Authors:T. Kiss, K. Balla, J. Bányai, O. Veisz and I. Karsai
Studies on plant development phases and yield component patterns of wheat are essential for a better understanding of adaptation in wheat. Our main aim was to carry out detailed phenological analyses of 18 wheat genotypes in three sowing times for determining the effect of sowing date on individual phenophases, and yield components. Sowing date had the single greatest effect on the start of intensive stem elongation. The longer vegetation period had a favourable effect on main spike length and on the spikelet number per spike, but had no influence on thousand-kernel weight and grain number per spike. The time between the first node appearance and start of intensive stem elongation had a significant effect on the number of reproductive tillers. A close association (R2 = 0.191) was observed during the second phase of intensive stem elongation between the boot stage-to-heading interval and the number of spikelets per spike. Two-way analysis of variance on the yield components showed that the sowing date, as a main factor, had a weaker effect on the phenophases than on morphological and developmental parameters. The insensitive allele of the Ppd-D1 gene shortened the time required for first node appearance and heading both in autumn and spring sowing.
The transitions between various developmental phases are critical in determining the ecological adaptation and yield of cereals. In order to elaborate a methodology for establishing the timing of the consecutive plant developmental phases from germination to the fully developed plant, regular measurements of changes in developmental components were carried out on one winter (Kompolti Korai) and one spring (Morex) barley cultivar in a model experiment. Under the controlled environmental conditions linear regression was characteristic of the associations between the chronological time and all or most of the time course data of plant height, tiller and leaf numbers. The initial growth of the spring barley was twice as intensive as that of the winter barley. The length of the stem elongation phases was similar for the two varieties, but the winter barley cultivar showed significantly more intensive stem growth compared to the spring barley. The spring barley reached all the plant developmental phases significantly earlier than the winter barley. For both cultivars, tillering continued till after first node appearance and there was a definite delay between first node appearance and the beginning of the stem elongation phase. The determination of the full series of phenophases, together with the evaluation of various yield components on the same plant, provide an excellent way of establishing plant developmental patterns and may make a significant contribution to achieving a better understanding of the associations between plant developmental patterns and the adaptation and yielding ability of cereals.