Influence of the Shade with Structure on Growth of Turnip (Brassica campestris L. rapa group) and Modeling About It

Abstract

We tried modeling on the influence of shade with a structure on the growth of turnip (Brassica campestris L. rapa group), and discussed on the results obtained from the model.
1. The changes of four characters (total dry weight (DW), top DW, root DW and leaf area) with growth were fitted quadratic equations, when the observed values were transformed to logarithmic ones.
2. The relationships between relative values of total photon flux density and each of four characters were shown with linear regression.
3. Time courses of coefficients and constants in the linear regression equations obtained were fitted for polynomial equation.
4. Estimated values of every character by model were very close to the observed ones.
5. The results obtained from the model suggested that in the early developmental stage, the growth of foliage (top) being photosynthetic organ was depressed by the shade of structure, whereas in the later stage, the top was not affected but root being the non-photosynthetic organ markedly by shading. The degree of shading effect on the total DW was not almost changed through the developmental stage.