Impact of seeding rate and depth on mycosphaerella blight and seed yield of field pea

2006 ◽  
Vol 86 (3) ◽  
pp. 845-853 ◽  
Author(s):  
S. F. Hwang ◽  
R. L. Conner ◽  
K. F. Chang ◽  
B. D. Gossen ◽  
H. Su ◽  
...  

Mycosphaerella blight (Mycosphaerella pinodes) occurs throughout western Canada and can severely reduce field pea (Pisum sativum) seed yield. Field trials were conducted at two sites (Edmonton, AB, and Morden, MB) from 2001 to 2003 to assess the impact of seeding rate and seeding depth on blight severity. Mycosphaerella blight severity in the canopy was greater at higher seeding rates; treatments seeded at 30 plants m-2 had lower levels of disease than those seeded at more than 100 seeds m-2. However, yield potential was reduced at low seeding densities. Depth of seeding did not affect seedling density, disease severity, yield or final seed weight. In addition, field trials were conducted at Edmonton to quantify yield losses associated with mycosphaerella blight in Alberta. In trials inoculated with M. pinodes, application of a foliar fungicide (chlorothalonil) increased yield by about 20% over the unprotected control. Key words: Pisum, Mycosphaerella, fungicide, crop management, yield loss

2002 ◽  
Vol 82 (4) ◽  
pp. 639-644 ◽  
Author(s):  
A. M. Johnston ◽  
G. W. Clayton ◽  
G. P. Lafond ◽  
K. N. Harker ◽  
T. J. Hogg ◽  
...  

The impact of seed placement and seeding rate on crop yield is not clearly understood for field pea (Pisum sativum L.). A field experiment was conducted at Melfort, SK, and Lacombe, AB, in 1998 and 1999, to evaluate the effect of three seed placements (distinct row: 23 cm and 30 cm with a hoe opener; and spread band: a 20-cm spread using a 28-cm sweep on a 23-cm row spacing) and three seeding rates (50, 100, and, 150 seeds m-2) on pea seedling density, seed yield and seed weight of a leafy prostrate and semi-leafless upright cultivar. A follow-up experiment was conducted at seven sites across Saskatchewan in 2001 to further examine the influence of a wider range of seeding rates (20, 30, 40, 50, 60, 70, 80, 90, 100, and 120 target plants m-2). Pea productivity for both cultivars was not affected by the different seed placements, despite a 4 mg greater seed weight for distinct row seed placements compared with spread band placement across all 1998–1999 sites. Moreover, the absence of a seed placement by seeding rate interaction indicated that greater spacing between plants was not associated with improved pea yield when seeding rate was increased, regardless of the cultivar. Yield component compensation occurred where increased plant density from higher seeding rates reduced seed weight. In the 2001 study, seed yield benefits were small at seeding rates greater than 50 target plants m-2. There was a tendency for lower yields with seeding rates less than 50, especially at sites with higher yield potential. Yields of field peas grown under relatively weed-free conditions should be optimized with a seeding rate of 50 to 75 seeds m-2. Key words: Pea (Pisum sativum L.), plant arrangement, row spacing, opener type, seeding rate


2000 ◽  
Vol 80 (2) ◽  
pp. 403-406 ◽  
Author(s):  
T. D. Warkentin ◽  
A. G. Xue ◽  
D. W. McAndrew

Mycosphaerella blight (MB) [Mycosphaerella pinodes (Berk. & Blox.)Vestergr.] causes substantial yield loss to field pea in western Canada in most seasons and is a disease for which genetic resistance is lacking. The objective of this research was to evaluate the effectiveness of foliar application of mancozeb for the control of MB of field pea. Field trials of split-plot design were conducted at two sites per year from 1996 to 1998 in southern Manitoba, with cultivars as main-plots and fungicide treatments as sub-plots. In most site-years, a single application of mancozeb at the early flowering stage was effective in reducing MB severity and in increasing yield. Mancozeb had similar efficacy to chlorothalonil, the only currently registered fungicide for control of MB in field pea. The beneficial effect of both fungicides was greater for the highly MB susceptible cultivars AC Tamor and Carrera than the moderately MB susceptible cultivar Radley. Key words: Pisum sativum, field pea, mycosphaerella blight, mancozeb, chlorothalonil


2014 ◽  
Vol 94 (7) ◽  
pp. 1211-1218 ◽  
Author(s):  
K. F. Chang ◽  
S. F. Hwang ◽  
H. U. Ahmed ◽  
S. E. Strelkov ◽  
B. D. Gossen ◽  
...  

