scholarly journals Management of Tomato Bacterial Spot in the Field by Foliar Applications of Bacteriophages and SAR Inducers

Plant Disease ◽  
2004 ◽  
Vol 88 (7) ◽  
pp. 736-740 ◽  
Author(s):  
A. Obradovic ◽  
J. B. Jones ◽  
M. T. Momol ◽  
B. Balogh ◽  
S. M. Olson
Keyword(s):  
Disease Control ◽  
Untreated Control ◽  
Field Experiments ◽  
Total Yield ◽  
Copper Hydroxide ◽  
Bacterial Spot ◽  
Central Florida ◽  
Harpin Protein ◽  
Marketable Fruit ◽  
Control Application

Various combinations of the harpin protein, acibenzolar-S-methyl, and bacteriophages were compared for controlling tomato bacterial spot in field experiments. Harpin protein and aciben-zolar-S-methyl were applied every 14 days beginning twice before transplanting and then an additional four applications throughout the season. Formulated bacteriophages were applied prior to inoculation followed by twice a week at dusk. A standard bactericide treatment, consisting of copper hydroxide plus mancozeb, was applied once prior to inoculation and then every 7 days, while untreated plants served as an untreated control. Experiments were conducted in north and central Florida fields during fall 2001, spring 2002, and fall 2002. In three consecutive seasons, acibenzolar-S-methyl applied in combination with bacteriophage or bacteriophage and harpin significantly reduced bacterial spot compared with the other treatments. However, it did not significantly affect the total yield compared with the standard or untreated control. Application of host-specific bacteriophages was effective against the bacterial spot pathogen in all three experiments, providing better disease control than copper-mancozeb or untreated control. When results of the disease severity assessments or harvested yield from the bacteriophage-treated plots were grouped and compared with the results of the corresponding nonbacteriophage group, the former provided significantly better disease control and yield of total marketable fruit.

scholarly journals Field Bio-efficacy and Residue Dynamics of the Fungicide Polyoxin D Zinc Salt 5% SC in Grape (Vitis vinifera)

2021 ◽  
Vol 12 (6) ◽  
pp. 603-610
Author(s):  
Pushpa Deore ◽  
◽  
Sandip Hingmire ◽  
Dattatray Shinde ◽  
Anjali Pudale ◽  
...  
Keyword(s):  
Disease Control ◽  
Untreated Control ◽  
Consumer Satisfaction ◽  
Field Experiments ◽  
Zinc Salt ◽  
Research Centre ◽  
Yield Data ◽  
Chromatography Tandem Mass Spectrometry ◽  
Percent Increase ◽  
Liquid Chromatography Tandem Mass

The field experiments were carried out to evaluate the bio-efficacy and residue dynamics of Polyoxin D Zinc salt 5% SC in grape during 2014–2015 and 2015–2016 at ICAR-National Research Centre for Grapes, Pune. Polyoxin D Zinc salt 5% SC @ 600 ml ha-1 gave the best control of the disease, both in the leaves and bunches with a percent disease control of 56.4 and 75.7 respectively, as compared to untreated control. The percent disease control of the test fungicide Polyoxin D Zinc salt 5% SC @ 600 ml ha-1 was superior to all the triazoles viz. Flusilazole 40 EC, Hexaconazole 5 EC and Myclobutanil 10 WP, used in the study. The yield data reflected a similar trend wherein the maximum percent increase in yield was observed in case of Polyoxin D Zinc salt 5% SC @ 600 ml ha-1 i.e. 57.47 as compared to untreated control. However, all the triazoles manifested a higher percent increase in yield as compared to the lowest dose of the test fungicide i.e. 200 ml ha-1. For the detection and quantification of polyoxin D residue in grape, we have developed an efficient and effective analytical method, using liquid chromatography-tandem mass spectrometry (LC-MS/MS), in field treated samples. The residue data had excellent fit to 1st+1st order models giving r2 value of >0.99 with a half-life (t1/2) 8.0 days for recommended dose and 14.5 days for double dose. These findings are useful for effective disease management in grape crop amalgamated with food safety and consumer satisfaction.

