Seed yield of canola (Brassica napus L.) is determined primarily by biomass in a high-yielding environment

2016 ◽  
Vol 67 (4) ◽  
pp. 369 ◽  
Author(s):  
Heping Zhang ◽  
Sam Flottmann

The better performance of hybrid canola compared with open-pollinated triazine-tolerant canola can be associated with greater biomass and harvest index. We compared several hybrid and open-pollinated canola cultivars in field conditions to (i) quantitatively analyse yield formation and identify the key drivers of yield formation process; (ii) investigate biomass accumulation and partitioning and evaluate the relative importance of biomass, harvest index and yield components. Six elite varieties, two from each of the three types (triazine-tolerant (TT), hybrid TT, and hybrid imidazolinone-tolerant (IT) or conventional (CV) (hybrid IT/CV)) of canola, were grown under the optimum crop management in the 3 years from 2009 to 2011 in the high-rainfall zone of south-western Australia. Leaf area, specific leaf area, light interception, biomass, seed yield and yield components were measured at key growth stages to determine biomass accumulation, crop growth rate (CGR), radiation-use efficiency and to investigate the relationship between yield, biomass, CGR, specific leaf area, yield components and harvest index. Hybrid IT/CV canola grew more vigorously with thicker leaves and greater leaf area, allocated more biomass into leaves, intercepted more radiation, produced higher biomass in the vegetative stage and maintained its biomass superiority throughout the whole crop cycle. It had radiation-use efficiency of 1.74 g MJ m–2 photosynthetic active radiation, 28% higher (P < 0.001) than TT canola (1.41 g MJ m–2 photosynthetic active radiation) and 16% higher (P < 0.001) than hybrid TT canola (1.52 g MJ m–2 photosynthetic active radiation). The average CGR for hybrid IT/CV canola (12.1 g m–2 day–1) was 32% higher than that of TT canola (9.2 g m–2 day–1) from budding to the beginning of pod filling. Hybrid IT/CV canola produced 38% higher seed yield than TT canola in favourable growing conditions (2009, 2011). However, there was no yield difference between the hybrid IT/CV, hybrid TT, and TT canola in the drought year (2010). The number of pods m–2 and seeds m–2 was highly associated with biomass at vegetative, budding, flowering, podding and maturity and CGR from budding to podding. High yield in hybrid canola was attributed mainly to higher biomass from each phenological phase from the vegetative stage to maturity and not to improved harvest index.

2011 ◽  
Vol 62 (3) ◽  
pp. 208 ◽  
Author(s):  
H. L. Li ◽  
Y. Luo ◽  
J. H. Ma

Radiation-use efficiency (RUE, g/MJ) and the harvest index (HI, unitless) are two helpful characteristics in interpreting crop response to environmental and climatic changes. They are also increasingly important for accurate crop yield simulation, but they are affected by various environmental factors. In this study, the RUE and HI of winter wheat and their relationships to canopy spectral reflectance were investigated based on the massive field measurements of five nitrogen (N) treatments. Crop production can be separated into light interception and RUE. The results indicated that during a long period of slow growth from emergence to regreening, the effect of N on crop production mainly showed up in an increased light interception by the canopy. During the period of rapid growth from regreening to maturity, it was present in both light interception and RUE. The temporal variations of RUEAPAR (aboveground biomass produced per unit of photosynthetically active radiation absorbed by the canopy) during the period from regreening to maturity had different patterns corresponding to the N deficiency, N adequacy and N-excess conditions. Moreover, significant relationships were found between the RUEAPAR and the accumulative normalised difference vegetation index (NDVI) in the integrated season (R2 = 0.68), between the HI and the accumulative NDVI after anthesis (R2 = 0.89), and between the RUEgrain (ratio of grain yield to the total amount of photosynthetically active radiation absorbed by the canopy) and the accumulative NDVI of the whole season (R2 = 0.89) and that after anthesis (R2 = 0.94). It suggested that canopy spectral reflectance has the potential to reveal the spatial information of the RUEAPAR, HI and RUEgrain. It is hoped that this information will be useful in improving the accuracy of crop yield simulation in large areas.


