A comparison of seed harvesting methods for perennial ryegrass treated with the growth retardant paclobutrazol

Methods of harvesting seed of perennial ryegrass cv. S24 treated with the growth retardant paclobutrazol applied at spikelet initiation at a rate of 2.0 kg active ingredient ha^?1 were examined in 1982. The greatest seed yield (2202 kg ha^?1) was obtained from swathing the crop at 35% seed moisture content and combining 2 days later, but this was not significantly different from that obtained from swathing at 48% seed moisture content or double direct combining at 35% seed moisture content. Seed yields from a single direct combining at either 35% or 25% seed moisture content were significantly lower than those of other treatments.