scholarly journals Effects of Rootstock and Budding Height on Bacterial Canker in French Prune

Plant Disease ◽  
2002 ◽  
Vol 86 (5) ◽  
pp. 543-546 ◽  
Author(s):  
R. J. Sayler ◽  
S. M. Southwick ◽  
J. T. Yeager ◽  
K. Glozer ◽  
E. L. Little ◽  
...  
Keyword(s):  
Tree Mortality ◽  
Prunus Persica ◽  
Disease Incidence ◽  
Fruit Trees ◽  
Field Trials ◽  
Bacterial Canker ◽  
Prunus Domestica ◽  
Severity Of Disease ◽  
Prunus Cerasifera ◽  
Disease Pressure

Bacterial canker is one of the most economically important diseases of stone fruit trees, including ‘French’ prune (Prunus domestica). Field trials were conducted to evaluate the effect of rootstock selection and budding height on the incidence and severity of bacterial canker in four orchards with low to high disease pressure. Treatments included French prune scions low-grafted on ‘Lovell’ peach (Prunus persica) rootstocks as well as Myrobalan 29C (Prunus cerasifera) plum rootstocks grafted at 15, 50, and 90 cm above the rootstock crown. Another treatment consisted of growing Myrobalan 29C plum rootstocks in the field for one growing season, then field-grafting French prune buds onto rootstock scaffolds. Lovell peach rootstock provided the greatest protection from bacterial canker as measured by disease incidence and tree mortality in all orchards. Field-budded rootstocks and rootstocks grafted at the highest budding height provided moderate levels of resistance to bacterial canker. These treatments reduced the incidence but not the severity of disease.

scholarly journals Evaluating Plant Population and Replant Method Effects on Peanut Planted in Twin Rows

2017 ◽  
Vol 44 (1) ◽  
pp. 19-25 ◽  
Author(s):  
J.M. Sarver ◽  
R.S. Tubbs ◽  
J.P. Beasley ◽  
A.K. Culbreath ◽  
T.L. Grey ◽  
...  
Keyword(s):  
Disease Incidence ◽  
Field Trials ◽  
Yield Potential ◽  
Seeding Rate ◽  
Pod Yield ◽  
Arachis Hypogaea L ◽  
Method Effects ◽  
Plant Stand ◽  
Reduced Rate ◽  
Disease Pressure

ABSTRACT Achieving and maintaining an adequate plant stand is a major priority when making planting and early season management decisions in peanut (Arachis hypogaea L.). Unpredictable and often extreme weather and high disease pressure in the southeastern United States can contribute to poor emergence and below-optimum plant stands. When plant stand is affected, replanting may be agronomically justified. This study was designed to determine i) the effect of plant stand on pod yield, market grade, and disease incidence in peanut seeded in a twin row pattern, (ii) if replanting is a viable option in a field with a below adequate stand and, iii) the best method for replanting peanut when an adequate stand is not achieved. Field trials were established at two locations in south Georgia in 2012 and 2013 to evaluate peanut production at four plant stands (7.4, 9.8, 12.3, and 14.8 plants/m [total plants/m across both units, or ‘twins' of the twin row pattern) and four replant methods (no replant, destroy the original stand and replant at a full seeding rate, add a reduced rate of seed to supplement the original stand with a single row between the original rows, and supplement with two additional rows with one between and the other next to the original rows). Replanting occurred when the stand had been established, an average of 24 days after initial planting. Pod yield at a stand of 12.3 plants/m was 6.6 and 5.8% greater than at a stand of 7.4 and 9.8 plants/m, respectively, with no benefit from increasing plant stand beyond 12.3 plants/m. Market grade was also maximized at 12.3 plants/m. Disease incidence was unaffected by plant stand. Yield was increased by supplementing an initial stand of 9.8 plants/m in both a single additional row and in two additional rows by 8.3 and 6.6%, respectively. A full replant of the original stand always resulted in lower yield, while grade was slightly increased in the full replant treatment. While an initial stand of 12.3 plants/m was needed in order to maintain yield potential, replanting via supplemental seed addition can recover lost yield at stands below this level.

