Dose Response of Glyphosate and Dicamba on Tomato (Lycopersicon esculentum) Injury

2012 ◽  
Vol 26 (2) ◽  
pp. 256-260 ◽  
Author(s):  
Greg R. Kruger ◽  
William G. Johnson ◽  
Douglas J. Doohan ◽  
Stephen C. Weller
Keyword(s):  
Lycopersicon Esculentum ◽  
Dose Response ◽  
Yield Loss ◽  
Field Studies ◽  
Vegetative Stage ◽  
Yield Losses ◽  
Marketable Yield ◽  
Processing Tomato ◽  
Commercial Processing ◽  
Tomato Cultivars

Field studies were conducted to determine the response of sublethal glyphosate and dicamba doses to processing tomato flowering loss and marketable yield. Dose–response studies for both herbicides were conducted on four commercial processing tomato lines (two different lines within each study) and plants were sprayed at either the vegetative stage or the early bloom stage. Both glyphosate and dicamba caused higher yield losses when sprayed at the early bloom stage. A 25% yield loss was observed with 8.5 and 7.5 g ae ha−1for glyphosate and dicamba, respectively, at the early bloom stage and 43.9 and 11.9 g ae ha−1for glyphosate and dicamba, respectively, at the early vegetative stage. Overall, these tomato cultivars were more sensitive to dicamba than to glyphosate. We conclude that glyphosate and dicamba drift could have serious implications on tomato yields especially if the drift occurs during flowering.

scholarly journals Pre-harvest field application of enhanced freshness formulation reduces yield loss in orange

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Jaspa Samwel ◽  
Theodosy Msogoya ◽  
Abdul Kudra ◽  
Hosea Dunstan Mtui ◽  
Anna Baltazari ◽  
...  
Keyword(s):  
Yield Loss ◽  
Sweet Orange ◽  
New Technology ◽  
Significant Negative Correlation ◽  
Field Application ◽  
Yield Losses ◽  
Factorial Experiments ◽  
Marketable Yield ◽  
Pest Damage ◽  
Marketable Fruit

Abstract Background Orange (Citrus sinensis L.) production in Tanzania is constrained by several pre-harvest factors that include pests. Hexanal, sprayed as Enhanced Freshness Formulation (EFF) is a relatively new technology that has been reported to reduce pre-harvest loss in fruits. However, the effects of hexanal on pre-harvest yield loss of orange are not known. We studied the effects of hexanal as EFF on yield losses of three sweet orange cultivars namely, Early Valencia, Jaffa, and Late Valencia. Factorial experiments tested the effects of EFF concentration, variety, and time of EFF application on number of dropped fruit, percentage of non-marketable fruit and incidence of pest damage. Results Results showed significant negative correlation (p < 0.001) between EFF and the percentage of dropped fruit, non-marketable yield, and incidence of pest damage. An increase in hexanal concentration by 1%, is expected to reduce number of dropped fruit by 50, percentage of non-marketable by 35.6, and incidences of pest damage by 36.5% keeping other factors constant. Results also show significant association (p < 0.001) between time of hexanal application and non-marketable yield. Percentage of dropped fruit is expected to increase by 1 for each day away from harvest, keeping other factors constant. Conclusion Pre-harvest application of hexanal as EFF can significantly reduce number of dropped fruits, percentage of non-marketable fruit and incidence of pest damage.

