Late Glyphosate Applications Alter Yield and Yield Components in Glyphosate-Resistant Canola (Brassica napus)

2015 ◽  
Vol 29 (4) ◽  
pp. 675-683 ◽  
Author(s):  
Eric Tozzi ◽  
K. Neil Harker ◽  
Robert E. Blackshaw ◽  
John T. O'Donovan ◽  
Stephen E. Strelkov ◽  
...  
Keyword(s):  
Weed Management ◽  
Yield Components ◽  
Growth Stages ◽  
Management Options ◽  
Seed Formation ◽  
Application Timing ◽  
Off Label ◽  
Leaf Stage ◽  
Time Of Application ◽  
Yield And Yield Components

The development of glyphosate-resistant canola has provided improved weed-management options for growers, but crop tolerance to glyphosate may be inadequate at later growth stages. In this study, glyphosate-resistant canola 45H28 (RR) was used to determine the effects of glyphosate application timing on yield and yield components at several sites in western Canada. Canola received a single glyphosate applications at the two-leaf, six-leaf, bolting, and early bloom stages and sequential applications at the two-leaf + six-leaf, two-leaf + bolting, and two-leaf + early bloom stages. Contrasts were made between early vs. late, single vs. sequential, and on-label (two to six-leaf stage) vs. off-label (above six-leaf stage). In general, differences between application timings were observed for yield and yield components in 3 of 8 site-yr. Off-label applications of glyphosate (later than six-leaf) significantly decreased yield, seeds per pod, and increased thousand-seed weight and aborted pods in canola at the Lethbridge and St. Albert locations. Increased glyphosate translocation because of adequate, but not excessive, moisture to new growth may have suppressed new seed formation and encouraged pod abortion at the time of application in the 2010 and 2011 seasons. Results from this experiment demonstrate the importance of proper application timing of glyphosate on canola and can help better predict the effects of late applications.

The effectiveness of flame weeding and cultivation on weed control, yield and yield components of organic soybean as influenced by manure application

2015 ◽  
Vol 31 (4) ◽  
pp. 288-299 ◽  
Author(s):  
Strahinja Stepanovic ◽  
Avishek Datta ◽  
Brian Neilson ◽  
Chris Bruening ◽  
Charles Shapiro ◽  
...  
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Yield Components ◽  
Field Experiments ◽  
Leaf Growth ◽  
Growth Stages ◽  
Soybean Production ◽  
Crop Injury ◽  
Yield And Yield Components ◽  
Soybean Plants

AbstractPropane flaming in combination with cultivation could be a potential alternative tool for weed control in organic soybean production. Field experiments were conducted at the Haskell Agricultural Laboratory of the University of Nebraska-Lincoln (UNL), Concord, NE in 2010, 2011 and 2012 to determine the level of weed control and the response of soybean grain yield and its components to flaming and cultivation within two fertility regimes (FRs) (with and without manure) utilizing flaming equipment developed at the UNL. The treatments included: weed-free control, weedy season-long and different combinations of banded flaming (intra-row), broadcast flaming and mechanical cultivation (inter-row). The treatments were applied at VC (unfolded cotyledon) and V4–V5 (4-leaf–5-leaf) growth stages. Propane doses were 20 and 45 kg ha−1 for the banded and broadcast flaming treatments, respectively. The data were collected for visual ratings of crop injury and weed control at 7 and 28 days after treatment (DAT) at V4–V5 growth stages, weed dry matter at 60 DAT, crop yield and yield components. The annual application of 101 t ha−1 manure did not alter weed community or influence the effectiveness of weed management treatment; however, it decreased soybean yield by 0.25 t ha−1 through an increased weed biomass of 0.16 t ha−1. The weed-free control plots yielded 4.15 t ha−1. The combination of mechanical cultivation and banded flaming applied twice (at VC and V4–V5) was the best treatment resulting in 80–82% weed control and 6–9% crop injury at 28 DAT and 3.41–3.67 t ha−1 yield. Cultivation conducted twice provided only 19% weed control at 28 DAT and 1.75 t ha−1 yield. Soybean plants recovered well after all flaming treatments, with the exception of broadcast flaming conducted twice (28% crop injury at 28 DAT). Combining flaming with cultivation has a potential to effectively control weeds in organic soybean production across a range of FRs.

