294 PATHOLOGY [Box. Absts., Vol. VII, 



ERADICATION AND CONTROL 



2050. Barthe, a. E. Lucha antiparasitaria. [Parasite controL] Rev. Agric. Com. y 

 Trab. 3 : 25&-265. 5 fig. 1920.— A general review of the classes of insect and plant parasites 

 is given with a resum^ of different spray materials, machinery, and other control measures. — 

 F. M. Blodgett. 



205L Bbooks, F. T. Plant sanitation in fruit plantations. Trans. British Mycol. Soc. 

 6: 253-262. 1920. — Diseased parts of trees and shrubs in or near fruit plantations should be 

 promptly cut off and burned to prevent spread of disease. When a tree is dying back to such 

 an extent that it has to be cut down it is important that the stump be either removed or cov- 

 ered with soil to prevent the development of dangerous fungi. Other suggestions for destroy- 

 ing breeding places of destructive fungi and insects are given. — W. B. McDougall. 



2052. Butler, C, and T. O. Smith. Relative adhesiveness of the copper fungicides 

 Phytopath. 9: 431-444. 1919.— Following a review and tabulation of previous work on the 

 adhesiveness of Bordeaux mixture, the authors tested various types of Bordeaux and Bur- 

 gundy mixtures for adhesiveness. Relative adhesiveness was determined by use of sprayed 

 leaves of Coleus golden bedder on which the spray was allowed to dry. Half leaf samples 

 were then taken, after which the plants were subjected to rain conditions. Plants were then 

 dried and further samples taken for analysis. Copper was determined by the electrolytic 

 method. The authors find that neutral and alkaline Burgundy mixtures are more adhesive 

 than Bordeaux mixtures and that the alkaline Burgundy mixture is more adhesive than the 

 neutral wash. The adhesiveness of the Bordeaux mixtures decreases with increase in per- 

 centage of lime. Within the temperature limits 10 and 30°C., adhesiveness of Bordeaux mix- 

 ture varies inversely with the degree of deterioration rather than being dependent on the 

 degree of hydration. Deteriorated Bordeaux mixture, having copper sulphate-lime ratio 

 1:1, is more adhesive than deteriorated Burgundy mixture, probably due to the lime present 

 in the former. The addition of ferrous sulphate decreases adhesiveness of Bordeaux mixture, 

 the addition of Paris green or arsenite of soda does not materially change adhesiveness, and 

 the addition of lead arsenate increases adhesiveness. Casein does not affect adhesiveness of 

 1 : 1 Bordeaux mixture. Copper acetates are more adhesive than Bordeaux mixture. The 

 addition of gelatin to normal and basic acetate of copper increases the adhesiveness of these 

 salts. Cuprammonium sulphate is very much more adhesive than Johnson's mixture. 

 "Pyrox" is inferior in adhesiveness to its equivalent 1 per cent Bordeaux 1:1 plus 0.5 per 

 cent arsenate of lead. Climatic conditions prevailing at the time the fungicide is applied 

 affect the adhesive properties of the wash. — G. H. Coons. 



2053. Childs, L. Spray gun versus rod and dust in apple orchard pest control. Oregon 

 Agric. Exp. Sta. Bull. 171. 46 p., fig. 1-17. 1920.— The dusting method has been found to 

 control scab and codling-moth in the Hood River Valley, but present known dust materials 

 will not effectively control anthracnose, mildew, leaf-roller, and the various apple aphids. 

 Applications made with a rod are most expensive. Sprays applied with one gun, using a 3| 

 horse-power machine, are least expensive, although the saving in time resulting from the 

 use of a big machine, together with the fact that a perfect spray is produced with no overload 

 to the machine, makes a big sprayer much more economical and efficient. — E. J. Kraus. 



2054. Howard, W. L. Circumventing the pear blight. Monthly Bull. Dept. Agric. Cali- 

 fornia 8: 603-604. 1919.— Bench grafting of Surprise scions upon Japanese seedling pear 

 roots is recommended. By using a long scion and a comparatively short root, the scion 

 may be made to form roots of its own. The Surprise tree on the Japanese root is allowed to 

 grow until desired shape is obtained by pruning during the first two years. The main 

 branches may then be grafted to Bartlett. It is thus impossible for blight to kill more than 

 the branches, which, if attacked, can be cut off and the stumps grafted the next spring. — 

 E. L. Overholser. 



