Windmill grass (Chloris truncata R.Br.) and feathertop Rhodes grass (Chloris virgata Sw.) are two weeds of the northern region of Australia that are rapidly expanding in range, being favoured by conservation agricultural systems and prevailing weed management using a narrow pool of herbicides. Information on competitiveness and seed-production dynamics of these weeds is lacking for mungbean (Vigna radiata (L.) Wilczek), a major summer crop in the region. Field studies were conducted to evaluate the effect of different densities of these weed species on crop yield of mungbean in the 2016–17 (2016) and 2017–18 (2017) seasons. Windmill grass reduced mungbean yields by 56% with 39 weed plants m^–2 in 2016 and 55% with 47 weed plants m^–2 in 2017. Windmill grass produced a maximum of 98 708 seeds m^–2 in 2016 and 118 613 seeds m^–2 in 2017, and there was 15–21% seed dispersal at crop harvest. Competition from feathertop Rhodes grass resulted in yield losses of 73% with 49 weed plants m^–2 and 65% with 45 weed plants m^–2. Feathertop Rhodes grass produced a maximum of 229 514 seeds m^–2 in 2016 and 367 190 seeds m^–2 in 2017, and seed dispersal at crop harvest was only 3–7%. Competition from both weed species resulted in a significant reduction in number of pods per m², grains per pod and 1000-grain weight of mungbean. These results show that windmill grass and feathertop Rhodes are highly competitive against mungbean, and their timely management is crucial for minimising yield loss. Although both weeds produced a substantial number of seeds, seed dispersal at crop harvest was low, especially for feathertop Rhodes grass. The high weed-seed retention relative to maturity of mungbean may help in managing these problematic weeds through various means including weed-seed capturing and destruction

风车草（Chloris truncata R.Br.）和Feathertop Rhodes草（Chloris virgata Sw。）是澳大利亚北部地区的两种杂草，它们的分布范围迅速扩大，受到保护性农业系统的青睐和目前使用窄池进行杂草管理的青睐除草剂。这些杂草的竞争力和种子生产动态的信息对于该地区的主要夏季作物绿豆（Vigna radiata（L.）Wilczek）来说是缺乏的。进行了田间研究，以评估这些杂草物种的不同密度对2016-17（2016）和2017-18（2017）季节绿豆作物产量的影响。风车草在2016年使39株杂草m ^–2使绿豆单产降低了56 ％，使47株杂草m降低了55％2017年为^–2。风车草在2016年最多产生98 708种子m ^–2，在2017年最多产生118 613种子m ^–2，作物收获时种子的散布率为15–21％。从feathertop罗德草竞争导致了与49种杂草植物73％的产量损失中号^-2和65％的45种杂草植物中号^-2。Feathertop Rhodes草在2016年最多产生229 514种子m ^–2，在2017年最多产生367 190种子m ^–2，而在作物收获时种子的散布仅为3–7％。两种杂草物种的竞争导致每m ²的豆荚数量显着减少，每个豆荚的谷物和1000粒重的绿豆。这些结果表明，风车草和罗汉斯罗德斯对绿豆具有很高的竞争力，而及时管理对减少产量损失至关重要。尽管两种杂草都产生了大量种子，但作物收成时种子的散播率较低，尤其是对羽顶罗兹草。相对于绿豆成熟度而言，较高的杂草保留率可能有助于通过包括杂草种子捕获和破坏在内的各种方式来管理这些有问题的杂草