EFFECT OF PLANT DENSITY ON DEVELOPMENT AND YIELD OF RAPESEED AND ITS SIGNIFICANCE TO RECOVERY FROM HAIL INJURY

1987 ◽  
Vol 67 (1) ◽  
pp. 43-51 ◽  
Author(s):  
D. I. McGREGOR

The ability of rapeseed crops (Brassica campestris L. ’Torch’ and B. napus L. ’Tower’) to recover from, and compensate for, loss of plants at the early vegetative stage of development was investigated by hand thinning plant populations established at commercial seeding rates with commercial seeding equipment. Plant density was reduced from 100-200 plants m−2 to 40 plants m−2 with less than a 20% loss in seed yield. Seeds per pod and seed weight in some instances increased with reduced plant density. However, compensation was attributed predominantly to an increased number of pods on the remaining plants, which increased from 20-90 to as many as 600. Branching increased from as few as 3 to, in some instances, almost 40. With reduced plant population there was a tendency for increased and prolonged accumulation of dry matter by the plants following flowering.Key words: Brassica campestris L., Brassica napus L., rapeseed, development, seed yield, hail.

2014 ◽  
Vol 94 (8) ◽  
pp. 1461-1469 ◽  
Author(s):  
Yun Ren ◽  
Jianfang Zhu ◽  
Nazim Hussain ◽  
Shanlin Ma ◽  
Genru Ye ◽  
...  

Ren, Y., Zhu, J., Hussain, N., Ma, S., Ye, G., Zhang, D. and Hua, S. 2014. Seedling age and quality upon transplanting affect seed yield of canola (Brassica napus L.). Can. J. Plant Sci. 94: 1461–1469. Seedling quality is an essential indicator for seed yield in canola, which is affected by many factors, including seedling age. Two field experiments were conducted to compare canola seedling quality and seed yield on 30-, 35-, 40-, 45-, 50-, 55-, and 60-d-old seedlings in 2011 and 2012. The relationship between seedling quality traits and seed yield of different seedling ages was also analyzed. Results revealed that the highest seed yield obtained from 40-d-old seedlings was attributed to more branches and siliques per plant. The negative effect of young seedlings (30-d-old) on seed yield was greater than that of old seedlings (60-d-old). The reduction rates in seed yield on the 30- and 60-d-old seedlings were 25.7 and 18.2%, respectively, compared with the 40-d-old seedlings. Increased root neck diameter, green leaf number, shoot, and root dry matter was the case on 40-d-old seedling transplanted plants compared with other ages. However, the increase was larger in the old seedlings than in the young seedlings. On average, the shoot and root dry weights of the 30-d-old seedlings were 1.9 and 1.7% of those in the 60-d-old seedlings. However, correlation analysis revealed that the seedlings with the highest shoot and root dry matter did not necessarily obtain the highest seed yield. Factor analysis suggested that the effects of root neck diameter and green leaf number on seed yield were more pronounced than those of shoot and root dry matter. Therefore, high seed yield in canola could be defined in terms of optimum green leaf numbers and branches per plant.


2002 ◽  
Vol 82 (3) ◽  
pp. 521-529 ◽  
Author(s):  
Steven J. Shirtliffe ◽  
Adrian M. Johnston

There is relatively little agronomic information on solid-seeded production of dry bean in western Canada. Recommended seeding density for dry bean can depend on the growth habit of the plant, the yield–density relationship, percent emergence, seed cost and environment. The objective of this study was to determine the yield–density relationships in two determinate bush type cultivars of dry bean and the optimum plant population under solid-seeded production in Saskatchewan. CDC Camino, a late-season pinto bean and CDC Expresso, a medium-season-length black bean were the cultivars evaluated. In most sites, the yield-density relationship of the cultivars was asymptotic and an optimum plant density for maximum yield could not be determined. Camino generally required a lower plant population to reach a given yield than Expresso. Increasing plant population did not affect 1000-seed weight. Higher seeding rate did result in a greater number of seeds produced m-2, with Expresso having a greater increase in seed produced m-2 compared with Camino. Expresso was required to be at higher plant densities than Camino to maximize economic returns. This reflects the differences between cultivars in yield-density relationship and seed cost, as Camino has a heavier 1000-seed weight than Expresso. Saskatchewan bean growers wishing to maximize profit should target plant populations for Expresso and Camino of approximately 50 and 25 plants m-2, respectively. Key words: Saskatchewan, yield components, non-linear regression, seeding rate, narrow rows, solid-seeded


