Growth patterns of Italian ryegrass cultivars established in different seasons

Abstract

A comparison is made between various Italian ryegrass cultivars established under irrigation on a well-drained upland site during the traditional autumn months, with plantings of the same cultivars at other times of the year. The dates on which pastures could be utilised for the first time, their relative growth pattern as well as weed infestation, flowering behaviour and persistency, were investigated. Some herbage quality determinations were also made. February plantings are considered the most favourable for maximum late autumn, winter and spring production. First utilisation following late autumn/winter plantings is, however, delayed considerably with the onset of cold weather. Late winter/early spring plantings, on the other hand, delay flowering for up to 16 months and the biennial growth pattern indicates vigorous growth immediately after planting, the possibility of variable late summer production followed by extremely poor autumn and winter production. This casts serious doubt on the merit of such a practice at the total exclusion of the traditional autumn plantings. Summer weed infestation from such spring plantings also gave cause for concern.

Keywords: cedara; cultivars; flowering; growth patterns; herbage; herbage yield; irrigation; italian ryegrass; lolium multiflorum; natal; pastures; production; relative growth; ryegrass; south africa; weed infestation

Journal of the Grassland Society of Southern Africa.