scholarly journals Effect of Variety and Weed Management Practices on Yield and Yield Attributes of Wheat

2013 ◽  
Vol 5 (2) ◽  
pp. 91-96
Author(s):  
MR Sultana ◽  
MA Alim ◽  
MB Hossain ◽  
S Karmaker ◽  
MS Islam
Keyword(s):  
Natural Resources ◽  
Grain Yield ◽  
Weed Management ◽  
Yield Components ◽  
Management Practices ◽  
Yield Attributes ◽  
Free Treatment ◽  
Yield And Yield Components ◽  
Hand Weeding ◽  
Plot Design

An experiment was conducted at Agronomy Field Laboratory of Rajshahi University to evaluate the effect of variety and weeding regime on yield and yield components of wheat. Four varieties viz. Prodip -V1, Gourab -V2, Shatabdi -V3, Bijoy -V4 and five weeding regime viz. a) No weeding -W0, b) Weed free -W1, c) One hand weeding at 20 DAS -W2, d) Two hand weeding (1st at 20 DAS and 2nd at 42 DAS) -W3 and e) Lintur 70 WG @ 250 g ha-1 -W4 were included as treatments in the experiment. The experiment was laid out in a Split-plot Design with three replications. The results revealed that Prodip produced the highest grain yield (5.33 t ha-1) followed by Gourab (4.85 t ha-1), while the lowest grain yield (3.98 t ha-1) was obtained from Shatabdi. The highest grain yield (5.09 t ha-1) was obtained in Weed free (W1) followed by W3 (Two hand weeding) (4.89 t ha-1) and the lowest grain yield (4.13 t ha-1) was obtained in no weeding treatment (W0). The highest grain yield (5.64 t ha-1) was obtained from the combination of Prodip and weed free treatment (V1W1) and the lowest (3.57 t ha-1) was obtained from the combination between Shatabdi and no weeding treatment (V4W0).DOI: http://dx.doi.org/10.3329/jesnr.v5i2.14800 J. Environ. Sci. & Natural Resources, 5(2): 91-96 2012

Winter Wheat (Triticum aestivum) Growth Stage Effect on Paraquat Bioactivity

1991 ◽  
Vol 5 (2) ◽  
pp. 439-441
Author(s):  
Randy L. Anderson ◽  
David C. Nielsen
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Growth Stage ◽  
Time Of Day ◽  
Growth Stages ◽  
Leaf Stage ◽  
Time Of Application ◽  
Biomass Reduction

Paraquat was applied at 0.28 and 0.56 kg ai ha-1to winter wheat at five growth stages at 0800, 1300, and 1600 hr to determine whether growth stage or time of application influenced winter wheat response to paraquat. Paraquat bioactivity was affected by growth stage. Biomass reduction by paraquat was 84% when winter wheat was in the 1 to 3 leaf stage, but only 68% when application was delayed until tillering. Paraquat bioactivity continued to decrease at later growth stages. The time of day when paraquat was applied did not affect its bioactivity on winter wheat.

Barnyardgrass (Echinochloa crus-galli) Control as Affected by Application Timing of Glufosinate Applied Alone or Mixed with Graminicides

2019 ◽  
Vol 33 (2) ◽  
pp. 272-279
Author(s):  
Amber N. Eytcheson ◽  
Daniel B. Reynolds
Keyword(s):  
Growing Season ◽  
The Other ◽  
Growth Stages ◽  
Control Applications ◽  
Application Timing ◽  
Time Of Application ◽  
Greenhouse Experiments ◽  
Variable Control ◽  
Timing Data ◽  
Control Response

