Management of Italian and Perennial Ryegrasses for Seed and Forage Production in Crop Rotations

Abstract

Italian ryegrass (Lolium multiflorum Lam.) and perennial ryegrass (L. perenne L.) can be grown for seed and forage in cold winter regions provided the stand persists well over winter. Seed yield and plant characteristics during primary growth, and forage yield during regrowth, were determined for two Italian and one perennial ryegrass cultivars in Atlantic Canada. Establishment methods and dates included sowing ryegrass in cultivated soil alone or with barley in mid-May and, after harvesting the barley crop, by sowing ryegrass following conventional or reduced cultivation and by no-till drilling into barley stubble in mid-August and early September. Despite some winterkill, particularly in Italian ryegrass, seed and forage yields were adequate in post-establishment growing seasons. Seed yield for Italian ryegrass was greatest (1270 kg ha−1) when it was sown into cultivated soil in mid-August and least (890 kg ha−1) when sown alone in May. Italian ryegrass yielded 15–17 % more seed when plots were established in mid-August rather than in mid-May or early September. Italian ryegrass cv. Lemtal had a greater density of fertile tillers (1030 m−2) in the sward than cv. Ajax (860 m−2) and its tiller density was greater when seeded into cultivated soil in September than in mid-August. There were fewer spikelets per seed head for sowing Italian ryegrass with barley in May than for the other methods of establishment. Forage yield in regrowth was greater for Italian ryegrass cv. Ajax (2770 kg ha−1) than for cv. Lemtal (2480 kg ha−1). Seed yield of perennial ryegrass was greater when seeded in mid-May than in mid-August or early September. The seed yield of perennial ryegrass was greater when it was sown with barley in May and harvested for grain, than when it was sown alone or with barley harvested at late milk stage. The establishment methods for mid-August and early September sowing had little effect on seed yield. However, the no-till and reduced tillage methods resulted in a greater tiller density than sowing into the cultivated seedbed. Fertile tillers tended to be denser under reduced cultivation for sowing in August. Forage yield of perennial ryegrass regrowth was not influenced by the sowing method and timing. In conclusion, Italian and perennial ryegrasses produce adequate seed and forage regrowth under different establishment methods and timing. However, the poor persistence of Italian ryegrass may limit commercial production after the establishment year in Atlantic Canada.