scholarly journals Nano-Magnesium Oxide: A Novel Bactericide Against Copper-Tolerant Xanthomonas perforans Causing Tomato Bacterial Spot

2019 ◽  
Vol 109 (1) ◽  
pp. 52-62 ◽  
Author(s):  
Y.-Y. Liao ◽  
A. L. Strayer-Scherer ◽  
J. White ◽  
A. Mukherjee ◽  
R. De La Torre-Roche ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Magnesium Oxide ◽  
Untreated Control ◽  
Structural Changes ◽  
Field Experiments ◽  
Negative Impact ◽  
Metal Oxide Nanoparticles ◽  
Spectrometric Analysis ◽  
Bacterial Spot ◽  
Xanthomonas Perforans

Bacterial spot caused by Xanthomonas perforans causes significant damage on tomato in Florida. Due to the presence of copper (Cu)-tolerant X. perforans strains, Cu bactericides are not effective in disease management. Hence, there is a critical need to find alternatives for Cu. Antibacterial activity of magnesium oxide (Nano-MgO), and other metal oxide nanoparticles, were evaluated against a Cu-tolerant and -sensitive X. perforans strain. In vitro experiments demonstrated high antibacterial activity of Nano-MgO against both strains compared with the commercial Cu. The minimum inhibitory concentration of Nano-MgO is 25 µg/ml and the minimum bactericidal concentration is 100 µg/ml against a Cu-tolerant X. perforans strain after 4 h of exposure. Structural changes in the bacterial membrane following exposure to Nano-MgO treatments compared with the controls were observed using transmission electron microscopy. In two greenhouse experiments with a Cu-tolerant strain, bacterial spot severity was significantly reduced by Nano-MgO at 200 µg/ml compared with Cu-ethylene bis-dithiocarbamate (grower standard), and the untreated control (P = 0.05). In three field experiments, Nano-MgO at 200 µg/ml significantly reduced disease severity with no negative impact on yield compared with the untreated control. Inductively coupled plasma mass spectrometric analysis of the fruit confirmed that Nano-MgO application did not lead to the accumulation of Mg, Cu, Ca, K, Mn, P, and S. This study is the first to demonstrate the potential of Nano-MgO against bacterial spot of tomato.

scholarly journals Reduction of Phytophthora cactorum in Strawberry Fields by Trichoderma spp. and Soil Solarization

Plant Disease ◽  
2007 ◽  
Vol 91 (2) ◽  
pp. 142-146 ◽  
Author(s):  
M. Porras ◽  
C. Barrau ◽  
F. T. Arroyo ◽  
B. Santos ◽  
C. Blanco ◽  
...  
Keyword(s):  
Disease Control ◽  
Methyl Bromide ◽  
Untreated Control ◽  
Field Experiments ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Phytophthora Cactorum ◽  
Trichoderma Spp ◽  
Soil P ◽  
Polyethylene Mulch

Field experiments were conducted in southwest Spain for three consecutive years from 2000 to 2003 to evaluate the effectiveness of solarization and Trichoderma spp., alone and combined, in reducing Phytophthora cactorum soil populations and consequently leather rot on fruit of strawberry plants. Plots (12.5 by 3.3 m), never treated with methyl bromide, were naturally infested by P. cactorum. Solarization was conducted during the summer, using clear 50-µm low-density polyethylene mulch. Trichoderma spp. were applied via drip and dip, adding to the soil 7 days before planting (108 conidia/m2), and strawberry roots were dipped in a suspension of Trichoderma spp. (106 conidia/ml) prior to planting. Solarization reduced the soil P. cactorum population 100% in year 1, 47% in year 2, and 55% in year 3 relative to the untreated control. Trichoderma spp. applications reduced soil populations of P. cactorum and reduced leather rot incidence 76.6% in year 1 and 33.8% in year 2 compared with the untreated control. The combination of solarization and Trichoderma spp. reduced P. cactorum soil population the most each year, 88.9% in January 2001, 97.6% in 2002, and 99.0% in 2003. The very promising effect of Trichoderma spp. and solarization against P. cactorum indicates that there may be future alternatives to traditional chemicals for disease control.

