The growth and development of sugar-beet with different nitrogen dressings was studied by measurement of leaf area and of dry weight and chemical composition (inorganic cations and anions) of several plant parts during the growth season.For a correct interpretation of the data, the losses in dry weight, leaf area and minerals due to leaf fall could not be ignored and were therefore estimated. The losses were calculated to be 4-5 tons dry matter . ha -1and 3-4 m 2leaf area . m -2soil area depending on the amount of nitrogen dressed. The losses of N, H 2 PO 4 and K were 90-140, 5-13 and 80-105 kg . ha -1, respectively.When the losses were included in the harvest data, other growth and uptake figures were obtained than when these losses were ignored. With no deficiency, instead of three growth stages, only two stages appeared in the distribution curve.Furthermore a hypothesis was developed which could explain the differences in dry weight, chemical composition and leaf area of the succeeding laminae of a sugar-beet plant. It was suggested that the laminae formed first stayed small due to competition for the produced minerals within the plant. Maximum leaf area and weight was found for the 10th to l5th leaf. Later formed laminae stayed small due to the shortage of light, minerals, water and time.
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