Chang, K. F., Hwang, S. F., Ahmed, H. U., Strelkov, S. E., Gossen, B. D., Turnbull, G. D. and Blade, S. F. 2014. Disease reaction to Fusarium avenaceum and yield losses in narrow-leafed lupin lines. Can. J. Plant Sci. 94: 1211–1218. Seedling blight and root rot caused by Fusarium avenaceum are important constraints to the expansion of lupin (Lupinus angustifolius) production in Alberta, Canada. The reaction of 19 narrow-leafed lupin lines to F. avenaceum was assessed in inoculated field trials in Alberta from 2006 to 2008. Although none of the lines were highly resistant to F. avenaceum, the lines F6RF, MLU-122 and MLU-318-1 had the smallest reduction in emergence and MLU-320 and MLU-324 had the smallest reduction in seed yield as a result of inoculation under field conditions. The stability analysis of yield revealed that lupin lines MLU-324, W12-W5, MLU-320 and MLU-318-1 were more stable in comparison to other lupin lines included in the study. Yield loss was not consistently associated with seedling emergence, likely because the seeding rate may have been higher than required to achieve the yield potential of these lines in Alberta. A companion field study was conducted at Lacombe, Alberta, in 2006 and Edmonton, Alberta, in 2007; seedling emergence and seed yield of the susceptible lupin cv. Arabella declined linearly with increasing levels of seed infestation, and the relationships were summarized using regression analysis. Seedling emergence and yield were strongly correlated.


2006 ◽  
Vol 86 (3) ◽  
pp. 855-863 ◽  
Author(s):  
T. F. Wang ◽  
B. D. Gossen ◽  
A. E. Slinkard

Mycosphaerella blight, caused by Mycosphaerella pinodes, is a serious disease of pea (Pisum sativum) world-wide. The objective of this study was to assess the impact of lodging (reduced lodging treatment vs. control) and foliar fungicide (three to four applications of chlorothalonil vs. control) on the severity of mycosphaerella blight, and on seed yield and 1000-seed weight of 10 pea genotypes (three adapted cultivars and seven genotypes with partial resistance). In the reduced lodging treatment, a wire mesh was secured 30 cm above the ground; the crop was allowed to grow up through the mesh and be supported by it. The study was conducted under irrigation at two locations in Saskatchewan for 2 yr. Blight severity on stems, foliage, and pods was rated three to four times per year. The reduced-lodging treatment and application of fungicide reduced blight severity and increased seed yield and 1000-seed weight. The effects of reduced lodging and fungicide application were additive. Overall, lodging was associated with the largest reductions in seed yield and seed weight, but the impact of fungicide application was slightly larger than that of lodging for the three commercial cultivars. We conclude that losses caused by mycosphaerella blight may be reduced by breeding for improved resistance to lodging, but that application of foliar fungicide and breeding for partial resistance also hold promise. Key words: Pisum sativum, Mycosphaerella pinodes, resistance, fungicide, yield loss, quality


2012 ◽  
Vol 92 (2) ◽  
pp. 289-296 ◽  
Author(s):  
R. L. Conner ◽  
B. D. Gossen ◽  
S. F. Hwang ◽  
K. F. Chang ◽  
K. B. McRae ◽  
...  

