INFLUENCE OF SEED SELECTION.

Otago Witness, Issue 2805, 18 December 1907, Page 9

INFLUENCE OF SEED SELECTION.

| How' necessary it is for a farmer to exercise caTe in the seleotion of the seed that ho commits to the ground is being increasingly demonstrated The iaat annual . report of the Ontario Agricultural College i contains a reminder on the subject. In the 1 course of a series or experimente on the ' influence of seed selctioh it was found that the large seeds of oats produced about eight bushels per acre more than the medium Bleed, and the medium about seven and a-h&li bushels more- than the * small-sized seed, or an advance of over 15 bushels per acre from the large as compared with the small seed. ■ . Averaging the results for each class of crop, it was found that the large seed'surpassed the small by 19.1 per cent, for the grain crops, 40.3 per oent. for the rape, and 3.1 per cent, for the root crops, j In another experiment * comparison was ! made between plump and shrunken seeds of barley, spring wheat, and winter wheat. In this case none but either plump or shrunken 6eeds were selected, and the Beleo- . tions were made regardless of the size of i the kernals. Th» same number of seeds (of the different selections for each class of grain was taken, and &c different lots I -mete sown on plot* of uniform sise. The ' average of several years' results show that i in weight of grain per measured bushel and yvaW of both straw and grain per aore, the large plump seed surpassed the ■hionken seed in every instance. In averaging all the results it was found that the plump seed gave a yield of 20.2 per oent. more than toe shrunken seedTJnlest care is exercised, a considerable amount of grain is frequently broken in the process of threshing. To ascertain the ■ amount of injury done to the germination of the grain py means of its being broken [ at the time of threehirigr, experiments have j been conducted for at least six years, by ' sowing both sound ssed «ujd broken seed lof Barley, winter wheat, and peas. The [ following gives the Average yield of grain per acre of each seleotion of each class of ©io©:— Barley : Sound seed, 63.8 bushels; broken seed, 46 -bushels. WjnteT wheat : Bound seed, 46.9 bushels ; broken seed, 9.3 bushels. Peas; Sound teed, 29.2 bushes; broken seed, 10,2 bushels. Ac the barley nearly always breaks orosswise, the germ lis üBU*UJg left uninjured. In the case pf j 'winter wneat ana peas, however, the grain usually breaks along the create, and in I wrr many oases the germ v either totally 41 partially destroyed*

POTATO DETERIORATION. Ifc appears from an interesting article in the Kew Bulletin that the degeneration of potatoes in England is due to the methods of selection and the lineg followed in attempts to improve various varieties of potatoes. In short, " degeneration appears to be due mainly to the vegetative method of reproduction commonly followed." Such methods have largely attained their object; this ie, increased yield, improved flavour, and smooth and even surface, with shallow "eyes"; but they have also led to otfier results? The vegetative method of reproduction, it is asserted, has favoured a comparative absence of diastase, the ferment responsible for the conversion of the 6tarch into the liquid sugar necewary to enable the potato to sprout. Absence of sprouting is, of course, due to a lack of the necessary food material which the diastase should prepare; indeed, in the case of tubers that had failed to sprout a total absence of diastase was proved. It is remarked that ..one correspondent stated that of 70 tons of high-grade potatoes specially intended for seed, only five tons showed signs of E routing, the result being a serious loss. Germany the loss due to this cause has varied from 5 per cent, to total lose, the average being 50 to 60 per cent. It has been shown in experiments conducted at Kew over three years that sterility, or failure to sprout, is accompanied by the comparative absence of diastase, as already stated, and by more or lees arrest of the development of the vascular system of the tuber. The absence of diastase results in non-formation of the necessary sugar from the starch, while the non-development of flbro-vascular bundles means that if food material is present it cannot be conducted to the growing points or eyes. If the food ie but scanty, owing to the comparative absence of diastase, sprouts may begin to grow, but will perish at an early age. Abandonment of all forcing, or selective tactics on the part of the grower enables the plants to regain their power of producing diaatase, but in such a case the good points won by the grower — increased crop, improved quality, etc. — appear to be largely lost. It was found also that a liberal dressing of superphosphate increased ■the amount of diastase much more than farmyard manure, while light favours the production of diastase jaore than does darkness. More diastase also, is produced id a high than in a low temperature.