THE RURAL WORLD.

King Country Chronicle, Volume V, Issue 405, 18 October 1911, Page 6

THE RURAL WORLD.

A POTATO EXPERIMENT. SUCCESSFUL WORK ON POOR LAND. (By G. Mills.) The potato crop of the Waerenga Experimental Farm of the past season encourages the belief that under proper treatment gum lands can be made to produce potatoes as well as the smaller farm crops to advantage. The returns were most satisfactory. The experiment was also interesting, from the fact that the varieties tested were few, and it was earned out upon lines which and every farmer can, and should, adopt. The site was parable land having a gentle slope facing the north, and for the previous two years had been carrying nursery stock in the shape of young pear trees. Prior to this it had produced a crop of potatoes on one part and vegetables on a portion of the rest. No manure in any shape was added after the nursery stock was planted. 1 The pear trees were lifted last autumn, and during September of last year the ground was ploughed once and disc-harrowed twice; once each way. The drills were made, by a doubiebreasted, or drill, plough, at a distance of 30in., and the ground remained in this condition till the crop was planted. The first lot of seed potatoes, Up-to-Dates, was obtained during September, the tubers being then picked over and placed in boxes prepartory for sprouting. On the 2nd October the potato sets in the boxes were sprayed with Bordeaux mixture, the 4.4.40 formula being used. Planting was commenced on the 3rd October, and each drill was given one stroke with a one-horse Plante Jr. hoe. The manure consisted of 4cwt of bonemeal, 4cwt of basic slag, and J cwt. of sulphate of ammonia per acre, and was sown i'n the drills, toe seed being planted at the same time. The drills were closed by the Planet Jr. hoe with the drill attachent. The ground was then given one stroke with the tine harrows reversed. When the tops were about Sin to Ift high the crop was sprayed with Bordeaux 4.4.40 formula. After spraying, the Planet Jr. was used between tiie rows, once to scarrify and again afterwards to earth up the potatoes. The same process of spraying, scarifying, and earthing was carried out about five weeks later, and after that the crop received no labour till the potatoes were lifted on the 29th February. The crop when lifted and when sorted four weeks later gave alto gether about 11 tons Bcwt of sound potatoes, 1 cwt being blighted.

The gross return per aero was just over 11 tons, and was made up as follows! Marketable size, or potatoes over 3 oz, 9 tons: seed size, or potatoes between Hoz to 3oz inclusive, 1£ tons; small potatoes, under lhoz, J ton. The lessons to be taken from the above experiment are: —Firstly, use clean and even sized seed; secondly, spray tubers before planting; thirdly, spray during early stages of growth; fourthly, keep down weeds between drills by scarifying, and earth as high as possible; fifthly, do not use too much nitrogenous manure.

THE POTATO MOTH

A study of the potato moth under the conditions of the recent visitation, especially in the dry areas of Central Otago, points to the fact'that it is probably not going to be a source of trouble to. potato growers year after year, as apparently it is only through the continued drought that it has originated. I have found it is in the most light, dry soils where the tubers are most affected, heavy clav land, where the tubera are most affected, heavy clay land where the moisture has been retained, being practically free from the moth. The moth practically attacks those tubers which are exposed above ground first; then gradually works downward. In a number of cases I have known the famer to dighis crop on finding the exposed tubers affected; bagging the potatoes; and, in a few days, whole sacks were found to be riddled from top to bottom. This procedure, obviously, is inadvisable, ns it merely is exposing the whole crop to the moth. I would advise the following: Firstly, great care should be taken in moulding up the soil nice and fine, to allow; the mould to knit well along the top of the drills, thus tending to hold the moisture; then, as soon as the moth appears, which will be in exposed tubers first, go carefully over and pick up the whole of those tubers which are showing above the ground. Mould up again, and do not lift the main crop until after a few nights' early frost, when the trouble of having the crop destroyed after lifting w ; II have disappeared; and also in any tubers dug which may have been affected, the grub will be found to be dead.

This was carried cut by a grower or upwards of a thousand sacks, who had only about thirty sacks affected. These were mostly those picked up and which were exposed above ground some time before lifting the main crop. I examined these, and in every case on cutting open the potato found the grub dead after a light frost or two. I certainly think that by lifting the crop in dry weather the moth does more damage than by leaving it in the soil and endeavouring to keep the mould damp. (It should be pointed out, remarks the biologist no the above interesting note, that leaving the cropundug until after a frost is only alicable as a preventive of infection in those districts where the climate is severe. In many parts of the North Island the moth is liable to be found on the wing almost throughout the year,)— Journal of Department of Agriculture,