Temperature and rhizome chain effect on sprouting of purple nutsedge (Cyperus rotundus) ecotypes

Abstract

The effect of constant or various fluctuating temperature regimes and single or multiple tubers in rhizome chains on tuber sprouting of six purple nutsedge ecotypes was determined. After 24 d at constant 20 C, budbreak of tubers detached from the rhizome chain (single tubers) ranged from 11 to 85% among ecotypes. When dormant tubers were exposed to a single 0.5- to 12-h, 35 C pulse followed by constant 20 C, budbreak increased for all ecotypes; daily 0.5-h, 35 C pulses from a 20 C base temperature for three to seven cycles did not significantly increase budbreak more than these did for a single cycle. Shoot length increased linearly for all ecotypes as the number of 0.5-h, 35 C pulse cycles increased, although the magnitude of shoot elongation varied with ecotype. At a 20 and 30 C (12:12 h) daily alternating temperature regime, 98% of single tubers from a Kamuela, HI, ecotype produced actively growing shoots (active tubers), whereas only 32 to 60% of tubers in two- to six-tuber chains were active. The rhizome chain effect on budbreak was minor because ≥ 90% of the tubers in rhizome chains had budbreak. Using a range of constant and alternating temperatures on single tubers and four-tuber chains, similar results were observed for all six ecotypes as for the Kamuela ecotype. Although alternating temperature increased active tubers for both single tubers and tubers in chains, it did not overcome apical dominance among tubers in rhizome chains in suppressing active tubers. The budbreak and shoot elongation stimulation by alternating temperatures and high-temperature pulses appear to be common physiological responses to all purple nutsedge ecotypes examined in this study.

Increased Purple Nutsedge (Cyperus rotundus) Tuber Sprouting with Diurnally Fluctuating Temperatures

“…5 to 15 cm) and sprouting characteristics (Travlos et al 2009). A previous study reported a linear relationship between tuber weight and tuber sprouting (Kawabata and Nishimoto 2003). In addition, while uniform tuber size used in the current study may have assisted in eliminating some of the variability in temperature response due to tuber age and/or amount of reserves, it may provide a less realistic in situ response of the propagule-bank relative to the Travlos et al (2009) sampling method.…”

“…The purple nutsedge tubers used in this study were adapted to Georgia environmental conditions, and responded to temperature fluctuations similar to those experienced in the early spring when aerial shoots of nutsedge tubers begin to emerge. Kawabata and Nishimoto (2003) observed differential responses to temperature of purple nutsedge tubers collected from various latitudes. Locales near the equator have less daily temperature fluctuation; data revealed that tubers collected from lower latitudes had greater dormancy and were less responsive to fluctuating temperatures (Kawabata and Nishimoto 2003).…”

“…Kawabata and Nishimoto (2003) observed differential responses to temperature of purple nutsedge tubers collected from various latitudes. Locales near the equator have less daily temperature fluctuation; data revealed that tubers collected from lower latitudes had greater dormancy and were less responsive to fluctuating temperatures (Kawabata and Nishimoto 2003). The current experiment was conducted on tubers collected from latitude 31.51uN, while the Travlos (2009) study used tubers from latitude 37.97uN, explaining some of the differences observed between these studies.…”

Lowland ecotype Cyperus rotundus L. affects growth and yield of rice under flooded conditions in the Philippines

“…C. rotundus has many ecotypes distributed around the world [22,23]. In the Philippines, earlier reports showed that it has a lowland ecotype that can grow in irrigated lowland ricefields [24][25][26][27].…”

Effect of Low Temperature on Purple Nutsedge (Cyperus rotundus) Reproductive Biology

“…Nishimoto (2001) indicated that no sprouting occurs below 10 C or above 45 C, and maximal sprouting is achieved under constant temperatures between 25 and 35 C. A daily short duration of high temperature in his experiments was found to increase sprouting to nearly 100% of the tubers. However, most buds did not elongate if the tuber remained at 20 C. Daily fluctuations in soil temperature are probably a major signal for purple nutsedge emergence (Horowitz 1972;Kamabata and Nishimoto 2003;Sun and Nishimoto 1999;Webster 2003), and its distribution is limited by its sensitivity to cold temperature (Glaze 1987;Okoli et al 1996). Purple nutsedge tubers exposed to 2 C for 3 months lost their ability to germinate (Stoller 1973).…”