Quality and germination of rapeseed and canola seed damaged by adult cabbage seedpod weevil, Ceutorhynchus assimilis (Paykull) [Coleoptera: Curculionidae]

1995 ◽  
Vol 75 (2) ◽  
pp. 539-541 ◽  
Author(s):  
G. D. Buntin ◽  
J. P. McCaffrey ◽  
P. L. Raymer ◽  
J. Romero

Adult feeding injury by the cabbage seedpod weevil (Ceutorhynchus assimilis Paykull) on pods and seeds of winter rapeseed and canola (Brassica napus L.) in Georgia and Idaho reduced seed weight and oil content an average of 16.2 and 2.2%, respectively. Injury also reduced seed germination by 40.5%, increased me proportion of germinated seed with abnormal growth and reduced seedling emergence from soil. Key words: Insecta, Ceutorhynchus assimilis, canola, rapeseed, Brassica napus, seed injury

2009 ◽  
Vol 120 (5) ◽  
pp. 921-931 ◽  
Author(s):  
Wolfgang Ecke ◽  
Rosemarie Clemens ◽  
Nora Honsdorf ◽  
Heiko C. Becker

1978 ◽  
Vol 58 (2) ◽  
pp. 549-550 ◽  
Author(s):  
J. M. CLARKE ◽  
F. R. CLARKE ◽  
G. M. SIMPSON

Broadcast and drill seeding of Brassica napus L. were compared at four seeding rates. Drill-seeded material yielded more than broadcast-seeded material, particularly at the low seeding rates. Broadcast-seeded plants had more branches and pods than drill-seeded plants. Seeding method did not affect number of seeds per pod or 1,000-seed weight.


2012 ◽  
Vol 125 (2) ◽  
pp. 285-296 ◽  
Author(s):  
Pu Yang ◽  
Chang Shu ◽  
Lin Chen ◽  
Jinsong Xu ◽  
Jiangsheng Wu ◽  
...  

1978 ◽  
Vol 58 (3) ◽  
pp. 731-737 ◽  
Author(s):  
J. M. CLARKE ◽  
G. M. SIMPSON

An analysis of the yield components of rape (Brassica napus L.) was carried out under field conditions for 2 yr at Saskatoon. Plant morphology and the crop environment were altered by the use of four planting densities and three water regimes. The number of branches per plant was scarcely affected by irrigation, but was reduced by high seeding rates. Number of pods per plant was increased by irrigation and reduced by high seeding rates. The number of seeds per pod was increased by irrigation, but reduced by high seeding rates. The 1,000-seed weight was increased both by irrigation and increased seeding rate, as was seed yield. Yield was positively correlated with 1,000-seed weight in both years. Yield component compensation was evident in the relationship of 1,000-seed weight to pod number and number of seeds per pod.


2004 ◽  
Vol 84 (2) ◽  
pp. 463-471 ◽  
Author(s):  
L. V. Gusta ◽  
E. N. Johnson ◽  
N. T. Nesbitt ◽  
K. J. Kirkland

Seedling vigour is a key critical component to produce well-established canola (Brassica napus) seedlings under less than ideal conditions in western Canada. Our objective was to determine if seed lots from late October (fall) or early spring (April) seeding dates improve seed vigour relative to mid-May (May) seeding dates. We compared seed size, seed maturity, germination percentage, and seedling emergence under controlled-environment conditions from six seed lots obtained from fall-sown (1997, 1998), April-sown (1998, 1999) and May-sown canola (1998, 1999) cv. Quest. On average, 80% of fall-derived seed for both years was larger than 1.7 mm compared to only 32% for May-derived canola seed. April-derived seed was intermediate. Fall and April derived seed were considered 40% mature compared to 16% for May-derived seed. In germination tests at 8°C, May derived seed germinated and emerged slower with a lower total germination percentage compared to falland April-derived seed lots. Priming reduced differences in emergence between the seed lots. Field studies at Scott, SK, sown in the fall of 1999 and 2000, and in early May of 2000 demonstrated that seed derived from fall- and April-sown canola produced higher plant densities, higher biomass at bolting, and higher seed yield than seed derived from May-sown canola. Yield was 10 to 45% less from seed derived from May-sown canola than seed derived from fall- and April-sown canola. This study established the impact of seeding date on seed quality and vigour, which in turn affected emergence, seedling vigour and yield. Also, seed vigour slowly declined within 1 yr, primarily with seed derived from the May-sown canola. Key words: Canola, Brassica napus, vigour (seed), seeding (fall), emergence, yield (quality)


