Archive image from page 45 of Development and activities of roots. Development and activities of roots of crop plants; a study in crop ecology . developmentactiv00weav Year: 1922 28 Development and Activities of Roots of Crop Plants. the layer occupied by the roots, did the available moisture fall below 11 per cent. Beginning with April 21, when the atmometers were installed, the daily evaporation averaged but 18 c. c. per day. During the last days of May, however, more favorable growth conditions ensued, and the plants passed into the next period under circumstances conducive to rapid develo
Archive image from page 45 of Development and activities of roots. Development and activities of roots of crop plants; a study in crop ecology . developmentactiv00weav Year: 1922 28 Development and Activities of Roots of Crop Plants. the layer occupied by the roots, did the available moisture fall below 11 per cent. Beginning with April 21, when the atmometers were installed, the daily evaporation averaged but 18 c. c. per day. During the last days of May, however, more favorable growth conditions ensued, and the plants passed into the next period under circumstances conducive to rapid development. The final examination was made on July 8, 94 days after planting, when growth was complete and about one-third of the leaves were dead (plate 1 b). One-half of the mature root system is shown in figure 11. The root system was very unlike those of the cereals, in that there was an almost entire ab- sence of roots penetrating vertically downward from the base of the plant. Fig. 11.—One-half of root system of a mature potato plant. In form it was almost identical with that found in the earlier stage of its development. Practically the only difference was in its extent. With a few exceptions, the roots extended outward and downward until they reached a distance of to feet from the vertical and a depth of to 1 foot from the surface. They then turned more or less abruptly downward and continued their irregular course to a depth of 2 to feet. A few roots extended out almost horizontally at a depth of 2 or 3 inches to a maximum distance of 15 to 20 inches, but did not turn downward at that point. All these roots, including both the shallow and deep ones, were freely branched throughout their course, even to their very tips, with fine white branches
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Keywords: 1920, 1922, archive, book, bookauthor, bookdecade, bookpublisher, booksubject, bookyear, crist_john_w_joint_author, crops_and_climate, drawing, historical, history, illustration, image, jean_frank_covert_1880_joint_author, page, picture, plant_ecology, print, reference, roots_botany_, vintage, washington_carnegie_institution_of_washington, weaver_john_e_john_ernest_1884_1966
