scholarly journals Macro- and Microelement Fertilizers Influence the Severity of Fusarium Crown and Root Rot of Tomato in a Soilless Production System

HortScience ◽  
1999 ◽  
Vol 34 (2) ◽  
pp. 287-291 ◽  
Author(s):  
B.K. Duffy ◽  
G. Défago
Keyword(s):  
Disease Severity ◽  
Nutrient Solution ◽  
Root Rot ◽  
Management Strategy ◽  
Ammonium Nitrogen ◽  
Mineral Fertilizers ◽  
Solution Ph ◽  
Host Nutrition ◽  
Crown And Root Rot ◽  
Plant Pathogen Interactions

Host nutritional variables were evaluated for their effects on the severity of crown and root rot of tomato caused by Fusarium oxysporum f.sp. radicis-lycopersici. Tomato (Lycopersicon esculentum Mill.) seedlings (cv. Bonnie Best) were grown in a pathogen-infested, soilless rockwool system in the greenhouse and were fertilized with a nutrient solution that was amended with macro- and microelements at various rates. Disease was evaluated after 2 weeks using an index of 0 to 4, and plant fresh weight was measured. Regression analysis indicated that disease severity was significantly increased by ammonium-nitrogen [NH4Cl, (NH4)6Mo7O24, and (NH4)2SO4], NaH2PO4·H2O, Fe-EDDHA, MnSO4, MoO3, and ZnSO4·7H2O. Disease severity was reduced by nitrate-nitrogen [Ca(NO3)2·4H2O] and CuSO4·H2O. Low rates of NH4NO3 (39 to 79 mg·L-1 N) reduced disease, but rates above 100 mg·L-1 N increased it. Disease was not affected by MgSO4·7H2O. In all cases, plant growth was inversely related to disease severity. Mineral fertilizers had no effect on nutrient solution pH. This information sheds new light on environmental factors that influence plant-pathogen interactions, and may be applied to develop a management strategy for Fusarium crown and root rot based on host nutrition.

EVALUATION OF ALFALFA CULTIVARS FOR REACTION TO CROWN AND ROOT ROT

1985 ◽  
Vol 65 (1) ◽  
pp. 95-98 ◽  
Author(s):  
R. MICHAUD ◽  
C. RICHARD
Keyword(s):  
Disease Severity ◽  
Root Rot ◽  
Dry Matter ◽  
Forage Yield ◽  
Dry Matter Yield ◽  
Crown And Root Rot ◽  
Disease Free

Fourteen alfalfa cultivars were grown for 2 yr at three locations and evaluated for forage dry matter yield and crown and root rot. Significant differences were found among cultivars for dry matter yield. All cultivars were affected by crown and root rot, most cultivars showing between 20 and 30% of infected tissues. Differences were observed among as well as within the cultivars for disease severity. The frequency of disease-free plants was less than 1.3% of the plants evaluated. Correlation between root rot index and forage yield was −0.87 [Formula: see text] when data were pooled over years and locations.Key words: Lucerne, root rot, cultivar, yield

scholarly journals Pathogenicity of Fusarium species associated with crown and root rot of wheat (Triticum aestivum) under different condition

2019 ◽  
Vol 7 (1) ◽  
pp. 1-9
Author(s):  
Bareen Sidqi Shareef Al-Tovi ◽  
Raed Abduljabbar Haleem
Keyword(s):  
Disease Severity ◽  
Root Rot ◽  
Field Experiments ◽  
Fusarium Species ◽  
Test Tube ◽  
Spore Suspension ◽  
Wheat Crop ◽  
Pathogenicity Test ◽  
Crown And Root Rot