1986 ◽  
Vol 66 (3) ◽  
pp. 425-430 ◽  
Author(s):  
R. R. DUNCAN ◽  
C. S. HOVELAND

Since rainfall generally exceeds 500 mm during the winter months and soil erosion is a problem in the southern U.S.A., a cover crop is essential to reduce soil losses. Continuous cultivation of a crop on the same land also provides the opportunity for pest problems to develop. A winter rapeseed (Brassica napus L.)-grain sorghum (Sorghum bicolor (L). Moench.) double-cropping system was investigated in the field from 1981 to 1984. Conventional tillage (CT) and no-till (NT) systems were used for both crops. Gullivar rape was planted in October and harvested in June. Winter rapeseed yields averaged 2.87 t ha−1 on CT plots in 1982. Averaged over 1983 and 1984, rape yields were 1.66 and 0.73 t ha−1 on CT and NT plots, respectively. However, the seeding method biased the rapeseed performance. Problems were encountered with winter weed control and pod shattering in the winter rape plots. Two sorghum hybrids, R. C. Young Oro Txtra and Funks G-550, were planted in June and harvested in October. Grain yields were not significantly different between hybrids (Oro 5.69 t ha−1, Funk 5.67 t ha−1) or between tillage systems (CT 5.59 t ha−1, NT 5.78 t ha−1). Grain yield differences were noted for year × hybrid × tillage interactions. Rape was a weed problem in the sorghum plots. The winter rape-sorghum double-cropping system offers an alternative to current winter small grains-sorghum/soybean (Glycine max (L.) Merr.) or winter annual legume-sorghum/soybean (Glycine max (L.) Merr.) systems; however, markets for the winter rapeseed and production economic analyses are needed prior to adoption of the system. Additional winter rapeseed research is needed to evaluate yields properly under NT conditions.Key words: Sorghum bicolor (L.) Moench, Brassica napus L., conservation tillage, multiple cropping, sorghum, rapeseed


1987 ◽  
Vol 67 (3) ◽  
pp. 675-684 ◽  
Author(s):  
G. C. BEAULIEU ◽  
D. J. HUME

In order to determine regions of adaptation of winter rapeseed (Brassica napus L.), field trials were planted at about 30 locations in Ontario in 1981 and 1982. Four cultivars were tested each year. Winter survival was poor in northern Ontario in both years, and along the north shore of Lake Erie in the first year. Over all sites, mean winter survival was 52%. At sites which did not completely winterkill, plant survival and yield averaged 70% and 2.38 t ha−1. Best winter rapeseed performance in Ontario occurred at well-drained sites with good winter snow cower and an absence of excessive flooding or cold temperatures in the spring. Cultivars did not differ in survival or yield in 1981–1982. The cultivar Jet Neuf had higher yields than the other cultivars in 1982–1983. There were differences in oil and protein content among the cultivars. The results suggest that winter rapeseed could become a viable crop in Ontario.Key words: Rapeseed (winter), Brassica napus, seed yield, winter survival, adaptation


2009 ◽  
Vol 89 (4) ◽  
pp. 613-619 ◽  
Author(s):  
S Gruber ◽  
K Emrich ◽  
W Claupein

Secondary dormancy is the major reason for seed persistence of canola (Brassica napus L.) in the soil. Volunteers emerging from the soil seed bank can lead to unwanted gene dispersal. More than 40 B. napus canola cultivars were tested for secondary dormancy under laboratory conditions. All cultivars were classified into groups of low, medium, and high dormancy by performing a cluster analysis. The results suggest that secondary dormancy is a cultivar-specific trait. Additionally, inter-year variation in dormancy indicates that it seems to be influenced by a set of environmental factors. Among years, classification of cultivars based on relative rank was more robust than classification based on absolute dormancy values. The classification of cultivars by their dormancy level would allow farmers to select and grow low-dormancy cultivars. Knowledge about the relative secondary dormancy of the currently grown cultivars could help growers and breeders lower canola seed bank persistence. Key words: Brassica napus, cluster analysis, genotype, secondary dormancy, soil seed bank


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