POTATO MANURING

Press, Volume LXIX, Issue 20790, 25 February 1933, Page 6

POTATO MANURING

DEPARTMENTAL EXPERIMENTS. A SUMMARY. A detailed description of the potato manuring experiments in the South Island is published in the February issue of the "Journal of Agriculture." The report is too lengthy for republication in full, but a summary shouid be informative: — The average increase in yield due to super 3cwt an acre, was, in four experiments, 16cwt of table and 15cwt of seed potatoes. The average increase due to the use of super 3cwt in 48 experiments conducted since 1925-26, including the above, is 19cwt table and 6cwt sSSti potatoes. In one trial where super scwt was compared with super 3cwt, there was nn increase in favour of the larger quantity by 1.6 tons table and 4cwt seed. This trial was on better-class potato soil. The use of sulphate of ammonia at lewt an acre as an addition to super in five trials shows a general average increase over super alone of about Bcwt table, 9cwt seed, and 22cwt total potatoes. When used with super plus potash, the ettect of sulphate of ammonia is slightly less. In 41 trials conducted since 1925-2o the average increase due to the addition of lewt of sulphate of ammonia to super has been'lOcwt table, 6cwt seed, and 18cwt total potatoes. The average increase when lewt sulphate of ammonia has been • added to super plus potash in 42 experiments conducted to date has been 9cwt table, 4cwt seed, and 17cwt total potatoes. The relatively large increases in seed and small-grade potatoes resulting from the use of sulphate of ammonia : in the 1931-32 season is no doubt largely due to the extremely dry condi tions experienced during the growing season. * Sulphate of potash was effective at one centre (Gore Experimental Area), although in another trial at Gore white there were no significant increases, small but consistent increases in table potatoes with increased quantities ot sulphate of potash suggested that its effect was definite. At Kimberley both sulphate of potash and sulphate of ammonia added to super had the effect of increasing yield to a significant extent. However, the combined addition of . these to super, giving a complete mixture,, resulted in a lower yieW than either super plus sulphate of ammonia or super plus sulphate of potash. On the other hand, at Tuatapere, sulphate of potash added to super caused a significant depression in yield of table potatoes, but when sulphate of potash was used as an addition to super plus sulphate of ammonia the yield was increased above that ot super plus sulphate of ammonia or super plus sulphate of potash. The best way to remedy a cold is the logical way. Use "NAZOL"! It acts logically at the points ;>f infection. No cold is "NAZOL"-proof. 60 doses for Is fid;•l2o doses for 2s 6d. —3