This study was conducted to test the pathogenicity of Fusarium species, the causes of crown and root rot disease of wheat crop, under three different conditions (Laboratory, Greenhouse and Field) and to show the best method for pathogenicity among different conditions. Pathogenicity test of six isolates of Fusarium species (F. graminearum, F. oxysporum, F. avenaceum, F. nivale, F. solani and F. udum) was tested on durum (Simeto) cultivar of wheat by test tube method in the laboratory, the tested fungi had substantial effect on seed germination. F. oxysporum showed the highest germination failure (44.44%) which significantly differed with other species. In the greenhouse, seedlings were inoculated by spore suspension at the base of each plant stem. The most virulent fungus after 35 days of inoculation was F. oxysporum (0.78) followed by F. solani (0.70) and F. graminearum (0.66), while the lowest disease severity was recorded by F. udum (0.16). Also in the field pathogenicity experiments of three Fusarium species (F. graminearum, F. oxysporum and F. solani) were performed on a durum (Simeto) and soft (Cham6) cultivars. Spore suspension was applied at the 2- to 3-leaf Zadoks’s growth stage. Disease severity was calculated at two stages of wheat growth (Booting and Ripening).The most virulent fungus was F. graminearum (0.42) that was significantly different from  other fungi. This work indicated that F. graminearum, F. oxysporum and F. solani showed higher infection than remaining tested species under threeconditions. Pathogenicity test in laboratory by test tube method (In-vitro) appeared more effective than greenhouse and field experiments

Influence of Glyphosate on Rhizoctonia Crown and Root Rot (Rhizoctonia solani) in Glyphosate-Resistant Sugarbeet

Weed Science ◽  
2012 ◽  
Vol 60 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Kelly A. Barnett ◽  
Christy L. Sprague ◽  
William W. Kirk ◽  
Linda E. Hanson
Keyword(s):  
Rhizoctonia Solani ◽  
Ammonium Sulfate ◽  
Disease Severity ◽  
Root Rot ◽  
Radial Growth ◽  
Field Experiments ◽  
Herbicide Treatments ◽  
Tolerant Variety ◽  
Crown And Root Rot

Previous greenhouse studies with a noncommercial glyphosate-resistant sugarbeet variety indicated that susceptibility to Rhizoctonia crown and root rot could increase after glyphosate was applied. Greenhouse and field experiments were conducted in 2008 and 2009 to determine if glyphosate influenced disease severity in potential commercially available varieties of glyphosate-resistant sugarbeet. In the first greenhouse experiment in 2008, Hilleshög 9027RR, the most tolerant variety to Rhizoctonia crown and root rot, exhibited an increase in disease severity when glyphosate was applied. There were no significant differences between herbicide treatments in Hilleshög 9028RR, and glyphosate decreased disease severity in Hilleshög 9032RR when compared with the no-herbicide treatment. Experiments conducted to determine if glyphosate influenced Rhizoctonia solani growth in vitro indicated that glyphosate did not increase the radial growth of R. solani, except at 10× (190 µg ae ml−1) the normal rate of glyphosate plus ammonium sulfate (AMS). Field and additional greenhouse experiments were conducted using four commercial varieties. Differences in disease severity were observed when comparing varieties, but glyphosate did not significantly influence the severity of Rhizoctonia crown and root rot when compared with the no-herbicide control. Choosing a glyphosate-resistant sugarbeet variety with the best demonstrated tolerance to Rhizoctonia crown and root rot is an important factor in reducing disease severity and maintaining sugarbeet yield.

Decrease in Disease Severity in Sugarbeet in an Established Rhizoctonia Crown and Root Rot Nursery

1999 ◽  
Vol 36 (3) ◽  
pp. 29-39
Author(s):  
J. M. Halloin ◽  
W. M. Bugbee ◽  
A. H. Lammers
Keyword(s):  
Disease Severity ◽  
Root Rot ◽  
Crown And Root Rot

scholarly journals (303) Challenges of Organic Hydroponic Production of Strawberries (Fragaria ×ananassa)

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1010E-1011 ◽  
Author(s):  
Brandon Jewell ◽  
Chieri Kubota
Keyword(s):  
Dissolved Oxygen ◽  
Nutrient Solution ◽  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
Nitrifying Bacteria ◽  
Oxygen Level ◽  
Coconut Fiber ◽  
Solution Ph ◽  
Organic Nutrient

