Effect of Emergence Time on Growth and Fecundity of Redroot Pigweed (Amaranthus retroflexus) and Slender Amaranth (Amaranthus viridis): Emerging Problem Weeds in Australian Summer Crops

Weed Science ◽  
2021 ◽  
pp. 1-26
Author(s):  
Asad M. Khan ◽  
Ahmadreza Mobli ◽  
Jeff A Werth ◽  
Bhagirath S. Chauhan
Keyword(s):  
Seed Production ◽  
Weed Management ◽  
Management Practice ◽  
Growth Period ◽  
Amaranthus Retroflexus ◽  
Planting Date ◽  
Late Spring ◽  
Planting Dates ◽  
Planting Time ◽  
Redroot Pigweed

Abstract Redroot pigweed (Amaranthus retroflexus L.) and Slender amaranth (Amaranthus viridis L.) are considered emerging problematic weeds in summer crops in Australia. An outdoor pot experiment was conducted to examine the effects of planting time of two populations of A. retroflexus and A. viridis at the research farm of the University of Queensland, Australia. Both species were planted every month from October to January (2017-18 and 2018-19), and their growth and seed production was recorded. Although both weeds matured at a similar number of growing degree days (GDDs), these weeds required a different number of days to complete their life cycle within each planting date. The growth period was reduced, and flowering occurred sooner as both species experienced cooler temperatures and shorter daylight hours. Compared to other planting times, both species exhibited increased height, biomass, and seed production for the October-sown plants, and these parameters were reduced by delaying the planting time. The shoot and root biomass of A. retroflexus and A. viridis (averaged over both populations) was reduced by more than 70% and 65%, respectively, when planted in January, in comparison to planting in October. When planted in October, A. retroflexus and A. viridis produced 11,350 and 5,780 seeds per plant, but these were reduced to 770 and 365 seeds per plant in planting date January, respectively. Although the growth and fecundity of these species were dependent on planting time, these weeds could emerge throughout the late spring to summer growing season (October to March) in southeast Australia and produce a significant number of seeds. The results showed that when these species emerged in the late spring (October), they grew vigorously and produced more biomass, in comparison with the other planting dates. Therefore, any early weed management practice for these species could be beneficial for minimizing the subsequent cost and inputs towards their control.

Effect of Corn-Induced Shading and Temperature on Rate of Leaf Appearance in Redroot Pigweed (Amaranthus retroflexus L.)

Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 590-593 ◽  
Author(s):  
Stephane M. Mclachlan ◽  
Clarence J. Swanton ◽  
Stephan F. Weise ◽  
Matthijs Tollenaar
Keyword(s):  
Field Experiments ◽  
Linear Increase ◽  
Amaranthus Retroflexus ◽  
Planting Date ◽  
Weed Interference ◽  
Redroot Pigweed ◽  
Field Temperature ◽  
Effects Of Temperature ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Leaf development and expansion are important factors in determining the outcome of crop-weed interference. The comparative effects of temperature and corn canopy-induced shading on the rate of leaf appearance (RLA) of redroot pigweed were quantified in this study. Growth cabinet results indicated a linear increase in RLA with increased temperature. Weed RLA was predicted utilizing both this function and field temperature data. The ratio of observed to predicted RLA of redroot pigweed grown in field experiments decreased in 1990 and 1991 as shading increased with increased corn density and delayed weed planting date. Results indicated that RLA is substantially affected by canopy-induced shading in addition to temperature.

Interference of Redroot Pigweed (Amaranthus retroflexus) in Corn (Zea mays)

Weed Science ◽  
1994 ◽  
Vol 42 (4) ◽  
pp. 568-573 ◽  
Author(s):  
Stevan Z. Knezevic ◽  
Stephan F. Weise ◽  
Clarence J. Swanton
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Seed Production ◽  
Field Experiments ◽  
Amaranthus Retroflexus ◽  
Corn Yield ◽  
Leaf Stage ◽  
Redroot Pigweed ◽  
Emergence Date