scholarly journals 015 Evaluation of Fungicides for Use with TOM-CAST on Fresh-market Tomatoes in Northern New Jersey

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 443C-443
Author(s):  
M.H. Maletta ◽  
W.P. Cowgill ◽  
S.A. Johnston
Keyword(s):  
Disease Control ◽  
Early Blight ◽  
Total Yield ◽  
Weekly Schedule ◽  
Copper Hydroxide ◽  
Fresh Market ◽  
Mature Fruit ◽  
Forecast System ◽  
Marketable Yield ◽  
Foliar Disease

A research trial evaluation of fungicides and fungicide combinations in conjunction with weekly or TOM-CAST (an early blight forecast system) spray schedules was conducted in 1998. Fungicide regimens were: Quadris (alternating with Bravo Weatherstik); Bravo Weatherstik; Manzate followed by Bravo Weatherstik; Champ; Champ and Bravo; Nu-Cop; NuCop and Bravo The weekly schedule resulted in 15 fungicide applications; the TOM-CAST schedule required five applications. Foliar disease was rated weekly. Mature fruit were harvested weekly to obtain total and marketable yields. All fungicide treatments reduced foliar disease compared to the untreated control. Quadris alternating with Bravo Weatherstik on a weekly or TOM-CAST schedule provided better disease control than any other material on either schedule. There were no significant differences in disease control among the other materials applied weekly. Disease control achieved with the TOM-CAST schedule was somewhat less than with the weekly schedule for all materials. Quadris/Bravo or Bravo provided the best control and Champ or Nu-Cop alone provided the least control on the TOM-CAST schedule. Total yield was not affected by fungicide or schedule. Marketable yield was reduced by weekly applications of copper fungicides compared to most other treatments. Chemical names used: tetrachloroisophtalonitrile (chlorothalonil); [methyl (E)-2-{2-[6-(2-cyanophenoxy) pyrimidin-4-yloxy]phenyl}-3-methoxyacrylate (asoxystrobin); copper hydroxide; manganese ethylene bisdithiocarbamate and zinc.

scholarly journals Effect of Application Frequency and Reduced Rates of Acibenzolar-S-Methyl on the Field Efficacy of Induced Resistance Against Bacterial Spot on Tomato

Plant Disease ◽  
2012 ◽  
Vol 96 (2) ◽  
pp. 221-227 ◽  
Author(s):  
Cheng-Hua Huang ◽  
Gary E. Vallad ◽  
Shouan Zhang ◽  
Amin Wen ◽  
Botond Balogh ◽  
...  
Keyword(s):  
Disease Severity ◽  
Untreated Control ◽  
Systemic Acquired Resistance ◽  
Field Experiments ◽  
Acquired Resistance ◽  
Foliar Spray ◽  
Field Trials ◽  
Plant Diseases ◽  
Bacterial Spot ◽  
Field Efficacy

Acibenzolar-S-methyl (ASM), a plant activator known to induce systemic acquired resistance, has demonstrated an ability to manage a number of plant diseases, including bacterial spot on tomato caused by four distinct Xanthomonas spp. The aim of this study was to evaluate application rate and frequency of ASM in order to optimize field efficacy against bacterial spot in Florida, while minimizing its impact on marketable yields. ASM was applied biweekly (once every 2 weeks) as a foliar spray at a constant concentration of 12.9, 64.5, and 129 μM throughout four field experiments during 2007–08. A standard copper program and an untreated control were also included. Overall, biweekly applications of ASM did not significantly reduce disease development or the final disease severity of bacterial spot compared with the copper-mancozeb standard or the untreated control. Only one experiment showed a significant reduction in the final disease severity on plants treated with ASM at 129 μM compared with the untreated control. Three additional field trials conducted during 2009–10 to evaluate the effects of weekly and biweekly applications of ASM at concentrations of 30.3 to 200 μM found that weekly applications provided significantly better disease control than biweekly applications. The tomato yields were not statistically improved with the use of ASM relative to the untreated control and standard copper program. Weekly ASM applications at rates as low as 75 μM (equivalent to 1.58 g a.i./ha in 100 liters of water or 0.21 oz. a.i./acre in 100 gallons of water) to 200 μM (equivalent to 4.20 g a.i./ha in 100 liters of water or 0.56 oz. a.i./acre in 100 gallons of water) were statistically equivalent in managing bacterial spot of tomato without significantly reducing yield compared with the untreated control.