1999 ◽  
Vol 79 (2) ◽  
pp. 175-180 ◽  
Author(s):  
Altaf Ahmad ◽  
Y. P. Abrol ◽  
M. Z. Abdin

According to prevalent agronomic practices for cultivation of Brassica genotypes, N is applied in split doses, while S is applied as a basal dose. This may create imbalance in the supply of these nutrients during the growth and development of the crop because metabolism of N and that of S are closely linked and play a central role in protein synthesis. The requirement of one depends on the supply of the other, and the imbalance in their supply causes a reduction in the yield because of reduced uptake and assimilation of the two nutrients. In the present investigation, therefore, S was applied in split doses, along with N, to study its effect on growth and yield attributes of Brassica juncea (L.) Czern. and Coss. (V1) and Brassica campestris L. (V2). In the experiment, conducted in the field, 40 kg S ha−1 as CaSO4 (gypsum) was applied either in a single basal application (S1) or in two (S2) or three (S3) split applications; and 100 kg N ha−1 as urea was applied either in two (N2) or three (N3) splits. Biomass accumulation, leaf-area index (LAI), leaf-area duration (LAD), crop growth rate (CGR) and photosynthesis in the leaves were determined at various phenological stages. Split application of S and N (S2N2 or S3N3) resulted in significant improvement in growth and yield of both the genotypes compared with the application of S in a single basal application and N in two splits (S1N2). Genetic variability was observed between the two genotypes in response to split application of S and N. V1 responded better when S and N was applied in two split doses (S2N2) than when it was applied as S1N2 or S3N3 This S2N2 treatment resulted in 40.0, 39.7, 35.5, 48.2 and 18.1% enhancement in biomass accumulation, LAI, LAD, CGR and photosynthetic rate, respectively in comparison with S1N2. Seed yield, biological yield and harvest index were improved by 38.3, 26.3 and 9.5%, respectively, by S2N2 over the results obtained with S1N2. In the case of V2, three split applications of S and N (S3N3) resulted in maximum growth and yield. Increases in biomass accumulation, LAI, LAD, CGR and photosynthetic rate due to application of S3N3 were 48.4, 81.3, 77.9, 101.1 and 28.6% respectively, over the results of S1N2. Seed yield, biological yield and harvest index improved by 41.3, 26.9 and 11.6% respectively, with this treatment.On the basis of results obtained in this study, it can be concluded that S must be applied in split doses for optimum growth and yield of Brassica genotypes. The variability in response of these genotypes to split application of S and N was due to differences in flowering time, as V1 flowered earlier (just after the application of the second dose of S and N) than V1 (just after the application of the third dose of S and N). Key words: Brassica genotypes, nitrogen, sulphur, split application, growth, yield


2021 ◽  
Vol 22 (3) ◽  
pp. 285-294
Author(s):  
KOUSHIK BAG ◽  
K.K. BANDYOPADHYAY ◽  
V.K. SEHGAL ◽  
A. SARANGI ◽  
P. KRISHNAN

In this study, we have evaluated the effect of different tillage (conventional tillage (CT) and no tillage (NT)), residue (with crop residue mulch (R+) and without residue (R0)) and nitrogen (60, 120 and 180 kgN ha-1) interaction for radiation interception, radiation use efficiency (RUE), evapotranspiration (ET) partitioning and yield of wheat in a split-split plot design for 2017-18 and 2018-19. Results showed that Leaf Area Index (LAI), Leaf area duration (LAD), Total intercepted photosynthetically active radiation (TIPAR), Grain and Biomass yields were higher in R+ during both the years of study. With increasing Ndoses LAI, LAD, TIPAR, RUE, grain and biomass yields increased and extinction coefficient decreased significantly in both the years. Fraction intercepted photosynthetically active radiation (fIPAR) followed a similar trend with LAI. Seasonal ET was partitioned into soil evaporation (Ep) and crop transpiration (Tp) to take into account the productive transpiration effects on crop growth and yield. It was found that NT and residue could reduce Ep (6% and 5.6%) and increased Tp (2.6% and 2.4%) over CT and no mulch treatments, respectively. With higher N-dose, Ep decreased while Tp increased significantly. Thus besides higher nitrogen doses, NT and crop residue mulching could be a better strategy to harness higher radiation interception vis-a-vis higher crop productivity.