scholarly journals Evaluation of Oxathiapiprolin for the Management of Sunflower Downy Mildew

Plant Disease ◽  
2019 ◽  
Vol 103 (10) ◽  
pp. 2498-2504 ◽  
Author(s):  
Ryan M. Humann ◽  
Keith D. Johnson ◽  
Michael J. Wunsch ◽  
Scott M. Meyer ◽  
James G. Jordahl ◽  
...  
Keyword(s):  
Downy Mildew ◽  
Disease Incidence ◽  
Systemic Infection ◽  
Field Trials ◽  
Effective Rate ◽  
Management Tool ◽  
Damping Off ◽  
Severe Stunting ◽  
Treated Seed ◽  
Disease Pressure

Downy mildew is a yield-limiting disease of sunflower, caused by the pathogen Plasmopara halstedii. Zoospore infection of root tissue shortly after planting results in systemic infection, causing postemergence damping off or severe stunting and head sterility. Although fungicide-applied seed treatments can be an effective management tool, the pathogen is resistant to phenylamide fungicides in many growing regions, and other available fungicides have limited efficacy. Oxathiapiprolin, the first member of the piperidinyl thiazole isoxazoline fungicides, was evaluated for efficacy on downy mildew in field trials conducted from 2011 to 2015 in North Dakota. Throughout the course of the study, the rate range was narrowed from active ingredient (a.i.) at 0.45 to 116.0 µg a.i. seed−1 to an optimal effective rate of 9.37 to 18.75 µg a.i. seed−1. Within that optimal range, the downy mildew incidence of sunflower planted with oxathiapiprolin-treated seed was significantly lower than the incidence in the nontreated sunflower in all 11 trials with disease pressure. Additionally, downy mildew incidence of sunflower planted with oxathiapiprolin-treated seed was significantly lower than sunflower planted with competitive commercially available fungicide-treated seed in 10 of those 11 trials. The use of oxathiapiprolin by sunflower growers is likely to reduce disease incidence and subsequent yield loss to downy mildew.

Host suitability analysis of the bark beetle Scolytus amygdali (Coleoptera: Curculionidae: Scolytinae)

2015 ◽  
Vol 105 (4) ◽  
pp. 434-440
Author(s):  
A. Zeiri ◽  
M.Z. Ahmed ◽  
M. Braham ◽  
M. Braham ◽  
B.-L. Qiu
Keyword(s):  
Development Time ◽  
Prunus Persica ◽  
Insect Pest ◽  
Reproductive Potential ◽  
Fruit Trees ◽  
Prunus Dulcis ◽  
Prunus Armeniaca ◽  
Suitability Analysis ◽  
Prunus Domestica ◽  
Polyphagous Insect

AbstractScolytus amygdali is a polyphagous insect pest that feeds on fruit trees and forest trees. Our study assessed the host preference and reproductive potential of S. amygdali on four tree species: almond (Prunus dulcis), apricot (Prunus armeniaca), peach (Prunus persica), and plum (Prunus domestica). Females of S. amygdali produced maternal galleries that were longer on peach than the other three trees, and female fecundity was highest on peach. Females with longer maternal galleries produced more eggs, indicating a positive correlation between maternal gallery length and female fertility. The under-bark development time of S. amygdali is significantly shorter on plum (45 days) and almond (56 days) than on apricot (65 days) and peach (64 days). Despite this longer development time on peach, our results still suggest that, of the four types of tree tested, peach is the most preferred host for S. amygdali.

scholarly journals Response of lentil cultivars to Sclerotinia white mold and Botrytis grey mould infection under irrigated and dryland conditions