Economic and interference threshold densities of quackgrass (Elytrigia repens) in potato (Solanum tuberosum)

Weed Science ◽  
1998 ◽  
Vol 46 (2) ◽  
pp. 176-180 ◽  
Author(s):  
Régis Baziramakenga ◽  
Gilles D. Leroux
Keyword(s):  
Yield Loss ◽  
Dry Weight ◽  
Field Studies ◽  
Potato Yield ◽  
Hyperbolic Function ◽  
Yield Losses ◽  
Economic Threshold ◽  
Elytrigia Repens ◽  
Shoot Number ◽  
Dry Biomass

Field studies were conducted in 1989 and 1990 at St-Augustin, Quebec, Canada, to determine the economic threshold density of quackgrass in potato. Potato yield losses due to quackgrass interference increased with quackgrass population density. Potato yield ranged from 33 to 73% in 1989, and from 19 to 44% in 1990. The relationship between potato yield losses and quackgrass densities was described by a rectangular hyperbolic function. Dry weight of quackgrass proved to be the best predictor of potato yield loss compared to shoot number. The interference thresholds for 10% potato yield loss amounted to 25 shoots m−2or 20 g total dry biomass m−2. The economic threshold varied between 0.04 and 2 shoots m−2or 0.0165 and 1.5 g total dry biomass m−2, depending on the variables considered.

Critical timing of Palmer amaranth (Amaranthus palmeri) removal in sweetpotato

2020 ◽  
Vol 34 (4) ◽  
pp. 547-551 ◽  
Author(s):  
Stephen C. Smith ◽  
Katherine M. Jennings ◽  
David W. Monks ◽  
Sushila Chaudhari ◽  
Jonathan R. Schultheis ◽  
...  
Keyword(s):  
North Carolina ◽  
Logistic Model ◽  
Yield Loss ◽  
Relative Yield ◽  
Field Studies ◽  
Palmer Amaranth ◽  
Amaranthus Palmeri ◽  
Marketable Yield ◽  
Yield Data ◽  
Critical Timing

AbstractPalmer amaranth is the most common and troublesome weed in North Carolina sweetpotato. Field studies were conducted in Clinton, NC, in 2016 and 2017 to determine the critical timing of Palmer amaranth removal in ‘Covington’ sweetpotato. Palmer amaranth was grown with sweetpotato from transplanting to 2, 3, 4, 5, 6, 7, 8, and 9 wk after transplanting (WAP) and maintained weed-free for the remainder of the season. Palmer amaranth height and shoot dry biomass increased as Palmer amaranth removal was delayed. Season-long competition by Palmer amaranth interference reduced marketable yields by 85% and 95% in 2016 and 2017, respectively. Sweetpotato yield loss displayed a strong inverse linear relationship with Palmer amaranth height. A 0.6% and 0.4% decrease in yield was observed for every centimeter of Palmer amaranth growth in 2016 and 2017, respectively. The critical timing for Palmer amaranth removal, based on 5% loss of marketable yield, was determined by fitting a log-logistic model to the relative yield data and was determined to be 2 WAP. These results show that Palmer amaranth is highly competitive with sweetpotato and should be managed as early as possible in the season. The requirement of an early critical timing of weed removal to prevent yield loss emphasizes the importance of early-season scouting and Palmer amaranth removal in sweetpotato fields. Any delay in removal can result in substantial yield reductions and fewer premium quality roots.

The Critical Period of Bengal Dayflower (Commelina Bengalensis) Control in Peanut

Weed Science ◽  
2007 ◽  
Vol 55 (4) ◽  
pp. 359-364 ◽  
Author(s):  
Theodore M. Webster ◽  
Wilson H. Faircloth ◽  
J. Timothy Flanders ◽  
Eric P. Prostko ◽  
Timothy L. Grey
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Plant Pathogens ◽  
Yield Loss ◽  
Maximum Yield ◽  
Field Studies ◽  
Yield Losses ◽  
Competitive Effects ◽  
Peanut Crop ◽  
The Relationship

