Hard Red Spring Wheat (Triticum aestivum) Response to Propanil

Weed Science ◽  
1984 ◽  
Vol 32 (2) ◽  
pp. 191-193 ◽  
Author(s):  
Stephen D. Miller ◽  
John D. Nalewaja ◽  
Ian B. Edwards

The phytotoxicity of postemergence propanil (3′,4′-dichloropropionanilide) to hard red spring (HRS) wheat (Triticum aestivumL.) was determined in the field and controlled environmental chamber. HRS wheat tolerance to propanil was influenced by cultivar, crop growth stage at time of application, and posttreatment temperature. Injury to wheat from propanil was greater at the five- than two-leaf stage of application and at 30- than at 10- or 20-C posttreatment temperatures. ‘Butte’ wheat was the most susceptible HRS wheat cultivar to propanil, with yield reductions ranging from 15 to 40% depending upon year and crop growth stage at application.

1991 ◽  
Vol 5 (2) ◽  
pp. 439-441
Author(s):  
Randy L. Anderson ◽  
David C. Nielsen

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.


2000 ◽  
Vol 80 (2) ◽  
pp. 407-410 ◽  
Author(s):  
David A. Wall ◽  
Marjorie A. H. Smith

Field studies were conducted from 1995 to 1997 at Morden and Brandon, Manitoba, Canada, to evaluate the effect of crop growth stage at application on common buckwheat (Fagopyrum esculentum Moench.) tolerance to low rates of 2,4-D amine, MCPA amine and the sodium salt of MCPA. Each formulation was applied at 140 g a.i. ha−1 to common buckwheat at the two- to three-leaf, four- to five-leaf, and six- to eight-leaf stages. Levels of buckwheat injury and seed yield loss were very similar for the three phenoxy herbicide formulations. Although early-season crop injury was severe, injury was often less, and crop recovery from injury greater, when herbicide was applied at the two-leaf stage than at the four-leaf or six-leaf stage. When herbicide was applied at the two-leaf stage, a significant yield reduction occurred in only one of the five trials. However, buckwheat seed yield decreased when phenoxy-herbicide application was delayed past the two-leaf stage. If low application rates of phenoxy herbicides to early stage buckwheat are effective in suppressing weed growth, then this treatment may enable the crop to out-compete weeds without sustaining yield losses in most years. Key words: Common buckwheat, tolerance, crop growth stage, yield, phenoxy herbicide


1997 ◽  
Vol 77 (4) ◽  
pp. 661-663 ◽  
Author(s):  
J. M. Clarke ◽  
R. M. DePauw ◽  
T. N. McCaig ◽  
M. R. Fernandez ◽  
R. E. Knox ◽  
...  

AC Elsa, hard red spring wheat (Triticum aestivum L.), is adapted to the Canadian Prairies. It combines high grain yield with high grain protein concentration in a short strawed background. It has improved resistance to leaf spots compared with the check cultivars, and resistance to prevalent races of leaf rust, stem rust, loose smut, and common bunt. AC Elsa is eligible for grades of Canada Western Red Spring wheat. Key words: Triticum aestivum L., red spring wheat, cultivar description, yield, protein, disease resistance


Weed Science ◽  
1997 ◽  
Vol 45 (4) ◽  
pp. 538-545 ◽  
Author(s):  
David A. Wall

Field studies were conducted at Morden, Manitoba, in 1994 and 1995 to investigate the effect of crop growth stages on canola and sunflower tolerance to sublethal doses of thifensulfuron:tribenuron (2:1). Thifensulfuron:tribenuron at doses of 0, 0.23, 0.45, 0.9, 1.8, and 3.6 g ai ha−1plus a nonionic surfactant at 0.5% v/v were applied to canola and sunflower at the two- to three-leaf, four- to five-leaf, and six- to seven-leaf stages. Crop leaf stage at the time of application affected tolerance of both crops to thifensulfuron:tribenuron. Crop injury was lowest, and flowering, seed yield, and seed oil content were least affected when low doses of thifensulfuron:tribenuron were applied at the two- to three-leaf stage. At the highest dose, there was little practical difference among growth stages since yield of both crops was severely reduced. Producers with drift-affected canola or sunflower can expect less effect on crop yield when thifensulfuron:tribenuron injury occurs during early crop growth.


