POTATO BLIGHT.

Wanganui Chronicle, Volume XLIX, Issue 12646, 6 November 1905, Page 7

POTATO BLIGHT.

A good number of farmers and others assembled at the Chinamen's gardens in Chapel Street, Masterton, on Wednesday morningj to witness an exhibition of potato-spraying by Mr Fitch, the representative of the Agricultural Department. Included among those present were several hoys from the secondary classes at the District High School. Before giving the exhibition Mr Fitoh gave some information on tlhe most important points in preparing and applying the Bordeaux mixture as a preventive of blight. His remarks were on the lines of Professor Kirk's lecture here. He stated that very great care should 'be taken to see that the bluestone was pure, otherwise the results would not be satisfactory. To test it a small quantity should be dissolved in a tumbler and a little ammonia added. If pure it would tucrn a dark ultra-marine blue, without sediment; if not pure there would be a brown sediment. In preparing the liquid it was also very necessary that wooden vessels should 'be used in which to dissolve the 'bluestone, and the limewater should 'be poured into the bluestone, and not vice versa. This was important. Where pure limestone was not obttainaible, washing soda could 'be substituted, using 51!bs instead of 41bs of lime. Soda had i-ts advantages, inasmuch as there was no sediment, and it did not require straining. To obtain the 'best results, - only sufficient quantity of the liquid should be mixed to ket for one day's spraying. The dime and bluestone could 'be kept for some time after dissolving, but they should be kept in separate vessels. Care -should be taken to spray the under-part of the leaves, for it was there that the fungus chiefly developed.

In answer to questions, Mr Fitph further stated that the spnaying should be done in fine weather, if possible, as,.if done in wet weather, a large proportion of the mixture •would be washed off. It would be wise to spray, even if there was no sign of the disease, as in any case the wash acted as a stimulant and improved the crop. Two sprayings dhould be enough, but a third should be given if the disease should make its appearance. The first should (be given when the potato stalks were about six inches high, as the cost would then be much less than if left till they were, say,

18 inches high. The cost might be put down at about fifteen shillings an acre. He did not reoomimend tihe use of vermorite instead of Milestone. It 'had good qualities, 'but 'is strength could not be depended mpon, and va great deal of harm might be done. Mir Fitch, concluded his address by I saying that if good crops of potatoes were to 'be obtained, spraying would have to be done as a matter of routine, the dame as in fruit growing. As an ordhardist himself he would not attempt to grow fruit in New Zealand without spraying at least (twice in the season. An exhibition of the spraying, which was then given, on a patch of potatoes, j was watched -with considerable interest, I and Mr Fitch was called upon to answer many questions. Speaking of the prospects for the present season, he said it -was impossible to say whether the ! blight would be as 'bad as last year. It j all depended on the weather. If the season was a dry,one, there would possibly 'be very (little 'Wight ; but if, on the other hand, it should be wet, it might be a groat deal worse, than ever. He strongly urged tall those growing potartoes to spray their crops under any conditions.

The Bordeaux mixture which the Department recommend for spraying is prepared as follows:—4lb sulphate of copper, 41b fresh lime, 40 gallons water. Dissolve the copper in, say, five gallons of water in a wooden vessel; the best way is to tie it in a loosely-woven bag, and suspend the bag from a stick laid across the tub; or, in if in a hurry, use hot water. Slack the lime in another vessel, and add it to the copper solution; stir well till thoroughly mixed, then add sufficient water to bring the whole up to 40 gallons. Now strain out any dirct. The addition of 31b of treacle makes the mixture more adhesive, and should he used if damp weather is feared.