Cost of crop losses in processing tomato and cabbage in southwestern Ontario due to insects, weeds and/or diseases

2004 ◽  
Vol 84 (3) ◽  
pp. 915-921 ◽  
Author(s):  
J. H. Tolman ◽  
D. G. R. McLeod ◽  
C. R. Harris
Keyword(s):  
Yield Loss ◽  
Management Program ◽  
Yield Losses ◽  
Crop Losses ◽  
Control Programs ◽  
Processing Tomato ◽  
Key Words Tomato ◽  
Significant Yield ◽  
Control Disease ◽  
One Year

The relative importance of insects, weeds and diseases to yield losses in processing tomato (Lycopersicon esculentum Mill.) and cabbage (Brassica oleracea L. var. capitata L.) was measured by comparing yields in the presence and absence of appropriate control programs. In the absence of any pest control, average crop losses exceeded 80% in both crops. Average yield losses due to weeds alone approached 80% in processing tomato and 60% in cabbage. Insects alone did not significantly reduce yield of processing tomato in either year. In the absence of insect control, significant yield loss in cabbage approached 50% in only one year. When diseases were not controlled, yield of processing tomato declined significantly by nearly 30% in one trial. Failure to control disease had no significant impact on cabbage yield in this study. Monetary losses and costs of each management program were calculated. Key words: Tomato, cabbage, yield loss, insects, weeds, diseases

Puccinia triticina (wheat brown rust).

2021 ◽  
Author(s):  
Henriette Goyeau
Keyword(s):  
Leaf Rust ◽  
Yield Loss ◽  
Genetic Resistance ◽  
Puccinia Triticina ◽  
Multiple Point ◽  
Yield Losses ◽  
Flowering Stage ◽  
Crop Losses ◽  
Pathogen Virulence ◽  
Cropping Season

Abstract Leaf rust seldom kills wheat, but it is capable of causing 35-50% yield loss in endemic areas on susceptible cultivars, where severity levels of 25-40% are reached at the tillering stage and 100% at the flowering stage. The disease causes more damage worldwide than other wheat rusts. Quarantine is of no relevance as leaf rust is of worldwide occurrence and virulences spread freely between nations and zones. Crop losses are dependent on the genetic resistance of each cultivar, pathogen virulence and environmental conditions. Losses caused by leaf rust particularly originate from reductions of the wheat photosynthetic area. Infected plants normally produce a lower number of tillers, lower amounts of grains per head and smaller grains. The earlier the epidemic in the cropping season, the higher the yield losses. Mathematical models for estimating disease severity and crop losses have been developed based on multiple-point disease recording at different physiological stages of the plant (Burleigh et al., 1972; Eversmeyer and Kramer, 1998, 2000).

scholarly journals Density and Time of Emergence of Yellow Nutsedge Affect Squash Yield

HortScience ◽  
2004 ◽  
Vol 39 (4) ◽  
pp. 845D-846
Author(s):  
J. Pablo Morales-Payan* ◽  
William M. Stall
Keyword(s):  
Crop Yield ◽  
Cucurbita Pepo ◽  
Yield Loss ◽  
Cyperus Esculentus ◽  
Yield Losses ◽  
Crop Season ◽  
Yellow Nutsedge ◽  
Live Oak ◽  
Significant Yield ◽  
Direct Seeded

A field experiment was conducted in Live Oak, Fla., to determine the effect of yellow nutsedge (Cyperus esculentus L.) (YN) density and time of emergence on the yield of direct-seeded squash (Cucurbita pepo L.). YN densities (0, 20, 40, 60, and 100 plants/m2) were established from tubers planted at different times onto polyethylene-mulched beds, so that YN would emerge the same day as the crop or 5, 15, or 25 days later than the crop (DLTC). YN was not controlled after its emergence. The extent of squash yield loss was affected by YN density and time of emergence. When YN emerged the same day as the crop, the yield of squash was reduced by ≈7% (20 YN/m2) to 20% (100 YN/m2). When YN emerged 15 DLTC, crop yield loss was ≈13% at the density of 100 YN/m2>. Regardless of density, YN emerging 25 DLTC did not significantly reduce crop yield as compared to weed-free squash. Thus, in soils with high YN densities (≈100 viable tubers/m2) herbicides and/or other means of YN suppression in squash should be effective for at least 25 days after crop emergence to prevent significant yield loss. If squash yield losses <5% were acceptable, YN control may not be necessary when densities <20 YN/m2 emerge at any time during the squash season or when <100 YN/m2 emerge >25 DLTC. However, YN emerging during the first 15 days of the squash season may produce tubers, which could increase the YN population at the beginning of the following crop season.

