BUREAU OF PLANT INDUSTRY. 139 



In connection with the classification of wheats a very comprehen- 

 sive varietal survey has been undertaken in cooperation with the 

 Bureau of Crop Estimates. Schedules to determine the distribution 

 of wheat varieties, the source from which they came, the date of their 

 introduction into the community, and the percentage Avhich each one 

 represents of the total wheat acreage in the community have been 

 sent out to some C5,000 crop reporters. The return schedules have 

 been studied, and in thousands of cases letters of inquiry sent asking 

 for additional information and for samples. For the first time in 

 the history of wheat growing in America it will be ix)ssible to map 

 the distribution of wheat varieties and to learn the large number of 

 names under which the same varieties are known in different parts of 

 the country. 



In connection with the problem of the winterkilling of wheat it has 

 been necessary to study the effect of different methods of seeding on 

 the winter survival of the resulting plants. Preliminary cooperative 

 experiments seem to indicate that drilling may be a factor in some 

 sections. The geographic scope of these experiments is being 

 broadened. 



RICE. 



A method of shocking rice developed cooix^rativcly at the Crowley 

 Rice Station in Louisiana proved its value again in the autumn of 

 1018. AVherever this method was used, comparatively little damage 

 was done to the shocked grain by the heavy rains prevailing after 

 harvest time. 



Experiments to determine what crop may be grown profitably in 

 rotation with rice in the Sacramento Valley again have resulted 

 negatively. The data obtained indicate that cotton may become a 

 commercial crop where the water table can be controlled and the 

 crop planted carh'. A careful survey was made in portions of 

 Ceorgia, Florida, and Alabama to determine what varieties and 

 methods of growing will permit the production of rice without 

 irrigation, in quantities sufficient for home use at least. 



A general survey of Porto Rico was made in 1917 to determine 

 the possibility of commercial rice growing on that island. This was 

 followed by experiments undertaken cooperatively with' the Porto 

 Rico Experiment Station and with sugar planters at several jDoints. 

 This work is being continued during the crop season of 1919, and the 

 results indicate that there is a promising outlook for commercial rice 

 growing in Porto Rico. One variety produced a fair yield under 

 conditions of drought so severe that the native varieties w^re a com- 

 plete failure. 



GRAIN SORGHUMS. 



Long-continued experiments in the production and improvement 

 of grain-sorghum varieties in the dry and elevated portions of the 

 southern Great Plains area warrant the following conclusions con- 

 cerning this group of grain crops so important in that section: 



(1) Many varieties produce weU in favorable seasons. Only well-adapted 

 varieties produce well in the less favorable and in unfavorable seasons, wliich 

 comprise about tlu-oe-quarters of (lie total number. 



(2) P^arliness is the most important single factor in the vari^.'tal adaptation 

 of grain-sorghum crops to the conditions obtaining on the high plains of the 

 Texas Panhandle. 



