Accumulation, distribution and redistribution of dry matter and mineral nutrients in fruits of canola (oilseed rape), and the effects of nitrogen fertilizer and windrowing

1993 ◽  
Vol 44 (6) ◽  
pp. 1377 ◽  
Author(s):  
PJ Hocking ◽  
L Mason

Field studies were made at Ariah Park and Cowra to investigate the accumulation and distribution of dry matter and 12 mineral nutrients in fruits (pods) of canola (oilseed rape), and to assess the significance of redistribution of nutrients from the pod walls to the seeds. Flowers 4-6 from the base of the primary inflorescence were tagged at anthesis, and pods which developed from these were harvested at weekly intervals until maturity. Pods reached maturity 82 days after anthesis of the parent flowers. N fertilizer increased seed yields at both sites, but had negligible effects on the dry matter per pod, pod length, 1000 seed wt, seed number per pod, seed oil concentration, and concentrations of mineral nutrients in the pod walls and seeds. Similarly, there were no differences in these parameters due to locality, with the exceptions that seed oil per cent and concentrations of S and Mn in the pod walls and IVln in seeds were higher at Cowra than at Ariah Park. Pods had attained their maximum length and fresh and dry weights by the end of the first half of their development, but seeds had accumulated only 35% of their mature dry weight at this stage. Seeds gained dry matter after dehydration of the fruit began, but the pod walls did not. Seeds had 61% of the pod's dry matter, >70% of its P, N, Zn, Fe and Mg, 30-55% of its K, S, Mn, Cu and Ca, but <20% of its Na and C1. Dry matter was redistributed from the pod walls with 20% efficiency, and nutrients with from 17% (Cu) to 88% (P) efficiency; however, there was negligible redistribution of K, S, Ca, Na, C1, Fe and Mn from the pod walls. Redistributed dry matter and nutrients from the pod walls could have provided from 11% (dry matter) to 25% (N) of the amount in mature seeds. Concentrations of N, P, Mg, Mn, Zn and Cu in the pod walls declined as they developed, whereas those of Ca and Cl increased. Concentrations of nutrients in developing seeds remained fairly static. Windrowing plants when 40% of the seeds had changed to their mature colour did not affect seed oil per cent or concentrations of nutrients, but reduced seed size and seed yields by 10%. Data from the pod study also support the current recommendation to windrow when 40-60% of seeds reach their mature colour.

Weed Science ◽  
1972 ◽  
Vol 20 (6) ◽  
pp. 588-592 ◽  
Author(s):  
Ellery L. Knake

Field studies were conducted with giant foxtail(Setaria faberiiHerrm.) under shade intensities of 0, 30, 60, 70, 80, and 98%. Seed weight, dry weight of plant tops exclusive of seed, and total dry weight per plant decreased linearly with increasing shade intensities. These decreases were due primarily to decreases in number of leaves, number of stems per plant, and number of heads per plant. Height of main culm was less affected than other morphological characteristics. Shading affected the length of internodes but had little influence on number of internodes on the main culm. The amount of shade required to control giant foxtail completely, once it is established, appears to be above 95%. Expressed as 2-year means, plants grew to as much as 135 cm, had as many as 188 leaves, 41 stems, and 31 heads, and produced 73 g of dry matter per plant including 6 g of seed. Maximum number of seeds per head was 1405.


Weed Science ◽  
1984 ◽  
Vol 32 (5) ◽  
pp. 631-637 ◽  
Author(s):  
William W. Donald

Jointed goatgrass (Aegilops cylindrica Host. ♯3 AEGCY) has a quantitative requirement for vernalization in order to flower. In greenhouse and field studies, increasing periods of vernalization progressively reduced the number of days needed for plants to mature following transfer from the cold treatment to favorable growing conditions. Plants that had been vernalized at 3 ± 2 C for 8 weeks as imbibed seed took 120 days to flower following transfer to the greenhouse. Unvernalized controls flowered 197 to 222 days after planting in the greenhouse. Lengthening periods of vernalization from 2 to 8 weeks increased the number of seedheads per plant and dry weight per seedhead. Vernalized plants partitioned more dry matter into seedheads than unvernalized controls. The ratio of seedhead dry weight to vegetative shoot dry weight increased with duration of vernalization, even though vernalization did not alter total shoot dry-matter production. In field studies, plants that were established in the fall flowered sooner and more synchronously after resumption of growth in the spring than those that were planted in the spring and flowered in the summer. Plants seeded after May failed to flower in the same summer.


