1910.] Summary of Agricultural Experiments. 313 



sulphate of ammonia, 524 lb. superphosphate, and 164 lb. sulphate of 

 potash per acre was applied in addition to 10 tons of farmyard manure, 

 the yield was more than 2\ tons greater than with the farmyard 

 manure alone. The effect was tried of leaving out each of the three 

 constituents of the dressing of artificials. The complete manure gave 

 the largest yield, though the differences were not great. 



Effect of Maturity on Seed Potatoes (Midland Agric. College, Bull. 6, 

 1909-10). — Seed lifted at three different dates was tested at two centres, 

 but no very conclusive results were obtained. 



Trials of Varieties of Potatoes (Monmouthshire Agric. Educ. Com., 

 Potato Trials, 1909). — Trials with a very large number of varieties 

 were carried out at Llanfair in 1909, and the weights produced from 

 eighteen selected sets are given, together with the results of a cooking 

 test. 



Manuring of Potatoes (Roy. Agric. Coll., Scientific Bull. No. 1, 

 1909). — Manurial trials were carried out in 1909 on duplicate plots, 

 which were planted with Scotch and Irish seed. There was no marked 

 difference in the yields of the two classes of seed. As regards the 

 effect of the manures, the addition of non-nitrogenous manures alone 

 produced no increase in yield. Nitrate of lime and superphosphate 

 gave an increase of 36 cwt. over the unmanured plot, or, with potash, 

 53 cwt. The best yield, however, was obtained when sulphate of 

 ammonia was substituted for the nitrate of lime, the complete dressing 

 then yielding an increase of 45 tons. 



Scotch and Irish Seed (Univ. Coll., Reading, Results of Expts. at 

 the College Farm, 1909). — Most farmers in the Midlands and South of 

 England agree that seed potatoes from Scotland produce better crops 

 of tubers than sets of the same variety obtained from a locally grown 

 crop of the previous season. In 1906 a comparative trial was conducted 

 of two varieties of potatoes grown from sets obtained from English, 

 Scotch, and Irish seed, and these potatoes have been grown for four 

 years without change of seed, in order to ascertain how long such a 

 practice may be profitably followed. A duplicate experiment on similar 

 lines was started in 1907. The varieties were British Queen and 

 Up-to-Date, and the plots were manured. each year with ten loads of 

 dung, 4 cwt. basic slag, and 2.\ cwt. kainit per acre. 



The results so far seem to point to the following conclusions : — (a) 

 That Irish and Scotch seed give a better yield than locally grown sets ; 

 '(b) That in the case of imported seed there is a very rapid falling off in 

 the yield after the second year. A change of seed every two years 

 seems necessary, (c) That where potatoes are grown without change 

 of seed for more than one year there is much less falling off in the 

 yield in the case of English sets than in the case of either Irish or 

 Scotch. In some cases in these experiments the English sets produced 

 a better crop in the second than in the first year. 



Experiments on Potatoes (Hertford C.C., Leaflet No. 8.) — This leaflet 

 gives the results of the potato experiments carried out by .the Agricul- 

 tural Department of Cambridge University for the Hertford County 

 Council. In the variety test, the potatoes of the Up-to-Date type gave 

 excellent results as regards yield and quality, but were more subject 

 to disease than most other varieties. Northern Star is stated to be 

 improving, and farmers are advised to include a fair proportion of this 



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