A NONDESTRUCTIVE STUDY OF THE EFFECT OF SOIL AND FERTILIZATION ON 3 WINTER WHEATS

The growth of three winter wheats of different origin and habitus, Mar is Marksman, Mironovskaya 808 and Mexique 50-B21 was studied nondestru ctively, on the basis of leaf growth and the rate of leaf development. The plants were grown in pots in growth chamber. Two soils were used, A and B, more and less fertile, resp. Both soils were either left unf ertilized (F1) or fertilized according to agrochemical recommendation (F2). The plants were evaluated in intervals of 3-7 days; they were ha rvested destructively after 34 days, in the period of tillering. The e ffect of both soil origin and fertilization treatments and their inter action with genotype could be detected as early as from the changes in growth of the second leaf, and the effect became gradually more prono unced. Fertilization (F2) increased plant growth in soil B, and slight ly depressed growth or left it unchanged in soil A. In all wheats, and irrespective of treatment, total and aboveground mass at harvest (day 34) was higher in soil A than B. Drought tolerant cv. Mexique 50-B21 was the least affected by soil origin; it had higher root/shoot ratio, higher total N content and pronouncedly lower N-total/N-NO3- ratio th an cvs. Maris Marksman and Mironovskaya 808.