Effects of row spacing, seeding rate and seed-placed phosphorus on root diseases of spring wheat and barley under zero tillage

Changes in tillage and other agronomic practices have shown benefits of increased grain yield for many crops, but these changes may alter the micro-environment resulting in changes to populations of disease-causing agents and other micro-organisms. This study examined the effects of row spacing (10, 20, 30 cm), seeding rate (54, 108, 161 kg ha−1 for barley; 67, 134, 202 kg ha−1 for spring wheat) and seed-placed phosphorus (0, 8, 16 kg ha−1) on root diseases in spring wheat and barley using a zero-tillage production system in four environments. Root rot severity was assessed by visual ratings and the causal agents were identified. Analyses of variance indicated significant differences in root rot severity and the incidence of some causal agents for the main treatment effects (i.e. row spacing, seeding rate, seed-placed phosphorus) and no significant interactions between locations, years, and cultural practices. Contrasts of treatment means showed that higher rates of seeding decreased root rot severity and the incidence of Fusarium in wheat but these effects were small (less than 6%). The higher rates of monoammonium phosphate fertilizer reduced root rot severity in barley by 7% and the incidence of Gaeumannomyces graminis var. tritici in wheat by greater than 40%. Wider row spacings showed a small reduction of 6% in root rot severity in wheat but mostly had no effect on root diseases. Wheat yields were negatively associated with root rot severity in three of four environments. Fertility, root rot severity, and seeding rate had the greatest impact on wheat yield. Root diseases did not affect barley yields. Therefore, the use of wider row spacings and higher seeding rates with zero tillage practices will not lead to adverse effects on root diseases in wheat and barley. Phosphorus fertilizer should be used to reduce losses resulting from take-all disease in wheat. Key words: Zero tillage, cultural practices, common root rot, take-all, cereals

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Bacillus sp. L324-92 for Biological Control of Three Root Diseases of Wheat Grown with Reduced Tillage

Phytopathology ◽

10.1094/phyto.1997.87.5.551 ◽

1997 ◽

Vol 87 (5) ◽

pp. 551-558 ◽

Cited By ~ 101

Author(s):

Dal-Soo Kim ◽

R. James Cook ◽

David M. Weller

Keyword(s):

Biological Control ◽

Root Rot ◽

Gaeumannomyces Graminis ◽

Limiting Factors ◽

Bacillus Species ◽

Bacillus Sp ◽

Pythium Irregulare ◽

Root Diseases ◽

Rhizoctonia Root Rot ◽

Take All

Strain L324-92 is a novel Bacillus sp. with biological activity against three root diseases of wheat, namely take-all caused by Gaeumannomyces graminis var. tritici, Rhizoctonia root rot caused by Rhizoctonia solani AG8, and Pythium root rot caused mainly by Pythium irregulare and P. ultimum, that exhibits broad-spectrum inhibitory activity and grows at temperatures from 4 to 40°C. These three root diseases are major yieldlimiting factors for wheat in the U.S. Inland Pacific Northwest, especially wheat direct-drilled into the residue of a previous cereal crop. Strain L324-92 was selected from among approximately 2,000 rhizosphere/rhizoplane isolates of Bacillus species isolated from roots of wheat collected from two eastern Washington wheat fields that had long histories of wheat. Roots were washed, heat-treated (80°C for 30 min), macerated, and dilution-plated on 1/10-strength tryptic soy agar. Strain L324-92 inhibited all isolates of G. graminis var. tritici, Rhizoctonia species and anastomosis groups, and Pythium species tested on agar at 15°C; provided significant suppression of all three root diseases at 15°C in growth chamber assays; controlled either Rhizoctonia root rot, takeall, or both; and increased yields in field tests in which one or more of the three root diseases of wheats were yield-limiting factors. The ability of L324-92 to grow at 4°C probably contributes to its biocontrol activity on direct-drilled winter and spring wheat because, under Inland Northwest conditions, leaving harvest residues of the previous crop on the soil surface keeps soils cooler compared with tilled soils. These results suggest that Bacillus species with desired traits for biological control of wheat root diseases are present within the community of wheat rhizosphere microorganisms and can be recovered by protocols developed earlier for isolation of fluorescent Pseudomonas species effective against take-all.