AbstractField and greenhouse studies were conducted to evaluate the antagonism potential of glufosinate applied sequentially or mixed with graminicides on barnyardgrass control. Applications of glufosinate alone provided variable control throughout the growing season in both field and greenhouse experiments. In the field, barnyardgrass control was not adversely affected by glufosinate- and clethodim-mix applications or sequential applications of glufosinate before or after clethodim. Soybean yield was not affected by application timing or clethodim rate, with yield ranging from 1,748 to 2,733 kg ha−1. In the greenhouse, glufosinate applied 1 and 3 d before graminicides generally reduced barnyardgrass control compared with the graminicides applied alone. The response with quizalofop-P was not as dramatic as with the other graminicides. Although significant visual barnyardgrass control differences were detected due to application timing of glufosinate, barnyardgrass biomass with fluazifop-P and quizalofop-P did not differ between the application timings of glufosinate. However, glufosinate applied 1 and 3 d before clethodim had significantly greater biomass compared with glufosinate applied 1 and 3 d after clethodim. The differences in environmental conditions and growth stages at the time of application may have contributed to barnyardgrass control response differences between the field and greenhouse experiments. Although barnyardgrass control in the field was not affected by glufosinate application timing, data from the greenhouse indicate potential exists for reduced control if glufosinate is applied 1 or 3 d before graminicides.

Yield and yield components of wheat subjected to water stress under rainfed conditions in Pakistan

2003 ◽  
Vol 51 (3) ◽  
pp. 315-323 ◽  
Author(s):  
R. H. Kazmi ◽  
M. Q. Khan ◽  
M. K. Abbasi
Keyword(s):  
Water Stress ◽  
Leaf Area ◽  
Yield Components ◽  
Flag Leaf ◽  
Growth Stages ◽  
Terminal Drought ◽  
Yield And Yield Components ◽  
Rainfed Conditions ◽  
Control Terminal ◽  
Stalk Length

The investigation was concerned with the effects of water stress on the yield and yield components of wheat grown under rainfed conditions in Rawalakot, Pakistan. A pot experiment was conducted with four wheat genotypes, Inqlab-91, Chakwal-97, Rawal-87 and Kohsar-95, tested against five irrigation levels with drought imposed at different growth stages including control, terminal drought, post-anthesis drought, three irrigations and pre-anthesis drought. The parameters studied were flag leaf area, ear stalk length, number of grains per spike and grain yield per pot. Flag leaf area and ear stalk length exhibited a significant reduction of 14 and 36%, respectively, when wheat was subjected to water stress. The proportional reduction in yield was 40% with three irrigations and 98% in the case of pre-anthesis drought depending upon the extent and degree of stress. Results showed that wheat could withstand and tolerate drought only up to anthesis, after which water stress resulted in the complete failure of the crop. It could be deduced that the critical stage for moisture in wheat started 60 days after germination, and became more severe at 90 days, i.e. at the anthesis stage. Among the genotypes, Inqlab-91 was found to be more tolerant of drought and could thus be a good option for further testing and recommendation for rainfed areas.

Weed management options in transgenic stacked and non transgenic maize (Zea mays) hybrids-A review

2017 ◽  
Vol 38 (04) ◽  
Author(s):  
K. Sivagamy ◽  
C. Chinnusamy ◽  
P. Parasuraman
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Crop Growth ◽  
Control Programme ◽  
Growth And Yield ◽  
Growth Stages ◽  
Management Options ◽  
Maize Crop ◽  
Weed Growth ◽  
Vigorous Growth

Weeds are generally hardy species having fast growth, deep root system and capable of competing very efficiently with cultivated crops for the available resources and adversely affect the crop growth and yield. Weed management systems that rely on post emergence control assume that crops can tolerate competition for certain periods of time without suffering yield losses. Initial slow growth particularly at early crop growth stages and wider plant spacing of maize crop encourages fast and vigorous growth of weeds. It is of paramount importance that, competition from weeds must be minimized to achieve optimum yield. Among the different weed control methods, chemical method bears many advantages in suppressing weed growth and to get healthy and vigorous crop stand. Non-selective herbicide molecules with a variety of mode of action were discovered, developed and marketed for successful weed control programme.

