720 EXPERIMENT STATION RECORD. 



is, on the average, for Nordland's ami (Norway, 65 to 69° latitude), for 

 barley 103£ days, oats 113£ days, spring rye 111 days. While light is 

 a potent factor in plant growth, it is only one of the important factors; 

 a sufficient supply of heat and moisture are as essential, and northern 

 regions are especially at a disadvantage as regards the former. — f. w. 

 woll. 



A study of the roots of perennial plants, E. S. Goff ( Wisconsin 

 Sta. Bpt. 1897, pp. 286-298, figs. 6). — The author states that while the 

 root growth of many annual crops has been more or less thoroughly 

 investigated, the study of roots of perennial plants seems to have been 

 to a large extent neglected. A modification of the root cage previously 

 described (E. S. R., 5, p. 480) was made. In order to expose the roots 

 more fully to view, instead of the iron cage there described, a wide 

 board was used and wires thrust through holes bored through it. This 

 apparatus was soon found to be unsuitable, and a slatted frame was 

 substituted for the boards with perfect success. Studies were made of 

 the roots of strawberry, raspberry, grape, and apple trees. 



The roots of the strawberry were contained within a very small com- 

 pass, the deepest extending a little less than 2 ft., while the horizontal 

 roots reached scarcely beyond the area covered by the leaves. This 

 limited root range of the strawberry plant readily explains its well- 

 known susceptibility to drought, as well as its ready response to fer- 

 tilizers. These studies emphasize the importance of providing for irri- 

 gation wherever large and regular crops are to be depended upon and 

 also suggest the importance of a method of culture whereby the rows 

 of plants should be slightly lower than the spaces between the rows. 



The roots of the raspberry were found to extend horizontally a dis- 

 tance of 4 ft., and vertically something more than 5 ft. The shallowness 

 of the main root is noticeable, as well as the large number of vertical 

 roots. The shallow depth traversed by the main root would suggest 

 the inadvisability of too deep plowing between the rows. 



The author states that as the grapevine is not required to support its 

 own trunk and in culture is heavily pruned each year, he had antici- 

 pated rather shallow and scanty root development. It appears, how- 

 ever, that almost no roots were found at a depth less than 18 in. The 

 main root continued something more than 13 ft. Dead roots in the 

 upper layers of soil were frequently observed. Whether these shallow 

 roots had been destroyed by severe freezing or whether they had per- 

 ished on account of the severe drought of 1894 and 1895 is unknown. 

 Below the main root the whole system seemed to be alive and for the 

 most part in excellent condition. The soil was rather light clay loam 

 to a depth of about 2 ft. ; below this was a layer of sandy clay, 2 J ft. 

 thick, resting on a stratum of heterogeneous drift gravel consisting of 

 loose sand mingled with pebbles mostly of small size, but a few larger 

 than a man's fist. The longer vertical roots extended with compara- 

 tively few branches into this gravel stratum. The numerous white 

 root tips indicated that the roots were active at a depth of 6 or 8 ft. 



