Where phosphoric acid is necessary, it can be had in the form of ground bone or acidulated rock, and potash can be had in the form of sulphate or as kainit. Where the scab is prevalent, it may prove better to use kainit, on account of the salt which it contains, as will be presently explained.
Planting.—It requires from seven to ten bushels of tubers to plant an acre. Some growers use as much as fifteen bushels. The date of planting, depth, distance between rows, etc., are details for individual determination. Flat culture is better than ridge culture, so far as conservation of moisture is concerned. It is important that good Northern-grown seed be planted; tubers which have not lost their strength by excessive sprouting. Storage in a cool, dark, dry place is best for potatoes. Whether planted early or late, or at successional dates, must be determined by the market requirements of the grower.
Varieties.—The varieties of potatoes are many, and while it is wise to experiment in a small way on new kinds, it is best to depend for business purposes on standard sorts that have been fully tested.
Irrigation.—After the farmer has exhausted his best efforts in the preparation and fertilization of the soil, and after good seed has been planted and the best possible culture given, there may come a season of prolonged drouth that will defeat his purpose of securing a large crop. This result is not common, but neither is it rare; and where farmers are looking toward the high culture of certain special crops, it would be well for them to consider the matter of artificially watering their potato fields.
An Average Tuber of Table King, One of the Best All Around Potatoes.
Diseases and Enemies.—Not counting dry weather, which sometimes robs the farmer of two-thirds of his crop, there are four diseases which exert a disastrous influence on the potato, and which are liable to occur any season. Two of these diseases are of the leaf and stem and two of the tubers.
The two leaf troubles are respectively known as blight or downy mildew and the Macrosporium disease. The two tuber troubles are scab and rot.
Leaf Blights.—No attempt will be made here to separately describe the two leaf diseases. Both destroy the foliage and check the further growth of both vine and tuber. The leaves turn brown or black, and the stem quickly wilts and falls. There can be no growth of tuber without vigorous health of vine. Spraying with Bordeaux mixture, in advance of the occurrence of any disease, is recommended.