Lämpötilan ja poutajakson vaikutus jauhosavikan (Chenopodium album L.) ja viljan väliseen kilpailuun

Authors

• Leila-Riitta Erviö Helsingin yliopiston kasvinviljelytieteen laitos

DOI: https://doi.org/10.23986/afsci.71819

Abstract

The effect of temperature on C. album and oats (Experiment I) was studied in phytotrons at the temperatures of 24° and 12° C. The effect of a dry-weather period on C. album and wheat (Experiment II) was studied in a roofed coolhouse for pot experiments. Experiment I. Both C. album and oats developed much faster at 24° than at 120 C. At 24° C equal temperature summations were needed for both species to reach the two-leaf stage; from that stage on the temperature requirement of C. album was less than that of oats. At 12° C oats were able to attain the two-leaf stage at a lower temperature summation than C. album. The low temperature was found to retard the weight increase of C. album more than that of oats. The yields per unit area of pure stands of oats and C. album were almost as large as the yield from a mixed population. The competition between the two species did not affect the individual plant weight of C. album significantly but it did reduce the plant weight and total yield of oats. In a mixed stand C. album accounted for 22.6 % and oats for 77.4 % of the total yield. Experiment II. A period of dry weather had no effect on the growth of C. album but reduced the individual plant weight and total yield of wheat. The greatest yield reductions were found when a dry period occurred at the seedling stage of wheat. Competition with C. album reduced the plant weight and total yield of wheat. The plant weight of C. album remained lower in intraspecific competition than in a mixed population with wheat. The increase in plant weight during the growing period was proportionally larger for C. album than for wheat. The weight of C. album increased more in a mixed stand than in a pure one, while the reverse was true for wheat. C. album accounted for 65.3 %, wheat for 34.7 % of the total yield of a mixed stand. C. album proved a stronger competitor than wheat; its invasion coefficient was considerably higher than that of wheat.