2003 ◽  
Vol 51 (14) ◽  
pp. 4004-4007 ◽  
Author(s):  
Gail A. Bresnahan ◽  
Frank A. Manthey ◽  
Kirk A. Howatt ◽  
Monisha Chakraborty

Author(s):  
S. A. Sawant ◽  
M. Chakraborty ◽  
S. Suradhaniwar ◽  
J. Adinarayana ◽  
S. S. Durbha

Satellite based earth observation (EO) platforms have proved capability to spatio-temporally monitor changes on the earth's surface. Long term satellite missions have provided huge repository of optical remote sensing datasets, and United States Geological Survey (USGS) Landsat program is one of the oldest sources of optical EO datasets. This historical and near real time EO archive is a rich source of information to understand the seasonal changes in the horticultural crops. Citrus (Mandarin / Nagpur Orange) is one of the major horticultural crops cultivated in central India. Erratic behaviour of rainfall and dependency on groundwater for irrigation has wide impact on the citrus crop yield. Also, wide variations are reported in temperature and relative humidity causing early fruit onset and increase in crop water requirement. Therefore, there is need to study the crop growth stages and crop evapotranspiration at spatio-temporal scale for managing the scarce resources. In this study, an attempt has been made to understand the citrus crop growth stages using Normalized Difference Time Series (NDVI) time series data obtained from Landsat archives (<a href="http://earthexplorer.usgs.gov/"target="_blank">http://earthexplorer.usgs.gov/</a>). Total 388 Landsat 4, 5, 7 and 8 scenes (from year 1990 to Aug. 2015) for Worldwide Reference System (WRS) 2, path 145 and row 45 were selected to understand seasonal variations in citrus crop growth. Considering Landsat 30 meter spatial resolution to obtain homogeneous pixels with crop cover orchards larger than 2 hectare area was selected. To consider change in wavelength bandwidth (radiometric resolution) with Landsat sensors (i.e. 4, 5, 7 and 8) NDVI has been selected to obtain continuous sensor independent time series. The obtained crop growth stage information has been used to estimate citrus basal crop coefficient information (Kcb). Satellite based Kcb estimates were used with proximal agrometeorological sensing system observed relevant weather parameters for crop ET estimation. The results show that time series EO based crop growth stage estimates provide better information about geographically separated citrus orchards. Attempts are being made to estimate regional variations in citrus crop water requirement for effective irrigation planning. In future high resolution Sentinel 2 observations from European Space Agency (ESA) will be used to fill the time gaps and to get better understanding about citrus crop canopy parameters.


2021 ◽  
Author(s):  
Samantha Ward ◽  
Paul A. Umina ◽  
Hazel Parry ◽  
Amber Balfour-Cunningham ◽  
Xuan Cheng ◽  
...  

AbstractBACKGROUNDEstimating parasitoid abundance in the field can be difficult, even more so when attempting to quantify parasitism rates and the ecosystem service of biological control that parasitoids can provide. To understand how ‘observed’ parasitism rates (in-field mummy counts) of the green peach aphid, Myzus persicae (Sulzer) (Homoptera: Aphididae) translate to ‘actual’ parasitism rates (laboratory-reared parasitoid counts), field work was undertaken in Australian canola fields over a growing season. Parasitoids were reared within a controlled laboratory setting.RESULTSTotal observed and actual parasitism rates of M. persicae varied considerably across regions, but less so on a field level. Overall, actual parasitism was on average 2.4 times higher than that observed in the field, with rates an average of 4-fold higher in South Australia. As crop growth stage progressed, the percentage of mummies observed increased. Percentage of parasitoids reared also increased with crop growth stage, averaging 3.4% during flowering and reaching 14.4% during podding/senescing. Although there was a greater diversity of reared parasitoid species at later crop growth stages, actual parasitism rate was unaffected by parasitoid species. Diaeretiella rapae was the most commonly reared parasitoid, increasing in abundance with crop growth stage.CONCLUSIONThese findings indicate that mummy counts alone do not provide a clear representation of parasitism within fields.


1988 ◽  
Vol 2 (4) ◽  
pp. 445-455 ◽  
Author(s):  
Steven J. Carlson ◽  
William W. Donald

Effects of repeated late-fall applications of the isopropylamine salt of glyphosate at 1.7 kg ae/ha plus 0.5% (v/v) surfactant on adventitious root buds, thickened propagative roots (> 1.3 mm diam), and shoot density of Canada thistle were studied in continuous hard red spring wheat over a 4-yr period. Glyphosate suppressed Canada thistle shoot density more quickly and to a greater extent than thickened root fresh weight or root bud number. A single fall application of glyphosate drastically decreased Canada thistle shoot density for 1 yr after treatment. However, shoot density was the same as the untreated control by 2 yr after a single fall treatment. Two consecutive late-fall applications of glyphosate in 2 yr decreased Canada thistle shoot density 94% in the fall 1 yr after the last treatment. Glyphosate reduced Canada thistle thickened root fresh weight 70% in the first fall 1 yr after a single fall treatment. However, 2 yr after a single fall application of glyphosate, root fresh weight equalled the controls. Two consecutive fall applications of glyphosate reduced thickened root fresh weight 77% 1 yr after the second treatment.


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