PROTECTING ORCHAEDS.

New Zealand Herald, Volume LXIII, Issue 19236, 27 January 1926, Page 12

PROTECTING ORCHAEDS.

CAMPAIGN AGAINST PESTS,

DISEASES NOW CONTROLLED. HORTICULTURAL DIVISION WORK Biological control of pests which afflict the or'chardist and farmer is the dream of the scientist, perhaps also of the visionary farmer. That dream will not be realised this year, but; recent -events have demonstrated that' it has been brought measurably closer to the realm of practical things. Inquiry made regarding the prospects of the fruit season in "the Auckland district and the prevalence of pests revealed that all the usual diseases that have .come to be regarded as inevitable are with us. A gratifying feature is that they are not causing the widespread damage that signalised their advent in past seasons. A prominent orchardist stated the great evil to be feared was the introduction of pests as yet unknown to the Dominion. Those that had made their appearance had been combated with a great measure of success. Orchardists, in conjunction with the Horticultural Division of the Department of Agriculture and tho Cawthron Institute, were using much more scientific methods in dealing with both insect and fungoid diseases. The most conspicuous success had attended the war on the woolly aphis, or American blight, the introduction of its parasite, the aphelinus mali, having practically eradicated it from the Dominion. It had, of course, the drawback of all parisitical remedies that when the host of the pest disappeared the parasite had no food to sustain it. However, it bred so rapidly and was so easily distributed that fresh supplies could always bo obtained when necessary. Brown Rot and Pear Midge, Regarding brown rot, which has been responsible for such severe losses, m stone fruit in particular, the orchardist said that spraying was keeping the. disease fairly well under controL The practice of winter spraying with full strength solutions of bordeaux mixture or lime sulphur followed, when tho fruit had formed, with more diluted solutions of lime sulphur had proved a very satisfactory remedy. The pear midge, whicji was epidemic in Auckland, added, the' grower, was still a yery'difficult pest to deal with, arid many orchards' still suffered, severely .from its ravages. A great deal of work had been done by ■ the ' Horticultural Division and individual orchardists in . the direction of finding a remedy for this, pernicious inject. There was promise in ' the methods lately introduced of fumigating the soil to kill the larvaewhich hibernate beneath the surface. The Horticultural Division was also breeding out a'parasite which it was hoped would play a large part, in the control of the pear midge. The outstanding success that had attended the introduction of the appelinus mali'to combat the woolly aphis encouraged the hope that'the parasitical attack on the pear midge would prove successful Control of Fungoid Diseases.

: Many of the common and very destructive fungoid diseases like le'af; ( . curl had been kept practically sunder control by the judicious., use , ,pf - sulphate Sprays. The codlin moth, pest, once regarded as .almost , uncontrollable,, and Which threatened to rjiJfi-; the apple industry in' the Auckland; 'Province, had become practically innocuous since the introduction of arsenate of .lead' sprays, i .The dreaded fire blight, which: threatened to have such dire effects on several kinds of fruit trees, received a great check- by the drastic ' action of the orchardists, supported t by . the • horticultural division. Although it , caused the destruction of thousands of'trees' the comprehensive" methods of the growers in ruthlessly sacrificing their" trees proved effective; ' Apparently the pest . was sporadic •in its incidence, and the prchardists had not been troubled with it this season. Since every fruitgrower kept careful watch for the appearance -of this disease and cut out affected branches or trees and destroyed host plants such as hawthorn it was not likely to again become a serious menace.

Eternal vigilance apparently is tho price the orchard ist has to pay for even partial immunity from the pests that at times threaten to overwhelm him. This season has been marked by the fact that the pests in the Auckland Province have been kept well under control. Such Achievement has only been possible by the application of tho methods dictated by the scientific discoveries of recent years. Heed of Progressive Action. It has been demonstrated beyond contradiction that the commercial orchardist to be successful must be progressive in thought and action to protect and market his crops. The amateur growers, of whom there are many, are fortunate in having only to follow the lead. Specifics for the various pests that hitherto have 'made their appearance in the district are 'readily available,- and garden and orchard ,can be made and kept clean at a reasonable cost. The horticultural division of the Department of Agriculture is doing remarkably valuable work in plant pathology. It possesses now a number -of highly skilled and earnest officers to whom the orchardists of New Zealand owe much and whose services are becoming very highly appreciated. To the Cawthron Institute, established in the fruitgrowing province of Nelson, the orchardists of the Dominion are much indebted. Dr. Tillyard and his associates at the institute, besides being responsible for the eradication of the .woolly aphis, are unremitting in their efforts to benefit the fruitgrowers of the Dominion.