DISEASES OF PLANTS. 961 



the chrysiinthemuni rust [Piicr'nild rJiriisantlu'ini) showed that it was a speciaUzed 

 form confined to Chr!/.san(hemui)i liidicHiii. Inoculation experiments were conducted 

 with the rust of cultivated and wild violets from which it was learned that Puccinia 

 violic is autoecious, the different phases in its life cycle being spent upon a single spe- 

 cies of host plant. Experiments were conducted in preventing the rust of pinks 

 ( Uromyces caryopliyllinus) . Bordeaux mixture seems to be of little value in combat- 

 ing this fungus. Its spores were subjected to several fungicides, such as solutions of 

 copper sulphate and liver of suliihur; copj)er acetate; sulphuric acid; zinc sulphate 

 and borax; and copper sulphate and borax. The spores failed to grow in very dilute 

 sohitions of the tirst and last two, and it is believed that tliese fungicides could be 

 suc( essfully euijjloyed in combating the disease. The effect of adding sugar to Bor- 

 deaux mixture upon bees visiting trees sprayed with the mixture was studied, and 

 it is claimed that bees failed to visit or eat any of the solutions prepared and placed 

 accessible to them. 



The effect of winter and summer spraying of apple trees for the prevention of 

 Fusicladium was investigated. Winter sprayings, summer sprajdngs, and winter and 

 sunnner treatments of apple trees were compared. But little disease appeared upon 

 any of the trees and but slight difference could be seen as the effect of the treatments 

 until the end of the season. There was little difference even then, except in those trees 

 which had received summer applications only after the leaves had become large and 

 well developed. These were more affected than any others. When summer appli- 

 cations were made while the leaves were young the effect was as good as where both 

 winter and summer sprayings were given the trees. The author reports occasional 

 injury to apple and pear trees when sprayed with copper sulphate solutions as dilute 

 as 0.5 per cent. It is claimed that a 1 per cent Bordeaux mixture can be substituted 

 for stronger ones for summer use. Adding sugar to Bordeaux mixture increased its 

 adhesive property, and experiments showed that soda-Bordeaux mixture was le.ss 

 ethcient than ordinary Bordeaux mixture, and that the substitution of iron salts for 

 copper is not advisable. 



Report of the government mycologist, J. B. Carrithers {Trap. Agr., 20 

 {1900-1901) y pp. 707-710). — The first report of the government mycologist of Cey- 

 lon, who assumed the duties of his position during the summer of 1900, is given. The 

 report covers investigations made during 6 or 7 months, which w^ere principally 

 devoted to a studj'^ of the diseases to which tea is subject. The principal studj' was 

 made of the fungus causing gray blight {Pestalozzia guepini). Investigations have 

 been begun in order that the life history of the fungus may be ascertained, and a 

 series of experiments planned to ascertain the distriliution of the Ijlight. The effect 

 of screens interposed between the tea bushes and the prevailing winds is to be inves- 

 tigated, as well as the effect of pruning upon the distril)ution and extent of the disease. 

 The effect of removing diseased leaves was examined into and found to greatly dimin- 

 ish the occurrence and spread of the fungus. Where the s^wtted leaves were picked 

 from the bushes soon after pruning the percentage of diseased leaves was greatly 

 reduced, and this treatment, it is believed, will prove the most economical and 

 effectual method for combating the disease. The leaf fungus ( Cladosponum herbarum) 

 was ol>served on leaves, but without producing a great amount of injury. The para- 

 sitic lichen Cephaleurvs mycoidea was found occurring on the leaves of tea in a number 

 of districts. It produces characteristic reddish or white and gray spots upon the leaf, 

 but does little harm and spreads very slowly. A root disease of the tea, caused by 

 the fungus Rosellixin radiriperda, was investigated and was found to occur most fre- 

 (juently in clearings .where the stumps of the forest trees remained. The fungus 

 occurring upon these stumps spread by its mycelium and spores to the tea jilants, 

 causing considerable damage. The means suggested for combating this disease is the 

 remoyal of all stumps and application of lime about the place where they were for- 

 merly grown. 