2014 ◽  
Vol 7 (4) ◽  
pp. 764
Author(s):  
Thieres George Freire da Silva ◽  
Magna Soelma Beserra de Moura ◽  
Sérgio Zolnier ◽  
Luciana Sandra Bastos de Souza ◽  
José Francisco Alves do Carmo

Os índices morfofisiológicos e parâmetros de eficiência do uso de radiação foram determinados para a cana-de-açúcar irrigada, RB92579. O experimento foi conduzido no município de Juazeiro-BA, Semiárido brasileiro. Foram obtidas medições de biomassa seca acumulada pelas folhas, colmos e total da parte aérea, e do índice de área foliar. Adicionalmente, dados de radiação solar global e de radiação fotossinteticamente ativa foram medidos acima e abaixo do dossel da cultura. Por meio desses dados foram calculados os índices morfofisiológicos, a fração da radiação fotossinteticamente ativa (fRFA), o coeficiente de extinção (ke), o uso eficiente de radiação (UER) e a eficiência fotossintética (EFT). A taxa de crescimento absoluto aumentou substancialmente até atingir o valor máximo de 41,8 g m-2 d-1 aos 200 dias após o corte (DAC). O valor máximo de fRFA foi em torno de 99%, permanecendo constante dos 213 DAC até o final do ciclo. A magnitude do parâmetro ke foi 0,72. Baseado nas medições do BSTPA verificou-se que os valores aproximados de EFT e UER foram 2,67 g MJ-1 e 1,29 g MJ-1, respectivamente. Os resultados mostraram que a cana-de-açúcar irrigada no Semiárido brasileiro possui padrões de crescimento superiores aos de outros ambientes de cultivo registrados na literatura.  A B S T R A C T The morphphysiological indices and parameters of radiation use efficiency were determined for irrigated sugarcane, RB92579 cultivar. The experiment was carried out in the district of Juazeiro, State of the Bahia, located in the Brazilian semi-arid. Measurements of dry biomass accumulated by leaves, stalk and total shoot, and leaf area index (LAI) were carried out. Additionally, global solar radiation and photosynthetic active radiation were measured above and below the crop canopy. Using these data, morphphysiological indices, the photosynthetic active radiation fraction (fPAR), the extinction coefficient (ke), the radiation efficient use (REU) and the photosynthetic efficiency (PTE) were calculated. The absolute growth rate tended to increase substantially until reaching the maximum value of 41.8 g m-2 d-1, which was observed 200 days after cutting (DAC). The maximum value of the fPAR was around 99%, remaining constant from 213 DAC until the end of the crop cycle. The magnitude of the ke parameter was 0.72. Based on measurements of DBTS, it was verified that the approximate values of the PTE and REU were 2.67 g MJ-1 and 1.29 g MJ-1, respectively. Results showed that the irrigated sugarcane has excellent growth patterns when cultivated under semi-arid conditions when compared to others environments cited in literature. Keywords: growth, extinction coefficient, radiation use efficiency.  


Author(s):  
Shrabani Basu ◽  
Pramiti K. Chakraborty ◽  
Rajib Nath

Aim: The present study was conducted for identifying sowing windows and cultivars of green gram in spring – summer and rainy seasons depending on light interception pattern and photo synthetically active radiation use efficiency (PARUE) in the lower Gangetic Plains of Eastern India. Methodology: Five green gram varieties (V1, V2, V3, V4 and V5) were sown on four dates (D1, D2, D3 and D4) in the spring –summer season starting from 15th February and on three dates (D1, D2 and D3) in the rainy season, starting from 20th August at interval of 10 days. Cumulative intercepted PAR (CIPAR), PARUE for above ground biomass and green gram seed and the seed yield were measured. The experiments were conducted under strip –plot design. Results: Results showed that CIPAR increased gradually in both the seasons under different dates of sowing. The mean PARUE for above ground biomass were 3.97, 4.58, 3.18 and 2.64 gMJ-1 for D1, D2, D3 and D4 sowings during spring – summer season. In rainy season the same was declined from 8.67 to 3.73 g MJ-1 with the delay in sowing. Maximum seed yield was obtained under D2 and V3 in the spring –summer and under D1 and V5 in the rainy season. The mean PARUE for seed yield were 0.65 and 0.64 g MJ-1 and 0.40 and 0.42 g MJ-1 in the spring summer seasons of 2011 and 2012 respectively. In the rainy season the maximum PARUE were 0.91 and 0.55 g MJ-1 under D1 for two experimental years. Conclusion: Depending on PARUE Pant Mung – 5 and Mehashould be sown during 3rd week of February and August in this zone.


Author(s):  
Muhammad Zeeshan Mehmood ◽  
Ghulam Qadir ◽  
Obaid Afzal ◽  
Atta Mohi Ud Din ◽  
Muhammad Ali Raza ◽  
...  

