SELECTING SEED POTATOES.

Otago Witness, Issue 2815, 26 February 1908, Page 9

SELECTING SEED POTATOES.

It is a common practice among those who grow potatoes to plant enly the small potatoes and culls that are loft in the spring after the supply for the house has been picked out. This is. of couise, the worst possible kind of selection, and always results in degeneration, or w hat is known, as running out of the stock. Because of this, varieties of one generation are \inknown hi the next. On the other hand, there are localities where the same variety of potatoes has been grown for the past 25 years, and is better and more producthc now than when introduced.

Commercial growers have not made this mistake to 60 great an extent, but ha\c generally made a practice of selecting- a good type and a medium size of tuber from the bins diiring the winter for the following crop. In this way come good seed is planted., but for soveial reasons a large per cent, is poor seed. A potato tuber is not a seed, but a part of the plant from which it came, consequently the characteristics of the parent plant arc more sure to be reproduced in the new plant than in plants that are grown from seed that are the union of two parent plants. A little observation in the field when digging will show that there is a great variation in the different hills of potatoes on a given area. One plant may have ten or twelve good-sized, smooth, marketable potatoes. The next may have one good potato with three or f our small or inferior potatoes, or possibly a hill may have but two medium-sized potatoes of the same type as the first hill. Now, if the selection is made in the cellar, about as many of the seed potatoes will come from poor hills as from good, and the result will be to produce more poor bills, and this carried on from year to year tends to decrease the yield of potatoes. The best w T ay to select is to take only good potatoes from hills that produce nothing but goo,d potatoes, and a goodly number of them. This work may be done by digging by hand, but €O many hills have to be discarded that it makes the work slow and expensive. If the potateos cling to the vines, the selection can be made by following the digger. The system used at the Colorado agricultural college experiment station is to plough out the rows with a common mould-board plough. This leaves the potatoes on tJie vines with most of the tubers exposed' on the surface of the turned furrow. Not more than 10 per cent, of the hills will be suitable to select from the first year, but these planted ought to produce a much higher grade of potatoes from which to select the next year.