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Impact of Preceding Crop and Cultural Practices on Rye Growth in Winter Wheat

Weed Technology ◽

10.1614/wt-09-014.1 ◽

2009 ◽

Vol 23 (4) ◽

pp. 564-568 ◽

Cited By ~ 10

Author(s):

Randy L. Anderson

Keyword(s):

Winter Wheat ◽

Spring Wheat ◽

Yield Loss ◽

Cultural Practices ◽

Wheat Yield ◽

Seeding Rate ◽

Starter Fertilizer ◽

Preceding Crop ◽

Winter Wheat Yield ◽

The Impact

Improving crop vigor can suppress growth of weeds present in the crop. This study examined the impact of preceding crop and cultural practices on rye growth in winter wheat. Preceding crops were soybean, spring wheat, and an oat/dry pea mixture. Two cultural treatments in winter wheat were also compared, referred to as conventional and competitive canopies. The competitive canopy differed from the conventional in that the seeding rate was 67% higher and starter fertilizer was banded with the seed. The study was conducted at Brookings, SD. Rye seed and biomass production differed fourfold among treatments, with winter wheat following oat/pea being most suppressive of rye growth. Rye produced 63 seeds/plant in winter wheat with a competitive canopy that followed oat/pea, contrasting with 273 seeds/plant in conventional winter wheat following spring wheat. Yield loss in winter wheat due to rye interference increased with rye biomass, but winter wheat was more tolerant of rye interference following oat/pea compared with the other preceding crops. Regression analysis indicated that winter wheat yield loss at the same rye biomass was threefold higher following spring wheat or soybean compared with oat/pea as a preceding crop. Winter wheat competitiveness and tolerance to rye can be improved by increasing the seeding rate, using a starter fertilizer, and growing winter wheat after an oat/pea mixture.

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Yield Responses of Direct-Seeded Wheat to Rhizobacteria and Fungicide Seed Treatments

Plant Disease ◽

10.1094/pdis.2002.86.7.780 ◽

2002 ◽

Vol 86 (7) ◽

pp. 780-784 ◽

Cited By ~ 45

Author(s):

R. James Cook ◽

David M. Weller ◽

Adel Youssef El-Banna ◽

Dan Vakoch ◽

Hao Zhang

Keyword(s):

Spring Wheat ◽

Root Rot ◽

Soil Fumigation ◽

Seed Treatments ◽

Root Diseases ◽

Pythium Root Rot ◽

Rhizoctonia Root Rot ◽

Direct Seeded ◽

Yield Responses ◽

Take All

Field trials were conducted with winter and spring wheat in eastern Washington and northern Idaho over several years to determine the benefit, as measured by grain yield, of seed treatments with rhizobacteria and formulated fungicides in cropping systems favorable to root diseases. The trials were conducted with wheat direct-seeded (no-till) in fields with a history of intensive cereals and one or more of the root diseases: take-all caused by Gaeumannomyces graminis var. tritici, Rhizoctonia root rot caused by Rhizoctonia solani AG8 and R. oryzae, and Pythium root rot caused mainly by Pythium irregulare and P. ultimum. The seed treatments included Bacillus sp. L324-92, Pseudomonas fluorescens Q69c-80, Pseudomonas fluorescens Q8r1-96, difenoconazole + metalaxyl (Dividend + Apron), difenoconazole + mefenoxam (Dividend + Apron XL = Dividend XL), tebuconazole + metalaxyl (Raxil XT), and tebuconazole + thiram (Raxil-thiram). Controls were nontreated seed planted into both nontreated (natural) soil and soil fumigated with methyl bromide just prior to planting. Although the data indicate a trend in higher wheat yields with two rhizobacteria treatments over the nontreated control (171 and 264 kg/ha, respectively), these higher yields were not significantly different from the nontreated control (P = 0.06). Fungicide seed treatments alone similarly resulted in yields that were 100 to 300 kg/ha higher than the nontreated control, but only the yield responses to Dividend on winter wheat (289 kg/ha) and Dividend + Apron on spring wheat (263 kg/ha) were significant (P ≤ 0.05). The greatest yield increases over the nontreated control occurred with certain rhizobacteria-fungicide combinations, with three treatments in the range of 312 to 486 kg/ha (6.1 to 17.7%; P ≤ 0.05). Some rhizobacteria-fungicide combinations brought average yields to within 85 to 90% of those obtained with soil fumigation. Only soil fumigation produced a measurable reduction in the incidence of take-all and Rhizoctonia root rot, as assessed on washed roots. No reliable method exists for visual quantification of Pythium root rot on wheat.

