01175naa a2200133 a 450000100080000000500110000800800410001910000180006024502010007826000090027952006800028865300240096877300490099216486362023-04-17       1947    bl uuuu     u00u1 u    #d1 aWATSON. D. J.  aComparative physiological studies on the growth of field cropsbVariation in net assimilation rate and leaf area between species and varieties, and within and between years.h[electronic resource]  c1947  aDeterminations of net assimilation rate (NAR) and of leaf area per plant or per metre of dril row were made at intervals throughout the growth of field-crops of wheat, barley, potatoes, mangolds, and sugar-beet at Rothamsted. Data are presented from 15 experiments in 6 years. The experiments included comparisons of varieties of the same crop, and of sowings made on different dates. Net assimilation rate showed similar variation with time in all years, rising during the spring months from very low values in winter to a maximum at midsummer, and subsequently falling during the late summer and autumn. This time trend is attributed to seasonal change in climatic factors.  aFisiologia vegetral  tAnnals of Botanygv.11, n.41, p.47-76, 1947.