Effect of nitrogen doses, stand density and supplemental irrigation on a model maize hybrid. 2. Photosynthetic capacity of the leaf
1996
Mudry, P. | Juracek, J. | Sedlak, A. (Zeainvent a.s., Trnava (Slovakia))
From 1991-1993, in a semi-arid maize-growing region (Trnava, Slovak Republic), the effect of maize stand density, nitrogen doses and irrigation on the photosynthetical capacity of the central part of a leaf lamina (position +1 above ear) of the model hybrid TA-TO 260 S was observed in the generative stages of ontogeny. Net assimilation rate (P sub i) was observed in the field during the day by the portable apparatus Li-6000. The aim of this work was to reconsider the possibility of applying the value P sub i as a parameter for evaluation of physiological and productive conditions of a maize stand. Results confirmed the convenience of applying this parameter, while the measurements at noon or in the first afternoon hours were much more suitable. From the measured values, a very positive effect of a supplemental irrigation on the values of P sub i resulted. The positive effect of nitrogen was manifested mainly under irrigation. Without irrigation, high nitrogen doses had a minimum to negative effect on the net assimilation rate. Increasing the stand density had a negative effect on the leaf photosynthetical capacity as well
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