2021 ◽  
Author(s):  
Kazi Kader ◽  
Scott Erickson ◽  
Robyne Bowness ◽  
Mark A Olson ◽  
Syama Chatterton
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Disease Incidence ◽  
Grey Mould ◽  
Field Trials ◽  
Limiting Factors ◽  
White Mold ◽  
Limiting Factor ◽  
Dry Land ◽  
Grey Mold ◽  
Disease Pressure

Diseases such as Sclerotinia white mold (SWM) caused by the fungus Sclerotinia sclerotiorum (Lib.) de Bary and Botrytis grey mold (BGM) caused by the fungus Botrytis cinerea Pers. may be limiting factors for lentil production in wetter areas of Alberta, Canada. Field trials were conducted at the Lethbridge Research and Development Centre from 2013-2015 to evaluate the response of lentil cultivars to SWM and BGM and yield impacts. Ten lentil cultivars from five market classes were evaluated under irrigated and dry land plots with two planting densities (120 plants m-2 and 160 plants m-2).Year and irrigation had the largest effect on disease incidence, with highest SWM incidence occurring under irrigation in 2013, followed by 2014 and 2015. Conversely, BGM incidence under irrigation was highest in 2015 and lowest in 2013, but levels were lower than SWM. Significantly (P <0.05) lower disease incidences were observed in dryland plots, which also produced higher yield than irrigated plots. Cultivars varied significantly in SWM incidence and yield under irrigated and dryland conditions, perhaps due to variable disease pressure, but there was no consistent trend in cultivar performance. BGM incidence was similar in cultivars, but differed among years. These findings indicate that SWM may be a limiting factor to lentil production in wetter areas, as the ten cultivars from five market classes tested were all highly susceptible to SWM.

scholarly journals Identification and description of Fruit fly species associated with different hosts in some Tripoli Fruit Orchards

2019 ◽  
pp. 338-353
Author(s):  
Eman A. Zentani
Keyword(s):  
Ceratitis Capitata ◽  
Prunus Persica ◽  
Fruit Fly ◽  
Punica Granatum ◽  
Fruit Trees ◽  
Psidium Guajava ◽  
Peach Fruit ◽  
Prunus Cerasifera ◽  
Fruit Orchards ◽  
First Time

The present field study was carried out to identify fruit fly species in Tripoli fruit orchards during 2016 – 2017 seasons by using fruit rearing method. Five hosts were examined in this study namely Guava Psidium guajava L. , Pear Pyrus communis، , Plum Prunus cerasifera, pomegranate Punica granatum and Peach Prunus persica The results revealed that three species of fruit flies that belong to family Tephritidae were identified; the Peach fruit fly, Bactrocera zontana (Saunders) and the Mediterranean fruit fly Ceratitis capitata (Wiedemaan), which were found in all fruit trees examined, and Bactrocera sp.that was recorded for the first time on Guava in the area. The fourth fruit fly species recorded was the African fig fly, Zaprionus indianus (Gupta) in pomegranate and Guava fruits.

Bacterial canker of stone-fruit trees in California

Hilgardia ◽  
1933 ◽  
Vol 8 (3) ◽  
pp. 83-123 ◽  
Author(s):  
Edward E. Wilson
Keyword(s):  
Fruit Trees ◽  
Stone Fruit ◽  
Bacterial Canker

scholarly journals In-Furrow Applications of Metalaxyl and Phosphite for Control of Pink Rot (Phytophthora erythroseptica) of Potato in New Brunswick, Canada

Plant Disease ◽  
2007 ◽  
Vol 91 (10) ◽  
pp. 1305-1309 ◽  
Author(s):  
Khalil I. Al-Mughrabi ◽  
Rick D. Peters ◽  
H. W. (Bud) Platt ◽  
Gilles Moreau ◽  
Appanna Vikram ◽  
...  
Keyword(s):  
New Brunswick ◽  
Disease Incidence ◽  
Field Trials ◽  
Russet Burbank ◽  
Viable Option ◽  
Potato Plants ◽  
Pink Rot ◽  
Phytophthora Erythroseptica ◽  
Sensitive Isolate ◽  
The Mean

