BUREAU OF PLANT INDUSTRY. 145 



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plants were affected by a serious root trouble apparently due to a 

 species of Rhizoctonia. In several localities in Florida and Georgia 

 some damage was occasioned by a wilt caused by Bacterium 

 solonacearum^ the brown-rot organism which produces the well- 

 known wilting of tomatoes, potatoes, and tobacco. The cutworm 

 has been quite prevalent in the castor-bean fields of some sections, 

 and several other insects have inflicted minor injury. In Florida 

 the fields have been attacked by the semitropical army worm, and 

 already the crop on perhaps 1,500 acres or more has been totally 

 destroyed. This is the most serious outbreak of this worm experi- 

 enced during the last 12 years, and its general occurrence is a menace 

 to the crop of the entire" State. Both State and Federal authorities 

 are giving all possible aid to the farmers in fighting the pest, and 

 vigorous control measures are being taken wherever the worm has 

 appeared. 



The castor-bean program has had the active support of the Office 

 of Extension Work of the States Relations Service, and many of the 

 county agents have rendered efi'ective service in this connection, for 

 which they iire deserving of credit. 



It is still too early to forecast what the probable outturn of the 

 crop will be. The very unfavorable weather conditions experienced 

 in some sections have operated to increase the uncertainty. How- 

 ever, on much of the acreage the crop now gives promise of a favor- 

 able outcome. 



DRY FARMING ON THE GREAT PLAINS. 



While many problems are yet to be solved, the results of the experi- 

 mental work of the past several years on the Great Plains are now 

 authoritative on the fundamental questions of the adaptation of each 

 crop to each section and the returns to be expected from its growth 

 by all the different methods of cultivation likely to be employed. The 

 surety of producing a crop or the hazard of failure, Avhich is as im- 

 portant as the average yield, is also known. This information has 

 been of immeasurable value in advising and directing endeavor, both 

 individual and organized, in its effort to increase food production to 

 meet the war emergency. It has also been the foundation of the 

 assistance rendered the Geological Survey in its classification of 

 public lands under recent homestead laws. 



A long-continued series of experiments covering a wide range of 

 soils, crops, and climatic conditions has conclusively proved that 

 subsoiling does not generally increase average yields and does not 

 afford any protection against drought. Neither is amelioration of 

 dry-farming conditions to be obtained through deep tilling with 

 dynamite or special plows. 



In cooperative shelter-belt work with farmers on the northern 

 Great Plains, active cooperation is now maintained with 507 farmers, 

 who were furnished stock and planted shelter belts in 1916; 201 who 

 planted in 1917 ; and 392 who are applicants for future planting. In 

 1916, 701,911, and in 1917, 357,700 trees were sent out. In 1916 the 

 percentage of growth was 80 per cent, and in 1917 it was 81.2 per 

 cent. 