2020 ◽  
Vol 8 (4) ◽  
pp. 400-409
Author(s):  
A. K. M. Aminul Islam ◽  
F. M. Era ◽  
N. K. Aminul Chowdhury

Forty four testcross progenies obtained from crossing between five CMS and forty one candidate lines were evaluated both in field and laboratory condition to identify candidate restorer line(s). Nineteen testcross progenies were recorded as fully fertile with 100% plant fertility by counting the number of fertile plants from the total number of plants per lines. On the other hand from pollen fertility test, 11 testcross progenies [206A × 001(6), 9905A × 030(2), 9905A × 027(6) (0.57), 206A × 37(1) (0.68), 9904A × 027(4) (0.83), 248A × 020(6) (1.08), 248A × 018 (1.12), 248A × 022 (1.13), 248A × 017 (1.58), 248A × 038(2) (1.96) and 248A × 001(6) (2.02)] were found with 0-2.02% pollen sterility that could be mentioned as fertile or restorer lines for making hybrids. Agronomic performances were also satisfactory for these selected test cross progenies. The genotype 248A × 017 took the shortest time (30.00) for first flowering as well as ripening followed by 248A × 007(1). The highest number of pods per plant was observed in the testcross progeny 248A × 022 (649.59) and the highest number of seeds per pod (30.33) in 248A × 020(6). For seed weight per plant, 206A × 001(6) was recorded with maximum value (0.08g) while the lowest (23.33) number of seeds per plant was found in this progeny. In case of seed yield per plant, 248A × 022 gave the highest yield (30.30). The seed yield of the progenies 248A × 017 (23.49), 9905A × 027(6) (20.39), 248A × 001(6) (17.26), 9904A × 027(4) (17.02) and 248A × 038(2) (16.53) were also in the highest level.


1992 ◽  
Vol 43 (3) ◽  
pp. 623
Author(s):  
N Thurling ◽  
R Kaveeta

Agronomic characteristics of two groups of early flowering Brassica napus lines and their respective parents were compared at East Beverley in the Western Australian wheatbelt. These lines had been derived through two generations of backcrossing and subsequent selfing from crosses of the B. napus cultivar Wesbrook (recurrent parent) with an early flowering B. napus line RU2 and an even earlier flowering B. campestris population Chinoli C42. Lines selected for this experiment had flowered earliest in a previous controlled environment experiment. Only RU2 and one WesbrookxRU2 line (IB72) had significantly higher yields than Wesbrook (149% and 166% respectively), and one Wesbrookxchinoli C42 line was the only line to have a significantly lower yield than Wesbrook. None of the lines had significantly higher yields than their respective non-recurrent parents. Although RU2 and IB72 flowered much earlier than Wesbrook, there was no significant relationship between flowering time and seed yield over all lines. Lines which were the earliest to commence stem elongation tended to have higher seed yields. However, of all the growth and development characters measured, the biological yield and the dry weight increment between commencement of flowering and maturity were most closely related to seed yield. RU2 and IB72 accumulated far more dry matter over the post-anthesis period than Wesbrook and all other lines except another WesbrookxRU2 line. The superior post-anthesis growth of RU2 and IB72 may simply be a manifestation of the longer period available for growth under more favourable environmental conditions or deeper roots extracting more water from a greater depth. However, since there was no relationship between flowering time and the post-anthesis dry matter increment, it seems more likely that IB72 has received genes for superior post-anthesis growth as well as those determining early flowering from RU2. Given the rapid decline in soil moisture availability during post-anthesis development in this environment, these genes may affect post-anthesis growth through determining a greater capacity for drought avoidance. The implications of these results are discussed with particular reference to the breeding of higher yielding B. napus cultivars for lower rainfall environments.


1978 ◽  
Vol 58 (4) ◽  
pp. 1103-1105 ◽  
Author(s):  
J. M. CLARKE

The effects of time of leaf removal on Brassica napus L. were studied under field conditions at Saskatoon in 1976 and at Swift Current in 1977. Leaf removal at the start of flowering reduced the number of pods per plant, increased seed weight, and reduced seed yield. Leaf removal at the end of flowering did not affect yield or its components.


