HINTS ON POTATO GROWING.

New Zealand Mail, Issue 1247, 23 January 1896, Page 5

HINTS ON POTATO GROWING.

HOW TO RAISE PROFITABLE CROPS. The potato is the most prod active crop grown if reckoned by the amount of food elements contained in it. That is to say, it may be made the most productive source of food if full advantage is taken of its natural proclivity uuder a generous culture. We do not by any means rate this vegetable at its true value; for one reason, among others, that it is considered only as a human food, and of little account for feeding farm stock. And yet it r is a suitable food for all kinds of domestic animalsAll farm animals eat these tubers with avidity, and while they are somewhat objectionable in a raw state, because of the large quantity of indigestibe starch they contain, yet when cooked they are entirely free from the least objectionable quality, and ar quite agreeable even to horses, the most particular of all our farm animals in respect to their choice of food. But farmers will hardly need any certificate of character for this crop. What are more wanted are some practical suggestions as to .its most profitable culture. It is a costly crop to grow under disadvantageous circumstances, but with all the modem labour-saving appliances, as planters and diggers, with rich soil and good culture, it is one of the most profitable. It will yield four tons per acre under average good management, and has been made to produce over ten tons by skilful culture. It is an oft-repeated fact that but a few farmers are successful potato growers, and one need not search far to find the reason. The ordinary farmer will put in all the other crops before giving even a thought to his potato ground ; then he will take the odds and ends for his potatoes —plough his ground in a-.careless manner, plant carelessly, and really expect a crop therefrom.

CULTIVATION AND MANURE In preparing the soil for the potato it is desirable that it should bestirred I deep in autumn or the beginning of winter, and that as little working of the soil in spring as is consistent with securing a fine mould should be studied, it being found highly important to retain the moisture which is in the soil, partly to push away the .young shoots, and to supply, during the dry weather . in spring and summer, the moisture necessary for a healthy growth. During the winter months the action of the atmosphere on soils exposed to it by being roughly ploughed disintegrates the soil in a manner that no mere mechanical action can . effect. If a grower intends to achieve complete success it is not sufficient that he should plant one good variety • it is also necessary to cultivate in a rational manner, and to give to the soil a suit-

able kind of manure. In the immense majority of cases there is a want of phosphoric acid, and to meet this requirement the application of phosphates is recommended. The or Thomas phosphate generally gives good results. The basis of the manure should consist of good dung, given in moderate quantities, and to this may be added, if the soil is somewhat exhausted, a small quantity of nitrate of soda, which it is necessary to cover in with the plough. Potash is |g |oy H g ug | |Ai gg M g j|ijM

to the potato plant being rather hurtful than useful. Farmyard manure should always be applied in autumn, supplemented in spring with a few hundredweights per acre of artificial manure.' The manure applied in autumn should be only partially decomposed. The quantity may range from 10 to 30 tons per acre, but, as the liability to disease is considerably increased with extra manuring, moderate doses are advisable where the average percentage of. diseased tubers in the dis trict is considerable. Farmyard manure can be occasionally judiciously applied at the period pf planting, but fresh manure is certainly detrimental to the growth of sound tubers. If a single eye, with only a small piece oi potato attached, is used for seed, the young plant will npt have that abundant store of food ready for use that it would if a whole potato were planted. It is the general practice among farmers to cut their potatoes for seed, and some cut to a single eye in a pi ce, believing that to be sufficient. .Experiments have been reported where good yields were obtained by the use of single eyes for seed, but it was under the most favourable conditions, when the soil was very rich, and contained abundance of food ready for the use of the young plant. In general field culture the condition is different and the food supply scanty, so that the single eye affords insufficient food for the plant. SEED POTATOES. The largest crops can be obtained by the use of large whole potatoes for seed, but it is by no means demonstrated that the practice can be economically adopted, on account of the immense portion of the crop which would have to be carried over for; seed, with all the risks attending such keeping, or the great expense of purchasing. The most economical way, taking all things into consideration, is to use fair-sized potatoes cut into about four pieces. It has frequently been demonstrated that the practice of cutting single eyes is a good way to save sc. u and lose a crop. If potatoes are cut in flat pieces or halved through the middle, it is sometimes a question which side should be put down. Our experience, carefully attested years-ago, is strongly in favour j of putting iffe eyes down, and pressing

the piece firmly into the soil with the foot before covering. Then the roots are in immediate contact with the earth when they push out, and it does no harm for the stem to turn upwards from under the potato set. We think it all the better for it. The yield of potatoes depends largely upon the kind of seed used, whether it is cut or whole, and whether lai'ge or small potatoes are planted. It also makes a difference whether the potatoes are in a vigorous condition or have been weakened by improper keeping or by having sprouts broken off from them All young plants during the early stages of growth depend largely upon the food in the seed for nourishment to promote growth. SMALL POTATOES V. LARGE CUTS. A small potato whole produces much belter results than a large potato cut in pieces. A farmer whom we know tried planting small whole potatoes about lin in diameter beside large pototoes cut to the same size, and the result was largely in favour of the small potato. Then lest it be said that the small potatoes did best because they had the most eyes he commenced a series of experiments, which he continued for seven years. He removed all the eyes but two from the small potatoes, and cut the large potatoes to two eyes, making the weight of the two pieces the same as that of the small potatoes# i The land was all prepared alike, while in every other hill were planted two small whole potatoes ; the hills between them were planted with two pieces of large potatoes. At harvesting time the product of the small potatoes was assorted, weighed, and recorded ; and small tubers were selected each year for seed. The aggregate result for the seven years was as follows: —Number of good eating potatoes from the small whole potatoes, 2061’0 large and 621 b of small potatoes. The same number of hills of the large cut potatoes yielded 1991 b large and 711 b of small potatoes, the small whole seed producing 141 b more of large and 91b less of small potatoes than the large seed. This experiment seems to indicate that cutting a potato weakens its power to proi duce a vigorous growth. When a whole potato is planted beside a cut tuber the ■ whole potato starts first and usually ; keeps ahead of the plant from a cut

