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 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.

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.

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.

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

scholarly journals Detection of Fusarium oxysporum f. sp. melonis Race 1 in Soil in Colima State, Mexico

Plant Disease ◽  
2004 ◽  
Vol 88 (12) ◽  
pp. 1383-1383 ◽  
Author(s):  
M. de Cara ◽  
E. J. Fernández ◽  
R. Blanco ◽  
J. C. Tello Marquina ◽  
F. J. Estrada ◽  
...  
Keyword(s):  
Fusarium Species ◽  
Selective Medium ◽  
Soil Samples ◽  
Potato Dextrose Agar ◽  
Conidial Suspension ◽  
State University ◽  
Yield Losses ◽  
Pennsylvania State University ◽  
Differential Cultivars ◽  
Race 1

During the winters of 2002 and 2003, a wilt occurred in melons cultivated on 1,500 ha in Colima State, Mexico. Yield losses reached 25% of final production, despite soil disinfestation with 60% methyl bromide and 40% chloropicrin. On the basis of the observation of plants with necrotic xylem, yellowing, and wilting of leaves, this disease was identified provisionally as Fusarium wilt. During February 2003, four soil samples from affected fields were plated onto a Fusarium-selective medium (1), which resulted in the detection of 2,260 ± 357, 179 ± 76, 668 ± 357, and 1,391 ± 256 CFU/g of F. oxysporum (3). Thirty-one randomly chosen isolates were used to inoculate differential cultivars of melon as described by Risser et al. (4). The cultivars were Amarillo Canario (susceptible to all races), Diana (resistant to races 0 and 2), Tango (resistant to races 0 and 1), and Vulcano (resistant to races 0, 1, and 2) (2). Ten plants of each cultivar, grown on sterilized vermiculite, were inoculated at the first true-leaf stage by drenching with 200 ml of a conidial suspension (1 × 105 CFU/ml) of each isolate. Noninoculated plants of each cultivar served as controls. Plants were maintained in a growth chamber with a 16-h photoperiod (18 × 103 lux) and temperatures at 23 to 25°C. Yellowing, wilt, and vascular discoloration symptoms developed on cvs. Amarillo Canario and Diana following inoculation with each of the 31 isolates, while noninoculated plants remained symptomless. F. oxysporum was consistently reisolated on potato dextrose agar from the affected plants. On the basis of the combination of affected cultivars, all isolates were identified as F. oxysporum f. sp. melonis race 1. To our knowledge, this is the first report of F. oxysporum f. sp. melonis race 1 in Colima State, Mexico. References: (1) H. Komada. Rev. Plant Prot. Res. 8:114, 1975. (2) J. Marín Rodríquez. Portagrano 2004. Vadmecum de Variedades Hortícolas. Agrobook, Spain. 2004. (3) P. E. Nelson et al. Fusarium Species: An Illustrated Manual for Identification. Pennsylvania State University Press, University Park, 1983. (4) G. Risser et al. Phytopathology 66:1105, 1976.

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.

Effect on scald (Rhynchosporium secalis (Oud.) J. Davis) infection on yield response of Stirling barley to various sowing rates

1988 ◽  
Vol 28 (2) ◽  
pp. 263 ◽  
Author(s):  
TN Khan
Keyword(s):  
Yield Loss ◽  
Plant Density ◽  
Grain Weight ◽  
Yield Response ◽  
Rhynchosporium Secalis ◽  
Yield Losses ◽  
Significant Yield

The effect of a range of sowing rates on scald infection and yield in barley cv. Stirling was studied to investigate if increased plant density will lead to more ears/m2 and therefore compensate for yield losses due to scald. Increased sowing rate (50 v. 100 kg/ha) did not compensate for yield loss due to scald. However, significant yield increases (3.0 v. 4.0 t/ha) with increased sowing rates (25 v. 125 kg/ha) occurred when scald was controlled. Such yield in creases were accompanied by increases in the number of ears/m2 and number of grains/ha, but decreases in number of grains/ear and 100-grain weight. The severity of scald infection was not affected by sowing rates.

scholarly journals Quantifying Alfalfa Yield Losses Caused by Foliar Diseases in Iowa, Ohio, Wisconsin, and Vermont