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Effect of Placement of Inoculum of Gaeumannomyces graminis var. tritici on Severity of Take-all in Winter Wheat

Plant Disease ◽

10.1094/pdis.2002.86.3.298 ◽

2002 ◽

Vol 86 (3) ◽

pp. 298-303 ◽

Cited By ~ 6

Author(s):

Mehdi Kabbage ◽

William W. Bockus

Keyword(s):

Disease Severity ◽

Field Experiments ◽

Linear Models ◽

Cultural Practices ◽

Spatial Location ◽

Gaeumannomyces Graminis ◽

Wheat Seed ◽

Root Diseases ◽

Gaeumannomyces Graminis Var Tritici ◽

Take All

Take-all, caused by Gaeumannomyces graminis var. tritici, is one of the most important root diseases of wheat worldwide. Because of the lack of highly effective chemical control, cultural practices, such as crop rotation, play a major role in managing disease severity. In Kansas, many producers do not use these measures and continue to suffer losses from take-all. Greenhouse and field experiments were established to assess the effect of horizontal versus vertical distribution of G. graminis var. tritici inoculum on disease severity. Oat kernel inoculum was placed at 0 (seed level), 5, 10, or 15 cm below the wheat seed or 5, 10, or 15 cm to the side of the wheat seed at a depth of 5 cm. Inoculum spatial location and distance greatly influenced take-all. Experiments showed more severe losses due to take-all when inoculum was placed below the seed than to the side of the seed. Regression analyses were used to develop take-all risk models relating inoculum distance from the seed to yield loss. Quadratic models were a better fit for data from experiments where inoculum was placed to the side of the seed, whereas linear models significantly fit data from experiments where inoculum was positioned below the seed. Within the same direction, take-all decreased as the inoculum was placed at greater distances from the seed, often to insignificant levels at 10 to 15 cm. According to the regression models, significant reduction (≥50%) in take-all might be achieved by plowing under the infested residues (crowns) to depths greater than 15 cm, or placing seed >6.0 cm to the side of inoculum. Therefore, under no-till conditions, sowing parallel to and exactly between the previous years' stubble rows (inoculum) might help manage take-all. These possibilities need to be investigated under field conditions.

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Seeding Rate Effects on Hybrid Spring Wheat Yield, Yield Components and Quality

Agronomy ◽

10.3390/agronomy11061240 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1240

Author(s):

Peder K. Schmitz ◽

Joel K. Ransom

Keyword(s):

Spring Wheat ◽

Yield Components ◽

Wheat Yield ◽

Triticum Aestivum L ◽

Yield Component ◽

Economic Feasibility ◽

Protein Yield ◽

Seeding Rate ◽

Hard Red Spring Wheat ◽

End Use

Agronomic practices, such as planting date, seeding rate, and genotype, commonly influence hard red spring wheat (HRSW, Triticum aestivum L. emend. Thell.) production. Determining the agronomic optimum seeding rate (AOSR) of newly developed hybrids is needed as they respond to seeding rates differently from inbred cultivars. The objectives of this research were to determine the AOSR of new HRSW hybrids, how seeding rate alters their various yield components, and whether hybrids offer increased end-use quality, compared to conventional cultivars. The performance of two cultivars (inbreds) and five hybrids was evaluated in nine North Dakota environments at five seeding rates in 2019−2020. Responses to seeding rate for yield and protein yield differed among the genotypes. The AOSR ranged from 3.60 to 5.19 million seeds ha−1 and 2.22 to 3.89 million seeds ha−1 for yield and protein yield, respectively. The average AOSR for yield for the hybrids was similar to that of conventional cultivars. However, the maximum protein yield of the hybrids was achieved at 0.50 million seeds ha−1 less than that of the cultivars tested. The yield component that explained the greatest proportion of differences in yield as seeding rates varied was kernels spike−1 (r = 0.17 to 0.43). The end-use quality of the hybrids tested was not superior to that of the conventional cultivars, indicating that yield will likely be the determinant of the economic feasibility of any future released hybrids.