Feasible protocols for organic hydroponic production of strawberry are necessary and this study compares the yield and fruit quality of organic and conventional inorganic hydroponic production. Some issues identified with organic hydroponic strawberry production are: 1) dominant ammonium nitrogen form; 2) solution alkalinity; and 3) dissolved oxygen level of nutrient solution. Eighty bare-rooted `Diamante' plantlets were planted in coconut fiber pots with a mixture of coconut coir (30%) and perlite (70%) and grown in a modified nutrient film technique system inside a polycarbonate greenhouse. The organic nutrient solution contains mostly ammonium nitrogen and little nitrate nitrogen. To enhance colonization and activities of nitrifying bacteria, coconut fiber mats were placed in the organic nutrient solution reservoir. A similar system was also introduced for stock solution pre-conditioning where nitrification and pH stabilization were achieved before application to the strawberry plantlets. The organic nutrient solution prior to pre-conditioning had only 1.53 mg·L-1 nitrate nitrogen, although the nitrate nitrogen level increased to 63.2 mg·L-1 after pre-conditioning. The organic nutrient solution pH was 4.5 initially, 8.5 after 24 hours of pre-conditioning, and finally, shifted to and stabilized at 5.7–5.9 after 3 days. Dissolved oxygen level is critical for both nitrifying bacteria activities and plantlet root growth; therefore, oxygen enrichment was achieved by constantly aerating the nutrient solution in the reservoir, which raised the oxygen level from 2.5 to 7.4 mg·L-1. Comparisons of yield and quality of strawberry fruits between organic and inorganic nutrient solutions will be presented and further improvements of hydroponic systems will be discussed.

scholarly journals Effects of Low pH of Hydroponic Nutrient Solution on Plant Growth, Nutrient Uptake, and Root Rot Disease Incidence of Basil (Ocimum basilicum L.)

HortScience ◽  
2020 ◽  
Vol 55 (8) ◽  
pp. 1251-1258
Author(s):  
Daniel P. Gillespie ◽  
Chieri Kubota ◽  
Sally A. Miller
Keyword(s):  
Plant Growth ◽  
Nutrient Solution ◽  
Nutrient Availability ◽  
Root Rot ◽  
Disease Incidence ◽  
Ph Effects ◽  
Solution Ph ◽  
Effects Of Ph ◽  
Decreasing Ph ◽  
Rot Disease

Rootzone pH affects nutrient availability for plants. Hydroponic leafy greens are grown in nutrient solutions with pH 5.5 to 6.5. Lower pH may inhibit plant growth, whereas pathogenic oomycete growth and reproduction may be mitigated. General understanding of pH effects on nutrient availability suggests likely toxicity and deficiency of specific micronutrients. We hypothesized that if adjustments are made to the micronutrient concentrations in solution, plants will grow in lower-than-conventional pH without nutrient disorders, while oomycete disease incidence and severity may be reduced. To develop a new nutrient solution management strategy, we examined pH of 4.0, 4.5, 5.0, and 5.5 with or without micronutrient adjustments for growing two cultivars of basil plants Dolce Fresca and Nufar in a greenhouse hydroponic deep-water culture (DWC) system. Micronutrient adjustments included reduced concentrations of copper, zinc, manganese, and boron by one-half and doubled molybdenum concentration. Plants harvested 20 to 28 days after transplanting did not show significant effects of pH or the micronutrient adjustment. Phosphorus, calcium, magnesium, sulfur, boron, manganese, and zinc concentrations in leaves significantly declined, while potassium and aluminum concentrations increased with decreasing pH. However, these changes and therefore micronutrient adjustments did not affect basil plant growth significantly. ‘Nufar’ basil plants were then grown in a growth chamber DWC system at pH 4.0 or a conventional 5.5 with and without inoculation of Pythium aphanidermatum zoospores. Fourteen days after inoculation, P. aphanidermatum oospore production was confirmed only for the inoculated plants in pH 5.5 solution, where a significant reduction of plant growth was observed. The results of the present study indicate that maintaining nutrient solution pH at 4.0 can effectively suppress the severity of root rot caused by P. aphanidermatum initiated by zoospore inoculation without influencing basil growth.

