1906.] 



Potato Growing. 



25 



to depreciate somewhat seriously the value of a potato for cook- 

 ing purposes. A moderate dressing is considerably less harmful, 

 whilst the addition of a well-balanced mixture of artificials to a 

 moderate dressing of dung will, other things being equal, pro- 

 duce potatoes of the first quality. Sulphate of ammonia is 

 preferable to nitrate of soda when used along with dung, but 

 when no dung is applied nitrate of soda, as an ingredient of a 

 mixture of artificials, may be quite as satisfactory as sulphate 

 of ammonia. 



{b) Disease : Nothing very definite can be said on this point. 

 Any manures, however, which tend unduly to stimulate the 

 growth of the foliage, such as heavy applications of dung or 

 mixtures of artificials containing a rather high percentage of 

 nitrogen, appear to encourage the disease. 



Time to Lift. — It is highly important that potatoes should be 

 lifted as soon as they are ripe. It has been demonstrated 

 repeatedly that comparatively healthy crops can be obtained 

 from even those varieties which are generally regarded as being 

 very liable to disease {Phytop/ithora) if attention is given to the 

 above point. 



Forviation of the Pie. — The general principles on which a pie 

 or clamp is made are practically the same throughout the country. 

 The method of covering the pie, however, varies considerably, 

 but the following, which is practised in some parts of Yorkshire, 

 may be safely recommended. The usual roof-shaped pie is 

 covered with a layer of straw about 6 in. thick. A plank about 

 I ft. broad and from 8 to 10 ft. long is then placed along the 

 top of the pie, and the sides to the length of the plank are 

 covered with an inch or two of soil. The plank is then moved 

 on and another length is covered with soil. In this way the 

 top of the pie is kept free from soil, and provision made for 

 ventilation. It may be necessary to add more soil to the sides 

 later in the year, but the top is left untouched except, perhaps, 

 in a time of severe frost, when a covering of potato haulm is put 

 over the straw. 



J. G. Stewart. 