Weed Science ◽  
1987 ◽  
Vol 35 (5) ◽  
pp. 673-677 ◽  
Author(s):  
Neal W. Holt ◽  
Jim H. Hunter

Field studies were conducted in Saskatchewan to evaluate the effect of herbicides on annual canarygrass (Phalaris canariensisL.) and associated weeds. Bromoxynil (3,5-dibromo-4-hydroxybenzonitrile) at 0.35 kg ai/ha, tank mixes of bromoxynil at 0.28 kg/ha plus the ester of MCPA [(4-chloro-2-methylphenoxy)acetic acid] at 0.28 kg ae/ha, linuron [N′-(3,4-dichlorophenyl)-N-methoxy-N-methylurea] at 0.28 kg ai/ha plus MCPA amine at 0.56 kg/ha, or propanil [N-(3,4-dichlorophenyI)propanamide] at 1.0 kg ai/ha plus MCPA ester at 0.28 kg/ha resulted in annual canarygrass seed and dry matter yields equal to the unsprayed check and excellent wild mustard (Sinapis arvensisL. # SINAR) and cow cockle (Vaccaria pyramidataMedik. # VAAPY) control. Metribuzin [4-amino-6-(1,1-dimethylethyl)-3-(methylthio)-1,2,4-triazin-5(4H)-one] at 0.21 kg ai/ha plus MCPA amine at 0.56 kg/ha reduced the crop stand in 1 out of 5 yr and seed yield every year. Postemergence application of difenzoquat (1,2-dimethyl-3,5-dipheny1-1H-pyrazolium) at 0.84 kg ai/ha or flamprop [N-benzoyl-N-(3-chloro-4-fluorophenyl)-DL-alanine] at 0.53 kg ai/ha, or preplant-incorporated triallate [S-(2,3,3-trichloro-2-propenyl)bis(1-methylethyl)carbamothioate] at 1.40 kg ai/ha optimized wild oat (Avena fatuaL. # AVEFA) control with seed yields. Diclofop {(±)-2-[4-(2,4-dichlorophenoxy)phenoxy)propanoic acid} at 0.70 kg ai/ha severely damaged annual canarygrass in all years. Triallate applied at 1.40 kg/ha preplant or preemergence incorporated marginally reduced the crop stand and seed yield compared to the untreated controls in tolerance tests.


1980 ◽  
Vol 60 (4) ◽  
pp. 1315-1326 ◽  
Author(s):  
B. A. McBLAIN ◽  
D. J. HUME

The physiology of three soybean (Glycine max (L). Merrill) cultivars of Maturity Group 00 was studied to determine why the new cultivars Maple Arrow and McCall outyield the older cultivar Altona. Field trials were conducted at Elora, Ontario, in 1977 and 1978. The seed yields of the new cultivars averaged 12% higher than Altona over both years, although the three cultivars were within 3 days of the same maturity. The higher yields in the new cultivars appeared to be related to consistently longer bean-filling periods than in Altona, although a difference (P < 0.05) was detected only in 1978. Rates of bean filling in the new cultivars were no greater than in Altona, which also indicated that longer bean-filling periods contributed to higher yields in the new cultivars. Flowering dates for cultivars were not different. Similar maturity dates indicated that the new cultivars had shorter periods than Altona from maximum bean dry weight to final maturity. Other attributes differed little among cultivars in either year. Total dry matter accumulations were similar until bean filling began. Leaflet areas and dry weights, leaf area durations and harvest indices also did not differ. The results suggested that a long bean-filling period was a desirable trait in early-maturing soybeans.


1986 ◽  
Vol 13 (6) ◽  
pp. 767 ◽  
Author(s):  
RA Fischer ◽  
YM Stockman

This study of the effect of major Norin 10 dwarfing genes (Rht1, Rht2) on kernel number in spring wheat emphasised three near-isogenic pairs of spring wheat, differing in the presence or absence of both genes. Plants were grown under controlled environment conditions with equal light intensities at their tops and were restricted to main stems by repeated tiller trimming. The dwarf wheats had a higher proportion of shoot dry weight in the spike at anthesis, an effect which field studies suggest is closely associated with their production of more kernels per unit land area. Stems of dwarf genotypes were somewhat shorter as early as 50 days before anthesis (i.e. before floral initiation) but relative differences became especially great commencing at 35 days before anthesis. Apex and spike lengths were never very different. A greater proportion of dry matter was distributed to leaf lamina from 50 days before anthesis until the end of lamina growth in dwarf wheats, while partitioning to stems was lower from 50 days before anthesis onwards. Partitioning to spikes was only higher in the 15 days preceding anthesis. Stem water-soluble carbohydrate (WSC) contents at anthesis were greater in dwarf wheats but maximum spike WSC contents reached at about 15 days before anthesis were lower. Spike morphogenesis including floret production and grain setting did not differ generally, except for a tendency with dwarf wheats for a longer floral initiation to anthesis interval and for more kernels per unit of spike weight at anthesis. The major unique feature of dwarf genotypes, the higher proportion of dry matter partitioned to the spike, appeared to be due to reduced competition from growing stems in dwarf wheats rather than intrinsic differences in the growth potential of their spikes.


