3.1 Allelopathic potential of Elymus nutans to alpine crops
Germination force of the tested crops seeds to different extracts were dependent on crop varieties and extract types (Figure1a). Compared to control, the whole extract of drooping wildryegrass had no significant effect on the germination force of hulless barley, oat and rape, but decreased germination force of wheat and increased that of quinoa. Significant inhibitory effects of pieces extract on the germination force of hulless barley, oat, wheat, and rape were detected except quinoa. Root zone soil extracts reduced the germination force of hulless barley, oat, wheat and rape and increased that of quinoa.
All the three kinds of extract significantly reduced the germination percentage of tested crops as shown in Figure 1b. Oat, wheat and rape presented similar pattern and their germination percentage decreased by three kinds of extract compared to control, but no differences among the extract treatments. Pieces aqueous extracts of drooping wildryegrass significantly inhibited the germination of hulless barley and quinoa. Hulless barley germination was sensitive to pieces aqueous extracts.
Comparably, the three extracts have less effect on the germination index of rape and quinoa, in contrast, but they had greater impact on that of barley, oats and wheat (Figure 1c). The root zone soil extracts could improve the germination index of quinoa, but no effects on rape. Both whole plant extract and pieces extract could significantly decrease the germination index of hulless barley and oat. The effects of and the three extracts on the germination index of wheat varied with extracts.