Effects of the timing and intensity of spring grazings on reproductive development, tillering, and herbage production of perennial ryegrass dominant pasture

Abstract Reproductive development, tillering, and herbage production were studied in mixed pastures containing ‘Grasslands Nui’ perennial ryegrass (Lolium perenne L.) and ‘Grasslands Huia’ white clover (Trifolium repens L.), which were rotationally grazed by sheep. The effects of interruption of ryegrass reproductive development during early culm elongation (TI) or 30% inflorescence emergence (T2), by either hard grazings (H; residual leaf area index (LAI) 0–0.7) or lax grazings (L; residual LAI 0.8–2.2) were compared. These grazing intensity treatments were continued until mid summer; and in late summer and autumn all pastures received the same grazing management. Culm elongation in an initial group of reproductive tillers, 2400/m2, started in October, and 30% inflorescence emergence occurred in mid November. During November and December a further 1000/m2 secondary reproductive tillers appeared. Few new reproductive tillers appeared after December. Vegetative ryegrass tiller density declined markedly dur...

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