scholarly journals INTERACTION OF TEMPERATURE AND CO2 ENRICHMENT ON SOYBEAN: PHOTOSYNTHESIS AND SEED YIELD

1987 ◽  
Vol 67 (3) ◽  
pp. 629-636 ◽  
Author(s):  
N. SIONIT ◽  
B. R. STRAIN ◽  
E. P. FLINT

Seed yield and photosynthetic responses of soybean (Glycine max L. Merr. ’Ransom’) were studied in growth chambers at day/night temperatures of 18/12, 22/16, and 26/20 °C and atmospheric CO2 concentrations of 350, 675 and 1000 μL L−1. No seeds were produced at 18/12 °C within any of the CO2 concentrations. Numbers of pods and seeds increased with increasing temperature and CO2 levels. Carbon dioxide enrichment increased seed yield of soybean grown at moderately cool temperatures. This increase was associated with an increase in net photosynthetic rate. Leaf photosynthesis in response to CO2 enrichment increased more at 22/16 °C than at 26/20 °C. Increases in temperature and CO2 levels enhanced total growth of plants but hastened senescence of leaves. The extended photosynthetic capacity at cool temperatures did not result in allocating more dry matter to developing pods. CO2 enrichment at 26/20 °C resulted in greater seed yield increases than CO2 enrichment at lower temperatures.Key words: Soybean yield, low temperature, CO2 × temperature

2000 ◽  
Vol 51 (2) ◽  
pp. 279 ◽  
Author(s):  
J. A. Palta ◽  
C. Ludwig

Indeterminate narrow-leafed lupin (Lupinus angustifolius L. cv. Merrit) was exposed to enriched atmospheric CO2 during pod-filling to enhance the availability of carbon resources for pod-filling in order to determine whether or not seed-filling, yield, and harvest index are limited by the availability of photosynthetic assimilate. Plants were grown in a glasshouse and the flowers painted with an aqueous solution containing either N6-benzylaminopurine (BAP) or no BAP to generate 2 different numbers of pods per plant. From the time when pods began to fill seeds (≥5 mg/seed) until maturity, plants were exposed to either ambient (350–360 L/L) or enriched (700 L/L) CO2 by enclosing them in 2 transparent, box-shaped tunnels with similar temperatures, light, and water conditions. Whether or not BAP was applied to flowers, CO2 enrichment increased the final number of pods and the number of pods that filled large seeds (≥150 mg) by 20–22 pods/plant. Enriched CO2 reduced to zero the number of pods that had small seeds (≥30–80 mg) and reduced the number of pods with unfilled seeds from 16 to 1 pod/plant. This increased seed yield per plant by 44–66%, but did not affect the harvest index. Harvest index was unchanged because enriched CO2, while increasing pod-filling, also increased pod set and dry matter accumulation on the developing branches. This indicates that an increased availability of carbon resources during-pod filling changed the allocation of assimilates by filling small seeds and producing new branches. The 47–56% increase in dry matter per plant was reflected in the increase in seed yield, which occurred largely through an increased number of pods and seeds per plant. These data support the idea that seed-filling and hence seed yield in well-nodulated, indeterminate narrow-leafed lupin is limited by carbon resources at the stage when the plant is most source-limited, which is during podset and pod-filling.


