Effect of decaying couch grass rhizomes on the growth of barley.
In pot experiments, the growth of barley seedlings was significantly retarded by the presence of live rhizomes of Agropyron repens near their roots. Decaying rhizomes of A. repens caused severe damage to seedlings and sometimes killed them. Damage was least in moist soil and most in soil with added fertilizer. Damage was greater when rhizomes had been decaying for 5 weeks rather than 4 weeks at the time of sowing. However, when rhizomes had been decaying for 7 weeks, the inhibitory effect disappeared and growth was stimulated. The results are consistent with Fusarium culmorum being a major cause of the damage. See also WA 30, 1456 and 3209.