WEATHER BUREAU. 85 



EFFECT OF WEATHER ON CROPS. 



It has been determined that most crops have a critical period of 

 j^rowth, usually short, when favorable weathei- will cause a pfood 

 yield and unfavorable weather a poor yield, re^rardless, mainly, of 

 earlier or later weather conditions. Studies to determine this critical 

 period are carried on as far as time and opportunity Avill permit. 

 Some of the studies carried to completion relate to the effect of tem- 

 perature, rainfall, and snow on winter wheat, cultivation and rain- 

 fall in the Great Plains, relation between precipitation and the graz- 

 in«r capacity of ran<2:es, the seasonal distribution of precipitation, 

 and sunshine in the Ignited States. 



The <rreatest need in this direction is the estal)lishment of a^rri- 

 cultural meteorolofrical stations at the agricultural experiment sta- 

 tions in the principal crop-growinir areas. AVhen established a 

 careful and systematic record can be beirun of the temperature, rain- 

 fall, sunshine, etc., and at the same time a complete record of the 

 development of the various crops. By maintaining these stations 

 for a period of years, the most critical period of growth and the 

 "weather factor most affecting the crop can be determined. 



WEATHER BUREAU PRINTING OFFICE. 



The principal publications issued during. the year included the 

 Daily Weather ^lap, Monthly Weather Review, and Supplements, 

 Daily River Stages at river-gage stations in the United States for 

 1918, National Weather and Crop and Snow^ and Ice Bulletins com- 

 bined, forecast cards, weekly forecast, and Form 1030, ^Monthly 

 Meteorological Summary for Wasliington. D. C. 



At the end of the year there were 934 paid subscribers on our 

 various mailing lists, exclusive of the Monthly Weather Review, and 

 the total receijits from subscriptions amounted to $823.97. Sub- 

 scriptions for the Monthly Weather Review are received and filled 

 by the superintendent of documents. Government Printing Office, 

 who requires "200 copies each month. 



The amount allotted the Weather liureau for printing and bind- 

 ing at the (rovernment Printing Office is inadequate, and. as a conse- 

 quence, several important publications had to be suspended until 

 the allotment for the present fiscal j'ear became available. 



MONTHLY WEATHER REVIEW. 



The increased size of the Monthly Weather Review, occasioned l»y 

 the larger numl)er of Cf)ntribiitions received during the year follow- 

 ing the signing of the armistice, was maintained until January 1, 

 lO'iO. when a reduction of 30 per cent was rendered necessary l>v the 

 low state of the |)rinting funds. Although the sections dealing with 

 the weather and earth(|uakes of the montli were conden.sed somewhat, 

 the major portion of the cut fell on the section devoted to original 

 contributions. Duiiug (he remaincier of tlie fiscal year this resulted 

 in an appreciable increai-e in the number of papers awaiting publica- 

 tion and also in a reduction in the supi>ly of new contril)ution.<; re- 

 ceived, for lack of ready publication tends to dampen the enthusiasm 

 of potential contributors. That the Monthly Weather Review is 



