135 



IMd.WA I'LAN'r KISKASES. lJ)ir».' 

 Max W. <; AitD.NKH. 



Tlio parasitif fuiiui <>f ccoiioniic iniportancr in Indiana lia\(' Ikmmi previ- 

 ously recorded l)y Tipal-' and by OsnerV- While additions to (his list will 

 he included in suhse(iuent reiwrts the nature of the report will li(> e<sen- 

 (ially altered so that it will constitute a somewhat detailed accoiuit of the 

 ^'cneral crop patholojry and the diseases of considerahlo economic import- 

 ance durins^ the season in (piestion. Relative prevalence, fieo^raphical dis- 

 triliutioii, local epidemics, new or unusual featiu'es observed, and los-cs in- 

 curred, especially specific instances, will be among the data inchided. It is 

 hoi)ed that by such au annual procedure, a clearer understanding of Indiana 

 l>lant disease conditions may be obtained. For this report no claim of 

 completeness is made. Diseases of forest trees and ornamentals are not in- 

 cluded. Diseases not reported in the previous lists are enumerated in the 

 summary. 



WEATHKB COXDITIONS. 



P.ecause of the very intimate hearing of the weather uiion crop path- 

 ology, it is <leemed not out of place to present a brief resume of the weather 

 conditions prevailing dui'ing the 101!) growing season as summarized by 

 Mr. J. H. Armiiigton in the monthly reports of the, "Weather liureau at 

 Indianapolis. 



Very warm weather early in April advanced vegetation very rapidly 

 and caused fruit to blossom in the central and southern portions of the 

 state. Consequently the freezing temperatures attained April 25th. to 27th. 

 resulted in very serious injury to i)eaches, cherries, plums, apples, wheat, 

 and rye. After this followed a month of cool, cloudy, wet weather resulting 

 in a marked retardation of grains, a yellowing of wheat and rye in wet soil, 

 a suitsecpient lodging of wheat, and a delayed planting (tf corn and truck 

 crops. 



June and July were exceptionally hot and dry. The rainfall during June 

 was in the form of local thunder storms and was deficient in the east and 

 central portions of the state. In general, however, the weather during June 

 was not unfavorable to crops. Except for a light rain. July 14th.. there 

 was practically no rain at all during that month until the 31st. This pro- 

 longed drouth, coupled with the excessive heat, resulted in severe retarda- 



^Pipal, P. J. A list of plant di.soasos of poonomie importaiifc in Indi.-uia with 

 bibliography. Proc. Ind. Acad. Sci. 1915 :379-413. 1916. 



■•Osner, Geo. A. Additions to the list of plant diseases of economic importance in 

 Indiana. Proc. Ind. Acad. Sci. 1016:327-332. 1917. 



"Osner, George A. Additions to the list of plant diseases of economic importance 

 in Indiana. Proc. Ind. Acad. Sci. 1917:145-147. 1918. 



H'ontribulion from the Hotanical Department of Purdue University Agricultural 

 Experiment Station. Lafayette. Indiana. 



-The writer wishes to acknowledge the assistance of Prof. H. S. Jackson. Mr. 

 F. .1. I'ipal, Mr. G. N. Hofftr. Dr. O. T. irresorv. rind TO. 13. Alains in oreparintr 

 this report. 



