340 JOUKNAL OF THE DEPARTMENT OF AGRICULTURE. OcT., 192^. 



pest when the infestation is rather severe. Results dernonstrate that 

 one half-pound of calcium caseinate in 40 gallons of diluted concen- 

 trated lime-sulphur of 5 degrees Beaume improves considerably the 

 efficiency of lime-sulphur in the control of red scale. [Compare 

 Eieffer (6) 6 degrees Beaume records with Kielfer (c) 5 degrees 

 Beaume, plus spreader: Louise Bonne, 4 degrees Beaume and 

 5 degrees Beaume records with Louise Bonne 4 degrees Beaume, plus 

 spreader.] Further experimentation with this material in lime- 

 sulphur may lead to the discovery that one application of the calcium 

 caseinate lime-sulphur mixture, which is much cheaper than a 

 miscible oil, will effectively control severe infestations of red scale on 

 pear trees. Further trials are necessary to determine the question. 



Eecords of the 1921-22 season (see table I) conhrm those of last 

 year (2) in respect to the determination that a dormant spray of 

 concentrated lime-sulphur of 4 degrees Beaume (1-10 dilution) fol- 

 lowed by two foliage applications of concentrated lime sulphur of 

 1 degree Beaume, or slightly less (dilution of 1-40 and 1-50) applied 

 to the trees during the first two codling sprays, will effectively control 

 red scale, and is as efficient as one dormant spray of South African 

 manufactured miscible oil diluted 1-18. [Compare the following 

 records in Table I with other records : — Duchesse, Beurre Hardy, 

 Louise Bonne, and Kieffer (b) 4 degrees Beaume, plus two foliage 

 sprays of lime-suiphu]'. and Kieffer (c) miscible oil 1-lS. j Concentrated 

 lime-sulphur, diluted either 1-40 or 1-50 was found during both seasons 

 to cause some burning of foliage, not sufficient to aft'ect the crops of 

 fruit, but possibly enough to cause some alarm among very cautious 

 fruit growers. During the 1921-22 season, the foliage of the Duchesse 

 variety was more susceptible to burning than that of the Louise 

 Bonne, Kieffer, Forelle, and Beurre Hardy varieties, but not so severe 

 as to affect the fruit crop. It is interesting to note that burning of 

 foliage in the Forelle and Duchesse trees occurred about a day after 

 the application of the first foliage spray. The burning was immedi- 

 ately preceded l)y a heavy fall of dew, followed by sunshine. The 

 burning was somewhat intensified in these varieties, and first appeared 

 in the Kieffer, Louise Bonne, and Beurre Hardy trees a number of 

 days after the application of the sprays, and not until the temperature 

 reached 90 degrees Fahrenheit. 



Although the writer hesitates, on account of a certain amount ol 

 burning of foliage, to go so far as to advise fruit growers in the 

 coastal regions of the Cape Province to substitute diluted concentrated 

 lime-sulphur for Bordeaux where red scale or mites and fusicladium 

 must be combated, he may state that this material has been used in 

 the Elsenburg orchard for two successive years, and that he knows of 

 several progressive fruit growers in the Western Province coastn! 

 region who have used this insecticide as a foliage spray for several 

 years without aff'ecting the crops. Further experimentation will be 

 continued at Elsenburg to determine if burning of foliage may be 

 avoided, and if self -boiled lime-su]phur, which is less likely to cause 

 burning, may be effectively substituted for the concentrated. 



Summary and Conclusions. 



{a) A dormant spray of concentrated lime-sulphur, concentrated 

 to 4, 5, or G degrees Beaume, will not satisfactorily control red scale 

 on pear trees wlien infestation is considerable. 