Bengal dayflower (also known as tropical spiderwort) is one of the most troublesome weeds in peanut in Georgia, United States. Field studies conducted in 2004 and 2005 evaluated the relationship between the duration of Bengal dayflower interference and peanut yield in an effort to optimize the timing of weed control. In 2004, the critical period of weed control (CPWC) necessary to avoid greater than 5% peanut yield loss was between 316 and 607 growing degree days (GDD), which corresponded to an interval between June 8 and July 2. In 2005, the CPWC ranged from 185 to 547 GDD, an interval between May 30 and July 3. Maximum yield loss in 2005 from season-long interference of Bengal dayflower was 51%. In 2004, production of peanut pods was eliminated by interference with Bengal dayflower for the initial 6 wk (495 GDD) of the growing season. Robust Bengal dayflower growth in 2004 shaded the peanut crop, likely intercepting fungicide applications and causing a reduction in peanut yield. Therefore, the competitive effects of Bengal dayflower are likely complicated with the activity of plant pathogens. In spite of higher Bengal dayflower population densities, greater Bengal dayflower growth, and greater peanut yield losses in 2004 than in 2005, the CPWC was a relatively similar 4-wk period that ended during the first week of July, for peanut that was planted in the first week of May.

Response of Rice (Oryza sativa) to Low Rates of Glyphosate and Glufosinate

2011 ◽  
Vol 25 (2) ◽  
pp. 198-203 ◽  
Author(s):  
Brad Davis ◽  
Robert C. Scott ◽  
Jason K. Norsworthy ◽  
Edward Gbur
Keyword(s):  
Yield Loss ◽  
Flag Leaf ◽  
Field Studies ◽  
Leaf Length ◽  
University Of Arkansas ◽  
Yield Losses ◽  
Time Of Application ◽  
Flag Leaf Length ◽  
The University ◽  
Significant Injury

Field studies were conducted in 2007 and 2008 at the University of Arkansas at Pine Bluff farm near Lonoke to evaluate and compare the effects of low rates of glufosinate and glyphosate on rice. Two rice cultivars were seeded, and glyphosate and glufosinate were applied at 1/2, 1/4, and 1/8 of the labeled use rate of 870 g ae ha−1and 616 g ai ha−1, respectively, at the three- to four-leaf, panicle initiation (PI), and boot stages. Rice canopy height reductions, reduction in flag leaf length, prolonged maturity, and yield losses were caused by both herbicides at all evaluated application timings. Although both herbicides caused significant injury, symptoms varied greatly between the two herbicides. Glufosinate injury to rice was more rapid and visually intense than with glyphosate. Glufosinate symptoms, which consisted of rapid necrosis, were visible in 1 to 2 d, whereas glyphosate symptoms, stunting and chlorosis, became visible after 7 to 10 d or not at all depending on time of application. Glyphosate applied at the 1/2× rate to rice in the boot growth stage caused less than 10% injury at 3 wk after treatment but resulted in 80% yield loss. Glufosinate at boot caused 80% injury and 80% yield loss. Glyphosate symptoms from PI and boot timings were typically only visible at heading and included malformed panicles and shortened flag leaves. Harvested grain seed weights were reduced as much as 14% by either herbicide applied at PI and boot. Germination of harvested grain was not affected by any treatment. At the rates evaluated in this research, glufosinate-induced injury to rice can be just as detrimental as glyphosate in reducing yield.

scholarly journals Evaluation of Grafting Using Hybrid Rootstocks for Management of Bacterial Wilt in Field Tomato Production

HortScience ◽  
2012 ◽  
Vol 47 (5) ◽  
pp. 621-625 ◽  
Author(s):  
Theodore McAvoy ◽  
Joshua H. Freeman ◽  
Steven L. Rideout ◽  
Stephen M. Olson ◽  
Mathews L. Paret
Keyword(s):  
Bacterial Wilt ◽  
Disease Incidence ◽  
Field Studies ◽  
Marketable Yield ◽  
Tomato Production ◽  
Tomato Plants ◽  
Four Seasons ◽  
Tomato Cultivars ◽  
The Impact ◽  
Wilt Incidence