Ethametsulfuron Interactions with Grass Herbicides on Canola (Brassica napus, B. rapa)

1995 ◽  
Vol 9 (1) ◽  
pp. 91-98 ◽  
Author(s):  
K. Neil Harker ◽  
Robert E. Blackshaw ◽  
Ken J. Kirkland
Keyword(s):  
Brassica Napus ◽  
Brassica Rapa ◽  
Field Experiments ◽  
Yield Loss ◽  
Growth And Yield ◽  
Yield Response ◽  
Sulfonylurea Herbicides ◽  
Yield Losses ◽  
Significant Yield ◽  
Injury Potential

Field experiments were conducted from 1986 to 1988 at Lacombe and Lethbridge, Alberta and Scott, Saskatchewan to determine growth and yield response of canola to mixtures of ethametsulfuron with specific grass herbicides. Ethametsulfuron did not usually cause canola injury when mixed with sethoxydim. However, ethametsulfuron mixtures with the following grass herbicides listed in decreasing order of injury potential, often caused canola injury and yield loss: haloxyfop > fluazifop > fluazifop-P > quizalofop > quizalofop-P. Canola yield losses were severe in some experiments, ranging from 59% with quizalofop mixtures to 97% with haloxyfop mixtures; in other experiments, the same mixtures did not cause significant yield losses. ‘Tobin,’ aBrassica rapacultivar, tended to be more susceptible to injury than theB. napuscultivars ‘Pivot’ and ‘Westar.’ Canola injury symptoms were consistent with those expected from sulfonylurea herbicides. Therefore, we suggest that specific grass herbicides differentially impair the ability of canola to metabolize ethametsulfuron to inactive forms.

scholarly journals Assessing the Representativeness of Data on Yield Losses Due to Rice Diseases in Tropical Asia

Plant Disease ◽  
1998 ◽  
Vol 82 (6) ◽  
pp. 705-709 ◽  
Author(s):  
Serge Savary ◽  
F. A. Elazegui ◽  
Paul S. Teng
Keyword(s):  
Yield Loss ◽  
Production Systems ◽  
Rice Production ◽  
Yield Losses ◽  
Tropical Asia ◽  
Bacterial Diseases ◽  
Potted Plants ◽  
Rice Tungro Disease ◽  
Rice Ecosystems ◽  
One Year

The representativeness of information on yield losses due to rice diseases in tropical Asia was studied. Published studies involving different groups of diseases (viral, bacterial, and fungal) and conducted in different rice production ecosystems were compared to help identify research gaps, the filling of which could improve current disease management in rice and help in developing strategies that fit the management needs of fast-evolving rice production systems in the future. Four criteria of representativeness of yield loss information were used: representativeness over time (the proportion of studies conducted over more than one crop cycle), representativeness over space (the proportion of studies conducted in more than one location), representativeness of scale (the proportion of studies conducted on the scale of plots or fields), and representativeness of injury (the standard deviation of the proportion of studies using inoculation, spontaneous infection, or chemical control). A strong imbalance in both the number and the representativeness of studies dealing with fungal, viral, and bacterial diseases was found. Most of the few studies of yield loss due to viral diseases (mainly rice tungro disease) were conducted on the scale of individual (potted) plants or were based on one-year data sets, often reflecting strong epidemics only. Studies of bacterial diseases were conducted in single locations only, and whether such results can be extrapolated still needs to be addressed. There is an acute need to better document yield losses in rice ecosystems other than the irrigated ecosystem. While studies conducted in the upland, rain-fed lowland, and deep-water rice ecosystems seem to have a high degree of representativeness, this cannot compensate for their small number in view of the great diversity of these environments. Studies of irrigated rice tend to concentrate on one year and one location. This approach may be based on the erroneous view that the irrigated ecosystem is homogeneous, and possible extrapolation of data from these studies needs to be examined.

Lettuce big-vein disease: sources, patterns of spread, and losses

2004 ◽  
Vol 55 (2) ◽  
pp. 125 ◽  
Author(s):  
L. J. Latham ◽  
R. A. C. Jones ◽  
S. J. McKirdy
Keyword(s):  
Weight Loss ◽  
Yield Loss ◽  
Yield Losses ◽  
Fresh Weight ◽  
Straight Line ◽  
Sigmoid Curve ◽  
History Of ◽  
Significant Yield ◽  
Vein Disease ◽  
Leaf Symptoms

