scholarly journals Improved Biocontrol Efficacy of Trichoderma harzianum 1295-22 for Foliar Phases of Turf Diseases by Use of Spray Applications

Plant Disease ◽  
1997 ◽  
Vol 81 (10) ◽  
pp. 1132-1138 ◽  
Author(s):  
C.-T. Lo ◽  
E. B. Nelson ◽  
G. E. Harman
Keyword(s):  
Trichoderma Harzianum ◽  
Root Rot ◽  
Field Experiments ◽  
Root Zone ◽  
Creeping Bentgrass ◽  
Dollar Spot ◽  
Trichoderma Spp ◽  
Brown Patch ◽  
Pythium Root Rot ◽  
Spray Applications

Trichoderma harzianum strain 1295-22 is an effective biocontrol agent for several fungal diseases. The efficacy of granule and spray applications of strain 1295-22 for control of Pythium root rot, brown patch, and dollar spot of creeping bentgrass was investigated. Spray applications of conidial suspensions (SA) of strain 1295-22 significantly reduced all three diseases of creeping bentgrass turf in both greenhouse and field experiments. Control was greatest when Triton X-100 at 0.1% was added to aqueous spray suspensions. When SA were applied weekly, the biocontrol treatments were equivalent to standard fungicides. Broadcast granule applications (GA) also significantly reduced foliar symptoms of Pythium root rot, dollar spot, and brown patch; turf quality also was enhanced. The populations of Trichoderma spp. in the root zone of a bentgrass putting green treated with SA or GA of strain 1295-22 increased 10- to 100-fold after treatment compared with untreated plots. However, strain 1295-22 was present at high levels on bentgrass leaves only following SA. Collectively, the results suggest that strain 1295-22 possesses both rhizosphere and phylloplane competence. The combination of broadcast applications of granules followed by spray applications of conidia reduced damage from both root and foliar diseases.

scholarly journals Application of Pseudomonas aureofaciens Tx-1 through Irrigation for Control of Dollar Spot and Brown Patch on Fairway-height Turf

HortScience ◽  
2004 ◽  
Vol 39 (7) ◽  
pp. 1750-1753 ◽  
Author(s):  
Glenn A. Hardebeck ◽  
Ronald F. Turco ◽  
Richard Latin ◽  
Zachary J. Reicher
Keyword(s):  
Disease Control ◽  
Field Experiments ◽  
Irrigation System ◽  
Creeping Bentgrass ◽  
Golf Courses ◽  
Dollar Spot ◽  
Brown Patch ◽  
Pseudomonas Aureofaciens ◽  
Disease Pressure

Pseudomonas aureofaciens strain Tx-1 is suggested as a biological control for Sclerotinia homoeocarpa (F.T. Bennett) and brown patch (Rhizoctonia solani Kuhn) on golf courses. To overcome application difficulties, a field bioreactor is used to grow Tx-1 daily and then inject into nightly irrigation on the golf course. Though Tx-1 shows some promise for disease control in vitro, it is relatively untested under field conditions. We conducted three field experiments to 1) evaluate the efficacy Tx-1 when applied through an irrigation system for the control of dollar spot and brown patch; 2) determine if there is an interaction between nitrogen fertility or fungicides on efficacy of Tx-1; and 3) determine if Tx-1 can extend the duration of dollar spot control by a single application of fungicide. Nightly applications of Tx-1 through irrigation did not affect brown patch on `Astoria' colonial bentgrass (Agrostis capillaris Sibth.) during the 2 years of our study. Tx-1 reduced dollar spot in `Crenshaw' creeping bentgrass (Agrostis palustris Huds.) by 37% in 1998 compared to non-Tx-1 treatments, but Tx-1 had no effect on dollar spot in 1999. Under low disease pressure, Tx-1 increased the dollar spot control of fungicides by 32% and increased the duration of control by 2.6 days. However, Tx-1 had no effect on fungicide efficacy or duration of control later in the summer when dollar spot pressure was high. Fungicides did not negatively affect Tx-1's control of brown patch or dollar spot, nor did fertilizer regime affect brown patch or dollar spot control by Tx-1. Although delivery of Tx-1 in our studies was optimized, disease control was marginal and occurred only under low disease pressure. Therefore, we conclude Tx-1 has limited practical value for turfgrass disease control on golf courses.

