Simulating evolution of glyphosate resistance in Lolium rigidum II: past, present and future glyphosate use in Australian cropping   总被引：1，自引：0，他引：1  

P Neve  A J Diggle†  F P Smith‡  & S B Powles 《Weed Research》2003,43(6):418-427

Glyphosate is a key component of weed control strategies in Australia and worldwide. Despite widespread and frequent use, evolved resistance to glyphosate is rare. A herbicide resistance model, parameterized for Lolium rigidum has been used to perform a number of simulations to compare predicted rates of evolution of glyphosate resistance under past, present and projected future use strategies. In a 30‐year wheat, lupin, wheat, oilseed rape crop rotation with minimum tillage (100% shallow depth soil disturbance at sowing) and annual use of glyphosate pre‐sowing, L. rigidum control was sustainable with no predicted glyphosate resistance. When the crop establishment system was changed to annual no‐tillage (15% soil disturbance at sowing), glyphosate resistance was predicted in 90% of populations, with resistance becoming apparent after between 10 and 18 years when sowing was delayed. Resistance was predicted in 20% of populations after 25–30 years with early sowing. Risks of glyphosate resistance could be reduced by rotating between no‐tillage and minimum‐tillage establishment systems, or by rotating between glyphosate and paraquat for pre‐sowing weed control. The double knockdown strategy (sequential full rate applications of glyphosate and paraquat) reduced risks of glyphosate and paraquat resistance to <2%. Introduction of glyphosate‐resistant oilseed rape significantly increased predicted risks of glyphosate resistance in no‐tillage systems even when the double knockdown was practised. These increased risks could be offset by high crop sowing rates and weed seed collection at harvest. When no selective herbicides were available in wheat crops, the introduction of glyphosate‐resistant oilseed rape necessitated a return to a minimum‐tillage crop establishment system.  相似文献   

Inheritance mode of the awnlessness of darnel (Lolium temulentum L.)     

TAKAYUKI SENDA  TOHRU TOMINAGA 《Weed Biology and Management》2003,3(1):46-48

  相似文献   

多花黑麦草品种比较试验   总被引：9，自引：2，他引：9  

王明蓉  王松  罗富成 《四川草原》2004,(5):15-17

通过对现行生产中常用的4个多花黑麦草品种在昆明地区的物候期、株高、草产量、生长率、净同化率等指标的规定表明,在生长初期,特高的生产性能比其余3个品种都好,但生长一段时间后,邦德的生产性能明显超过特高(P<0.05),抗锈王略高于特高(P>0.05),旺饲的生产性能最差(P<0.05)。因此,邦德是一个在生产中值得推广应用的品种。  相似文献   

Spatial distribution of Lolium rigidum seedlings following seed dispersal by combine harvesters     

J M Blanco-Moreno  L Chamorro  R M Masalles  J Recasens†  & F X Sans 《Weed Research》2004,44(5):375-387

This paper considers the relationships between the dispersal of seeds and the distribution pattern of an annual weed. A comparative study of seed dispersal by combine harvesters, with and without a straw chopper attached, was established using Lolium rigidum, a common weed in Mediterranean cereal crops. Seed dispersal distance was quantified and the relationships between dispersal and fine‐scale seedling distribution evaluated. Primary dispersal of L. rigidum seeds occurs in a very limited space around the parent plants, but the density of seed is low because most seeds do not fall from spikes spontaneously. In contrast, many seeds are spread by combine harvesters. In this study the maximum dispersal exceeded 18 m from established stands in cereal fields, although the modal distance was close to the origin. In addition, the action of the combine harvesters tended to accumulate L. rigidum seeds predominantly under the straw swath, with some lateral movement. This action could explain the fine‐scale banded pattern of L. rigidum in cereal fields. Although the treatment of straw by the standard and straw chopper combines differed, the resultant seed distribution showed few differences.  相似文献   

Awn of darnel (Lolium temulentum L.) as an anthropogenic dispersal organ: A case study in Malo, south-western Ethiopia     

TOHRU TOMINAGA  TAKESHI FUJIMOTO 《Weed Biology and Management》2004,4(4):218-221

Darnel ( Lolium temulentum ), a weed of wheat and barley, is either awned or awnless. The role of the darnel awn in dispersal was investigated in relation to human's agricultural practices in cereal cultivation in a Malo village, Gaytsa, south-western Ethiopia. In 24 free-threshing wheat fields and 11 emmer wheat fields, 129 and 88 spikes (one spike per plant), respectively, of darnel were randomly sampled. At the market in Gaytsa, 11 free-threshing wheat grain samples and eight emmer wheat grain samples of 150–200 g were collected. For each grain sample, the number of wheat grains and awned and awnless grains of darnel were recorded. The relative percentage of the awned form in free-threshing wheat fields was 8.53% and that in emmer wheat fields was 70.45%. The relative percentage of awned grains in free-threshing wheat grains from the market collection was 3.55% and that in emmer wheat grain lots was 75.20%. The morphology of awned darnel grains resembles emmer wheat grains and awnless darnel grains resemble free-threshing wheat grains. Thus, grain mimicry controls the close association of the two forms of darnel with the wheat species. The lack of an awn itself functions for darnel grain as a dispersal mechanism in free-threshing wheat cultivation systems compared with other wild grass species.  相似文献   

