Competition of sorghum cultivars and densities with Japanese millet (Echinochloa esculenta)

Abstract

Field studies were conducted at two locations in southern Queensland, Australia during the 2003-2004 and 2004-2005 growing seasons to determine the differential competitiveness of sorghum (Sorghum bicolor L. Moench) cultivars and crop densities against weeds and the sorghum yield loss due to weeds.Weed competition was investigated by growing sorghum in the presence or absence of a model grass weed, Japanese millet (Echinochloa esculenta). The correlation analyses showed that the early growth traits (height, shoot biomass, and daily growth rate of the shoot biomass) of sorghum adversely affected the height, biomass, and seed production of millet, as measured at maturity."MR Goldrush" and "Bonus MR" were the most competitive cultivars, resulting in reduced weed biomass, weed density, and weed seed production.The density of sorghum also had a significant effect on the crop's ability to compete with millet.When compared to the density of 4.5 plants per m 2 , sorghum that was planted at 7.5 plants per m 2 suppressed the density, biomass, and seed production of millet by 22%, 27% and 38%, respectively. Millet caused a significant yield loss in comparison with the weed-free plots. The combined weed-suppressive effects of the competitive cultivars, such as MR Goldrush, and high crop densities minimized the yield losses from the weeds. These results indicate that sorghum competition against grass weeds can be improved by choosing competitive cultivars and by using a high crop density of >7.5 plants per m 2 .These non-chemical options should be included in an integrated weed management program for better weed management, particularly where the control options are limited by the evolution of herbicide resistance.

Determining the critical period for grass control in high-yielding cotton using Japanese millet as a mimic weed

“…As an alternative to undertaking experiments using naturally occurring weeds, a range of mimic weeds have been used in competition experiments, as they have the advantages of greater experimental controllability and repeatability, with better control over weed density and more uniform weed emergence (Charles et al 2019b). Mimic grass weeds used in competition experiments have included barley (Hordeum vulgare L.) (Strydhorst et al 2008), Japanese millet (Wu et al 2010), oats (Avena sativa L.) (Brain et al 1999), perennial ryegrass (Lolium perenne L.) (Afifi and Swanton 2012), and winter wheat (Triticum aestivum L.) (Cerrudo et al 2012). A mimic weed is generally chosen that has morphological characteristics similar to those of the real weed for which it is being substituted and is often of the same genus as the real weed.…”

A study on Sorghum bicolor (L.) Moench response to split application of herbicides

“…In this case, the study results did not verify the hypothesis that herbicide application in corn (Gołębiowska and Rola 2004;Idziak et al 2006) and in sweet corn (Waligóra and Szpurka 2007) will also be eff ective for sorghum. Moreover, fi eld tests should also include the sorghum variety factor because of the different responses to weed competition (Wu et al 2010;Mishra et al 2015).…”

Glyphosate Resistance of Chloris virgata Weed in Australia and Glyphosate Mobility Are Connected Problems

“…Crop competition can be used as an effective strategy against Chloris virgata, especially when herbicides like glyphosate fail or underperform [83]. Crop competition to control weeds has proven to be one of the most effective cultural strategies in Australian cropping systems, aiming at suppression of weed biomass and fecundity resulting in crop yield gains [84].…”