 cated in each case. The general aspects of weed control, the Colorado pure-seed 

 law, the losses caused by weeds, the introduction, spread, and distribution of 

 weeds in Colorado, some principles and methods of weed control for both dry 

 land and irrigated farms, and the utilization of weeds for silage are discussed. 



Weed immigration into Michigan, H. T. Darlington {Ann. Rpt. Mich. Acad. 

 Sci., 20 (1918), pp. 261-267).— Ot 225 weeds mentioned by Beal (E. S. R., 36, 

 p. 739), the author states that 147 have been introduced into the State. Based 

 on oflicial catalogues of plants in Michigan, lists have been prepared giving 

 the names of those weeds present in 1839, and new weeds appearing between 

 1839 and 1860, 1860 and 1881, 1881 and 1904, and 1904 and 1915, respectively. 

 It is stated, further, that of the introduced weeds 56 per cent are native of 

 Eurasia, 4 per cent of the West or Southwest, 8 per cent of the East or 

 Southeast, and 3 per cent of South America, while 20 of the 25 worst weeds of 

 the State are said to be indigenous to Europe. 



The weeds of wheat on the pampas [Argentina], J. Williamson {Bol. ilin. 

 Agr. [Argentina^, 22 {1917), No. 2, pp. 1^1-148, flgs. 6).— The distribution, hab- 

 its, and means of eradication of the principal weeds infesting wheat on the 

 pampas are discussed. The plants dealt with include Chenopodiuni sp., Salsola 

 tragus, Arjone bulbosa, Arena fatua, and Polygonum convolvulus. 



Devitalization of the seed of Cuscuta, M. Bbesaola {Staz. Sper. Agr. Ital., 

 52 {1919), No. S-4, pp. 193-207).— The author discusses further (E. S. R., 31, 

 p. 835) the effect of heat and of sulphuric acid treatment upon the germination 

 of the seed of C. arvensis and C. trifolii. 



Exposure to dry heat at 75" C (167° F.) for one hour practically inhibited 

 the germination of dodder seed. The seed of Medicago saliva, Trifolium 

 pratense, and T. repens under similar conditions was not seriously injured, 

 while that of Lotus comiculatu^ was actually benefitted by the high tem- 

 perature. The sulphuric acid treatment appeared to be unsatisfactory. 



HORTICULTURE. 



Carbohydrate metabolism in green sweet corn during storage at different 

 temperatures, C. O. Appleman and J. M. Authub {Jour. Agr. Research [U. S.], 

 17 {1919), No. 4, pp. 137-152, flgs. 2). — A contribution from the Maryland Ex- 

 periment Station, dealing with the character and kinetics of the processes 

 involved in the rapid depletion of sugar in green sweet corn after it is sepa- 

 rated from the stalk, and more particularly with the relative rates of these 

 processes at different storage temperatures, accurately controlled. 



A method was devised by which the rate of sugar loss from green sweet 

 corn could be determined for consecutive 24-hour periods of storage by com- 

 paring analyses of corn from the same ear. Stowell Evergreen corn, picked 

 in the typical milk or best eatable stage and having a water content of approxi- 

 mately 80 per cent, was used in the study. 



The depletion of sugar in green sweet corn after it is separated from the 

 stalk does not proceed at a uniform rate, but becomes slower and slower until 

 finally the loss of sugar ceases when the initial total sugar has decreased 

 about 62 per cent and the sucrose about 70 per cent. Calculated on the basis 

 of original moisture, the corn contained, when the depletion of sugar ceased, 