2000 ◽  
Vol 80 (4) ◽  
pp. 713-719 ◽  
Author(s):  
Ken J. Kirkland ◽  
Eric N. Johnson

Brassica napus L. canola production on the Canadian prairies often is limited by hot, dry growing conditions in early July and a short growing season. Brassica napus canola seeded in the fall just prior to freeze-up or in the early spring as soon as fields are passable may allow canola to avoid these adverse conditions. Our objective was to determine if late October (fall), or mid- to late April (April) seeding dates improve canola yield and quality relative to a mid-May (15 to 20 May) seeding date. Plant density and height, phenological development, seed yield, seed weight and seed oil content were assessed in plots sown to herbicide-tolerant B. napus canola at three seeding dates on five fallow sites and three stubble sites at Scott, SK, from 1994 to 1998. A thinner plant stand occurred for the fall compared with spring seeding dates; however, this difference rarely corresponded with less canola yield. Fifty percent flowering occurred 20 d earlier (June rather than July), reproductive growth (50% flowering to maturity) was 10 d longer, plants were 23 (fall) or 8 (April) cm shorter, and maturity occurred 13 d earlier when canola was seeded in the fall and April compared with mid-May seeding. Canola seed yield was 38% greater when seeded on the alternative dates rather than the more traditional mid-May seeding date. The yield advantage for alternative seeding dates was greater and more consistent on stubble than on fallow likely because of lack of soil crusting and temperature and wind protection from stubble. The response of seed weight to seeding date was similar to that for seed yield, indicating that a portion of the positive yield response to alternative seeding dates was associated with larger seed size. Oil content also was greater for the fall and April compared with mid-May seeding dates, but the improvement was smaller (6%) than that for seed yield. Fall- and April-seed-ed canola tolerated spring frosts and avoided adversely hot, dry weather during the flowering period, thus improving canola seed yield and quality. Alternative seeding dates provide canola producers in semi-arid regions with a sustainable option to diversify their cropping systems. Key words: Seeding date, dormant, stubble, fallow, herbicide tolerant, alternative cropping practice


2014 ◽  
Vol 67 (1) ◽  
pp. 61-74
Author(s):  
Valiollah Rameeh

Abstract Half F2 diallel crosses of spring rapeseed (Brassica napus L.) varieties along with their parents were evaluated for plant height, first siliqua height, siliquae on main axis, siliquae per plant, 1000-seed weight and seed yield. The Analysis of variance based on Cockerham’s method revealed significant mean squares of general combining ability (GCA), specific combining ability (SCA) for all the traits indicating that both additive and non-additive genetic effects were involved in controlling these traits. Parent vs crosses mean square which is indicating average heterosis was significant for all the traits. In Hayman’s method the regression lines estimated for all the traits except plant height cut the Wr axis below the origin in the negative zone, suggesting the overdominance type of gene action for these traits except plant height. Based on the array points on the regression lines, 19H had maximum dominant genes for siliquae on main axis, siliquae per plant 1000-seed weight and seed yield, being closest to the origin, while 0ption500 possessed recessive genes for first siliqua height, siliquae per plant and 1000-seed weight, as evidenced by its distant position from the origin. Due to low narrow-sense heritability estimates for most of the traits, selection for improving these traits should be carried out in delayed segregating generations.


2014 ◽  
Vol 47 (1) ◽  
pp. 71-79 ◽  
Author(s):  
Ejaz Ul-Hasan ◽  
H.S.B. Mustafa ◽  
Tahira Bibi ◽  
T. Mahmood

ABSTRACT The present research was carried out to determine the best selection criteria for yield improvement in rapeseed (Brassica napus L.). Nine genotypes of Brassica napus were sown at Oilseeds Research Institute, Faisalabad, during the years 2011- 2012, to evaluate the means and components of variability (genotypic and phenotypic), heritability (h2 B.S), correlation (genotypic and phenotypic) and path analysis for yield and various yield components. At phenotypic and genotypic level, seed yield/plant had significant positive correlation with plant height, seeds/plant and siliqua/plant. A positive and highly significant genetic relationship was found between plant height and seeds/plant, siliqua length and seeds/siliqua, days to maturity and 1000 seed weight, days to flowering and seeds/plant, days to maturity and seeds/plant. Path coefficient revealed that the seeds/siliqua, 1000 seed weight, days to flowering, days to maturity and seeds/plant had direct positive contribution towards seed yield per plant. For rapeseed breeding seed per plant was the variable with maximum potential of selection for seed yield improvement because this trait possessed high h2 B.S, highly significant positive correlation and maximum positive direct effects with yield


1974 ◽  
Vol 10 (1) ◽  
pp. 71-76
Author(s):  
A. H. El Nadi ◽  
M. H. Lazim

SUMMARYFour local sesame varieties were tested at three plant populations. Increase in plant density increased seed yield, which was positively related to number of pods per plant, seeds per pod, 1000-seed weight, heights of main stems and numbers of nodes per plant. Changes in soil moisture did not affect relative turgidity, whereas stomatal openness decreased as the irrigation interval became longer.


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