Redroot pigweed is a major weed in corn throughout Ontario. Field experiments were conducted at two locations in 1991 and 1992 to determine the influence of selected densities and emergence times of redroot pigweed on corn growth and grain yield. Redroot pigweed densities of 0.5, 1, 2, 4 and 8 plants per m of row were established within 12.5 cm on either side of the corn row. In both years, redroot pigweed seeds were planted concurrently and with corn at the 3- to 5-leaf stage of corn growth. A density of 0.5 redroot pigweed per m of row from the first (earlier) emergence date of pigweed (in most cases, up to the 4-leaf stage of corn) or four redroot pigweed per m of row from the second (later) emergence date of pigweed (in most cases, between the 4- and 7-leaf stage of corn) reduced corn yield by 5%. Redroot pigweed emerging after the 7-leaf stage of corn growth did not reduce yield. Redroot pigweed seed production was dependent upon its density and time of emergence. The time of redroot pigweed emergence, relative to corn, may be more important than its density in assessing the need for postemergence control.

Response of soya beans to planting date in south-eastern Queensland. II.* Vegetative and reproductive development

1974 ◽  
Vol 25 (5) ◽  
pp. 723 ◽  
Author(s):  
RJ Lawn ◽  
DE Byth
Keyword(s):  
Seed Yield ◽  
Vegetative Growth ◽  
Growth Period ◽  
Reproductive Development ◽  
Planting Date ◽  
Biological Efficiency ◽  
Vegetative Development ◽  
Planting Dates ◽  
Growing Period ◽  
Seed Yields

Vegetative and reproductive development of a range of soya bean cultivars was studied over a series of planting dates in both hill plots and row culture at Redland Bay, Qld. Responses in the extent of vegetative and reproductive development were related to changes in the phasic developmental patterns. The duration and extent of vegetative development for the various cultivar-planting date combinations were closely associated with the length of the period from planting to the cessation of flowering. Thus, vegetative growth was greatest for those planting dates which resulted in a delay in flowering and/or extended the flowering phase. Similarly, genetic lateness of maturity among cultivars was associated with more extensive vegetative development. Seed yield per unit area increased within each cultivar as the length of the growing period was extended until sufficient vegetative growth occurred to allow the formation of closed canopies under the particular agronomic conditions imposed. Further increases in the length of the period of vegetative growth failed to increase seed yield, and in some cases seed yields were actually reduced. Biological efficiency of seed production (BE) was negatively correlated with the length of the vegetative growth period. Differences in BE among cultivar-planting date combinations were large. It is suggested that maximization of seed yield will necessitate an optimum compromise between the degree of vegetative development and BE. Optimum plant arrangement will therefore vary, depending on the particular cultivar-planting date combination. ___________________ \*Part I, Aust. J. Agric. Res., 24: 67 (1973).

Tillage and Planting Date Influence Foxtail (Setariaspp.) Emergence in Continuous Spring Wheat (Triticum aestivum)

1998 ◽  
Vol 12 (2) ◽  
pp. 223-229 ◽  
Author(s):  
Eric Spandl ◽  
Beverly R. Durgan ◽  
Frank Forcella
Keyword(s):  
Spring Wheat ◽  
Weed Management ◽  
Planting Date ◽  
Weed Species ◽  
Planting Dates ◽  
No Till ◽  
Emergence Patterns ◽  
Plant Densities ◽  
Chisel Plow ◽  
Moldboard Plow

Foxtail emergence patterns were evaluated in spring wheat under three tillage regimes, moldboard plow, chisel plow, and no-till, and three wheat planting dates. The first planting date was as soon as feasible in spring, and the second and third planting dates averaged 9 and 17 d later. Foxtail emergence patterns and seedbank density were evaluated each year for three consecutive years. Green foxtail was the dominant weed species. Tillage regime did not influence initial percent emergence of foxtail. Subsequent percent foxtail emergence was sometimes lower in no-till or chisel plow than in moldboard plow regimes until emergence approached 100%. By the third year, total foxtail plant emergence was greater in no-till and chisel plow than in moldboard plow and also greater in no-till than chisel plow. Earlier planting generally increased percent foxtail emergence until midseason. At 22 d after planting, average emergence of foxtail was 48, 67, and 81% for planting dates one, two, and three, respectively. Delayed planting increased rate of foxtail emergence but decreased density of emerged seedlings. Producers adopting chisel plow or no-till systems can expect to see greater foxtail infestations than in moldboard plow systems. Subsequently, more extensive weed management in reduced tillage systems will be needed to prevent heavy foxtail infestations. Delaying wheat planting may be a viable option for foxtail management through reduced plant densities and more simultaneous emergence patterns.