scholarly journals Evaluation of Application Methods of Metam Sodium for Management of Fusarium Crown and Root Rot in Tomato in Southwest Florida

Plant Disease ◽  
1998 ◽  
Vol 82 (8) ◽  
pp. 919-923 ◽  
Author(s):  
R. J. McGovern ◽  
C. S. Vavrina ◽  
J. W. Noling ◽  
L. A. Datnoff ◽  
H. D. Yonce
Keyword(s):  
Lycopersicon Esculentum ◽  
Disease Severity ◽  
Root Rot ◽  
Soil Surface ◽  
Metam Sodium ◽  
Southwest Florida ◽  
Industry Practice ◽  
High Disease Severity ◽  
Application Methods ◽  
Crown And Root Rot

Experiments were conducted during 1992 to 1995 to evaluate the effectiveness of application methods of metam sodium (MS; sodium N-methyldithio-carbamate) for the management of Fusarium crown and root rot (FCRR) caused by Fusarium oxysporum f. sp. radicis-lycopersici in mulched and staked tomatoes (Lycopersicon esculentum Mill.) grown on raised beds in commercial fields in southwest Florida. Efficacy of MS was compared with soil-injection of methyl bromide-chloropicrin (MBC), the current industry practice for production of tomatoes in Flor-ida. The incidence of FCRR was consistently high in nontreated plots (80 to 100%), but disease severity varied by site, and yields were reduced by 10 to 57% at sites with high disease severity when compared to sites treated with MBC at 336 to 448 kg/ha. Application of MBC reduced FCRR incidence in all experiments. Chemigation with MS at 701 or 935 liters/ha into mulched beds using either one or two drip irrigation tubes placed on the soil surface, and soil injection of MS at 935 liters/ha, failed to reduce the disease. The application of MS at 935 liters/ha to the soil surface prior to bed formation produced variable results. Rotovation of MS at the same rate into preformed beds consistently produced reductions in the incidence of FCRR equivalent to those achieved by MBC.

The epidemiology of common root rot in Manitou wheat: disease progression during the growing season

1974 ◽  
Vol 52 (7) ◽  
pp. 1757-1764 ◽  
Author(s):  
P. R. Verma ◽  
R. A. A. Morrall ◽  
R. D. Tinline
Keyword(s):  
Triticum Aestivum ◽  
Disease Severity ◽  
Plant Development ◽  
Root Rot ◽  
Growing Season ◽  
Cochliobolus Sativus ◽  
Infection Rates ◽  
Common Root ◽  
Common Root Rot ◽  
Disease Rating

Common root rot in Triticum aestivum cultivar Manitou caused primarily by Cochliobolus sativus was followed during plant development in 1969, 1970, and 1971 at Matador, Saskatchewan. Plants were sampled at intervals, and three variables based mainly on the occurrence of lesions on subcrown internodes were studied: number of diseased plants per square meter; percentage of diseased plants; and disease rating which integrated percentage of diseased plants and disease severity on each plant. All variables increased with time, and the progression curves in all 3 years were hyperbolic, indicating that the increases were like those of a simple interest disease as described by Van der Plank. In two of the years, almost 100% of the plants were diseased considerably before the end of the season. The transformation proposed by Van der Plank for simple interest diseases, log10[1/(1 − x)], was applied to the percentages of diseased plants, and regressions were calculated. The slopes of these lines (infection rates) were as follows: 1969, 0.99% plants per day; 1970, 1.32%; and 1971, 1.96%. In 1969 the onset of disease was later than in 1970 and 1971, and there was correspondingly less disease at the end of the growing season.

Effects of aluminum on nutrient solution pH and nitrate/ammonium uptake by triticale

1997 ◽  
Vol 20 (10) ◽  
pp. 1391-1401 ◽  
Author(s):  
A. M. G. Antunes ◽  
M. Antonieta Nunes
Keyword(s):  
Nutrient Solution ◽  
Ammonium Uptake ◽  
Solution Ph
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