Spring and autumn establishment of Caucasian and white clovers with different sowing rates of perennial ryegrass

Abstract

The effect of sowing date (SD) and sowing rate of perennial ryegrass (PRG) on the establishment of Caucasian and white clovers in New Zealand was assessed. Clovers were sown in spring on 24 September (SD1) and 9 November (SD2) 1999, and in autumn on 4 February (SD3) and 31 March (SD4) 2000. On each date, clovers were sown with 0, 3, 6 or 12 kg ha )1 of PRG. Total herbage dry matter (DM) production up to 6 November 2000 was 13-16 t DM ha )1 for SD1 and SD2 when sown with 3-12 kg ha )1 of PRG, and 7-10 t DM ha )1 for sown clover monocultures. For SD3 and SD4, total herbage production was 6-9 t DM ha )1 with PRG, while total herbage production of clover monocultures was 5AE4 t DM ha )1 for SD3 and 2AE6 t DM ha )1 for SD4. By 6 November 2000, white clover contributed proportionately more than 0AE15 of herbage mass when sown with 3-12 kg ha )1 of PRG on SD1, SD2 or SD3, but less than 0AE09 when sown on SD4. The proportion of Caucasian clover never exceeded 0AE09 of herbage mass in any of the swards. White clover was successfully established in spring and in autumn with 3-12 kg ha )1 of PRG provided the 15-mm soil temperature was above 14°C. None of the combinations of Caucasian clover and PRG provided an adequate proportion of legumes during the establishment year. This unsuccessful establishment of Caucasian clover with PRG was attributed to its inability to compete for available light as a seedling due to slow leaf area expansion from secondary shoot development and a high root:shoot ratio. Alternative establishment strategies for Caucasian clover may include the use of slow establishing grasses, cover crops and temporal species separation.

‘MaxClover’ grazing experiment: I. Annual yields, botanical composition and growth rates of six dryland pastures over nine years

“…The increase in Caucasian clover in the first three years (Figure d) was consistent with its emergence as a long‐term pasture option. However, the autumn sowing of Caucasian clover in this experiment meant it was not given its maximum opportunity to establish (Black et al ., ). In hindsight, sowing a winter annual forage such as kale and establishing the Caucasian clover in spring would have been in line with best management recommendations (Black and Lucas, ; Hurst et al ., ).…”

Development and growth characteristics of Caucasian and white clover seedlings, compared with perennial ryegrass

“…In white Figure 6 Number of leaves plant )1 of Caucasian clover (s, CC), white clover (h, WC) and perennial ryegrass (n, PRG), grown at a mean air temperature of 19°C, plotted against accumulated thermal time above a base temperature of 0°C. Genrich et al, 1998;Widdup et al, 1998;Black et al, 2006). Arrows indicate the initiation of crown shoot, stolon or tiller development.…”

“…In a previous field experiment, Caucasian clover was shown to fail to establish in pasture seed mixtures with 3-12 kg ha )1 of PRG (Black et al, 2006). Spring sowing of Caucasian clover should be recommended to minimize the interval in days between sowing and exponential leaf production.…”

“…Appropriate strategies can then be developed to assist the successful establishment of all species. Sowing strategies that have been used to establish white clover in PRG-based pastures do not result in successful establishment of Caucasian clover (Hurst et al, 2000;Black et al, 2006). Recently, Caucasian clover (Trifolium ambiguum M.…”

“…Information about these development stages and growth characteristics was used to explain the relative establishment success of each species in the field, particularly the slow establishment of Caucasian clover (Black et al, 2006). The objectives were to quantify the Tt requirements for germination (Experiment 1), emergence, phyllochron and shoot development (Experiments 2 and 3) of each species.…”