1910.J Summary of Agricultural Experiments. 315 



ties of soils to ascertain (i) the most suitable varieties, and (2) the effect 

 of a moderate dressing of farmyard manure only, compared with a 

 combined dressing of farmyard and artificial manure. As regards 

 varieties, Sir John Llewelyn did best of the first earlies, and British 

 Queen of the second earlies in all four cases. Duchess of Cornwall 

 was the best of the main crops in two out of three cases. 



On three soils out of four the addition of a complete dressing of 

 artificial manures to farmyard manure (10 tons per acre) gave a marked 

 increase. The plot where it had little effect was on chalk, very shallow 

 and deficient in organic matter. 



Experiments with Potatoes (Edinburgh and East of Scotland Coll. of 

 Agric, Bulletin 20).— The relative value of a number of varieties was 

 tested on a farm at Prestonpans, and, taking into account yield, cook- 

 ing quality, and power of resisting disease, the following varieties 

 gave the best results in 1909 : — 



Earlies. — For earliest use — Mid-Lothian Early. For later use — Mac- 

 pherson, Dalmeny Early, Conquest, and Epicure. 



Second Earlies. — Dalmeny Acme, Johnston's Diamond, British 

 Queen, King Edward VII., and Dalmeny Gem. 



Maincrop Varieties. — Northern Star, and the following of the Up-to- 

 Date type — Up-to-Date, Factor, Dalmeny Hero, and Dalmeny Regent. 



Langworthy Type. — Langworthy, Peacemaker, Golden Wonder, and 

 Fascinator were all practically of equal merit. Their outstanding char- 

 acteristic is excellence of cooking quality. 



The effect of a change of seed was tested and was satisfactory. 



With regard to the effect of manures, the following mixture of 

 artificials had been found satisfactory in previous experiments, viz. : — 

 1 cwt. sulphate of ammonia, 4 cwt. superphosphate (30 per cent, sol.), 

 1 cwt. sulphate of potash (87 per cent, purity). This was again tested 

 at three centres, and it is observed that this may generally be depended 

 upon to yield a profitable return, even when used along with a moderate 

 dressing of dung. 



Calcium cyanamide was used as a source of nitrogen in place of the 

 sulphate of ammonia on three plots, but did not prove so satisfactory, 

 while carbonate of magnesia, applied in addition to a complete mixture 

 of artificials, was not profitable. 



A comparison was made of large and small seed, but the results 

 were inconclusive. 



Manuring of Potatoes {West of Scotland Agric. Coll., Bulletin 51). — 

 The experiments which form the subject of this report were carried 

 out in 1907 on seventeen farms, and in 1908 on fourteen farms in the 

 centre and south-west of Scotland. The chief object was to determine 

 the value of certain manures not previously tested, viz., calcium 

 I cyanamide, nitrate of lime, potash manure salt, and basic slag. 

 > Fourteen plots were laid out at each centre, two of which were un- 

 manured, two received farmyard manure only, and the remainder 10 tons 

 j of farmyard manure per acre and various combinations of artificials. 



The farmyard manure alone gave a very satisfactory return, though 

 |; a dressing of 10 tons per acre was proportionately more profitable than 

 I one of 20 tons, but generally it appeared that larger and more profit- 

 1 able crops can be grown by small dressings of farmyard manure with 

 I 'he addition of a suitable mixture of artificials than with large dressings 

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