Most batches of lettuce seedlings taken over an 18-month period from a vegetable nursery were infested with lettuce big-vein disease (LBVD) with an up to 31% incidence. Using lettuce seedlings in bait tests, contamination was detected at the nursery in potting mix composted for different periods and in dirt from under the benches, and at the bark supplier's site in this ingredient of the potting mix and waste 'bark' from the ground. In a field experiment in which lettuce seedlings from the infested nursery were inoculated with infested roots or left uninoculated before transplanting into subplots on land with no history of lettuce planting, disease progress followed a sigmoid curve with the former but an almost straight line with the latter. However, significant clustering of symptomatic plants was found only in the subplot with the uninoculated plants. Leaf symptoms of LBVD were more severe in lettuces infested later, whereas symptoms in those infested earlier were obvious initially but then became milder. The disease impaired formation of hearts: the proportion of symptomatic plants that lacked hearts was 24–36% when leaf symptoms first appeared 5–7 weeks after transplanting, but 14–16% after 8–9 weeks. When leaf symptoms first appeared at 5–6 weeks, there was a fresh weight loss of 14–15% for heads (all plants) and 39% for hearts (excluding plants without hearts). When leaf symptoms first appeared 7 weeks after transplanting, there was no significant yield loss for heads and only a 14% loss for hearts. At 8–9 weeks, there were no significant yield losses for heads or hearts.

scholarly journals Impact of Brown Spot Caused by Septoria glycines on Soybean in Ohio

Plant Disease ◽  
2010 ◽  
Vol 94 (7) ◽  
pp. 820-826 ◽  
Author(s):  
Christian D. Cruz ◽  
Dennis Mills ◽  
Pierce A. Paul ◽  
Anne E. Dorrance
Keyword(s):  
Growth Stage ◽  
Yield Loss ◽  
Management Program ◽  
Brown Spot ◽  
Growth Stages ◽  
Yield Losses ◽  
Cultivar Development ◽  
Term Management ◽  
Different Levels

Brown spot, caused by Septoria glycines, is the most common foliar disease of soybean in Ohio, but its economic impact has not been assessed on modern cultivars. Therefore, the objectives of this study were to (i) evaluate the effect of S. glycines on soybean yield and (ii) evaluate the efficacy of strobilurin- and triazole-based fungicides on the control of brown spot. Yield loss associated with S. glycines was determined using weekly applications of chlorothalonil. The efficacy of azoxystrobin, pyraclostrobin, tebuconazole, and flutriafol alone and in combinations were also assessed using applications at the R3 and R5 growth stages at two locations over 3 years. Significantly different levels of brown spot developed following applications of chlorothalonil, with mean yield differences between treated and nontreated plots ranging from 196 to 293 kg/ha. Pyraclostrobin and azoxystrobin applied at the R3 growth stage significantly reduced final levels of brown spot; however, significant increases in yield occurred in only three of the six location-years. Triazoles, flutriafol and tebuconazole, applied at R3 or R5 did not significantly decrease levels of brown spot or impact yield. More data on the accurate timing of fungicides are still required to establish a long-term management program for this disease, and resistance to brown spot should be monitored in soybean cultivar development to prevent future yield losses.

Comparison of different methods used in calculating the effect of stripe rust on wheat grain yields

2007 ◽  
Vol 55 (1) ◽  
pp. 89-98
Author(s):  
N. Bolat ◽  
F. Altay
Keyword(s):  
Stripe Rust ◽  
Yield Loss ◽  
Agricultural Research ◽  
Yellow Rust ◽  
Yield Reduction ◽  
Yield Losses ◽  
Grain Yields ◽  
Unit Increase ◽  
Significant Yield ◽  
Disease Free

One of the most important diseases of wheat in Turkey is yellow rust. The severe epidemic in the 1997–1998 growing season, which caused significant yield reductions, and the absence of infection at the Hamidiye Substation of the Anatolian Agricultural Research Institute made it possible to calculate the yield losses due to stripe rust. This calculation was based on yield differences between genotypes at infected and disease-free locations using various methods.Using the method suggested by Campbell et al. (1975) the calculated yield loss due to stripe rust varied among genotypes and locations with an overall range of 12.7 to 87.0%.By the second method, entries were divided into five groups according to their Average Coefficients of Infection (ACI) and the yield losses in each group were calculated. Yield reductions when ACI was over 70 reached up to 57.5 % in Regional Yield Trials.In the third method, regression analysis was applied to estimate the effect of ACI on grain yields. A highly significant linear relationship was found between the ACI values of the entries and their grain yields, with an estimate of 21.4 kg/ha yield reduction per unit increase in ACI.