Plant Disease ◽  
2002 ◽  
Vol 86 (3) ◽  
pp. 269-277 ◽  
Author(s):  
F. W. Nutter ◽  
J. Guan ◽  
A. R. Gotlieb ◽  
L. H. Rhodes ◽  
C. R. Grau ◽  
...  
Keyword(s):  
United States ◽  
Remote Sensing ◽  
Disease Severity ◽  
Yield Loss ◽  
Disease Incidence ◽  
The United States ◽  
Yield Losses ◽  
Fungicide Treatment ◽  
Foliar Diseases ◽  
Significant Yield

Although foliar diseases of alfalfa occur throughout the United States wherever alfalfa is grown, little work has been done to quantify yield losses caused by foliar pathogens since the late 1980s. To quantify the yield losses caused by foliar diseases of alfalfa, field experiments were performed in Iowa, Ohio, Vermont, and Wisconsin from 1995 to 1998. Different fungicides and fungicide application frequencies were used to obtain different levels of foliar disease in alfalfa. Visual disease and remote sensing assessments were performed weekly to determine the relationships between disease assessments and alfalfa yield. Visual disease assessments of percentage of defoliation, disease incidence, and disease severity were performed weekly, approximately five to six times during each alfalfa growth cycle. Remote sensing assessments also were obtained weekly by measuring the percentage of sunlight reflected from alfalfa canopies using handheld, multispectral radiometers. Yield loss estimates were calculated as the yield difference between the fungicide treatment with the highest yield and the nonfungicide control, divided by the yield obtained from the highest yielding fungicide treatment × 100. Over the 4-year period, significant alfalfa yield losses (P ≤ 0.05) occurred on 22 of the 48 harvest dates for the four states. The average significant yield loss for the 22 harvests was 19.3%. Both visual and percentage of reflectance assessments were used as independent variables in linear regression models to quantify the relationships between assessments and alfalfa yield. From 1995 to 1998, visual disease assessments were performed for a total of 209 dates and remote sensing assessments were performed on 198 dates from the four states. Yield models were developed for each of these assessment dates. There were 26/209, 26/209, and 17/209 significant yield models based on percentage of defoliation, disease incidence, and disease severity, respectively. Most of the significant models were for disease assessments performed on or within 1 or 2 weeks of the date of alfalfa harvest. When the significant models were averaged, percentage of defoliation, disease incidence, and disease severity explained 51, 55, and 52% of the variation in alfalfa yield, respectively. There were a total of 68/198 significant alfalfa yield models based on remote sensing assessments, and the significant models (averaged) explained 62% of the variation in alfalfa yield. Alfalfa foliar diseases continue to have a significant negative impact on alfalfa yields in the United States and remote sensing appears to offer a better means to quantify the impact of foliar diseases on alfalfa yield compared with visual assessment methods.

scholarly journals Effects Of Spring Herbicide Treatments On Winter Wheat Growth And Grain Yield

2015 ◽  
Vol 46 (1) ◽  
pp. 1-6
Author(s):  
P. Hamouz ◽  
K. Hamouzová ◽  
K. Novotná
Keyword(s):  
Winter Wheat ◽  
Yield Loss ◽  
Low Cost ◽  
Yield Losses ◽  
Herbicide Application ◽  
Crop Injury ◽  
Minor Crop ◽  
Nitrate Fertilizer ◽  
Small Plot ◽  
Significant Yield

Abstract Herbicides provide a low-cost solution for protecting crops from significant yield losses. If weed infestations are below damage thresholds, however, then herbicide application is unnecessary and can even lead to yield loss. A small-plot field trial was conducted to examine the effect of herbicides on winter wheat yields. Weeds were removed manually from the trial area before herbicide application. Twenty-four treatments were tested in four replications. Treatment 1 consisted of an untreated weed-free control, whereas the other treatments comprised applications of the following herbicides and their combinations: metsulfuron-methyl + tribenuron-methyl (4.95 + 9.99 g ha−1), pinoxaden (30 g ha−1), fluroxypyr (175 g ha−1), and clopyralid (120 g ha−1). Water (250 l ha−1) or a urea-ammonium nitrate fertilizer solution (UAN, 120.5 l ha−1) was used as the herbicide carrier. Crop injury 30 days after treatment and yield loss were recorded. Results showed minor crop injury by herbicides and their combinations when applied without UAN and moderate injury caused by UAN in combination with herbicides. Yield losses reached 5.3% and 4.3% in those treatments where all of the tested herbicides were applied with and without UAN, respectively. The effect of all treatments on crop yield was, however, statistically insignificant (P = 0.934).

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