576 IOWA DEPARTMENT OF AGRICULTURE 



abunaance of Entyloma on the cultivated European poppy. This yeax it 

 was found abundantly after a rain on the same species of poppy in Steam- 

 boat Rock, Hardin County. The majority of the leaves on a small patch 

 were infected. 



Cabbage yellows {Fiisariuvi gentiannus). Cabbage yellow, for a num- 

 ber of years has been noted as a destructive disease in the cabbage dis"- 

 trict of Muscatine. Dr. I. E. Melhus reports the loss as serious. 



Black rot a'f cabbage {Pseudomonas campcstris) was not common. 



Clover anthracnose {Gloeosporiun trifolii). This disease attacks the 

 peduncle of the clover; causes the stem near head to break so that no 

 seed is produced. This disease was common in many parts of Iowa. This 

 disease was first reported in June in Iowa by Dr. I. E. Melhus, the first 

 time it has been reported in the state. It was also commop. ;.= Ill^';-J- 

 where Mr. Mosher found it, specimens of diseased planiy harlag *K. 

 forAvarded to me and identified by Dr. Melhus. 



Alfalfa leaf spot (Pseivdopeziza Medicaginis) was fairly aDundanr u 

 May. The dry weather of June seems to have checked the dise^rD fr^ine- 

 what. It did some damage later in the season though not as severe as 

 in 1915. 



The violet root fungus {RMzoctonia medicaginus) continues to spread 

 slowly in Scott County. 



Crown gall {Bacterium iumefaciens) seems to be on the increase in 

 Iowa. 



The Illinois Canker or Blister Canker (^iimnmilaria discreta) is in- 

 creasing in Western Iowa and spreading northward. It has been re- 

 ported from Floyd, Wright and Scott counties by Dr. Melhus. 



Apple blight (Bacillus aviylGvorus) was not abundant this year. Some 

 trees v/ere blighted early in June; then the disease was checked when the 

 dry period of June started. 



Apple scab {Fusicladhim dendriticum) was widely distributed in Iowa. 

 The leaves were not so seriously diseased as in 1915. There was how- 

 ever, considerable fruit diseased. Professor Laurenz Green, who has 

 been conducting some co-operative spraying experiments, reports that un- 

 sprayed fruits of Northwestern Greening in Webster County had one 

 per cent of clean apples. The untreated apples in the Bagley experiments 

 had 10-15 per cent clean. 



Yellow leaf disease of barley {Helmintosporium gramimim) was abun- 

 dant in places where barley is grown. It is an abundant crop in north- 

 eastern Iowa. The earliest report of the disease was June 21st and the 

 damage reported was 5 per cent. The spot disease of barley {H. sativum) 

 also on barley occurring on the leaves was less destructive. About three 

 per cent damage is reported. 



Ergot (Claviceps purpurea) was common on rye, also abundant on wild 

 rye and quack grass. 



The spot disease of cherry {Cylvndrosporium padi) though occurring in 

 nurseries was not as severe as in 1915. Very few of the leaves of or- 

 chard trees dropped. 



