The Influence of wet Weather upon parasitic Fungi"^ 



By Bvron D. Halsted 



April and May of the present year were interesting to both the 

 meteorologist and mycologist. There is doubtless some vital con- 

 nection between the weather and the development of parasitic fungi, 

 and it is the province of this paper to record some obscrv^ations, 

 with the hope that it may help to furnish data of value both to 

 science and crop growing. 



The following facts are gathered from the New Jersey Weather 

 Service, For April the average precipitation for the whole state 

 was 3.77 inches, or .40 inch above the normal. It rained on 12 

 days, 22 were cloudy and 8 were clear. In short, it was an over- 

 cast, but not a very wet month. 



For May the average precipitation was 7.00 inches, or 2.82 

 inches above the normal. It rained on 17 days, and there were 

 only 7 clear days out of the 31. In the language of the report, 

 ^^ The precipitation during the month of May', 1898, will long be 

 remembered as one of the greatest on record.** 



The following are some of the notes upon fungi for the spring 

 of the present year : 



The hollyhock rust, Pnccinia inalvaccarnm Mont., has been much 



more abundant and destructive this season than ever before. It 



came into spore production early and ruined many beds of plants. 



Leaves of the ordinary size sometimes had hundreds of spore sori 



that quickly became coated over with the promycelia and sporidia. 



Early in May the cedar apples in the southern part of the state 



-were abundant and resembled modern chrysanthemums in their 



large size. Many trees were seen where Gynosporangiuvi via- 

 . cropns Link., covered the branches and main stem of the trees 



(^Ju)iipcrns Virgi)iiana L.) with the gelatinous horns. 



Upon May 28 it was reported to me by a local botanist that 



the Azalea apples {Exobasidiuni azaliac Peck.) were unusually 

 ' abundant upon Azalia muUfiora (L.) and upon the same date the 



writer inspected many paeonia plants that while pushing their 



* Read before Section G. of the A. A. A. S. at its Ijoston meeting, August 23, 



1898. 



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