scholarly journals Effects of Oxygen Deprivation and Pythium Root Rot on Sugarcane Red Rot

Plant Disease ◽  
1998 ◽  
Vol 82 (11) ◽  
pp. 1237-1241 ◽  
Author(s):  
Zhi Yin ◽  
J. W. Hoy
Keyword(s):  
Root Rot ◽  
Field Experiments ◽  
Root Zone ◽  
Atmospheric Oxygen ◽  
Oxygen Deprivation ◽  
Red Rot ◽  
Colletotrichum Falcatum ◽  
Pythium Root Rot ◽  
Humidified Air ◽  
Poor Drainage

The effects of oxygen deprivation or poor drainage and Pythium root rot on development of red rot, caused by Colletotrichum falcatum, and spring shoot population of sugarcane were evaluated under controlled and field conditions. Detached stalks of five cultivars were exposed to low atmospheric oxygen (0.5 to 2.7%), created by enclosing stalks in sealed chambers through which humidified nitrogen gas was passed for 0, 1, or 2 weeks. Stalks were then inoculated with C. falcatum and maintained for 6 weeks with humidified air flow. Red rot severity, assessed as four disease traits, was not increased by previous oxygen deprivation. In field experiments, inoculation of stalks of three cultivars with C. falcatum before planting resulted in a reduction in shoot populations the following spring. Poor drainage resulted in an additional reduction in shoot populations developing from inoculated stalks. Soil atmospheric oxygen was reduced in the root zone below planted stalks under poor drainage conditions. However, only minor reductions in oxygen were detected in the zone of elevated rows in which planted stalks were located. The detrimental effect of poor drainage on shoot populations from inoculated stalks was alleviated by metalaxyl application. Pythium root rot, caused by Pythium arrhenomanes, reduced the initial root system and growth of shoots in greenhouse experiments. The combination of P. arrhenomanes and C. falcatum inoculation increased dead bud percentage in one of two cultivars and red rot severity for both. The results suggest that spring shoot populations developing from red rot-affected stalks exposed to poor drainage can be reduced by the combined effects of red rot and Pythium root rot.

scholarly journals Etiology and epidemiology of Pythium root rot in hydroponic crops: current knowledge and perspectives

2006 ◽  
Vol 32 (4) ◽  
pp. 307-321 ◽  
Author(s):  
John Clifford Sutton ◽  
Coralie Rachelle Sopher ◽  
Tony Nathaniel Owen-Going ◽  
Weizhong Liu ◽  
Bernard Grodzinski ◽  
...  
Keyword(s):  
Nutrient Solution ◽  
Root Rot ◽  
Root Zone ◽  
Pythium Ultimum ◽  
Stress Factors ◽  
Pythium Root Rot ◽  
Whole Plant ◽  
Phenolic Substances ◽  
Hydroponic Systems ◽  
The Impact

