SETTLERS' COLUMN

Bay of Plenty Times, 24 April 1890, Page 1

SETTLERS' COLUMN

PEOFBSSOR COOK ON &PRAYINO- FRUIT TREES.

At a recent meeting of the American Association for the Advancement of Science, tbe gtfbject of spraying trees with arsenites taken op by Professor A. J. Cook, who said:— Again, as oat wild fruits are more Cleared away, w#|only need to spray our apples once to destroy the codlin moth, and can treat the plnm trees three or four times with Paris green or carbonated It me in case wo hare only occasional showers. For the apples we can use London purple— lib to 200 gallons of water. For the plums against the Curculio we must! use Paris green—lib to 200 or 800 Ifallons of water. Expecting the injury done to foliage by the use of arsenites, he said : — London purple is more injurious to the foliage than is Paris green. This is doubtless owing to the soluble arsenic which is quite abandant in London purple and almost absent in Paris green. London purple may be tised on apple, pear, cherry, plum, and most ornamental trees, but on these should never be stronger than lib to 200 gallons of water. If the application is to be repeated, a3 it must be for | the Ourculio, to prove effective, or if j it js to be used during the first month \ oi summer. Peris green should be I used in the same proportion as above, j or else we should use only lib of London purple to 300 gallons of water. I, now think that this necessity is morfe due to time of application than to the fact- of increased quantity! oi the poison. If the areenites are to be used on the peach to defend it ! against the Curculio, Paris green only should be used, and that not stronger than lib to 300 gallons of water: The injury lone to the foliage is never immediately, apparent. It usually shows somewhat the second day, but frequently the full injury i« not manifest till the filth day, and often not till the- tenth. He likewise demonstrated that. there is no danger of cattle being poisoned by eating the grass under tbe sprayed trees. Pro-! fessor Clarence M. Weed, of Columbus, Q^iread a paper on the plum Curcalio, showing the good results of | spraying with London pHrple as a remedy for tbe Curculio.- Professor! Sanders, of "Ottawa, expressed his! opinion that Paris green was a better arseoite to use than London purple.