Author(s):  
Abito Asres ◽  
Solomon Tiruneh

The experiment was conducted in three locations Jari, Chefa and Sirinka of Eastern Amhara to select the best performing varieties, in terms of biomass yield, chemical composition, haulm yield, seed yield and other agronomic characteristics of Glycine max (L.) Merrill grown under the rain- fed condition of lowland areas of Eastern Amhara in a randomized complete block design with tree replications. Twelve released soybean varieties were Afgat ,Belesa-95, Boshe , Cheri , Dhidhessa, Gishama , Gizo, Korme, Pawe-03, katta, Wegayen and Wollo were used as a treatments. The seeds were planted in 40 cm between rows and 10 cm between plants on a plot size of 3.2m*4m. Spacing between blocks and plots were 1 and 0.5m, respectively. The seed rate was 60 kg/ha and a fertilizer rate 100 kg/ha NPS was applied during seed planting. The combined analysis of variance over two years at location Jari for dry matter yield of varieties Afgat, Gizo, Pawe-03, Wogayen and Wollo were significantly higher as compared to other soybean varieties. The combined analysis across locations at Jari and Sirinka (2019-second year) showed that varieties Afgat, Gishama, Gizo, Pawe-03, Wogayen and Wollo had higher dry matter yield and varieties Gishama (3.97 t/ha), Gizo (3.60 t/ha), Pawe-03 (4.04 t/ha) and Wogayen (3.36 t/ha) had higher haulm yield as compared with other varieties. The combined analysis across locations at Jari and Sirinka (2019) showed that varieties Pawe-03(2951 kg/ha), Gizo (2862 kg/ha), Afgat (2859 kg/ha), Gishama (2654 kg/ha),Wollo (2461 kg/ha) and Wogayen (2404 kg/ha) had higher seed yield as compared with other varieties. The variety Wollo gave higher crud protein content in two locations (Jari and Sirinka) .Therefore, varieties Afgat, Pawe-03 and Wollo were recommends for the given areas of Jari , Chefa, Sirinka and could be produced in similar environments for the best of produced optimal amount of dry matter, haulm and seed yield and good protein supplement for production of ruminants.Thus, further researches will be needed to investigate on the utilization of livestock.


HortScience ◽  
2000 ◽  
Vol 35 (1) ◽  
pp. 49-52 ◽  
Author(s):  
K. Stanciel ◽  
D.G. Mortley ◽  
D.R. Hileman ◽  
P.A. Loretan ◽  
C.K. Bonsi ◽  
...  

The effects of elevated CO2 on growth, pod, and seed yield, and gas exchange of `Georgia Red' peanut (Arachis hypogaea L.) were evaluated under controlled environmental conditions. Plants were exposed to concentrations of 400 (ambient), 800, and 1200 μmol·mol–1 CO2 in reach-in growth chambers. Foliage fresh and dry weights increased with increased CO2 up to 800 μmol·mol–1, but declined at 1200 μmol·mol–1. The number and the fresh and dry weights of pods also increased with increasing CO2 concentration. However, the yield of immature pods was not significantly influenced by increased CO2. Total seed yield increased 33% from ambient to 800 μmol·mol–1 CO2, and 4% from 800 to 1200 μmol·mol–1 CO2. Harvest index increased with increasing CO2. Branch length increased while specific leaf area decreased linearly as CO2 increased from ambient to 1200 μmol·mol–1. Net photosynthetic rate was highest among plants grown at 800 μmol·mol–1. Stomatal conductance decreased with increased CO2. Carboxylation efficiency was similar among plants grown at 400 and 800 μmol·mol–1 and decreased at 1200 μmol·mol–1CO2. These results suggest that CO2 enrichment from 400 to 800 μmol·mol–1 had positive effects on peanut growth and yield, but above 800 μmol·mol–1 enrichment seed yield increased only marginally.


1992 ◽  
Vol 72 (4) ◽  
pp. 1067-1074 ◽  
Author(s):  
B. L. Vasilas ◽  
R. L. Nelson