The etiology and epidemiology of Pythium root rot in hydroponically-grown crops are reviewed with emphasis on knowledge and concepts considered important for managing the disease in commercial greenhouses. Pythium root rot continually threatens the productivity of numerous kinds of crops in hydroponic systems around the world including cucumber, tomato, sweet pepper, spinach, lettuce, nasturtium, arugula, rose, and chrysanthemum. Principal causal agents include Pythium aphanidermatum, Pythium dissotocum, members of Pythium group F, and Pythium ultimum var. ultimum. Perspectives are given of sources of initial inoculum of Pythium spp. in hydroponic systems, of infection and colonization of roots by the pathogens, symptom development and inoculum production in host roots, and inoculum dispersal in nutrient solutions. Recent findings that a specific elicitor produced by P. aphanidermatum may trigger necrosis (browning) of the roots and the transition from biotrophic to necrotrophic infection are considered. Effects on root rot epidemics of host factors (disease susceptibility, phenological growth stage, root exudates and phenolic substances), the root environment (rooting media, concentrations of dissolved oxygen and phenolic substances in the nutrient solution, microbial communities and temperature) and human interferences (cropping practices and control measures) are reviewed. Recent findings on predisposition of roots to Pythium attack by environmental stress factors are highlighted. The commonly minor impact on epidemics of measures to disinfest nutrient solution as it recirculates outside the crop is contrasted with the impact of treatments that suppress Pythium in the roots and root zone of the crop. New discoveries that infection of roots by P. aphanidermatum markedly slows the increase in leaf area and whole-plant carbon gain without significant effect on the efficiency of photosynthesis per unit area of leaf are noted. The platform of knowledge and understanding of the etiology and epidemiology of root rot, and its effects on the physiology of the whole plant, are discussed in relation to new research directions and development of better practices to manage the disease in hydroponic crops. Focus is on methods and technologies for tracking Pythium and root rot, and on developing, integrating, and optimizing treatments to suppress the pathogen in the root zone and progress of root rot.

scholarly journals Role of Bradyrhizobium japonicum and Trichoderma spp. in the control of root rot disease of soybean

2014 ◽  
Vol 30 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Syed Ehteshamul-Haque ◽  
Abdul Ghaffar
Keyword(s):  
Grain Yield ◽  
Rhizoctonia Solani ◽  
Trichoderma Harzianum ◽  
Root Rot ◽  
Bradyrhizobium Japonicum ◽  
Seed Treatment ◽  
Trichoderma Spp ◽  
Root Rot Disease ◽  
Rot Disease

Seed treatment of soybean with <i>Bndyrhizobium japonicum, Trichoderma harzianum, T. viride, T. hamatum, T. koningii</i> and <i>T. pseudokoningii</i> significantly controlled the infection of 30-day-old seedlingsby <i>Maerophomina phaseolina, Rhizoctonia solani</i> and <i>Fusarium</i> spp. In 60-day-old plants <i>Trichoderma</i> spp.. and <i>B. japonicum</i> inhibited the grouth of <i>R. solani</i> and <i>Fusarium</i> spp., whereas the use of <i>B. japonicum</i> (TAL-102) with <i>T. harzianum. T. viride, T. koningii</i> and <i>T. pseudokoningii</i> controlled the infection by <i>M. phaseolina. Greater grain yield was recorded when B. <i>japonium</i> (TAI-102) was used with <i>T. hamatum</i>.

scholarly journals Cultivation and Topdressing Requirements for Thatch Management in A and G Bentgrasses and Creeping Bluegrass

HortScience ◽  
2003 ◽  
Vol 38 (6) ◽  
pp. 1227-1231 ◽  
Author(s):  
John C. Stier ◽  
Andrew B. Hollman
Keyword(s):  
Root Zone ◽  
Creeping Bentgrass ◽  
Shoot Density ◽  
Agrostis Stolonifera ◽  
Dollar Spot ◽  
Single Treatment ◽  
The Core ◽  
Turf Quality ◽  
Putting Green ◽  
New Cultivars

Empirical observations suggest certain new cultivars of creeping bentgrass (Agrostis stolonifera L.) with high shoot density require more intensive topdressing and core aeration to control thatch compared to less dense cultivars such as `Penncross. In addition, a variety of Poa annua var. reptans Hausskn., `DW-184, has recently been released for putting green use but management requirements are undocumented. The objective of our project was to determine the core aeration and topdressing requirements for thatch management of creeping bentgrass cultivars `A-4, `G-2, and `Penncross as compared to `DW-184. Plots were established on a sand-based root zone and maintained as putting green turf for 3 years. A factorial treatment arrangement was used to assess the effects of core aeration and topdressing on thatch, topdressing removal, turf quality, and disease. Both `A-4 and `G-2 produced more organic matter as (thatch/mat) than `Penncross and `DW-184. Grass type, core aeration frequency, and topdressing regime affected the amount of topdressing removed by mowing. An interaction between grass type and topdressing regime showed biweekly topdressing with verticutting resulted in less topdressing removal from all grasses except `G-2 compared to monthly topdressing without verticutting. Since no more than 3% of the topdressing applied was removed from any single treatment, however, the overall impact of grass type, core aeration frequency, or topdressing regime are unlikely to affect turf response. Both `A-4 and `G-2 provided consistently better quality turf than `Penncross or `DW-184 at 3.2 mm mowing height, though `A-4 was more susceptible to dollar spot disease (Sclerotinia homeocarpa F.T. Bennett) than `Penncross or `G-2. Cultivation and topdressing methods for management of `A-4 and `G-2 bentgrasses do not differ substantially from `Penncross or `DW-184 creeping bluegrass.