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Effect of Row Spacing and Seeding Rate on Russian Thistle (Salsola tragus) in Spring Barley and Spring Wheat

Plants ◽

10.3390/plants10010126 ◽

2021 ◽

Vol 10 (1) ◽

pp. 126

Author(s):

Judit Barroso ◽

Nicholas G. Genna

Keyword(s):

Seed Production ◽

Crop Yield ◽

Spring Wheat ◽

Plant Biomass ◽

Integrated Management ◽

Spring Barley ◽

Management Strategies ◽

Crop Productivity ◽

Row Spacing ◽

Seeding Rate

Russian thistle (Salsola tragus L.) is a persistent post-harvest issue in the Pacific Northwest (PNW). Farmers need more integrated management strategies to control it. Russian thistle emergence, mortality, plant biomass, seed production, and crop yield were evaluated in spring wheat and spring barley planted in 18- or 36-cm row spacing and seeded at 73 or 140 kg ha−1 in Pendleton and Moro, Oregon, during 2018 and 2019. Russian thistle emergence was lower and mortality was higher in spring barley than in spring wheat. However, little to no effect of row spacing or seeding rate was observed on Russian thistle emergence or mortality. Russian thistle seed production and plant biomass followed crop productivity; higher crop yield produced higher Russian thistle biomass and seed production and lower crop yield produced lower weed biomass and seed production. Crop yield with Russian thistle pressure was improved in 2018 with 18-cm rows or by seeding at 140 kg ha−1 while no effect was observed in 2019. Increasing seeding rates or planting spring crops in narrow rows may be effective at increasing yield in low rainfall years of the PNW, such as in 2018. No effect may be observed in years with higher rainfall than normal, such as in 2019.

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Characterization and aggressiveness of take-all root rot pathogens isolated from symptomatic bermudagrass putting greens

Phytopathology ◽

10.1094/phyto-05-21-0215-r ◽

2021 ◽

Author(s):

Cameron Stephens ◽

Travis W Gannon ◽

Marc Cubeta ◽

Tim L. Sit ◽

Jim Kerns

Keyword(s):

Plant Tissue ◽

Root Rot ◽

Pathogen Detection ◽

Infected Plant ◽

Gaeumannomyces Graminis ◽

In Planta ◽

High Resolution Melt ◽

Putting Greens ◽

Ultradwarf Bermudagrass ◽

Take All

Take-all root rot is a disease of ultradwarf bermudagrass putting greens caused by Gaeumannomyces graminis (Gg), Gaeumannomyces sp. (Gx), Gaeumannomyces graminicola (Ggram), Candidacolonium cynodontis (Cc), and Magnaporthiopsis cynodontis (Mc). Many etiological and epidemiological components of this disease remain unknown. Improving pathogen identification and our understanding of the aggressiveness of these pathogens along with growth at different temperatures will advance our knowledge of disease development to optimize management strategies. Take-all root rot pathogens were isolated from symptomatic bermudagrass root and stolon pieces from 16 different golf courses. Isolates of Gg, Gx, Ggram, Cc, and Mc were used to inoculate ‘Champion’ bermudagrass in an in planta aggressiveness assay. Each pathogen was also evaluated at 10, 15, 20, 25, 30, and 35C to determine growth temperature optima. Infected plant tissue was used to develop a real-time PCR high resolution melt assay for pathogen detection. This assay was able to differentiate each pathogen directly from infected plant tissue using a single primer pair. In general, Ggram, Gg, and Gx were the most aggressive while Cc and Mc exhibited moderate aggressiveness. Pathogens were more aggressive when incubated at 30C compared to 20C. While they grew optimally between 24.4 and 27.8C, pathogens exhibited limited growth at 35C and no growth at 10C. These data provide important information on this disease and its causal agents that may improve take-all root rot management.

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An Integrated Weed Management Approach to Managing Foxtail Barley (Hordeum jubatum) in Conservation Tillage Systems

Weed Technology ◽

10.1017/s0890037x00041841 ◽

1999 ◽

Vol 13 (2) ◽

pp. 347-353 ◽

Cited By ~ 19

Author(s):

Robert E. Blackshaw ◽

Greg Semach ◽

Xiangju Li ◽

John T. O'Donovan ◽

K. Neil Harker

Keyword(s):

