578 IOWA DEPARTMENT OF AGRICULTURE 



Cottonwood rust {MelamTpsora trcmulae) was widely scattered and 

 common only in the autumn. 



The absence of Phytopthora has heen noted. Dr. Melhus reports the 

 following diseases to me: Jelly end rot {Fusarium 7-adicicola) which he 

 observed. in three counties; Early Blight (Alternaria solani) also in a 

 number of counties; Blackleg {BaciUus Phytopthorus) in Story and Scott 

 counties. Potato scab was widely scattered. 



Melon anthracnose {C'ollctatrichum lagenarium) was widely scattered 

 but not common. 



The spot on tomiato {Septoria Lycopersici) so common in 1915, was 

 not observed to any extent this year. Dr. Melhus reports tomato mosaic 

 from Scott county, the first time it was observed in the state. 



The strawberry leaf spot {Microspliaerella Fragariae) was fairly com- 

 mon in old strawberry beds. 



Fungicides. 



In view of the widespread damage resulting from the various diseases 

 of our cultivated plants, it was thought to be appropriate to append here 

 a brief note relative to means of combatting these diseases. The common 

 fungicides are as follows: 



1. Bordeaux Mixture, one of the standard formulas for which is: 

 copper sulphate, four pounds; quick lime, four pounds; water, fifty gallons. 



2. Formaldehyde is a forty per cent solution is a general fungicide 

 for treating oat smut and onion smut. In the case of onion smut the drip 

 method is used and the usual formula is one pint to every twenty-five 

 to tliirty-three gallons af water. 



There are several combinations of E'ordeaux Mixture and formalin. In 

 some cases insecticides are added to destroy the insects. The best treat- 

 ment for oat smut is the formalin method. Lime, sulphur is also used to 

 a considerable extent. The different methods of treatment are set forth 

 in a number of publications from among which the following are recom- 

 mended: 



Shelby, A. D. : A Brief Handbook of the Di&eases of Cultivated Plants. 

 Bulletin of the Ohio Experiment Station, No. 214, pp. 355-360. 



Beach, S. A.: Spraying Practice for Orchard and Garden. Bulletin 

 of the Iowa Experiment Station, No. 127, pp. 73-77. 