scholarly journals Brachypodium: A Potential Model Host for Fungal Pathogens of Turfgrasses

2017 ◽  
Vol 107 (6) ◽  
pp. 749-757 ◽  
Author(s):  
Renee A. Rioux ◽  
Benjamin J. Van Ryzin ◽  
James P. Kerns
Keyword(s):  
Fungal Pathogens ◽  
Molecular Mechanisms ◽  
Brachypodium Distachyon ◽  
Creeping Bentgrass ◽  
Sclerotinia Homoeocarpa ◽  
Dollar Spot ◽  
Cool Season ◽  
Host System ◽  
Brown Patch ◽  
Compatible Interactions

Brachypodium distachyon is a C3 grass that is an attractive model host system for studying pathogenicity of major turfgrass pathogens due to its genetic similarity to many cool-season turfgrasses. Infection assays with two or more isolates of the casual agents of dollar spot, brown patch, and Microdochium patch resulted in compatible interactions with B. distachyon inbred line Bd21-3. The symptoms produced by these pathogens on Bd21-3 closely resembled those observed on the natural turfgrass host (creeping bentgrass), demonstrating that B. distachyon is susceptible to the fungal pathogens that cause dollar spot, brown patch, and Microdochium patch on turfgrasses. The interaction between Sclerotinia homoeocarpa isolates and Brachypodium ecotypes was also investigated. Interestingly, differential responses of these ecotypes to S. homoeocarpa isolates was found, particularly when comparing B. distachyon to B. hybridum ecotypes. Taken together, these findings demonstrate that B. distachyon can be used as a model host system for these turfgrass diseases and leveraged for studies of molecular mechanisms contributing to host resistance.

scholarly journals Residual Efficacy of Fungicides for Controlling Brown Patch on Creeping Bentgrass Fairways

Plant Disease ◽  
2013 ◽  
Vol 97 (12) ◽  
pp. 1620-1625 ◽  
Author(s):  
John P. Daniels ◽  
Richard Latin
Keyword(s):  
Field Experiments ◽  
Quantitative Description ◽  
Creeping Bentgrass ◽  
Weibull Function ◽  
Brown Patch ◽  
Flight Mass Spectrometry ◽  
Fungicide Efficacy ◽  
Residual Efficacy ◽  
Environment Chamber ◽  
Tof Ms

Residual efficacy of five fungicides (azoxystrobin, flutolanil, metconazole, polyoxin D, and pyraclostrobin) applied to creeping bentgrass (Agrostis stolonifera) maintained under golf course fairway conditions was determined using a bioassay method. During 2010 and 2011, six different field experiments were conducted. Each consisted of a single fungicide application followed by periodic (0, 3, 7, 10, 14, 17, and 21 days after application) turf sampling, inoculation of samples with an isolate of Rhizoctonia solani, and incubation in a controlled environment chamber for 48 h. For each sample date, fungicide efficacy was determined by measuring the extent of symptom expansion on fungicide treated and nontreated samples. Efficacy half-life values based on a two-parameter Weibull function were 3.1 to 14.0 days for the fungicides used in this study. Residual efficacy was further examined in 2011 by analyzing residues from creeping bentgrass verdure using liquid chromatography/time-of-flight mass spectrometry (LC/TOF-MS). Quantitative analysis from LC/TOF-MS revealed that fungicide residues were depleted rapidly following application to turfgrass and reinforced the precipitous decline in fungicide efficacy demonstrated by the bioassays. Regardless of fungicide, more than 90% of active ingredient applied was depleted from the verdure between 3 and 8 days after application, and more than 99% of fungicide was depleted at 17 days after application. This research provides a quantitative description of the temporal nature of loss of fungicide and fungicide protection from turf.