potato. This seems to be the reason that a small whole potato yields better than a cut potato. A potato that has sprouted at planting time, so that the sprouts break off in planting, will not, as a rule, produce much more than half as large a crop as potatoes that have been well kept and have the eyes started only just enough to show that they are in good condition. The condition of the potato at the time of planting affects the crop quite as much as the size, providing it is large enough to give the young plants a vigorous start. Cut potatoes should not be planted immediately after being cut, unless covered with plaster or some other material to shut the air out and prevent bleeding. They should be spread a few hours to stop the bleeding and dry them off. Of course, in order to succeed well with potato-raising, the farmer should select a productive variety to plant, secure good seed that has been kept cool and sufficiently moist, and plant at a favourable period. HILLING V. FLAT CULTURE. A great many farmers hill their potatoes. They do this sometimes when convinced that hilling is injurious, and in a vei'y dry season it is generally fatal to the crop. It is almost impossible for a moderate summer rain, or even a violent rain, to penetrate the potato hill so far as to furnish moisture to the roots. A rain which fell slowly for 24 hours might do this, but summer rains are not often of that character. The rain falls heavily, compacts the surface, and runs off in furrows between the rows made by hilling. These furrows are just where the feeding roots of potatoes should be if the loose soil were not earthed up around the hills. Why do farmers thus run counter to the plain laws of potato growth? It is usually to keep the potato from growing out of the ground and sunburning until the larger part are worthless for marketing. Some potatoes naturally form tubers nearer the surface than do other varieties. .Even those sorts that were most objectionable in this respect we would not hill up as is usually done. It is comparatively a light task to go over a field that has had level culture, and draw with a hoe a little earth above potatoes that appear above ground, rather than use a moulding-up plough, tearing to pieces the feeding roots of potatoes between the rows, on which the future growth of the tubers depends. If, as usually happens, the hilling is delayed until tubers are formed, the growth of these tubers is at once arrested, and the result at best is two crops of very small potatoes in each hill. SHALLOW PLANTING A MISTAKE. Too shallow planting of potatoes is the common mistake. The shallowplanted potatoes undoubtedly come up quicker, and if very early potatoes are deep planted on wet ground they may rot in the soil and not come up at all, especially if fresh cut. But by partially drying t.he cut potato-seed, it may be planted four or five inches deop, and come up every time. This deep planting has its advantage in allowing early cultivation before the potatoes are up. Then the harrow may be put cn to leave the surface as smooth as possible and keep the soil moist. The chief cause of light crops of potatoes is drought, and this is always most injurious on potatoes that are hilled. More than once have we seen acres of potatoes withering and dying in a few days after the hilling had been finished, even though rains had fallen, which on a level surface would have mainj tained growth for several weeks. It is probably true that hilling makes easier digging, and itis_partly owing to the

fact that in the hill the potatoes are fewer in number, and are necessarily bunched in a heap. When they have more room to spread the crop is increased, and proportionately the labour of digging. All kinds of potatoes, even those whose tubers are bunched, will spread their roots through the whole surface between the rows if the soil is not scraped out so as to leave furrows. In that case, of course, the roots are cramped, and the crop is accordingly lessened. PRODUCING NEW VARIETIES. It is most essential that the potatogrower should be constantly striving to produce new varieties. Until within the past few years new varieties were obtained from seed taken haphazard from the fruit or apples of any potato Systematic crossing by hybridising different varieties is now, however, generally practised by careful cultivators. When systematic hybridisation is carried out it is necessary tliat the plants employed should be kept perfectly isolated by putting them under a glass shade, or true crossing will in all probability be interfered with. After the plants have been fertilised they may be allowed to develop the seeds under natural conditions. When the “ apples ”or fruits are ripe they should be gathered and stowed away to dry. Subsequently they should be placed in water until they become plump again ; the seed can then be squeezed out, and, after being washed, should be allowed to dry, when it. may be stored until spring. It left dry until the spring the seed may be rubbed out, and should be sown in a fine tilth, the seed being deposited about half an inch below the surface. The plant will grow in the ordinary manner, and when it comes to maturity it will, in all probability, be found that there are a number of small tubers about the size of a bean, or larger. These will have to be planted in the following spring, when they may attain the size of a hen’s egg, and the produce of each year should be planted in each subsequent spring, until, at the end of four years, the tubers will have developed to the full size. By this time an experienced judge of potatoes will be able to form an. idea of the probable value of the stock ; an estimate of the vigour of the variety, its yielding powers, shape, depth of eyes, colour, habit of growth, cooking capabilities, and other characteristics can be arrived at, so that its probable value as a new introduction can be ascertained. The stock may not be altogether of one type, as potatoes are liable to “ sport ” —that is to produce, among others, specimens which differ from the majority. These “ sports ” should not be discarded without attention, for many good strains and varieties have been obtained in this way. When a season of abundant yields and low prices, such as last year, comes, always plant more potatoes than ever the next season, for thousands of growers will let such a season discourage them, and a reduced acreage the next year will '.'ring profit to those who plant. In growing vegetables of any sort for market, it is always a good rule to plant largely of those with which the market was overstocked the last season, and less largely of those which then ruled highest in price.—By “ Thistledown” in the Australasian.