Conner, R. L., Gossen, B. D., Hwang, S. F., Chang, K. F., McRae, K. B. and Penner, W. C. 2012. Field assessment of partial resistance to mycosphaerella blight in Pisum subspecies accessions. Can. J. Plant Sci. 92: 289–296. Mycosphaerella blight, caused by Mycosphaerella pinodes (Berk. & Bloxam) Vestergr., the teleomorph of Ascochyta pinodes Jones, is an important foliar disease of field pea in the major production areas of the world. Partial resistance to mycosphaerella blight has been reported in some field pea cultivars, but, at best, they are only moderately susceptible. A 3-yr field study was conducted to evaluate the mycosphaerella blight reactions of 28 accessions from a number of subspecies of Pisum sativum L. and one accession of P. fulvum Sibth. A few of the accessions carried mutations for the genes af, tl, and st that affect the morphology of the leaflets, stipules and tendrils. Reactions to mycosphaerella blight were characterized based on the mean of the severity ratings taken on the two final assessment dates before the crop matured and also on the change in mycosphaerella blight severity between these two dates. In many of the accessions, severity ratings were similar to that of the moderately susceptible check cultivar, CDC Peko, while a few had high severity ratings similar to those of the susceptible check cultivars. The accession PI 512079, which has small stipules, branched petioles with many leaflets but no tendrils, had the lowest ratings for mycosphaerella blight severity. Four other accessions exhibited the smallest change in mycosphaerella blight severity at the end of the growing season. Differences in leaf morphology likely influenced the change in disease severity, since all the semi-leafless and leafless accessions had smaller changes in mycosphaerella blight severity than the susceptible check cultivars. In a detached leaf assay with two isolates of Mycosphaerella pinodes (Berk. & Bloxam) Vestergr., the smallest lesions formed on PI 512079, but otherwise the results failed to show a relationship with the observed severity values in the field trials.


Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2382
Author(s):  
Jana Reinhardt ◽  
Pia Hilgert ◽  
Moritz Von Cossel

Industrial crop cultivation on marginal agricultural land limits indirect land-use change effects that pose a threat to food security. This review compiles results from 91 published crop-specific field trial datasets spanning 12 relevant industrial crops and discusses their suitability for cultivation on unfavorable soil types (USTs). It was shown that the perennial species Miscanthus (Miscanthus Andersson) and reed canary grass (Phalaris arundinacea L.) performed well on USTs with both high clay and/or high sand contents. Information on stoniness (particles sizes > 2 mm), where mentioned, was limited. It was found to have only a small impact on biological yield potential, though it was not possible to assess the impact on mechanization as would be used at a commercial scale. For soils with extreme clay or sand contents, half of the crops showed moderate suitability. The large yield variations within and between crops revealed large knowledge gaps in the combined effects of crop type and agronomy on USTs. Therefore, more field trials are needed on diverse USTs in different climates with better equipment and more consistent measurements to improve the accuracy of potential yield predictions spatially and temporally. Additionally, larger trials are needed to optimize cultivation and harvesting.


2002 ◽  
Vol 82 (4) ◽  
pp. 687-692 ◽  
Author(s):  
B. D. Gossen ◽  
J. J. Soroka ◽  
H. G. Najda

Little information is available on the management of turfgrass species for seed production in the Canadian prairies. The objective of these studies was to assess the impact of residue management and row spacing on seed yield under irrigation. A factorial experiment was seeded at Saskatoon, SK, in 1993 to assess the impact of burning or scalping (very close mowing with residue removal) vs. mowing, and 20- vs. 40-cm row spacing on seed yield of Kentucky bluegrass (KBG) (Poa pratensis), creeping red fescue (CRF) (Festuca rubra subsp. rubra) and creeping bentgrass (CBG) (Agrostis palustris). Also, a residue management trial on KBG was seeded at Brooks, AB, in 1993. At Saskatoon, yield was higher at 20-cm spacing across all three species in 1994, but spacing had no impact on winter survival, stand density, tiller growth or yield in subsequent years. Burning and scalping consistently resulted in earlier spring green-up, a higher proportion of fertile tillers, and higher seed yield than mowing. Even with residue management, yield declined after one harvest in CBG and CRF, and after two harvests in KBG. At Brooks, residue management had a similar impact on yield of KBG. A second trial at Brooks examined the impact of row spacing (20, 40, 60 cm) and seeding rate (0.5 to 6 kg seed ha-1) on KBG. Seed yield was highest at 40-cm spacings in 1994, at 60 cm in 1995, and at 40 to 60 cm in 1996. Seeding rate did not have a consistent effect on yield. We conclude that a combination of residue management and 20- to 40-cm spacings provide the highest, most consistent seed yields for these turfgrass species in this region. Key words: Burning, clipping, turfgrass, seed production, row spacing, Poa, Festuca, Agrostis


2016 ◽  
Vol 43 (2) ◽  
pp. 126-132
Author(s):  
J.M. Sarver ◽  
R.S. Tubbs ◽  
J.P. Beasley ◽  
A.K. Culbreath ◽  
T.L. Grey ◽  
...  

