BITTER PIT IN APPLES

New Zealand Times, Volume XXXIII, Issue 7446, 22 May 1911, Page 2

BITTER PIT IN APPLES

THE ALLEGED VICTORIAN DISCOVERY. Australian paxiers to hand contain .some accounts ox the alleged discovery of tho cause of the mysterious trouble with apples known as bitter jut, a cause, by the way; discounted by both pomulogista and leading fruitgrowers iu this country. 'The Melbourne statement was made in a paper prepaiod by Dr Jean While, and read before members of the Koyal Society of Melbourne by Professor A. J. Ewart. The Investigation of the disease. Professor Ewart explained, was undertaken about the middle of last year. The field work was performed at Burnley Horticultural Gardens, and also by Professor Ewart ia ills own orchard at BoxliiJl. The observations made during tho field work at Burnley gardens suggested that’the disease was caused by tne entrance of poisonous substances used as insecticides and sprayed over fruit. The disease occurred wnerc spraying with arsenate of load had taken place. It had been found, too, that pits could be artificially produced by simply rubbing the surfucO of a fairly young apple with some strong poison, such as chloroform. Or corosive sublimate. A particularly interesting observation was made by Professor Ewart at Box Hill, on. his own orchard, which was divided into two halves, tho trees belonging to one half-being sprayedwith ai senate of lead and those of the other half being left unsprayed. He examined every apple from each half, and whilst the majority of the trees in the sprayed portion possessed a greater or less number of pitted apples, not a single’ specimen was forthcoming from the .unsprayed portion. Severely pruning tho tree, said Professor Ewart, would render th© fruit moro concentrated, ami so moro readily reached by the spray. Sappj* varieties of fruit were more subject to the disease. By 1 using coarser-grained arsenate of lead the possibility 'of tho poison entering the fruit might be much lessoned, but it would also be less effective, and would not adhere so well. Although the amount of poison present in badly-pitted apples might not be very large or suilicient to produce injurious consequences, such apples should not be sold or eaten. In addition, in no circumstances should spraying with arsenate of lead be carried out after the fruit had attained a fair size, or when the fruit was wet, or the day cloudy and the ground moist. Sappy varieties should be less heavily sprayed than mealy ones.