102 Journal of the Department of Agriculture. — Aug., 1922. 



Codling-Motli in Pears. Dusting Experiments. 



One of the most difficult and the most important phases in the 

 farm economy of the fruit grower is the proper treatment of his trees 

 in the control of insect pests and fungous diseases, and those who read 

 the Journal will have learned from the frequent references to the 

 subject that the Department is engaged in much experiment designed 

 to ascertain for the guidance of growers the right materials of the 

 correct strength, and the proper time of application, to be used in 

 the suppression of these pests. In the September, 1921, issue of the 

 Journal there was published a useful spray programme for pear and 

 apple orchards in the coastal districts of the Western Province in 

 connection with the control of codling-moth, red spiders, fusi- 

 cladium, and red scale. Elsewhere in the present number of the 

 Journal there appears a further article by the same officer, Dr. Pettey, 

 Entomologist at the Elsenburg School of Agriculture, who deals 

 with another aspect of the subject, that of power dusting. Experi- 

 ments in this connection have been carried out at Elsenburg for 

 some years, for the successful substitution of power dusting in place 

 of spraying as at present would bring several advantages to the 

 grower. Dr. Pettey relates the testing of the method at Elsenburg, 

 and has come to the conclusion that under South African conditions 

 dusting will not satisfactorily control codling-moth and fusicladium 

 on pears. While in this respect it does not appear to hold any 

 ad^'antage, it is pointed out that dusting is destined to play an 

 inij)ortant part in the future control of insect pests, and is already 

 being used with much success in the control of tobacco, cotton, 

 potato, and other pests. It is a subject, therefore, of general interest 

 to South African farmers, and the improvement of the method in 

 regard to dusting machinery and materials will closely be followed 

 with a view to its introduction on a wider scale in this country. 



Pear Scab in the Western Province. 



While Dr. Pettey has been engaged in various experiments con- 

 nected with the insect pests, Mr. Putterill, of the Division of Botany, 

 has been carrying on investigations in regard to the several plant 

 diseases that are found in the Western Province, and his publications 

 on the subject that have appeared in the Journal from time to *.ime 

 have been of considerable benefit to fruit growers. The Department 

 has now published a bulletin* written by Mr. Putterill on " Pear 

 Scab in the Western Province." It is attractively illustrated and 

 explains the experiments carried out and discloses certain facts 

 relating to the control of the disease. A study of this bulletin 

 reveals the minute and thorough nature of the experiments which 

 prove, among other things, the importance and necessity of spraying 

 fruit trees four or five times, at least, during the season, either 

 with bordeaux mixture or with lime sulphur. They demonstrate 

 also the need of spraying at the right time if it is to be effective. 



* " Pear Scab in the Western Province," by V. A. Pntteiill, M.A., Bulletin No. 2, 1922. 

 Obtainable from this office. Price 3d. prepaid. 



