An experiment designed to show the effects of a complete fertilizer and of water applied extra to the rainfall on the yield of carrots grown on a gravel soil in good heart, has demonstrated that the fertilizer mixture was entirely without effect. The interaction water level × fertilizer was not significant, so that the increases in yield of carrot roots (increases which were 61·46 and 127·5 ― above the mean of the plots for rainfall only in the case of the total crop, and 61·73 and 111·5 ― for ware carrots, for 3 and 6 in. of water extra to the rainfall, respectively) were due entirely to the additional water. The response in yield of the roots of the total crop and of ware to the second application of extra water showed no falling off compared with the response to the first extra application. There was evidence to prove that additional water caused heavier infestation of the roots by aphis.