1996 ◽  
Vol 10 (2) ◽  
pp. 305-310 ◽  
Author(s):  
Daniel A. Ball ◽  
Donald J. Wysocki ◽  
Thomas G. Chastain

Field studies were conducted for two years at two locations near Pendleton and Moro, OR to evaluate the influence of single sub-surface nitrogen (N) fertilizer application timings and multiple N applications on downy brome and winter wheat growth and yield. N applications in fallow, at planting, during the crop season, and several split N application timings were compared to evaluate downy brome interference in winter wheat. N application rates varied between locations as a function of average annual precipitation and accepted agricultural practice. Pendleton and Moro were considered high and low precipitation sites, respectively. At Pendleton in a year of above average precipitation, N applied at planting, in-crop, or split applications of N with part of N applied at planting and part in-crop, increased downy brome dry matter production compared to N applied in fallow. Downy brome infestation eliminated otherwise positive wheat yield benefits of split N application compared to the conventional commercial practice of N application in fallow. In a year of moderate precipitation, N applications at planting, in-crop, or split N applications did not benefit wheat yield compared to N application in fallow, but downy brome dry matter was increased. In a dry season, N rates and timings did not increase downy brome dry weight or wheat grain yield. In the absence of downy brome, alternative N application techniques increased wheat yield only under high growing season precipitation.


1999 ◽  
Vol 133 (2) ◽  
pp. 131-139 ◽  
Author(s):  
C. N. JAY ◽  
S. ROSSALL ◽  
H. G. SMITH

Field trials were undertaken in Suffolk in commercial crops of autumn-sown oilseed rape cv. Capricorn during 1993/94, cv. Apex in 1994/95. Plots were artificially infected with beet western yellows virus (BWYV) using viruliferous Myzus persicae, giving 73 to 94% infection. Control plots had natural infection ranging from 0 to 17·8%. Destructive plant samples were taken from each of the infected and control plots throughout the seasons for growth analyses, and final yields were measured on 44 m2 areas combine harvested from each plot. The seed yields of infected plots were 26 and 11% lower than control plots in 1994 and 1995 respectively (P<0·001).Harvested seed yields were shown to be inversely proportional to the area of the plot that was inoculated with BWYV. Infection significantly lowered the oil content in 1995 from 47·9 to 46·8% (P<0·001), and increased glucosinolate levels from 16·12 to 18·37 μmol/g (P<0·01). BWYV caused a significant reduction in plant height and in numbers of primary branches in the 1993/94 trial and had an effect on the dry weight of the leaves, stalks, racemes and pods at some sample dates in both seasons. Virus-testing of infected plants showed that BWYV was present in the pod wall, the septum and seed coat; two of 78 embryo samples also contained virus. It was concluded that BWYV can cause significant yield losses in those years in which there is a high incidence of virus in the overwintered crops.


2009 ◽  
Vol 23 (3) ◽  
pp. 412-415 ◽  
Author(s):  
W. James Grichar ◽  
W. R. Ocumpaugh

Field studies were conducted from 2004 to 2006 to evaluate the tolerance of three annual medic species (bur, black, and barrel medic) to selected POST herbicides. 2,4-DB at 0.56 and 1.12 kg/ha caused the most stunting across all three species. Imazethapyr at 0.1 kg/ha stunted all three annual medics in 1 of 3 yr whereas flumetsulam at 0.04 kg/ha stunted black and barrel medics in 1 of 3 yr. Clethodim at 0.28 kg/ha did not cause any medic stunting. Imazethapyr, imazamox, and 2,4-DB at 0.56 kg/ha reduced henbit dry matter composition compared to the untreated check whereas clethodim, flumetsulam, and 2,4-DB at 1.12 kg/ha did not. In 2004, 2,4-DB at 1.12 kg/ha reduced dry weight yield of bur and barrel medic but not black medic when compared with the untreated check. Black medic treated with imazethapyr at 0.05 and 0.1 kg/ha and clethodim at 0.28 kg/ha produced higher dry weight yield than the untreated check. In 2006, both rates of 2,4-DB and flumetsulam at 0.04 kg/ha reduced dry weight yield of bur medic compared to the untreated check. Barrel medic dry weight yields were reduced by both rates of 2,4-DB and flumetsulam compared to untreated check. No herbicides reduced dry weight yields of black medic.


