Initial Plant Development Research Articles

Effect of seed treatment on the emergence of inbred lines of maize (Zea mays L.)

The emergence time and emergence percentage of four inbred lines with different degrees of chilling tolerance (Mo 17, HMv 5316, HMv 5301, HMv 5478) and the dry mass of young shoots were examined in a seed dressing experiment carried out in pots and sown early under field conditions, on soil infected with pathogens or free of infection (control). The advantage of seed dressing was manifested for all the traits examined, with the exception of emergence time, and the dressing agents were found to exhibit a certain degree of variety specificity. The time to emergence was determined chiefly by the genotype of the inbred lines. Differences were observed when the inbred lines were ranked on the basis of the emergence time and the emergence percentage. This was in agreement with the fact that no correlation was observed between the emergence percentage and the emergence time. Genotype HMv 5316 proved to be best on the basis of emergence time and HMv 5301 for emergence percentage. The poorest results for all the traits examined were recorded for Mo 17, which is in agreement with the poor chilling tolerance of this inbred line. In summary, the following conclusions can be drawn: if the chilling tolerance and growth vigour of the genotypes are to be satisfactorily described, traits characteristic of initial plant development (dry mass of the shoots, size of the leaf area, etc.) should also be considered in addition to the emergence time and emergence percentage.

The effect of temperature and light during storage of young seed potatoes on initial plant development at early plantings

Young seed tubers of several cultivars were exposed to storage temperatures of 4–24°C in light and dark intended to optimise their growth vigour following early plantings. In five experiments during four autumn and winter periods, the effects of storage conditions on subsequent initial plant development in the glasshouse were studied. Storage of seed potatoes for 2 months at temperatures of 12°C or higher greatly increased early plant development of five cultivars following early plantings. Light during storage had a favourable effect, but desprouting before planting was greatly disadvantageous.

Influence of Tillage Depths and P‐Fertilizer Application Rates on the Yields of Annual Cropped Winter‐Grown Wheat1

AbstractBecause of different climatical conditions during the growing season from those of reported experiments in literature and the relatively few data about annual cropped winter‐grown wheat (Triticum aestivum L.) yield response to depth of tillage and to incorporation of previously broadcasted P‐fertilizer, a 2‐year field trial was conducted to evaluate the effects of three tillage depths, 10, 20, and 40 cm; and three P‐fertilizer rates on grain yields and dry matter production. The three P‐fertilizer rates were: no P‐fertilizer, 12 kg P/ha per 10 cm depth of tilled soil, and a flat 60 kg P/ha rate.The field trial had a randomized split plot design with four replications and was simultaneously conducted on two soils of different texture.Grain yields, dry matter production, and P‐uptake over 2 years were not influenced by depths of tillage. Initial development of wheat plants was better on shallow tilled soil. Added P‐fertilizer markedly increased grain yields, dry matter production, and P‐uptake. P‐fertilizer rates based on volume of tilled soil were as effective as the flat P‐fertilizer rate. Dry matter production response to P‐fertilizer was influenced by soil texture, indicating limiting P‐availability with decreasing clay content of soil.From the data obtained it can be concluded that increasing depth of tillage has no significant effect on annual cropped winter‐grown wheat yields and secondly that there is no need to incorporate P‐fertilizer deeper than the top soil layer of 10 cm.Therefore, if plowing a wheat stubble becomes necessary, P‐fertilizer rate can be based on the P‐availability of the sampled top soil layer after plowing and adjusted to the depth of the planned seedbed preparation to keep P‐availability at the recommended level for wheat growing.

The effect of seed size and depth of seeding on the emergence of grassland plants

The seeding of grasslands in Finland fails relatively often owing to the difficult growing conditions for the young seedlings. As a result, the stands are in many cases rather thin and must sometimes be ploughed up without giving any yield at all. One of the factors hampering the initial growth and development of grassland plants is unsuitable sowing. Thus, for instance, a considerable proportion of the seed may be sown at too great a depth, which prevents the seedlings from emerging. On the other hand, the seeds scattered upon the soil surface will also meet difficulties in their germination stage, especially in dry periods. Hence, a valuable characteristic for a grassland plant seedling would be the ability to surmount the various obstacles arising from deficient seeding measures. The object of the present investigation is to study the emergence capacity of some grassland plants, the majority of which are grown extensively in Finland. For this purpose, seeds of the plants to be studied were sown on soil surface as well as at different depths. The influence of seed size in this connexion was examined, too. All the studies concerned were carried out in the greenhouse. The soil used as substrata in these experiments was heavy clay, representing the valuable arable soil type occurring fairly commonly, especially in Southwest Finland.