AbstractSeveral biotic and abiotic stresses significantly decrease the biomass accumulation and seed yield of sesame crops under rainfed areas. However, plant growth regulators (such as Paclobutrazol) can improve the total dry matter and seed production of the sesame crop. The effects of the paclobutrazol application on dry matter accumulation and seed yield had not been studied before in sesame under rainfed conditions. Therefore, a two-year field study during 2018 and 2019 was conducted with key objectives to assess the impacts of paclobutrazol on leaf greenness, leaf area, total dry matter production and partitioning, seed shattering, and seed yield of sesame. Two sesame cultivars (TS-5 and TS-3) were treated with four paclobutrazol concentrations (P0 = Control, P1 = 100 mg L−1, P2 = 200 mg L−1, P3 = 300 mg L−1). The experiment was executed in RCBD-factorial design with three replications. Compared with P0, treatment P3 improved the leaf greenness of sesame by 17%, 38%, and 60% at 45, 85, and 125 days after sowing, respectively. However, P3 treatment decreased the leaf area of sesame by 14% and 20% at 45 and 85 days after sowing than P0, respectively. Compared with P0, treatment P3 increased the leaf area by 46% at 125 days after sowing. On average, treatment P3 also improved the total biomass production by 21% and partitioning in roots, stems, leaves, capsules, and seeds by 23%, 19%, 23%, 22%, and 40%, respectively, in the whole growing seasons as compared to P0. Moreover, under P3 treatment, sesame attained the highest seed yield and lowest seed shattering by 27% and 30%, respectively, compared to P0. This study indicated that by applying the paclobutrazol concentration at the rate of 300 mg L−1 in sesame, the leaf greenness, leaf areas, biomass accumulation, partitioning, seed yield, and shatter resistance could be improved. Thus, the optimum paclobutrazol level could enhance the dry matter accumulation and seed production capacity of sesame by decreasing shattering losses under rainfed conditions.


Helia ◽  
2001 ◽  
Vol 24 (35) ◽  
pp. 101-110 ◽  
Author(s):  
S. Sridhara ◽  
T.G. Prasad

SUMMARYA field experiment was conducted at Gandhi Krishi Vignana Kendra, University of Agricultural Sciences, Bangalore to study the effect of irrigation regimens on the biomass accumulation, canopy development, light interception and radiation use efficiency of sunflower. The treatments includes irrigating the plants at 0.4, 0.6, 0.8 and 1.0 cumulative pan evaporation. The results indicated that the aboveground biomass, canopy development, radiation interception and radiation use efficiency were influenced favorably by the irrigation regimens. Irrespective of the irrigation regimen, the radiation use efficiency of sunflower increased from 15 DAS to 75 DAS and then tended to decline. The decrease in RUE after anthesis is coupled with decrease in leaf nitrogen content. In general the RUE of sunflower ranged from 0.49 g MJ-1 to 1.84 g MJ-1 at different growth stages. The light transmission within the canopy increased exponentially with plant height and the canopy extension coefficient is found to be 0.8.


Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 466
Author(s):  
Qibo Tao ◽  
Mengjie Bai ◽  
Cunzhi Jia ◽  
Yunhua Han ◽  
Yanrong Wang

Irrigation and nitrogen (N) are two crucial factors affecting perennial grass seed production. To investigate the effects of irrigation and N rate on seed yield (SY), yield components, and water use efficiency (WUE) of Cleistogenes songorica (Roshevitz) Ohwi, an ecologically significant perennial grass, a four-year (2016–2019) field trial was conducted in an arid region of northwestern China. Two irrigation regimes (I1 treatment: irrigation at tillering stage; I2 treatment: irrigation at tillering, spikelet initiation, and early flowering stages) and four N rates (0, 60, 120, 180 kg ha−1) were arranged. Increasing amounts of both irrigation and N improved SY, evapotranspiration, WUE, and related yield components like fertile tillers m−2 (FTSM) and seeds spikelet−1. Meanwhile, no significant difference was observed between 120 and 180 kg N ha−1 treatments for most variables. The highest SY and WUE was obtained with treatment combination of I2 plus 120 kg N ha−1 with four-year average values of 507.3 kg ha−1 and 1.8 kg ha−1 mm−1, respectively. Path coefficient and contribution analysis indicated that FTSM was the most important yield component for SY, with direct path coefficient and contribution coefficient of 0.626 and 0.592. Overall, we recommend I2 treatment (three irrigations) together with 120 kg N ha−1 to both increase SY and WUE, especially in arid regions. Future agronomic managements and breeding programs for seed should mainly focus on FTSM. This study will enable grass seed producers, plant breeders, and government program directors to more effectively target higher SY of C. songorica.


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