Extension Work in Plant Pathology, 1923 



17 



The more complete extension program includes the following: 



In seed-producing territory 



(1) Searching for disease-free seed stocks. 



(2) Development of isolated and closely rogued seed 



plats. 



(3) Conducting field and bin inspections. 



(4) Training inspectors. 



(5) Demonstrating roguing. 



(6) Conducting test plats of seed planted for certi- 



fication. 



(7) Teaching by means of farmers' tours and other 



agencies the methods necessary for production 

 of disease-free seed. 



In seed-consuming territory 



(1) Conducting seed-source test plats. 



(2) Inspecting seed-source test plats. 



(3) Establishing record demonstrations. 



(4) Teaching by means of farmers' tours and other 



agencies the value of disease-free seed (fig. 8). 



During 1923, 22 States reported projects in connection with po- 

 tato-seed improvement. In Utah, the work was begun for the first 

 time. B. L. Richards, associate professor of plant pathology at the 

 agricultural college, reported as follows: 



The year marked the first serious attempt at organized seed production and 

 certification. On the whole, owing to the large number of factors involved, the 

 results indicate a hopeful rather than a discouraging outlook. The work for 

 1923 points clearly to the fact that the problem of seed-potato production and 

 the establishment of a definite industry in Utah is essentially an educational 

 problem, and should be kept as an extension project to be definitely promoted 

 and intensified. 



Records kept by some of the States during the past few years 

 show that yields have been increased by use of certified seed. M. F. 

 Barrus, extension plant pathologist in New York, reported : 



That good seed is being used more commonly than in the past, due to its 

 availability and to the emphasis that has been placed upon it in extension work, 

 is further shown by the higher average yield per acre for the State during the 

 past five years than in previous years. A high average yield in any one year 

 may be explained as due to favorable weather or absence of epiphytotic diseases 

 or insects. But during the past five years there have been very dry seasons 

 and very wet seasons, hot seasons and cold seasons, blight years and no-blight 

 years, so that these factors can not have had more bearing on the average yield 

 during the last half-decade than in the past. Yet never before, since records 

 have been kept of the yield per acre of potatoes, have there been five consecu- 

 tive years when the yield per acre each year has exceeded 100 bushels. The 

 natural inference is that this must be due to the more general use of better 

 seed. The possibility of even greater improvement is shown in the following- 

 table : 



Average yield of potatoes per acre in Neiv York, 1916-1923 



Item 



1916 1917 



1918 



1919 



1920 



1921 



1 

 1922 1923 



Certified fields 



Bushels Bushels 

 128 233 



Bushels 

 204 



98 



Bushels 



221 



Bushels 

 247 



Bushels 

 228 

 103 



Bushels Bushels 

 225 1 209 



All fields 



70 95 



109 125 



110 122 





* 







In Kansas, records of demonstrations showed that there was an 

 average increase in yield of 40 bushels of potatoes to the acre, due 

 to the use of certified seed; in New Hampshire, 63 bushels; in 

 Ohio, 29.8 bushels; and in Delaware the increase in vield varied from 

 10 to 120 bushels. 



CORN 



It is estimated that in 1922, the root, stalk, and ear rots of corn 

 caused reductions of vield amounting to 120,837.000 bushels. The re- 