Planting Date and Preplant Weed Management Influence Yield, Water Use, and Weed Seed Production in Herbicide-Free Forage Barley

2008 ◽  
Vol 22 (3) ◽  
pp. 486-492 ◽  
Author(s):  
Andrew W. Lenssen
Keyword(s):  
Seed Production ◽  
Water Use ◽  
Great Plains ◽  
Weed Management ◽  
Planting Date ◽  
Management Systems ◽  
Northern Great Plains ◽  
Zero Tillage ◽  
Weed Seed ◽  
Early Planting

In the semiarid northern Great Plains, the adoption of zero tillage improves soil water conservation, allowing for increased crop intensification and diversification. Zero-tillage crop production relies heavily on herbicides for weed management, particularly the herbicide glyphosate, increasing selection pressure for herbicide-resistant weeds. Barley is well adapted to the northern Great Plains, and may be a suitable herbicide-free forage crop in zero-tillage systems. A 2-yr field study was conducted to determine if planting date influenced crop and weed biomass, water use (WU), and water-use efficiency (WUE) of barley and weed seed production in three preplant weed management systems: (1) conventional preplant tillage with a field cultivator (TILL); (2) zero tillage with preemergence glyphosate application (ZTPRE); and (3) zero tillage without preemergence glyphosate (ZT). None of the systems included an in-crop herbicide. Planting dates were mid-April (early), late May (mid), and mid-June (delayed). Early planting of ZT barley resulted in excellent forage yields (7,228 kg/ha), similar to those from TILL and ZTPRE. Early planting resulted in a small accumulation of weed biomass, averaging 76 kg/ha, and no weed seed production regardless of preplant weed management system. Early planting resulted in higher WU than delayed planting, averaging 289 and 221 mm, respectively, across management systems and years. The WUE of crop and total biomass did not differ among preplant weed management systems at harvest from the early planting date. Delayed planting resulted in decreased forage yield with high amounts of weed biomass and seed production, especially in ZT. A pre-emergence glyphosate application was not necessary for early-planted ZT forage barley. Early planting of herbicide-free barley for forage can be an excellent addition to northern Great Plains cropping systems as part of a multitactic approach for improved weed and water management.

Within-Season Changes in the Residual Weed Community and Crop Tolerance to Interference over the Long Planting Season of Sweet Corn

Weed Science ◽  
2009 ◽  
Vol 57 (3) ◽  
pp. 319-325 ◽  
Author(s):  
Martin M. Williams
Keyword(s):  
Sweet Corn ◽  
Growth Period ◽  
Field Studies ◽  
Planting Date ◽  
Growth And Yield ◽  
Planting Dates ◽  
Crop Tolerance ◽  
Weed Interference ◽  
Control Failure ◽  
Planting Season

Sweet corn is planted over a long season to temporally extend the perishable supply of ears for fresh and processing markets. Most growers' fields have weeds persisting to harvest (hereafter called residual weeds), and evidence suggests the crop's ability to endure competitive stress from residual weeds (i.e., crop tolerance) is not constant over the planting season. Field studies were conducted to characterize changes in the residual weed community over the long planting season and determine the extent to which planting date influences crop tolerance to weed interference in growth and yield traits. Total weed density at harvest was similar across five planting dates from mid-April to early-July; however, some changes in composition of species common to the midwestern United States were observed. Production of viable weed seed within the relatively short growth period of individual sweet corn plantings showed weed seedbank additions are influenced by species and planting date. Crop tolerances in growth and yield were variable in the mid-April and both May plantings, and the crop was least affected by weed interference in the mid-June and early-July planting dates. As the planting season progressed from late-May to early-July, sweet corn accounted for a great proportion of the total crop–weed biomass. Based on results from Illinois, a risk management perspective to weeds should recognize the significance of planting date on sweet corn competitive ability. This work suggests risk of yield loss from weed control failure is lower in late-season sweet corn plantings (June and July) than earlier plantings (April and May).