Trinexapac-Ethyl Influences Bispyribac-Sodium Absorption and Efficacy for Annual Bluegrass (Poa annua) Control in Creeping Bentgrass (Agrostis stolonifera)

2010 ◽  
Vol 24 (3) ◽  
pp. 326-331 ◽  
Author(s):  
Patrick E. McCullough ◽  
Stephen E. Hart
Keyword(s):  
Laboratory Experiments ◽  
Management Practices ◽  
Field Experiments ◽  
Creeping Bentgrass ◽  
Agrostis Stolonifera ◽  
Sodium Absorption ◽  
Dollar Spot ◽  
Cool Season ◽  
Annual Bluegrass ◽  
Wettable Powder

Bispyribac-sodium selectively controls annual bluegrass in cool-season turf but efficacy may be influenced by management practices, such as plant growth regulator use. Experiments were conducted in New Jersey to investigate efficacy and absorption of bispyribac-sodium applied with trinexapac-ethyl for annual bluegrass control and turfgrass tolerance. In laboratory experiments with annual bluegrass, creeping bentgrass, and perennial ryegrass, tank-mixing trinexapac-ethyl with14C-bispyribac-sodium increased presumed foliar absorption of14C-bispyribac-sodium compared with nontrinexapac-ethyl treated; absorption increased with trinexapac-ethyl rate. Differences in14C-bispyribac-sodium absorption were not detected among emulsifiable concentration, microencapsulated concentration, and wettable powder trinexapac-ethyl formulations. In field experiments, sequential bispyribac-sodium applications controlled annual bluegrass 93%, but trinexapac-ethyl did not affect efficacy. Tank-mixing all trinexapac-ethyl formulations with bispyribac-sodium provided similar annual bluegrass control and creeping bentgrass quality compared with bispyribac-sodium alone. Applications of bispyribac-sodium reduced dollar spot cover in both years, whereas trinexapac-ethyl reduced dollar spot cover only in 2005.

Management of Root Rot (Rhizoctonia solani) of Mothbean through Bio-Agents

2020 ◽  
Author(s):  
S. L. Godara ◽  
Narendra . Singh
Keyword(s):  
Grain Yield ◽  
Rhizoctonia Solani ◽  
Pseudomonas Fluorescens ◽  
Trichoderma Harzianum ◽  
Root Rot ◽  
Seed Treatment ◽  
Field Experiments ◽  
Disease Incidence ◽  
Management Strategies ◽  
Soil Application

Root rot caused by Rhizoctonia solani is an important disease of mothbean, under severe infestation it causes 58-68 % losses in grain yield. Three-year field experiments were conducted in hot arid conditions at Bikaner, Rajasthan during kharif seasons with the objective to find out suitable eco-friendly management strategies for root rot. The experiment was conducted on cv. RMO-225 with six different combination of Trichoderma harzianum + Pseudomonas fluorescens bio- agents viz, seed treatment, soil treatment and their combinations against the root rot disease and compared with an untreated control. Results of experiment showed that all the treatments brought significant decline in disease incidence and consequently enhancement of grain yield compared to control. The treatment having combination of Trichoderma harzianum + Pseudomonas fluorescens seed treatment (4+4 g/kg seed) + soil application of T. harzianum + P. fluorescens (1.25 +1.25 kg in 50 kg FYM for each/ha) had minimum (21.78 %) root rot incidence, highest grain yield (10.56 q /ha) and net return (Rs. 14,338/ha). The T. harzianum seed treatment 8 g/kg seed + soil application of T. harzianum 2.5kg in 100 kg FYM/ha was the next best treatment with 25.56 per cent disease incidence and 9.42 q/ha of grain yield. These treatments can provide an effective, economical and eco- friendly management of root rot of mothbean for cultivators.

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