Effect of root rot and stem canker caused by Leptosphaeria maculans on yield of Brassica napus and measures for control in the field

2010 ◽  
Vol 61 (1) ◽  
pp. 50 ◽  
Author(s):  
S. J. Sprague ◽  
J. A. Kirkegaard ◽  
B. J. Howlett ◽  
J. Graham
Keyword(s):  
Brassica Napus ◽  
Grain Yield ◽  
Root Rot ◽  
Field Experiments ◽  
Management Strategies ◽  
Leptosphaeria Maculans ◽  
Brassica Species ◽  
Grain Filling ◽  
Stem Canker ◽  
Eastern Australia

Leptosphaeria maculans causes blackleg of Brassica napus (canola), manifesting in symptoms including leaf lesions, stem canker, and root rot. Root rot is an extension of the stem canker phase of the disease resulting from foliar infection; however, the role of root rot in grain yield loss has not been investigated. Field experiments were conducted in south-eastern Australia to determine the efficacy of fungicides and host resistance to stem canker for the control of root rot, along with the association between root rot severity and grain yield. Fungicides applied as a seed dressing (fluquinconazole) or coated on fertiliser (flutriafol) reduced root rot severity by 16 and 41%, respectively. Root rot severity was 78% less in a B. napus cultivar with an Australian Blackleg Rating (ABR) of 9.0 (highly resistant to stem canker) than in a moderately resistant cultivar (ABR 5.5), and was also reduced in Brassica species with good resistance to stem canker. Root rot caused little or no additional reduction in yield or harvest index of individual B. napus plants above that caused by stem canker. Individual upright plants with greater than 80% of the stem cross-section blackened had significantly reduced seed yield; however, this was influenced by rainfall during the grain-filling period. This study shows that current management strategies for stem canker caused by L. maculans also control root rot in B. napus, as although the symptoms in roots are severe, these symptoms have no additional effect on yield.

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.

Growth, recovery, and yield of dual-purpose canola (Brassica napus) in the medium-rainfall zone of south-eastern Australia

2012 ◽  
Vol 63 (7) ◽  
pp. 635 ◽  
Author(s):  
Jeffrey I. McCormick ◽  
Jim M. Virgona ◽  
John A. Kirkegaard
Keyword(s):  
Brassica Napus ◽  
Grain Yield ◽  
Leaf Area ◽  
Dry Matter ◽  
Field Experiments ◽  
Growth And Yield ◽  
Shoot Biomass ◽  
Target Value ◽  
Eastern Australia ◽  
Supplementary Irrigation

The effect of grazing of vegetative canola (Brassica napus) with sheep on crop growth and yield was investigated in two field experiments (Expts 1 and 2) in 2008 at Wagga Wagga, New South Wales, Australia. The experiments included a range of cultivars, sowing rates, and grazing periods to investigate the influence of these factors on grazing biomass, crop recovery, and grain yield. Three spring canola cultivars (representing triazine-tolerant, conventional, and hybrid types) were used in both experiments and were sown at three sowing rates and grazed by sheep for 7 days in midwinter in Expt 1, while two different grazing periods were compared in Expt 2. Supplementary irrigation was applied to Expt 1 to approximate average growing season conditions, while Expt 2 received no irrigation. Increased sowing rate produced greater early shoot biomass for grazing, but the-triazine tolerant cultivar produced less biomass than the conventional or hybrid cultivars in both experiments. Grazing reduced dry matter and leaf area by >50%, delayed flowering by 4 days on average, and reduced biomass at flowering by 22–52%. However, there was no impact of cultivar or sowing rate on the recovery of biomass and leaf area after grazing. Grazing had no effect on final grain yield under supplementary irrigation in Expt 1, but reduced grain yield under the drier regrowth conditions in Expt 2. The results demonstrate that grazing canola is feasible under average seasonal conditions in a medium-rainfall environment (400–600 mm) without yield penalty, provided the timing and intensity of grazing are matched to available biomass and anticipated seasonal water supply to support grain production. More broadly, we suggest that grain yield reductions from grazing could be avoided if suitable conditions for regrowth (residual dry matter, length of regrowth period, and adequate moisture) can generate biomass levels in excess of a target value of ~5000 kg ha–1 at flowering. This target value represents a biomass level where >90% of photosynthetically active radiation was intercepted in our study, and in other studies represents a biomass level above which there is little further increase in potential yield. Such a target provides a basis for more objective grazing management but awaits further confirmation with experimentation and modelling.

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.