Seven hybrid tomato rootstocks with possible resistance to bacterial wilt caused by Ralstonia solanacearum and a known resistant cultivar were tested as grafting rootstocks to impart resistance to a bacterial wilt-susceptible cultivar, BHN 602. Greenhouse studies showed resistance of all the rootstocks to bacterial wilt. The disease incidence and yield of ‘BHN 602’ grafted to these rootstocks were evaluated in open-field tomato production in Florida and Virginia over four seasons. Significant differences in bacterial wilt incidence were observed between grafted entries in three of the four trials. In these three trials, grafted entries consistently exhibited the least bacterial wilt incidence compared with the controls; the self-graft, and non-grafted entries. Over all the trials, tomato plants grafted onto ‘Cheong Gang’, ‘BHN 1054’, and ‘BHN 998’ displayed the least bacterial wilt incidence. Rootstocks had a significant effect on total marketable yield in all the trials with certain grafted entries yielding significantly greater than non-grafted ‘BHN 602’. Field studies show that grafting holds promise for decreasing the impact of bacterial wilt on tomato cultivars as well as increasing the overall productivity of tomato cultivars.

Effects of foliar fungicide sprays on disease and yield of processing tomatoes in Ontario

1993 ◽  
Vol 73 (4) ◽  
pp. 1209-1215 ◽  
Author(s):  
V. Poysa ◽  
R. A. Brammall ◽  
R. E. Pitblado
Keyword(s):  
Lycopersicon Esculentum ◽  
Disease Development ◽  
Fungicide Application ◽  
Commercial Processing ◽  
Tomato Cultivars ◽  
Low Levels ◽  
Marketable Fruit ◽  
Restricted Use ◽  
Foliar Fungicide ◽  
Tomato Disease

The effects of controlling foliar diseases with a foliar fungicide applied following a TOMCAST regime were evaluated on commercial processing tomato (Lycopersicon esculentum Mill.) cultivars in three locations in Southwestern Ontario in 1990 and 1991. For each cultivar, one set of plants was sprayed with chlorothalonil (Bravo 500) and one set received no fungicide application during the growing season. At two of the three locations, fungicide application significantly reduced final foliar disease development, averaged across all cultivars, from over 60% of the foliage infected to 10% infected. At the third location disease development was more restricted. Use of foliar fungicide did not result in a significant increase in either total fruit yield or yield of marketable fruit measured across cultivars, years, and locations. The application of fungicide (4–10 sprays) reduced the average number of fruit infected with anthracnose by 50% over all cultivars treated. Several cultivars, however, had relatively low levels of anthracnose even without fungicide sprays. While fungicide sprays may be important in maintaining fruit quality, both with respect to solids levels and degree of mould contamination, fungicide may not be required to maintain yields every year for many tomato cultivars commercially grown in Ontario. Key words: Lycopersicon esculentum, tomato disease, anthracnose

Eastern Black Nightshade (Solanum ptycanthum) Interference in Processing Tomato (Lycopersicon esculentum)

Weed Science ◽  
1990 ◽  
Vol 38 (4-5) ◽  
pp. 385-388 ◽  
Author(s):  
Frances G. M. Perez ◽  
John B. Masiunas
Keyword(s):  
Lycopersicon Esculentum ◽  
Relative Yield ◽  
Field Studies ◽  
Eastern Black Nightshade ◽  
Solanum Ptycanthum ◽  
Processing Tomato ◽  
Black Nightshade ◽  
Tomato Yield ◽  
Greenhouse Plant ◽  
Marketable Fruit

In replacement experiments in the greenhouse, plant relative yield (PRY) of both eastern black nightshade and tomato increased as the proportion of nightshade plants increased in the pots, indicating that nightshade is less competitive than tomato. In field studies tomato yield was reduced by two-thirds if three nightshade plants m–1of row were allowed to grow with tomato more than 6 weeks following tomato establishment The percent marketable fruit decreased linearly from 73% with no nightshade to 49% when nightshade were present for 12 weeks. When nightshade and tomato were transplanted together, tomato yield was 9000 kg ha–1and 49% of the fruit was marketable, while tomato yields were 30 000 kg ha–1and 70% of the fruit was marketable when nightshade was established 9 weeks after tomato planting.