A positive relationship generally exists between the duration of seed-fill period (SFP) and seed yield in soybean, but exceptions have been reported. The objective of this research was to determine if differences in N2 fixation or N accumulation could explain inconsistent relationships between duration of SFP and seed yield in soybean. For this study, five experimental soybean (Glycine max L. [Men.]) lines were selected on the bases of differences in SFP and seed yield in previous experiments. The experiment was designed to compare lines differing in both SFP and seed yield, differing in SFP but not seed yield, and differing in seed yield but not SFP. Total N2 fixation, using 15N-dilution techniques; total N accumulation, using a semi-micro-Kjeldahl procedure; and total dry matter accumulation, including all vegetative material abscised before maturity were measured on these lines grown in a Flanagan silt loam (fine, montmorillonitic, mesic Aquic Argiudolls) in 1984 and 1985 at Urbana, IL. Mean dinitrogen fixed ranged from 36 to 76 kg ha−1 in 1984 and from 65 to 113 kg ha−1 in 1985. The percentage of the total plant N derived from fixation ranged from 17 to 35% in 1984 and from 32 to 48% in 1985. Statistically significant differences in seed yield were not detected in this experiment because of the high coefficient of variation associated with the small plot size. High N2 fixation was not related to duration of SFP or previous seed yield classification. Total plant N did not differ among these genotypes. For these soybean lines differences in duration of SFP and previous seed yield classification were not related to total N2 fixation or N accumulation.Key words: Glycine max, harvest index, N partitioning, N2 fixation, seed-fill period


Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1020
Author(s):  
Olena Sobko ◽  
Sabine Zikeli ◽  
Wilhelm Claupein ◽  
Sabine Gruber

Soybean (Glycine max L. Merrill) is one of the most important crops worldwide. In several European countries such as Germany, soybean cultivation is not traditional and as such remains to be optimized. One option to increase soybean production is to adapt and improve the seeding system. To investigate the effects of different seeding systems on seed yield, seed protein, and oil content, plant characteristics were assessed using a two-factorial (two seeding systems and four cultivars) field trial over two years (2017–2018) at two locations in southeast Germany. The seeding systems were drill (row spacing 14 cm) and precision seeding (row spacing 28 cm), and the cultivars were Viola 000, Lissabon 000, ES Mentor 00, and Orion 00. Depending on the seeding system, a seed yield of 3.8 t ha−1 dry matter (DM), 40.9% protein content (DM), and 18.8% oil content (DM) was achieved by drilling, and 3.6 t ha−1 yield (DM), 40.1% protein content (DM), and 19.1% oil content (DM) with precision seeding (average across four cultivars, two locations, and two years). No significant effects of the seeding system on all seed and plant characteristics were observed. As drilling and precision seeding did not affect the seed yield, seed protein, oil contents, and plant characteristics of soybean in this study, farmers are able to choose the seeding system which fits best into their farms and is economically most viable.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 481d-481
Author(s):  
Z. Wang ◽  
M.C. Acock ◽  
B. Acock

To develop models for estimating growth, flowering time and gum yield of opium poppy, we compared variability among five cultivars (T, L, B1, B2, B3) from different latitudes in three Southeast Asian countries. Variability in the relationships between gum yield, capsule volume, and dry weight was also examined. Plants were grown in six growth chambers at a 11-, 12-, 13-, 14-, 15-, or 16-h photoperiod (PP) with a 12-h 25/20 °C thermoperiod. The main capsule was lanced for opium gum at 10, 13, and 16 d after flowering (DAF). Plants were harvested at 21 DAF and separated into leaves, stems, and capsules. Flowering time for B2 was affected least by PP and B1 the most. Flowering times for B3, L, and T were similar across the range of PPs. All cultivars showed a significant increase in flowering time from 14 to 13 h PP. Cultivars that flowered late (such as B1) had greater biomass than those that flowered earlier. However, cultivars that flowered earlier (such as L) had more dry matter partitioned into capsule than late-flowering ones. B2, B3, and L had the highest gum yields while B1 had the lowest. Positive correlations were found between gum dry weight and capsule volume (or dry weight) for T and L, but no correlations were observed between these variables for B1, B2, and B3. Our results indicated that plant dry weight varied as much as 77% and flowering time varied up to 40% even though the critical photoperiod was the same for all cultivars. The ratio of gum yield to capsule dry weight were significantly different between B1 and T.


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.


Author(s):  
Juliana Soares Zeymer ◽  
Felipe Guzzo ◽  
Marcos Eduardo Viana Araujo ◽  
Richard Stephen Gates ◽  
Paulo Cesar Corrêa ◽  
...  

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