Effect of fertiliser phosphorus and nitrogen on the concentrations of oil and protein in grain and the grain yield of canola (Brassica napus L.) grown in south-western Australia

2007 ◽  
Vol 47 (8) ◽  
pp. 984 ◽  
Author(s):  
R. F. Brennan ◽  
M. D. A. Bolland
Keyword(s):  
Brassica Napus ◽  
Grain Yield ◽  
Western Australia ◽  
Field Experiments ◽  
Grain Production ◽  
Brassica Napus L ◽  
Single Superphosphate ◽  
P Deficiency ◽  
Soil P ◽  
Soil P Testing

The effect of fertiliser phosphorus (P) and nitrogen (N) on seed (grain) yield and concentration of oil and protein in grain of canola (oil-seed rape; Brassica napus L.) was measured in two field experiments undertaken at eight sites from 1993–2005 in south-western Australia, on soils deficient in P and N. Six rates of P (0–40 kg P/ha as single superphosphate) and four rates of N (0–138 kg N/ha as urea) were applied. Significant grain yield increases (responses) to applied P occurred in both experiments and these responses increased as rates of applied N increased. For grain production, the P × N interaction was significant in all eight years and locations of the two experiments. Application of P had no effect on concentration of oil and protein in grain. Application of N always decreased the concentration of oil and increased the concentration of protein in grain. For canola grain production in the region, responses to applied N always occur whereas responses to applied P are rare, but if soil P testing indicates likely P deficiency, both P and N fertiliser need to be applied.

The Role of Phytoalexins in the Seedling Resistance to Leptosphaeria maculans in Some Crucifers

1995 ◽  
Vol 50 (1-2) ◽  
pp. 15-20 ◽  
Author(s):  
Michael Storck ◽  
Maria D. Sacristán
Keyword(s):  
Brassica Napus ◽  
Leptosphaeria Maculans ◽  
Brassica Species ◽  
Fungal Isolate ◽  
Time Intervals ◽  
Seedling Resistance ◽  
Sinapis Arvensis ◽  
Resistant Lines ◽  
Resistance Reaction

Abstract Brassica juncea, Brassica carinata and Sinapis arvensis resistant lines to Leptosphaeria maculans and four Brassica napus cuitivars susceptible to this pathogen in seedling stage were analyzed in relation to the accumulation of phytoalexins after inoculation with L. maculans. Cotyledon inoculations with spore suspensions of an aggressive and a non-aggressive isolate of L. maculans were performed on seedlings of these lines. The quantity of accumulated phytoalexins in the cotyledons was determined at different time intervals after inoculation. The content and composition of phytoalexins differed considerably among the tested species and according to the fungal isolate used. In the tested Brassica species seedling resistance against L. maculans could not be related to phytoalexin accumulation. However, in Sinapis arvensis phytoalexins might contribute to the resistance reaction to this pathogen.

scholarly journals Effect of Water Deficiency and Potassium Application on Plant Growth, Osmolytes and Grain Yield of Brassica Napus Cultivars

2014 ◽  
Vol 73 (2) ◽  
pp. 299-314 ◽  
Author(s):  
Murad Ali ◽  
Jehan Bakht ◽  
Gul Daraz Khan
Keyword(s):  
Brassica Napus ◽  
Grain Yield ◽  
Water Content ◽  
Relative Water Content ◽  
Field Experiments ◽  
Dependent Manner ◽  
Water Deficiency ◽  
Brassica Crop ◽  
Relative Water ◽  
Potassium Application

Abstract One of the major issues with brassica oil seed production is the water requirement of the brassica crop. To address the problem, field experiments were conducted to evaluate the effect of potassium (K) and water deficiency levels on canola (Brassica napus L.). Analysis of the data revealed that application of K, irrigation and interactions between irrigation and cultivar (I x C), irrigation and potassium (I x K), potassium and cultivar (K x C), and irrigation and cultivar and potassium (I x C x K) had a significant (p < 0.05) effect on shoot proline content, relative water content, plant fresh weight and grain yield. Potassium application, irrigation and interaction between I x C, K x C, and I x C x K had a significant (p < 0.05) effect on shoot sugar content. Water deficiency increased shoot proline and sugar contents and decreased relative water content. Potassium application increased shoot proline level in a dose dependent manner. Minimum proline and sugar contents and maximum relative water content, plant fresh and dry weight and yield were obtained when 100% irrigation was applied. Maximum grain yield was obtained upon application of 100% irrigation in combination with 120 kg ha−1 K.

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