The efficacy of metalaxyl-m (Ridomil Gold 480EC) and phosphite (Phostrol) applied at planting in-furrow against pink rot (Phytophthora erythroseptica) of potato (Solanum tuberosum) ‘Shepody’ and ‘Russet Burbank’ was evaluated in field trials conducted in 2005 and 2006 in Florenceville, New Brunswick, Canada. Inoculum made from a metalaxyl-m-sensitive isolate of P. erythroseptica from New Brunswick was applied either in-furrow as a vermiculite slurry at planting or as a zoospore drench in soils adjacent to potato plants in late August. After harvest, the number and weight of tubers showing pink rot symptoms were assessed and expressed as percentages of the total tuber number and total weight of tubers. Metalaxyl-m applied in-furrow was significantly more effective against pink rot than phosphite. The mean percentage of diseased tubers as a percentage of total tuber weight was 1.5% (2005) and 1.2% (2006) for metalaxyl-m-treated plots and 9.6% (2005) and 2.8% (2006) for phosphite-treated plots, a percentage similar to that obtained in inoculated control plots with no fungicide treatment. The mean percentage of diseased tubers expressed as a percentage of the total number of tubers was 1.7% (2005) and 1.3% (2006) for metalaxyl-m-treated plots and 10.1% (2005) and 3.1% (2006) for phosphite-treated plots. Disease incidence was significantly higher using the late-season inoculation technique (respective means in 2005 and 2006 were 9.9 and 3.8% diseased tubers, by weight, and 10.6 and 3.9%, by number) than with the in-furrow inoculation method (respective means in 2005 and 2006 were 3.3 and 0.7% by weight, and 3.7 and 1.3%, by number). The potato cv. Shepody was significantly more susceptible to pink rot (9.9 and 3.3% diseased tubers, by weight, in 2005 and 2006, respectively, and 10.6 and 3.9%, by number) than Russet Burbank (respective means in 2005 and 2006 were 3.4,% and 1.2%, by weight, and 3.7,% and 1.2%, by number). Our findings indicate that metalaxyl applied in-furrow at planting is a viable option for control of pink rot caused by metalaxyl-sensitive strains of P. erythroseptica, whereas phosphite was ineffective.

Management strategies to reduce losses caused by fusarium seedling blight of field pea

2013 ◽  
Vol 93 (4) ◽  
pp. 619-625 ◽  
Author(s):  
K. F. Chang ◽  
S. F. Hwang ◽  
H. U. Ahmed ◽  
B. D. Gossen ◽  
G. D. Turnbull ◽  
...  
Keyword(s):  
Root Rot ◽  
Field Experiments ◽  
Management Strategies ◽  
Stand Density ◽  
Field Trials ◽  
Field Pea ◽  
Seedling Blight ◽  
Inoculum Level ◽  
Fusarium Seedling Blight ◽  
Disease Pressure

Chang, K. F., Hwang, S. F., Ahmed, H. U., Gossen, B. D., Turnbull, G. D. and Strelkov, S. E. 2013. Management strategies to reduce losses caused by fusarium seedling blight of field pea. Can. J. Plant Sci. 93: 619–625. Fusarium seedling blight can cause substantial reductions in the stand density of field pea in western Canada. In greenhouse experiments, emergence decreased and root rot severity rose with increasing inoculum density. In field trials in 2007 and 2008 near Edmonton, AB, seeding at different depths and seeding dates did not consistently affect emergence or yield in Fusarium-infested soils. In field experiments, emergence declined significantly with each increase in inoculum level. Also, seed yield were reduced at high levels of disease pressure. Treatment of seed with Apron Maxx improved emergence, nodulation and yield of treatments challenged with inoculum of F. avenaceum in both greenhouse and field experiments. This research demonstrates the need to prevent seedling blight and root rot through proper seed treatment.

