EDITOKIAL. 703 



In courses of instruction dealing so largely with crops it would 

 seem that more consideration should be given the principles under- 

 lying their growth, nutrition, water requirements, reproduction, etc. 

 Doubtless in some way the general facts are set forth, but it is prob- 

 ably true that comparatively few students have first hand informa- 

 tion regarding these subjects, and at most as related to more than a 

 single leading agricultural crop. 



There can hardly be anything more important to the farmer than 

 definite information and understanding regarding the growth of 

 his crops. As the writer referred to has stated, " plant industry as 

 a science must rest on an understanding of plants." And yet, the 

 normal rate of growth at various stages of development is practically 

 unknown to the average student and indeed to many experimenters 

 for the conditions under which the}' are working. The influence of 

 various factors on growth is little understood, except in a very 

 general way, although some of these factors can be controlled and 

 growth accelerated or retarded as is necessary or desirable. It is 

 probably true, as the writer referred to intimates, that very few 

 students follow through the various stages of a single crop to de- 

 termine its normal growth and the influence the more important en- 

 vironmental factors may exert upon it. 



Perhaps next in importance are the questions of transpiration and 

 water supply. In the regions where irrigation is generally prac- 

 ticed it is quite evident that there is little or no attempt at a system 

 of applying water that is based upon the physiological activities of 

 the plant. This leads to irrational practice in applying water that 

 may be wasteful and injurious. The assumption that alfalfa, sugar 

 beets, orchard, and horticultural crops all require the same amounts 

 of water and at the same intervals during the growing season is 

 manifestly wrong, yet in many localities the only measure is so many 

 inches of water at certain arbitrarily determined intervals. This 

 is often based upon the engineer's estimate of the amount of water 

 available and not upon what or when it is needed ; and it is not only 

 wasteful of water, but may be positively injurious to the crop and 

 detrimental to the soil. It is well known that the water factor can 

 be controlled to a considerable degree, and if students were required 

 to study the matter in detail, paying attention at the same time to 

 transpiration under controlled conditions, a new practice in irriga- 

 tion farming might ultimately result. 



It is probable that plant nutrition receives more attention in our 

 agricultural colleges than any other physiological function. But 

 even here the laboratory work is reduced to the minimum, and much 

 is done in field plats where definite control is lacking. There is need 

 of much more study of plant nutrition than is included in fertilizer 

 tests as they are usually made. Water cultures, supplemented with 