Optimizing chloroacetamide application timing in dicamba-resistant cotton production systems for control of glyphosate-resistant Palmer amaranth

2021 ◽  
pp. 1-23
Author(s):  
John T. Buol ◽  
Lucas X. Franca ◽  
Darrin M. Dodds ◽  
J. Anthony Mills ◽  
Janice L. DuBien ◽  
...  
Keyword(s):  
Yield Loss ◽  
Biomass Yield ◽  
Production Systems ◽  
Management Program ◽  
Palmer Amaranth ◽  
Yield Losses ◽  
Cotton Production ◽  
Single Application ◽  
Application Timing ◽  
Late Season

A chloroacetamide herbicide by application timing factorial experiment was conducted in 2017 and 2018 in Mississippi to investigate chloroacetamide use in a dicamba-based Palmer amaranth management program in cotton production. Herbicides used were S-metolachlor or acetochlor, and application timings were preemergence, preemergence followed by (fb) early postemergence, preemergence fb late postemergence, early postemergence alone, late postemergence alone, and early postemergence fb late postemergence. Dicamba was included in all preemergence applications, and dicamba plus glyphosate was included with all postemergence applications. Differences in cotton and weed response due to chloroacetamide type were minimal, and cotton injury 14 d after LP application was less than 10% for all application timings. Late-season weed control was reduced up to 30 and 53% if chloroacetamide application occurred PRE or LP only, respectively. Late-season weed densities were minimized if multiple applications were used instead of a single application. Cotton height was reduced by up to 23% if a single application was made LP relative to other application timings. Chloroacetamide application at any timing except PRE alone minimized late season weed biomass. Yield was maximized by any treatment involving multiple applications or EP alone whereas applications PRE or LP alone resulted in up to 56 and 27% yield losses, respectively. While no yield loss was reported by delaying the first of sequential applications until EP, foregoing a PRE application is not advisable given the multiple factors that may delay timely POST applications such as inclement weather.

scholarly journals Yield Comparison of Hybrid Agaricus Mushroom Strains as a Measure of Resistance to Trichoderma Green Mold

Plant Disease ◽  
2001 ◽  
Vol 85 (7) ◽  
pp. 731-734 ◽  
Author(s):  
M. G. Anderson ◽  
D. M. Beyer ◽  
P. J. Wuest
Keyword(s):  
Agaricus Bisporus ◽  
Yield Loss ◽  
State University ◽  
Yield Losses ◽  
Pennsylvania State University ◽  
Trichoderma Spp ◽  
Green Mold ◽  
Spawning Time ◽  
Significant Yield ◽  
Mold Resistance

Commercially available strains of hybrid white, hybrid off-white, and brown Agaricus bisporus mushrooms were compared for resistance to green mold caused by Trichoderma harzianum biotype 4 (Th4). Seven mushroom spawn strains were assessed for total weight of mushrooms (grams per 0.1 m2) with or without the addition of an aqueous Th4 spore suspension added at spawning time. Cropping studies were conducted at the Mushroom Research Center (Pennsylvania State University) to emulate commercial growing operations. Excessive spawn handling had no significant effect on development of green mold. Severity of green mold was related to time between infestation and green mold appearance, with more significant yield losses occurring when green sporulation was detected early in production. Significant differences in yield were measured among mushroom strains in response to Th4 infestation. Hybrid white strains were extremely susceptible, with a mean yield loss of 96%. Hybrid off-white strains exhibited intermediate susceptibility, with mean yield losses of 56 to 73%. Brown strains were highly resistant, with mean yield losses of 9 to 16%. From these findings, we report the existence of green mold resistance, with a continuum of resistance among spawn strains. The findings suggest use of brown strains to manage green mold outbreaks, particularly where benomyl resistance in Trichoderma spp. is a threat.

scholarly journals Incidence, yield losses and symptomatology of sclerotinia stem rot (SSR) of Indian mustard (Brassica juncea L.) incited by Sclerotinia sclerotiorum

2021 ◽  
Vol 16 (2) ◽  
pp. 103-108
Author(s):  
Irfan Khan ◽  
Pokhar Rawal ◽  
Roop Singh
Keyword(s):  
Yield Loss ◽  
Disease Incidence ◽  
Indian Mustard ◽  
Disease Outbreak ◽  
Yield Losses ◽  
Sclerotinia Stem Rot ◽  
Mustard Crop ◽  
White Mycelium ◽  
Significant Yield ◽  
Minimum Yield

SSR hamper successful cultivation and causes significant yield losses globally including India. The SSR disease incidence ranged from 3.59 to 18.50 per cent in mustard growing areas of Rajasthan and Bharatpur district having the highest (18.50%) disease incidence. However, the Udaipur district had the lowest (3.59%) disease outbreak. SSR was responsible to cause 18.80 per cent overall yield losses in two consecutive years (Rabi 2016-17 and 2017-18). Highest yield loss (43.82%) was observed from Bharatpur district while minimum yield loss (3.51%) had recorded from Udaipur district. Characteristics symptoms, formation of white mycelium on host stem and development of sclerotia on/inside the stem, of SSR on mustard crop were noted during survey.

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