2002 ◽  
Vol 53 (4) ◽  
pp. 459 ◽  
Author(s):  
C. Santonoceto ◽  
P. J. Hocking ◽  
J. Braschkat ◽  
P. J. Randall

Field studies of the oilseed crops canola, Indian mustard, and linseed/Linola were conducted over 2 seasons at 2 contrasting sites in the cropping regions of central and southern NSW to determine the uptake of mineral nutrients and quantities removed in seed. The sites were in the Junee region where production of these oilseeds is common, and at Condobolin, which is regarded as marginal for production of the crops. The 2 rates of nitrogen (N) fertiliser applied were either none or rates that growers in the Condobolin and Junee regions would apply to achieve high seed yields after a cereal crop in the rotation when soil mineral N is low. Concentrations of total N, the major cations (K, Ca, Mg, Na) and major anions (P, S, Cl), and the micronutrients Fe, Mn, Zn, and Cu were determined in shoots harvested at flowering and maturity. Nitrate and sulfate were also measured, and estimates were made of excess cation concentrations in the plant material. The ranges of concentrations of excess cations in shoots of the oilseeds at flowering were 83–206 cmolc/kg and 43–121 cmolc/kg for straw at maturity. Linola had lower concentrations of excess cations in vegetative material (83–108 and 43–82 cmolc/kg at flowering and maturity, respectively) than canola or Indian mustard. Concentrations of excess cations in seed of the crops were lower than for vegetative material, and ranged from 30 to 49 cmolc/kg. Nitrogen fertiliser had relatively little effect on concentrations of mineral nutrients or excess cations in either shoots at flowering and maturity, or in seed. However, N fertiliser increased the growth and seed yields of the crops, and thus the amounts of mineral nutrients and excess cations in shoots and seed. The results are discussed in the context of the depletion of soil nutrients due to their removal in harvested seed of the N-fertilised crops. The contribution of excess cation removal in seed to soil acidification is also discussed. It is estimated that the quantity of lime required to neutralise the acidity resulting from removal of 1 t seed is 22.4 kg for canola, 17.0 for Indian mustard, and 20.8 for linseed/Linola. Estimates of the relative contributions of seed removal and N fertiliser to soil acidification are presented.


2020 ◽  
Vol 71 (12) ◽  
pp. 1010
Author(s):  
Chang Tian ◽  
Xuan Zhou ◽  
Qiang Liu ◽  
Jianwei Peng ◽  
Zhenhua Zhang ◽  
...  

Oilseed rape (Brassica napus L.) is a crucial source of edible oil and livestock feeding, and is a promising biofuel crop. The increasing demand for oilseed rape requires strategies to increase yield while retaining quality. Field experiments were performed in southern China to evaluate the impacts of fertiliser level and planting density on dry matter accumulation, seed oil and protein content (%) and yield (per ha), oil quality, and the profitability of oilseed rape. Fertiliser treatments contained nitrogen (N), phosphorus (P), potassium (K), sulfur (S) and boron (B) at four increasing rates, compared with nil fertiliser, and there were six planting densities (range 7.5–45 × 104 plants ha–1). Dry matter accumulation significantly (P &lt; 0.05) increased in response to increasing plant population and fertiliser level, whereas harvest index decreased, suggesting that increasing the production of oilseed rape is limited to improvement of population quality. Seed oil and protein contents were significantly affected by fertiliser level rather than planting density. Increasing the fertiliser rate increased seed protein content, simultaneously slightly decreasing oil content. Glucosinolate content of rapeseed slightly decreased with increasing fertiliser but erucic and oleic acid contents were not affected, indicating that increasing the fertiliser rate might not reduce oilseed rape quality. Manipulation of fertiliser level was more effective than altering planting density for increasing seed oil and protein yields. Highest seed oil and protein yields resulted from the highest fertiliser application of 240 kg N, 52.4 kg P, 174.3 kg K, 15 kg S and 1.2 kg B ha–1, under a planting density of 22.5 × 104 plants ha–1. Maximum economic gain occurred with the two highest fertiliser levels, whereas planting density has no significant effect on profitability. A balanced application of NPKSB fertilisers should be employed with direct-sowing cultivation of oilseed rape, aimed at building a suitable population structure that balances plant population density and individual growth.


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