scholarly journals Disease Forecasting on Stake Cultured Tomatoes: Defining Decision Thresholds for Use of TOM-CAST in Northern New Jersey

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 676c-676
Author(s):  
M.H. Maletta ◽  
W.P. Cowgill ◽  
W. Tietjen ◽  
S.A. Johnston ◽  
P. Nitzsche
Keyword(s):  
Disease Control ◽  
Untreated Control ◽  
Early Blight ◽  
Total Yield ◽  
Cost Savings ◽  
Weather Data ◽  
Marketable Yield ◽  
Potential Cost ◽  
Foliar Disease ◽  
Ground Station

Fourteen different fungicide schedules for early blight control, including eight variations of TOM-CAST, were evaluated at the Snyder Research and Extension Farm, Pittstown, N.J. Weather data was collected with Sensor Instruments Field Monitors. All calendar-based schedules—weekly, biweekly, grower simulation—reduced foliar disease compared to the untreated control. All forecast generated schedules—TOM-CAST variations, FAST and CUFAST—reduced foliar disease compared to the untreated control. Several of the forecast schedules resulted in disease ratings not significantly different from those following calendar based schedules or from each other. The fourteen different schedules required as many as sixteen to as few as four fungicide applications. Disease control schedule did not affect total yield, marketable yield and postharvest losses. Disease control with a TOM-CAST generated schedule based on weather data from an electronic meteorological service was not different from disease control obtained with a TOM-CAST schedule based on ground station weather data. Potential cost savings of as much as $295 per acre resulting from reduced fungicide schedules were estimated. Chemical name used: tetrachloroisophtalonitrile (chlorothalonil).

Damping-off of sugar beet in Finland: II. Disease control 

1983 ◽  
Vol 55 (5) ◽  
pp. 431-450
Author(s):  
Mauritz Vestberg ◽  
Risto Tahvonen ◽  
Kyösti Raininko
Keyword(s):  
Sugar Beet ◽  
Disease Control ◽  
Field Experiments ◽  
Damping Off ◽  
Good Protection ◽  
Great Damage

In pot and field experiments carried out in 1979-1981, the systemic funqicide hymexazol prevented satisfactorily soil borne damping-off of sugar beet caused mainly by the fungus Pythium debaryanum auct. non Hesse. The results with the combination hymexazol + thiram were still better. This treatment gave very good protection against the disease up to about two to three weeks after emergence, increased the yield on the average by 5-10 % and produced considerably thicker and denser stands. Thereafter a large number of beets may have become infected, but no great damage was caused as only few died. Band spraying at emergence using hymexazol with a large amount of water as well as spraying into the seed furrow prevented the outbreak of the disease almost completely. Liming had little effect on damping-off.

scholarly journals Reduced Dosage of Methyl Bromide for Controlling Verticillium Wilt of Potato in Experimental and Commercial Plots

Plant Disease ◽  
1997 ◽  
Vol 81 (5) ◽  
pp. 469-474 ◽  
Author(s):  
A. Gamliel ◽  
A. Grinstein ◽  
Y. Peretz ◽  
L. Klein ◽  
A. Nachmias ◽  
...  
Keyword(s):  
Verticillium Wilt ◽  
Methyl Bromide ◽  
Large Scale ◽  
Field Experiments ◽  
Tuber Yield ◽  
Total Yield ◽  
Effective Control ◽  
Large Scale Field ◽  
Commercial Applications