The effects of weed density and different weed control applications on yield and yield components of chickpea cultivars

2019 ◽  
Author(s):  
Melih Yilar Omer Sozen ◽  
Ufuk Karadavut
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Yield Components ◽  
Control Method ◽  
Herbicide Application ◽  
Weed Species ◽  
Control Applications ◽  
Weed Density ◽  
Yield And Yield Components ◽  
Plot Design

This study was conducted to determine the effects of weed density and different weed control treatments on chickpea yield and yield components. The experiment was carried out in split plot design with 3 replications in experimental fields of Kirsehir Ahi Evran University during 2016 and 2017 crop seasons. Total nine treatments (no weed control, permanent weed control, one-time hoeing, two-time hoeing, three-time hoeing, herbicide application after emergence, one-time hoeing with herbicide application, two-time hoeing with herbicide application and three-time hoeing with herbicide application) were compared to know the most effective weed control method. Vaccaria pyramidata Medik., Sinapis arvensis L., Acroptilon repens L. weed species were found to be the most intense in the experimental area. All weed control applications had significant effect on chickpea yield and yield components compared to weedy plots. Three-time hoeing with herbicide application increased the yield by 361.55-478.50% compared to weedy plots. Likewise, three-time hoeing application even increased the yield by 348.50-357.09% compared to weedy plots. The results revealed that three-time hoeing with herbicide and three-time hoeing applications stood out in weed management to obtain a good yield in chickpea cultivation at Kirsehir province.

Effect of uneven emergence on rice yield, milling yield, and yield components

1994 ◽  
Vol 34 (7) ◽  
pp. 949 ◽  
Author(s):  
KA Gravois ◽  
RS Helms
Keyword(s):  
Yield Components ◽  
Management Practices ◽  
Rice Yield ◽  
Oryza Sativa L ◽  
The United States ◽  
Growth Stages ◽  
Yield And Yield Components ◽  
Rice Yields ◽  
High Yields ◽  
Milling Yield

Establishing a uniform rice (Oryza sativa L.) stand is an important beginning to managing a rice crop and attaining high yields. Most rice management practices in the United States are timed according to rice growth stages. Non-uniform rice stands, and subsequently non-uniform growth stages, present problems for the timely application of management practices for attaining high yields. Our objective was the determination of the effects of uneven emergence on rice yield, milling yield, and yield components. Experiments were conducted in 1988 and 1989 on a Hebert silt loam (Vertic Hapludoll) at the Southeast Branch Experiment Station near Rohwer, Arkansas. Uneven emergence was simulated by delayed (18 days from emergence) interseeding of rice to achieve 0, 20, 40, 60, and 80% uneven emergence. Each experiment was planted with the cultivars Lemont (semi-dwarf) and Tebonnet (tall) and was replicated 4 times. Rice yields for the uneven emergence treatment levels were significantly less than the rice yields seeded exclusively at PD1 (planting date 1), except for the uneven emergence levels 80-20 (80% planted at PD1 and 20% planted at PD2) and 60-40 for Tebonnet, and 60-40 in 1988 for Lemont. In 1989, there was a trend for head rice yields to decrease as uneven emergence levels increased. Average panicle density and number of grains per panicle for both Lemont and Tebonnet decreased with increasing uneven emergence, indicating a failure in the typical compensatory relationship between panicle density and grain per panicle. Lemont exhibited reduced average grain weights due to uneven emergence, especially at 80-20, 60-40, and 40-60 uneven emergence levels. Harvest indices were higher for PD1 than for PD2, except at 20-80 uneven emergence level. Essentially, the later emerging rice from the second planting acted much like a weed by competing against rather than contributing to rice yields. Late interseeding to enhance poor rice stands is unlikely to produce an economic return that could be expected from an adequate initial plant stand.

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