POTATOES are one of the most valuable sources of human and animal food in war-time, and it is of the greatest national importance that both the acreage devoted to this crop shall be increased and that the maximum yields shall be obtained. Questions of quality, colour and shape must now take second place and yield be the all-important aim of the grower. The National Institute of Agricultural Botany, Cambridge, has just issued a war-time edition of its Farmer's Leaflet No. 3, in which useful information to this end is supplied. Emphasis is laid on the necessity for using healthy seed, as otherwise attention to cultivation, manuring, etc., is of little value. A number of varieties are recommended for both early and main crops; but it is pointed out that to lift potatoes in an unripe condition is an unwarranted waste of tonnage in a time of emergency. As regards choice of varieties, most of those commonly grown are still recommended, but King Edward should be replaced by a heavier cropping kind such as Arran Banner, Arran Consul, Kerr's Pink, Majestic or Redskin.