BETTER CROPS.

New Zealand Herald, Volume LXVII, Issue 20721, 14 November 1930, Page 4

BETTER CROPS.

HIGHER POTATO YIELDS. CERTIFICATION OF SEED. INCREASING POPULARITY. No. 11. The nred for seed certification as ii s relates to potato yields is further stressor 0 in the paper contributed by tlio Farrr 0 Extension Service of the Fields Divisioi • and Plant Research Station, Palmcrston ' North. Differences in tho yields of lines ' grown in departmental trials last season, ' and reviewed in tho Journal of Agri- * culturo for August, aro taken ns convincing evidence of tho need for system- ' atic certification. "It, may bo assumed that tho owners of all tho lines on trial considered that 1 their seed was of more than average 1 merit; otherwise they would not have taken tho trouble to seek certification for them," says tho paper. " Further, it is necessary to bear in mind that all lines entered for certification aro grown under similar conditions of soil and treatment under official supervision. Tho yields that aro published aro tho ones which are obtained under such uniformity to all differences which occur may safely bo put down to differences between tho lines of seeds themselves. Ditlerencas in Yield. " Hero aro somo differences which occurred in last year's official trials under such uniform conditious: —Dakota ranged in yield from 11 tons 12cwt. an aero to 1 ton 14cwt.; Aucklander Short Top (often called Sutton's Supreme) ranged from 14 tons Bcwt. to 3 tons 2cwt.; Arran Chief ranged from 10 tons 12cwt. to 2 tons 4cwt.; Up-to-dato ranged from 11 lons scwt. to 2 tons 2cwt.; Epicure ranged from 9 tons 14cwt. to lOcwt., and Jersey Bennes from 6 tons Bcwt. to 1 ton 12cwt. Similar differences occurred in tho case of other varities. The significant feature of all this is that it was deemed worth while to seek certification for so many low-yielding lines. " Tho yield from certified seed may reasonably bo expected to bo superior to that from ordinary seed: To obtain definite ovidenco on the point, Mr. J. W. Mad field, agronomist, last season organised special trials in which certified and noncertified seed wero grown under similar treatment at six centres in Canterbury and one in Southland. The results of theso trials were:—Epicure certified seed yielded an average of 3 tons 2cwt. more than Epicure non-certified; Aucklander Short Top certified yielded 18cwt. an acre moro than Aucklander Short Top non-certified; Dakota certified yielded 3 tons 6cwt. an acre more than Dakota non-certified; Up-to-date certified yielded 6 tons more than Up-to-dato non-certified. Certification Percentages. " Further information on the same point is provided by last year's trials with the Dakota lines sent in by owners seeking certification. The yield of the lines which became entitled to certification was 8.5 tons an acre, while tho yield of tho lines which wero refused certification was 5.7 tons per acre. How ' pedigree ' counts in potatoes is indicated by the following results of the 1929-30 trials:—One hundred and two crops under trial originated from cartifiod seed or provisionally-certified seed. Of these 57 merited certification. Two hundred and sixty-three crops under trial originated from seed which had not been certified. Of these 53 merited certification. This means that when dealing with crops from certified seed rejections amounted to 44 per cent, of tho lines submitted, whereas when dealing with crops from non-certified seed the rejections amounted to 80 per cent, of the lines submitted. " From all this there aro three definite conclusions: (1) Tho uso of certified seed is very likely to result in substantially heavier crops; (2) the use of certified seed is generally tho most direct way toward enabling ono to become the producer of certified seed; (3) tho use of certified seed does not ensure that the seed from tho resultant crop will itself be entitled to certification. Last year approximately one out of every two crops from certified seed was rejected for certification purposes. Protection for the Buyer. " Because of its intrinsic value the work of potato seed certification is showing - remarkable growth in popularity. In 3927-28, 137 lines were entered; in 1928-29, 180 lines; and in 1929-30, 408 lines wero entered. " Ordinarily, certified potato seed i.s moro costly than non-certified seed. Buyers may protect themselves, and should protect themselves, by making sure that tho seed which is supplied as certified seed is from sacks which carry tho official tags which aro issued to growers of seed in sufficient number to enable ono tag to bo attached to each sack if seed which has passed tho final eximination entitling tho seed to certification. At tho present timo seed is being sold as entitled to certification or provisionally certified. This seed is in sacks o which the official tags aro not attached, md buyers of it find themselves in "ossession of an inferior lino they have mly themselves to blame because of their lisregard of tho official safeguard prodded. If there is no tag, the seed is not :erlificd."