The use of gas-impermeable films to reduce the dosage of methyl bromide (MB) required to control Verticillium wilt in potatoes was examined in field experiments, conducted in soils naturally infested with Verticillium dahliae. The incidence and severity of Verticillium wilt were significantly reduced (by 74 to 94%) by fumigation with MB at 50 g/m2 under standard low density polyethylene (LDPE) or at 25 g/m2 under gas-impermeable films. Fumigation at 25 g/m2 under LDPE was less effective. Disease severity was inversely correlated (r2 = 0.89 to 0.91) with chlorophyll content in the leaves. Fumigation also reduced (by 89 to 100%) stem colonization by the pathogen. Potato yield in the fumigated plots was significantly higher (26 to 69%), than in their nonfumigated counterparts, and was inversely correlated with disease index (r2 = 0.69 to 0.9). The percentage of high-value tubers (above 45 g) was 52 to 56% of total yield in the fumigated plots as compared with 32 to 40% in the nonfumigated controls. Thus, fumigation also improved the commercial quality of tuber yield. Effective control of V. dahliae and yield increases following MB fumigation at the recommended dosage or at a reduced dosage with gas-impermeable films was also observed in a consecutive crop. These results were verified in a large-scale field experiment using commercial applications, further demonstrating the feasibility of reducing MB dosages under farm conditions, without reducing its effectiveness in terms of disease control and yield improvement.

LAMB’S-QUARTERS INTERFERENCE WITH DIRECT SEEDED BROCCOLI

1990 ◽  
Vol 70 (4) ◽  
pp. 1215-1221 ◽  
Author(s):  
IRIS BITTERLICH ◽  
MAHESH K. UPADHYAYA
Keyword(s):  
Brassica Oleracea ◽  
Field Experiments ◽  
Chenopodium Album ◽  
Total Yield ◽  
Growth And Yield ◽  
Marketable Yield ◽  
Weed Density ◽  
Weed Interference ◽  
Lamb’S Quarters ◽  
Cole Crop

Field experiments were conducted in 1987 and 1988 to study the effect of lamb’s-quarters (Chenopodium album L.) interference on broccoli (Brassica oleracea L. var. botrytis ’Emperor’) growth and yield. Broccoli growth was initially affected by weed interference at 28–36 d after seeding. Generally, the negative effect of weed interference on broccoli growth increased with increasing weed density and time after seeding. Interference by 15 lamb’s-quarters plants m−2 reduced the biomass of broccoli plants by 71–73% compared to the weed-free control at 57–58 d after seeding. Weed density-crop yield relationship curves showed that one lamb’s-quarters plant m−2 decreased total yield by 18–20% and marketable yield by 22–37%. Lamb’s-quarters reduced the total yield per plot by decreasing the average head weight of broccoli. The number of heads per plot was not affected. Weed interference also reduced the weight of heads classified as marketable (> 10 cm across). However, in 1987 more heads failed to reach a marketable size which resulted in a much smaller marketable yield than in 1988.Key words: Brassica oleracea var. botrytis, broccoli, Chenopodium album L., weed density, weed interference, cole crop

Effects of potassium and magnesium fertilizers on yield and size distribution of potatoes

1973 ◽  
Vol 80 (3) ◽  
pp. 369-373 ◽  
Author(s):  
K. Simpson ◽  
P. Crooks ◽  
S. McIntosh
Keyword(s):  
Seed Potato ◽  
Field Experiments ◽  
Total Yield ◽  
Tuber Initiation ◽  
Factorial Experiments ◽  
K Fertilizer ◽  
Dry Conditions ◽  
History Of ◽  
Potato Crops ◽  
Low K

SummaryThirteen field experiments were made during 6 years on seed-potato growing farms in south-east Scotland, comparing three rates, 70, 140 and 280 kg K/ha as potassium chloride and four rates of 0–54 kg Mg/ha as kieserite in 3 × 4 factorial experiments.More than 70 kg/ha of potassium increased total yield only at one site, which had a recent history of low K application and very low available K. Yields were decreased by more than 70 kg/ha of potassium at three sites in a season with abnormally dry conditions just after planting. Applied magnesium had little effect on total yield.Extra potassium increased ware yield but decreased seed yield, both consistently, probably because the fertilizer damaged some stolons at or before tuber initiation and fewer tubers developed. The ware/seed ratio was generally increased by extra K, but after the dry spring this ratio was unaltered or reduced. Applied magnesium had little effect on the ratio.Our results suggest that the present rates of K fertilizer, used for commercial seed-potato crops (114–138 kg K/ha) in south-east Scotland are excessive, and a much lower rate of approximately 70 kg K/ha would be adequate except on very low K sites.

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