Crop Yield ◽

Weed Management ◽

Conservation Tillage ◽

Wheat Yield ◽

Integrated Weed Management ◽

Management Approach ◽

Row Spacing ◽

Seeding Rate ◽

Tillage Systems ◽

Perennial Plants

A 4-yr field experiment was conducted to determine the merits of combining cultural and chemical controls to manage foxtail barley in reduced-tillage systems. Factors studied were crop row spacing, seeding rate, and application rate and timing of glyphosate within a spring wheat-flax cropping sequence. Glyphosate applied preseeding at 400 or 800 g/ha killed foxtail barley seedlings but only suppressed established perennial plants. Glyphosate applied postharvest at 800 g/ha killed 60 to 70% of established plants. Combinations of preseeding and postharvest glyphosate gave the greatest reductions in foxtail barley biomass and seed production and resulted in the greatest increases in crop yield. Including flax in the rotation allowed use of grass herbicides such as quizalofop or sethoxydim that effectively controlled foxtail barley seedlings and provided some suppression of perennial plants. An increase in wheat seeding rate from 75 to 115 kg/ha reduced foxtail barley growth and increased wheat yield in 3 of 4 yr. Increasing the flax seeding rate from 40 to 80 kg/ha or reducing wheat and flax row spacing from 30 to 20 cm provided little benefit in managing foxtail barley or increasing crop yield. A multiyear approach combining agronomic practices and timely use of herbicides should allow growers to effectively manage foxtail barley in annual cropping systems using conservation tillage.

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Seeding Date, Seeding Rate, and Row Spacing Affect Wheat (Triticum aestivum) and Cheat (Bromus secalinus)

Weed Technology ◽

10.1017/s0890037x0003373x ◽

1991 ◽

Vol 5 (4) ◽

pp. 707-712 ◽

Cited By ~ 15

Author(s):

Jeffrey A. Koscelny ◽

Thomas F. Peeper ◽

John B. Solie ◽

Stanley G. Solomon

Keyword(s):

Triticum Aestivum ◽

Winter Wheat ◽

Field Experiments ◽

Wheat Yield ◽

Row Spacing ◽

Infestation Level ◽

Seeding Rate ◽

Seeding Date ◽

Bromus Secalinus ◽

Winter Wheat Yield

Field experiments were conducted in Oklahoma to determine the effects of winter wheat seeding date and cheat infestation level on cultural cheat control obtained by increasing winter wheat seeding rates and decreasing row spacing. Seeding rate and row spacing interactions influenced cheat density, biomass, or seed in harvested wheat (dockage) at two of three locations. Suppressive effects on cheat of increasing wheat seeding rates and reduced row spacings were greater in wheat seeded in September than later. At two other locations, increasing seeding rate from 67 to 101 kg ha–1or reducing row spacings from 22.5 to 15 cm increased winter wheat yield over a range of cheat infestation levels.

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Pseudomonas synxantha 2-79 Transformed with Pyrrolnitrin Biosynthesis Genes Has Improved Biocontrol Activity Against Soilborne Pathogens of Wheat and Canola

Phytopathology ◽

10.1094/phyto-09-19-0367-r ◽

2020 ◽

Vol 110 (5) ◽

pp. 1010-1017

Author(s):

Jibin Zhang ◽

Dmitri V. Mavrodi ◽

Mingming Yang ◽

Linda S. Thomashow ◽

Olga V. Mavrodi ◽

...

Keyword(s):

Root Rot ◽

Fusarium Culmorum ◽

Pythium Ultimum ◽

Gaeumannomyces Graminis ◽

Wild Type ◽

Wheat Roots ◽

Recombinant Strains ◽

Rhizoctonia Root Rot ◽

Take All

A four-gene operon (prnABCD) from Pseudomonas protegens Pf-5 encoding the biosynthesis of the antibiotic pyrronitrin was introduced into P. synxantha (formerly P. fluorescens) 2-79, an aggressive root colonizer of both dryland and irrigated wheat roots that naturally produces the antibiotic phenazine-1-carboxylic acid and suppresses both take-all and Rhizoctonia root rot of wheat. Recombinant strains ZHW15 and ZHW25 produced both antibiotics and maintained population sizes in the rhizosphere of wheat that were comparable to those of strain 2-79. The recombinant strains inhibited in vitro the wheat pathogens Rhizoctonia solani anastomosis group 8 (AG-8) and AG-2-1, Gaeumannomyces graminis var. tritici, Sclerotinia sclerotiorum, Fusarium culmorum, and F. pseudograminearum significantly more than did strain 2-79. Both the wild-type and recombinant strains were equally inhibitory of Pythium ultimum. When applied as a seed treatment, the recombinant strains suppressed take-all, Rhizoctonia root rot of wheat, and Rhizoctonia root and stem rot of canola significantly better than did wild-type strain 2-79.

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