scholarly journals Dormant Sprigging of Bermudagrass and Zoysiagrass

2021 ◽  
pp. 1-10
Author(s):  
Juming Zhang ◽  
Michael Richardson ◽  
Douglas Karcher ◽  
John McCalla ◽  
Jingwen Mai ◽  
...  
Keyword(s):  
Field Study ◽  
Cynodon Dactylon ◽  
Growing Season ◽  
Early Summer ◽  
Planting Date ◽  
Late Spring ◽  
Zoysia Japonica ◽  
Planting Dates ◽  
Dormant Season ◽  
Sod Production

Many bermudagrass (Cynodon sp.) and zoysiagrass (Zoysia sp.) cultivars are not available as seed and are commonly planted vegetatively using sprigs, especially for sod production or in sand-based systems. Sprig planting is typically done in late spring or early summer, but this can result in an extended grow-in period and delay the use of the turf in the first growing season. The objective of this study was to determine if sprigs of bermudagrass and zoysiagrass could be planted earlier in the year, during the dormancy phase, to hasten establishment. A field study was carried out in Fayetteville, AR, in 2014 and 2016 using ‘Tifway’ hybrid bermudagrass (Cynodon dactylon × Cynodon transvaalensis) and ‘Meyer’ zoysiagrass (Zoysia japonica), and in Guangzhou, China, in 2015, using ‘Tifway’ hybrid bermudagrass and ‘Lanyin III’ zoysiagrass (Z. japonica). Sprigs were planted in March (dormant), May (spring) and July (summer) in Fayetteville, and in January (dormant), March (spring) and May (summer) in Guangzhou. Sprigging rates of 30, 60, and 90 m3·ha−1 were tested at both locations and across all planting dates. Bermudagrass was less affected by planting date, with dormant, spring or summer plantings effectively establishing full cover in the first growing season. Zoysiagrass that was sprigged in the dormant season was successfully established by the end of the first growing season while a full zoysiagrass cover was not achieved with either spring or summer plantings in Arkansas. Dormant sprigging reached full coverage as fast or faster than traditional spring or summer planting dates at both locations, indicating that bermudagrass and zoysiagrass establishment can be achieved earlier in the growing season using dormant sprigging methods.

scholarly journals Interaction of Insects and Weeds in a Snap Bean Agroecosystem

HortScience ◽  
2004 ◽  
Vol 39 (2) ◽  
pp. 287-290 ◽  
Author(s):  
Joseph N. Aguyoh ◽  
John B. Masiunas ◽  
Catherine Eastman
Keyword(s):  
Weed Management ◽  
Leaf Beetle ◽  
Amaranthus Retroflexus ◽  
Integrated Weed Management ◽  
Trifoliate Leaf ◽  
Snap Bean ◽  
Redroot Pigweed ◽  
Snap Beans ◽  
Bean Leaf Beetle ◽  
Large Crabgrass

Integrated weed management strategies maintain sub-threshold levels of weeds. The remaining weeds may impact the feeding and habitation patterns of both potato leafhoppers and bean leaf beetles in a snap bean agroecosystem. The objective of our study was to determine the effect of interference between snap beans (Phaseolus vulgaris L.) and either redroot pigweed (Amaranthus retroflexus L.) or large crabgrass (Digitaria sanguinalis L.) on populations of potato leafhopper [Empoasca fabae (Harris)] and bean leaf beetle [Cerotoma trifurcata (Forster)]. Plots were seeded with redroot pigweed or large crabgrass at either the same time as snap bean planting (early) or when snap bean had one trifoliate leaf open (late). The weed density averaged two plants per meter of row. Bean leaf beetle populations, snap bean pod damage, and leaf defoliation were lower in weed-free plots compared to those with either early emerging pigweed or crabgrass. Leafhopper nymphs and adults were 31% to 34% less in plots with crabgrass emerging with snap beans compared to those in weed-free snap bean plots. Thus, the effect of sub-threshold densities of pigweed and crabgrass on insect pests in snap bean varied depending on the species and should be considered when deciding to integrate weed management approaches.