四川省2种生境条件下黑麦草种子生产性能的研究   总被引：1，自引：1，他引：1  

鄢燕  张新全  刘淑珍 《草业学报》2005,14(5):37-42

对四川省的丘陵区(洪雅)和中山地区(汉源)2种生境条件下的黑麦草种子生产性能进行了研究分析,结果表明,试验两地的种子产量和质量均有显著差异.其中,洪雅点种子产量为244.0 kg/hm2,汉源点的种子产量为532.8 kg/hm2.两样地的种子质量相比,汉源点的发芽势、发芽率、四唑染色数和四唑脱氢酶均高于洪雅点.两地的种子产量与其构成因素的相关性基本一致,均呈显著相关;相关性强弱依次为:每生殖枝种子数>生殖枝数>每生殖枝小花数>分蘖数>每生殖枝小穗数>千粒重.每生殖枝种子数对种子产量贡献最大.  相似文献   

Effects of forage type and gibberellic acid on nitrate leaching losses          下载免费PDF全文

R. R. Woods  K. C. Cameron  G. R. Edwards  H. J. Di  T. J. Clough 《Soil Use and Management》2016,32(4):565-572

Nitrogen (N) leaching from soil into water is a significant concern for intensively grazed forage‐based systems because it can cause a decline in water quality and is a risk to human health. Urine patches from grazing animals are the main source of this N. The objective of this study was to quantify the effect that forage type and gibberellic acid (GA) application had on N leaching and herbage N uptake from urine patches on perennial ryegrass–white clover (RGWC), Italian ryegrass and lucerne. A lysimeter study was conducted over 17 months to measure herbage growth, N uptake and N loss to water beneath each of the three forage types with the following treatments: control, urine (700 kg N/ha) and urine with GA (8 g GA active ingredient/ha). Compared with RGWC (205 kg N/ha), N leaching losses were 35.3% lower from Italian ryegrass (133 kg N/ha) and 98.5% higher from lucerne (407 kg N/ha). These differences in leaching loss are likely to be due to winter plant growth and N uptake. During the winter months, Italian ryegrass had higher N uptake, whereas lucerne had lower N uptake, compared with RGWC. The application of GA had no effect on N leaching losses, DM yield or N uptake of forage treated with 700 kg N/ha urine.  相似文献   

不同覆膜时间对复式草皮生产的影响     

艾光艳  车生泉  马燕青 《草原与草坪》2006,(1):33-36

在5个不同的时间(9月15日,10月1日,10月15日,10月30日,11月15日)覆盖处理冬季复式草坪,研究其对高羊茅和百慕大草坪组合的影响。通过对成坪时间、草坪质量、经济效益等综合因素的比较,采用LSD的最小差数显著法和灰色系统中的关联系数分析法得出,处理Ⅲ覆膜为最佳时间,处理Ⅱ其次,处理Ⅴ为最差。通过该试验可知在进行冬季复式草坪生产时,最好的覆膜时间为十月中上旬。  相似文献   

An investigation into the grazing efficiency of perennial ryegrass varieties     

Tomas Tubritt  Luc Delaby  Trevor Gilliland  Michael O’Donovan 《Grass and Forage Science》2020,75(3):253-265

The objective of this study was to compare the grazing efficiency of 30 perennial ryegrass varieties, differing in ploidy and heading date. Plots were grazed by lactating dairy cows and managed under a rotational grazing system with 19 grazing events occurring over two years. Pre-grazing and post-grazing compressed sward heights were measured with a rising plate meter. A mixed model was used to predict the post-grazing sward height of each variety based on year, grazing event, block and pre-grazing sward height. Residual grazed height (RGH) was derived as the difference between the actual and predicted post-grazing sward height and was used as the measure of grazing efficiency. Negative RGH values indicated that the actual herbage removed was greater than that predicted and so indicated a superior grazing efficiency. Varieties differed in their level of grazing efficiency (p < .001), with RGH values ranging from −0.38 to +0.34 cm. Tetraploid varieties exhibited significantly greater grazing efficiency performance than diploids (p < .001), with average RGH values of −0.13 and +0.13 cm respectively. A significant difference in grazing efficiency was found among recommended perennial ryegrass varieties that are not being recorded by mechanically harvested simulated grazing protocols. A variety reappraisal that included grazing efficiency could identify varieties capable of improving on-farm livestock productivity from grass.  相似文献   

Resistance to clethodim in Italian ryegrass (Lolium perenne ssp. multiflorum) from Mississippi and North Carolina     

Vijay K Nandula  Darci A Giacomini  Benjamin H Lawrence  William T Molin  Jason A Bond 《Pest management science》2020,76(4):1378-1385

  相似文献