ABSTRACT The University of Georgia Extension recommendation for optimum plant stand in peanut (Arachis hypogaea L.) is 13.1 plants/m, although previous work has shown that yield potential can be maintained at lower plant stands. The unpredictable and often extreme weather and the ubiquity of pathogens in the region often contribute to poor emergence and poor plant stands. When plant stand is adversely affected, replanting the field may be a practical option. The objectives of this study were to determine i) the effect of plant stand on yield, grade and disease incidence, ii) at what plant stand peanut gains an advantage from replanting and iii) the best method for replanting peanut when an adequate stand is not achieved. Field trials took place in Plains, GA in 2011, 2012, and 2013; and Tifton, GA in 2012 and 2013 to evaluate peanut production at six plant stands (3.3, 4.9, 6.6, 8.2, 9.8, and 11.5 plants/m, in addition to a 13.1 plants/m control) in combination with three replant practices; i) no replant, ii) destroy the original stand and replant at a full seeding rate, and iii) add a reduced rate of seed to supplement the original stand) in a randomized complete block design. A positive linear trend for yield and a negative linear trend for tomato spotted wilt Tospovirus incidence were discovered as plant stand increased. Yield advantages from replanting occurred via supplemental seed addition to initial stands of 3.3 and 8.2 plants/m. Destroying the initial stand and completely replanting was never beneficial when compared to the other two replant practices. Replanting is warranted via supplemental seed addition at plant stands equal-to or below 8.2 plants/m.


2006 ◽  
Vol 46 (8) ◽  
pp. 1023 ◽  
Author(s):  
E. C. Wolfe ◽  
J. A. Paul ◽  
P. D. Cregan

The purposes of this study were to evaluate subterranean clover-based leys on farms and in experiments using several pasture parameters, and to assess the impact of winter cleaning on the productivity and botanical composition of clover swards. Annual pastures were monitored on a group of 5 farms in the Wagga district and compared with an experimental subterranean clover (Trifolium subterraneum L.) pasture. The major problem in the farm paddocks was a lack of legume biomass due to poor legume densities, a consequence of the use of the soft-seeded cultivar Woogenellup and a high content of grassy weeds. The farmers in the group were unaware of the tools, parameters and benchmarks for making quantitative pasture comparisons. In 2 experiments, a range of subterranean clover swards were generated through the use of cultivars, seeding rate and winter cleaning treatments, grazed at 15 sheep/ha and monitored for 3 years. Appropriate benchmark values for the seed pool of subterranean clover were 300–350 kg/ha in winter and 600–700 kg/ha in summer. On the basis of both winter production, a function of May seedling density (target >1000 seedlings/m2) and spring production, which depended on the cultivar maturity, Junee was superior at Wagga to either Dalkeith (earlier maturing) or Woogenellup (softer seeded). Winter cleaning, using selective herbicides (fluazifop, simazine) to remove grasses and weeds, was advantageous in achieving a high content (>90%) and productivity of subterranean clover, provided that the legume content of the pasture was at least 28%, or >20% of total ground area before herbicide application in winter. In winter-cleaned swards, legume growth increased by up to 80%, legume biomass was improved by up to 46% and legume content increased from <50 to >95%. The main disadvantages of winter cleaning were increased areas of bare ground and reduced total biomass for several weeks after herbicide application, and the rapid development of ryegrass that was resistant to at least 1 of the herbicides used. The strategic use of observations to monitor the performance of pastures and their response to management is discussed.


Author(s):  
Dengjin Bing ◽  
Don Beauchesne ◽  
Debra L. McLaren ◽  
Richard Cuthbert ◽  
Hamid Naeem

AAC Asher is a semi-leafless, medium to large seeded yellow cotyledon field pea (Pisum sativum L.) variety developed at Agriculture and Agri-Food Canada, Lacombe Research and Development Centre, Lacombe, Alberta, Canada. It has high yielding potential, early to medium maturity and good lodging resistance. AAC Asher has maturity of 94 days, and one-thousand-seed weight of 257 g. AAC Asher is resistant to powdery mildew (caused by Erysiphe pisi Syd.), moderately tolerant to mycosphaerella blight (caused by Mycosphaerella pinodes) and fusarium wilt (caused by Fusarium oxysporum). AAC Asher is adapted to all field growing regions in western Canada.


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