Temperature Effects on the Germination of Herbage Legumes in New Zealand

Abstract

<jats:p>Percentage germination and germination rate (days to 75% germination) of 14 herbage cultivars from 5 legume species were assessed at constant temperatures of 5°, 10°, 15°, 20° and a fluctuating temperature of 5/1O°C. The percentage germination of white clover, red clover and lucerne was not affected by temperature. Germination of Woogenellup subterranean clover was reduced at 5"C, the germination of Mt Barker subterranean clover was reduced at 2O°C, and the germination of Maku lotus was reduced at 5°C and 5/10°C. Germination rates for all species slowed as temperatures moved away from the optimum, as did the number of days to the start of growth. The species order for germination rate was lucerne, white clover &gt;subterranean clover &gt; red clover &gt;lotus at 10° and 5/1O°C, and subterranean clover (except cv. Woogenellup), white clover, lucerne&gt;red clover&gt;lotus at 5°C. Germination rates differed between subterranean clover cultivars, and also between individual seedlots of subterranean clover, red and white clover and lotus, particularly at 5°C. The implications of these results for pasture establishment are discussed. Keywords: germination rate, pasture establishment</jats:p>

Base temperature and thermal time requirements for germination and emergence of temperate pasture species

“…5). Thus, results from this study do not substantiate the conclusion of Hampton et al (1987) that because herbage legumes germinate more rapidly than grasses "the time of sowing for seed mixtures will depend on the grass component." Implications for pasture establishment.…”

“…For example, Charlton et al (1986) reported the number of days to germination of eight temperate grass species across a 5 to 30°C range. Similarly, Hampton et al (1987) reported the germination responses of five temperate legumes between 5 and 20°C. In most cases cultivar differences were minimal and the germination rate declined as temperature moved away from the species-specific optimum.…”

“…Despite the routine use of the thermal time approach for describing phenological development of annual crops, T b and Tt requirements for common New Zealand pasture species have not been determined. A recent book published about temperate legumes makes no mention of the concept (Frame et al 1997), preferring to report trie germination results from Hampton et al (1987).…”

Trichodermaspecies for biocontrol of soil-borne plant pathogens of pasture species

“…These results, and those of Skipp et al (1986), were obtained from a glasshouse maintained at around 20 o C where pots were regularly watered to avoid moisture stress. They are therefore somewhat removed from a field situation, where average 10 cm soil temperature at sowing in New Zealand in autumn and spring is from 8-14 o C depending upon location (Hampton et al, 1987), and soil moisture contents may vary considerably. Such conditions exert more stress on seeds as germination may decrease and time to emergence increase as soil temperature decreases (Charlton et al, 1986), thus potentially allowing more time for pathogen attack.…”

Preplant Cultivation Techniques and Planting Date Effects on White Clover Establishment into an Existing Cool-season Turfgrass Sward

“…The optimum temperature range for WC germination is 20 to 30°C (Moot et al, 2000). Hampton et al (1987) reported delayed WC germination as temperatures decreased. Therefore, the slightly warmer temperatures in fall may have led to faster germination for the WC than in spring.…”