Evaluation of pruning wound protection products for the management of almond canker diseases in California

Plant Disease ◽  
2021 ◽  
Author(s):  
Leslie Amanda Holland ◽  
Renaud Travadon ◽  
Daniel P. Lawrence ◽  
Mohamed Taieb Nouri ◽  
Florent P Trouillas
Keyword(s):  
Biological Control ◽  
Fungal Pathogens ◽  
Tree Mortality ◽  
Biological Control Agent ◽  
Field Trials ◽  
Control Agent ◽  
Thiophanate Methyl ◽  
Pruning Wound ◽  
Wound Protection ◽  
Canker Pathogens

Almond trunk and branch canker diseases constitute a major cause of tree mortality in California. Numerous fungal pathogens have been associated with these canker diseases and pruning wounds act as major infection courts. Prior to this study, there were no products registered in California for the management of these diseases. In this study, fungicidal products including synthetic chemistries, biocontrols, paint and a sealant were evaluated for preventing fungal pathogen infection via pruning wounds. In four field trials conducted over two dormant seasons, sixteen pruning wound treatments were tested using hand-held spray applications, against five almond canker pathogens, namely Botryosphaeria dothidea, Neofusicoccum parvum, Cytospora sorbicola, Ceratocystis destructans, and Eutypa lata. The fungicide thiophanate-methyl (Topsin M) provided 82% overall disease prevention against four fungal pathogens. The biological control agent, Trichoderma atroviride SC1 (Vintec), tested at three application rates, resulted in 90 to 93% protection of pruning wounds in field trials, and for individual pathogens ranged from 81-100% protection for the three rates. At the time of this publication, Vintec is being considered for registration as a biological control product for the prevention of almond canker diseases, while Topsin M is recommended to growers for the prevention of almond canker diseases. This research indicates that effective protection of pruning wounds from infection by almond canker pathogens can be achieved with a one-time spray application of thiophanate-methyl or the biocontrol, T. atroviride SC1 (recommended 2 g/liter) after pruning.

scholarly journals Characterization of Antagonistic Bacillus methylotrophicus Isolated From Rhizosphere and Its Biocontrol Effects on Maize Stalk Rot

2019 ◽  
Vol 109 (4) ◽  
pp. 571-581 ◽  
Author(s):  
Xingkai Cheng ◽  
Xiaoxue Ji ◽  
Yanzhen Ge ◽  
Jingjing Li ◽  
Wenzhe Qi ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Disease Incidence ◽  
Field Trials ◽  
Control Measures ◽  
Disease Suppression ◽  
Effective Control ◽  
Stalk Rot ◽  
Bacillus Methylotrophicus ◽  
Transmission Electron ◽  
Potential Biocontrol Agent

Stalk rot is one of the most serious and widespread diseases in maize, and effective control measures are currently lacking. Therefore, this study aimed to develop a new biological agent to manage this disease. An antagonistic bacterial strain, TA-1, was isolated from rhizosphere soil and identified as Bacillus methylotrophicus based on morphological and biochemical characterization and 16S ribosomal RNA and gyrB gene sequence analyses. TA-1 exhibited a strong antifungal effect on the growth of Fusarium graminearum mycelium, with 86.3% inhibition at a concentration of 108 CFU per ml. Transmission electron microscopy showed that TA-1 could disrupt the cellular structure of the fungus, induce necrosis, and degrade the cell wall. Greenhouse and field trials were performed to evaluate the biocontrol efficacy of TA-1 on maize stalk rot, and the results of greenhouse experiment revealed that the bacterium significantly reduced disease incidence and disease index. Seeds treated with a 108 CFU ml−1 cell suspension had the highest disease suppression at 86.8%. Results of field trials show that seed bacterization with TA-1 could not only reduce maize stalk rot incidence but also increase maize height, stem diameter, and grain yield. The lipopeptide antibiotics were isolated from the culture supernatants of TA-1 and identified as surfactins and iturins. Consequently, B. methylotrophicus TA-1 is a potential biocontrol agent against maize stalk rot.

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