Integrated weed management in white bean production

2008 ◽  
Vol 88 (3) ◽  
pp. 555-561 ◽  
Author(s):  
Peter H Sikkema ◽  
Richard J Vyn ◽  
Christy Shropshire ◽  
Nader Soltani
Keyword(s):  
Phaseolus Vulgaris ◽  
Weed Management ◽  
Amaranthus Retroflexus ◽  
Profit Margin ◽  
Phaseolus Vulgaris L ◽  
Navy Bean ◽  
Common Lambsquarters ◽  
Redroot Pigweed ◽  
Green Foxtail ◽  
White Bean

A study was conducted over a 3-yr period (2004–2006) in Ontario to evaluate various weed management programs in white bean (Phaseolus vulgaris L.). Herbicide treatments evaluated caused no visible injury in white bean. Trifluralin provided 12% (percentage points) greater control of common lambsquarters (Chenopodium album L.) than s-metolachlor. There was no benefit of tank-mixing s-metolachlor and trifluralin for yield and profitability compared with either trifluralin or s-metolachlor alone. The postemergence (POST ) application of bentazon plus fomesafen following a soil-applied herbicide resulted in improved control of common lambsquarters by 15%. Two inter-row cultivations following a soil-applied herbicide resulted in improved control of redroot pigweed (Amaranthus retroflexus L.), common lambsquarters, and green foxtail [Setaria viridis (L.) Beauv.]. The addition of imazethapyr (60% of label dose; 45 g a.i. ha-1) to the soil-applied herbicide resulted in improved control of redroot pigweed (+6%), common lambsquarters (+16%), and green foxtail (+6%). The profit margin tended to increase if more than just a grass preplant-incorporated (PPI) herbicide was used. The best profit margin was with a grass PPI herbicide alone plus cultivation. The profit margin also tended to increase with the use of cultivation rather than a broadleaf POST herbicide. Key words: Bentazon, cultivation, fomesafen, imazethapyr, navy bean, s-metolachlor, trifluralin, Phaseolus vulgaris L.

scholarly journals Effect of Essential Oils and Hydrosols from Some Selected Lamiaceae Species on Redroot Pigweed (Amaranthus retroflexus L.)

2021 ◽  
Vol 26 (2) ◽  
pp. 2471-2475
Author(s):  
REYYAN YERGİN ÖZKAN ◽  
◽  
MURAT TUNÇTÜRK
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Weed Management ◽  
Germination Rate ◽  
Amaranthus Retroflexus ◽  
Chemical Effect ◽  
Integrated Weed Management ◽  
Aromatic Plants ◽  
Redroot Pigweed

Allelopathy refers to chemical effect of a plant direct or indirect on germination, growth or development of neighboring plants. Allelopathy can be considered as a component of biological control that reduces the development of other plants. This study was carried out to determine the effect of Greek sage (Salvia fruticosa Miller), basil (Ocimum basilicum L.), Dragonhead (Dracocephalum moldavica L.), spearmint (Menta spicata L.), sage (Salvia officinalis L.), lemon balm (Melissa officinalis L.), oregano (Origanum onites L.) and thyme (Thymus kotschyanus Boiss.) on the germination of redroot pigweed (Amaranthus retroflexus L.) which causes significant yield loss in agricultural production. Essential oil (9, 18, 36 µL/petri) and hydrosols (50, 75, 100%) of aromatic plants were applied to determine their inhibition effects on seed germination of A. retroflexus. The experimental design for in vitro was a randomized design with five replications. It has been shown that germination rate was decreasing by the increased concentration of essential oil and hydrosols of the tested plant species. Also, total germination inhibition of A. retroflexus depended on the essential oil doses; the rate ranged from-2.9 to 85%. Amongst the essential oils, the highest effect was observed in spearmint with 7% germination rate. It could be considered as an important solution, which would contribute in Integrated Weed Management of A. retroflexus by using different concentrations of essential oil and hydrosols from aromatic plants.

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