Influence of environmental factors on slender amaranth (Amaranthus viridis) germination

Abstract

Germination response of slender amaranth to temperature, solution pH, moisture stress, and depth of emergence was evaluated under controlled environmental conditions. Results indicated that 30 C was the optimum constant temperature for germination. Germination of slender amaranth seed at 21 d was similar, with 35/25, 35/20, 30/25, and 30/20 alternating temperature regimes. As temperatures in alternating regimes increased, time to onset of germination decreased and rate of germination increased. Slender amaranth germination was greater with acidic than with basic pH conditions. Germination declined with increasing water stress and was completely inhibited at water potentials below −0.6 MPa. Slender amaranth emergence was greatest at depths of 0.5 to 2 cm, but some seeds emerged from as deep as 6 cm. Information gained in this study will contribute to an integrated control program for slender amaranth.

Germination Response of Four Alien Congeneric Amaranthus Species to Environmental Factors

“…Similar germination response of A . viridis to water stress was also demonstrated in the study of Thomas et al [31]. In their study, extremely low germination (1.25% at 30/20°C) at -0.4MPa was reported which was the lethal osmotic potential causing complete inhibition in our study.…”

“…spinosus [32], and A . viridis [31], [32]. In a study by Ghorbani et al [26], the germination of A .…”

“…were reported. Thomas et al [31] and Chauhan and Johnson [32] demonstrated the seedling emergence responses of spiny amaranth ( A . spinosus ) and slender amaranth ( A .…”

Germination ecology of wild onion: a rainfed crop weed

“…Watanabe et al (2002) reported similar behavior for invasive weed species. Seed germination of many weed species remained unaffected (from pH 4 to 9) in various studies (Thomas et al, 2006;Chachalis et al, 2008;Wang et al, 2009). Germination of coolatai grass was 92% at pH level of 7.00, however at moderate level of pH (5.00) or (9.00) germination was reduced by around 10%.…”

“…However, reasonable emergence of A. tenuifolius also occurred at 1, 2 and 3 cm burial depths. Studies by Thomas et al (2006) showed that seeds of Amaranthus viridis (Slender Amaranth) emerged in between 0.5 and 2 cm. Contrary to the above findings, the emergence of threehorn bedstraw was negligible at soil surface and it increased with increasing burial depths up to 5 cm (Chauhan et al, 2006d).…”