No. 3. December, 1920) 



AGRONOMY 



129 



variety has its particular time of flowering, thick canes, as a class, flowering earlier than thin 

 ones. In a group of thick cane seedlings a small proportion show differences from the usual 

 type. These produce masses of flowers that arc especially fertile, yielding great numbers of 

 viable seeds. They flower early and are used for crossing with thick canes. Wild canes have 

 been used similarly. Various devices have been used to hasten the later flowering of the 

 thin canes and retard the early flowering of the thick canes, with the result that some of the 

 former have been hastened and a number of crosses formerly unobtainable have been secured. 

 Different varieties and groups show great diversity in development of arrows. The fullest 

 development is found in various highly developed thick canes, as well as in the most primitive 

 class of the Indian indigenous ones. Many of the North Indian canes have been induced to 

 flower for the first time and with further study the tardy, and at present infertile, members 

 may some day produce flowers which will add to the range of possible crosses. — E. Koch. 



888. Blair, T. A. A statistical study of weather factors affecting the yield of winter wheat 

 in Ohio. Monthly Weather Rev. 47: 841-847. 2 fig. 1919.— The statistical method is applied 

 to the problem of determining what are the important factors affecting the growth of winter 

 wheat in Ohio, and their relative importance. The results are expressed as partial correla- 

 tion coefficients and in linear regression equations, in which the coefficients are evaluated by 

 the method of least squares. Temperature and precipitation are used because of their general 

 nature and because observations of these features extend over the entire region. Tempera- 

 ture variations have more influence upon the yield than do precipitation variations, because 

 of the regular and frequent storms peculiar to the region. Calculated yields agreed very 

 closely with those given by the U. S. Bureau of Crop Estimates. The chief requisites for a 

 good yield are a warm March and June and a cool and dry May. The critical periods in the 

 growth of the plant are those connected with "jointing," "heading" and "filling." — E. N. 

 Munns. 



889. Cross, W. E. Cane nomenclature in Argentina. Internat. Sugar Jour. 22: 278-279. 

 1920. 



890. Gerlach, Prof. Dr. Kohlensauredungung. [Fertilizing with carbon dioxide.] 

 Mitteil. Deutsch. Landw. Ges. 35: 370-371. 1920. — The experiments on the effect of increas- 

 ing the carbon dioxide content of the air, first reported in this journal in 1919 (no. 5), were 

 repeated in a light, airy greenhouse. In a small section of the house the air was made to 

 contain 23 times as much carbon dioxide as it had before the experiment. No beneficial re- 

 sults were obtained, as is evident from the following condensed summary of the harvested 

 dry matter from the three plants named. 



TOMATO 

 FRUITS 



In the open 



In glass house without extra CO2 

 In glass house with extra CO2. . . 



100 

 98 

 73 



— A. J. Pieters. 



891. Howard, Albert, Gabriel L. C. Howard, and Abdtjr Rahman Khan. Studies in 

 the pollination of Indian crops. I. Mem. Dept. Agric. India. (Bot. Ser.) 10: 195-220. 1919. 

 — A report on the flowering, methods of pollination, fertilization, natural cross fertilization 

 and improvement of leguminous crops, such as Crotalaria juncea, Cajanus indicus Spreng., 

 Indigofera arrecta Hochst., Indigofera sumatrana Gaertn.; oil-seed crops, such as Linum usi- 

 tatissirnum L., Eruca sativa Lam., Sesamum indicum L., Guizotia abyssinica Cass.; and crops 

 grown for fiber, such as Corchorus capsularis L., Corchorus olitorius L., and Hibiscus sab- 

 dariffa L.—F. M. Scherts. 