Characterization of carinata tolerance to select herbicides using field dose-response studies

2021 ◽  
pp. 1-26
Author(s):  
Sandra R. Ethridge ◽  
Angela Post ◽  
Pratap Devkota ◽  
Michael J. Mulvaney ◽  
Ramon G. Leon
Keyword(s):  
Population Density ◽  
Dose Response ◽  
Field Experiments ◽  
Relative Yield ◽  
Field Studies ◽  
Yield Losses ◽  
Control Volunteer ◽  
Postemergence Herbicides ◽  
Response Field

Abstract Field experiments were conducted from 2017 to 2019 to determine the tolerance of carinata to several preemergence and postemergence herbicides. Preliminary screenings identified herbicides which caused large variation on carinata injury, indicating the potential for selectivity. Dose-response field studies were conducted to quantify the tolerance of carinata to select herbicides. Diuron applied preemergence at rates of 280 g ai ha−1 or above reduced carinata population density 54% to 84% compared to the nontreated control. In certain locations, clomazone applied preemergence caused minor injury with an acceptable level of carinata tolerance and only doses above 105 g ai ha−1 caused yield reductions. Napropamide doses of 2,856 g ai ha−1 or higher applied preemergence caused at least 25% injury to carinata; however, the damage was not severe enough to reduce yields. Simazine applied postemergence at rates above 1,594 g ai ha−1 caused 50% or more injury, resulting in yield losses ranging from 0 to 95% depending on location. Clopyralid applied postemergence at 2,512 g ai ha−1 caused 25% injury with relative yield reductions which varied across locations. The present study identified clomazone and napropamide applied preemergence, and clopyralid applied postemergence as potential herbicides for weed control in carinata. In contrast, diuron, simazine, metribuzin, imazethapyr, and chlorimuron caused high levels of carinata mortality and can be used to control volunteer carinata plants in rotational crops.

scholarly journals Winter Wheat Response to Preplant Applications of Aminocyclopyrachlor

2011 ◽  
Vol 25 (1) ◽  
pp. 51-57 ◽  
Author(s):  
Andrew R. Kniss ◽  
Drew J. Lyon
Keyword(s):  
Winter Wheat ◽  
Yield Loss ◽  
Wheat Yield ◽  
Field Studies ◽  
Wheat Crop ◽  
Yield Losses ◽  
Fallow Period ◽  
Winter Wheat Yield ◽  
Winter Wheat Crop ◽  
Preceding Winter

Field studies were conducted in Wyoming and Nebraska in 2007 through 2009 to evaluate winter wheat response to aminocyclopyrachlor. Aminocyclopyrachlor was applied at rates between 15 and 120 g ai ha−1 6, 4, and 2 mo before winter wheat planting (MBP). Redroot pigweed control was 90% with aminocyclopyrachlor rates of 111 and 50 g ha−1 when applied 4 or 2 MBP. Aminocyclopyrachlor at 37 g ha−1 controlled Russian thistle 90% when applied 6 MBP. At Sidney, NE, winter wheat yield loss was > 10% at all aminocyclopyrachlor rates when applied 2 or 4 MBP, and at all rates > 15 g ha−1 when applied 6 MBP. At Lingle, WY, > 40% winter wheat yield loss was observed at all rates when averaged over application timings. Although the maturing wheat plants looked normal, few seed were produced in the aminocyclopyrachlor treatments, and therefore preharvest wheat injury ratings of only 5% corresponded to yield losses ranging from 23 to 90%, depending on location. The high potential for winter wheat crop injury will almost certainly preclude the use of aminocyclopyrachlor in the fallow period immediately preceding winter wheat.

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