scholarly journals Simulating Growth and Development Processes of Quinoa (Chenopodium quinoa Willd.): Adaptation and Evaluation of the CSM-CROPGRO Model

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 832 ◽  
Author(s):  
Achim Präger ◽  
Kenneth J. Boote ◽  
Sebastian Munz ◽  
Simone Graeff-Hönninger
Keyword(s):  
Life Cycle ◽  
Grain Yield ◽  
Leaf Area ◽  
Environmental Conditions ◽  
Aboveground Biomass ◽  
Chenopodium Quinoa ◽  
Sowing Dates ◽  
Nitrogen Concentrations ◽  
The Mean

In recent years, the intra-annual yield variability of traditional food crops grown in Europe increased due to extreme weather events driven by climate change. The Andean crop quinoa (Chenopodium quinoa Willd.), being well adapted to drought, salinity, and frost, is considered to be a promising new crop for Europe to cope with unfavorable environmental conditions. However, cultivation guidelines and cropping experiences are missing on a long-term scale. The adaptation of a mechanistic crop growth model will support the long-term evaluation of quinoa if grown under the diverse environmental conditions of Europe. The objective of this study was to adapt the process-based cropping system model (CSM) CROPGRO, which is included in the Decision Support System for Agrotechnology Transfer (DSSAT). Therefore, species and genetic coefficients were calibrated using literature values and growth analysis data, including crop life cycle, leaf area index (LAI), specific leaf area (SLA), dry matter partitioning and nitrogen concentrations in different plant tissues, aboveground biomass, and yield components, of a sowing date experiment (covering two cultivars and four sowing dates) conducted in southwestern Germany in 2016. Model evaluation was performed on the crop life cycle, final aboveground biomass, and final grain yield for different sowing dates using an independent data set collected at the same site in 2017. The resulting base temperatures regarding photosynthetic, vegetative, and reproductive processes ranged between 1 and 10 °C, while the corresponding optimum temperatures were between 15 and 36 °C. On average, the crop life cycle was predicted with a root mean square error (RMSE) of 4.7 and 3.0 days in 2016 and 2017, respectively. In 2016, the mean predicted aboveground biomass during the growth cycle showed a d-index of 0.98 (RMSE = 858 kg ha−1). Furthermore, the LAI, SLA, and leaf nitrogen concentrations were simulated with a high accuracy, showing a mean RMSE of 0.29 (d-index = 0.94), 25 cm2 g−1 (d-index = 0.88), and 0.51% (d-index = 0.95). Evaluations on the grain yield and aboveground biomass across four sowing dates in 2017 suggested a good robustness of the new quinoa model. The mean predicted aboveground biomass and grain yield at harvest maturity were 6479 kg ha−1 (RMSE = 898.9 kg ha−1) and 3843 kg ha−1 (RMSE = 450.3 kg ha−1), respectively. Thus, the CSM-CROPGRO model can be used to evaluate the long-term suitability, as well as different management strategies of quinoa under European conditions. However, further development on the simulation of small seed sizes and under water or nitrogen-limited environments are needed.

Effect of N management approaches and planting densities on nitrogen accumulation by transplanted rice

2005 ◽  
Vol 53 (4) ◽  
pp. 405-415 ◽  
Author(s):  
P. Janaki ◽  
T. M. Thiyagarajan
Keyword(s):  
Grain Yield ◽  
Uptake Rate ◽  
Aboveground Biomass ◽  
N Uptake ◽  
Planting Density ◽  
Transplanted Rice ◽  
The Mean ◽  
N Uptake Rate ◽  
Management Approaches ◽  
N Management

Field experiments were conducted during 1998 and 1999 in June-September with rice variety ASD18 at the wetland farm, Tamil Nadu Agricultural University, Coimbatore, India to find out theeffect of N management approaches and planting densities on N accumulation by transplanted rice in a split plot design.The main plot consisted of three plant populations (33, 66 and 100 hills m-2) and the sub-plot treatments of five N management approaches. The results revealed thatthe average N uptake in roots and aboveground biomass progressively increased with growth stages. The mean root and aboveground biomass Nuptake were 26.1 to 130.6 and 6.4 to 17.8 kg ha-1, respectively. The N uptake of grain and straw was higher in theSesbania rostratagreen manuring + 150 kg N treatment, but it was not effective in increasing the grain yield. The mean total N uptake was found to be significantly lower at 33 hills m-2(76.9 kg ha-1) and increased with an increase in planting density (100.9 and 117.2 kg ha-1at 66 and 100 hills m-2density). N application had a significant influence on N uptake and the time course of N uptake in all the SPAD-guided N approaches. A significant regression coefficient was observed between the crop N uptake and grain yield. The relationship between cumulative N uptake at the flowering stage and the grain yield was quadratic at all three densities. The N uptake rate (µN) was maximum during the active tillering to panicle initiation period and declined sharply after that. In general, µNincreased with an increase in planting density and the increase was significant up to the panicle initiation to flowering period.thereafter, the N uptake rate was similar at densities of 66 and 100 hills m-2.

scholarly journals Soybean-corn succession according to seeding date

2018 ◽  
Vol 53 (1) ◽  
pp. 22-29 ◽  
Author(s):  
Rodrigo Arroyo Garcia ◽  
Gessí Ceccon ◽  
Guilherme Afonso da Silva Sutier ◽  
Anna Luiza Farias dos Santos
Keyword(s):  
Grain Yield ◽  
The State ◽  
Southern Region ◽  
Crop Season ◽  
Mato Grosso ◽  
Growing Seasons ◽  
Seeding Date ◽  
Sowing Dates ◽  
Mato Grosso Do Sul

Abstract: The objective of this work was to evaluate the grain yield of soybean and corn cultivars cropped in succession, in different sowing dates. The experiment was carried out in the municipality of Dourados, in the state of Mato Grosso do Sul, Brazil, during three growing seasons, in the sowing dates: 9/15, 10/1, 10/15, and 11/1 for soybean; and 2/1, 2/15, 3/1, and 3/15 for corn. Although soybean yields are strongly affected by the crop season, sowing between late September and early October results in higher long-term yields. Planting corn in succession in mid-February provides the highest grain yield in the southern region of the state Mato Grosso do Sul; therefore, there is no need for an early soybean sowing in September, in order to ensure corn planting in January. Soybean-corn succession in which soybean is sown in early October and corn in mid-February results in higher total grain yields and reduces the climatic risk associated with these crops in the region.

scholarly journals Observations on the female flowers and fruiting of Tape Grass Enhalus acoroides from South Andaman Islands, India

2019 ◽  
Vol 11 (5) ◽  
pp. 13617-13621
Author(s):  
Vardhan Patankar ◽  
Tanmay Wagh ◽  
Zoya Tyabji
Keyword(s):  
Life Cycle ◽  
National Parks ◽  
Monitoring Program ◽  
Average Density ◽  
Andaman Islands ◽  
Seagrass Meadows ◽  
Enhalus Acoroides ◽  
South Andaman ◽  
The Mean

Documenting phenologic events is crucial in obtaining deeper insights into the life cycle of seagrasses.  We documented and compared the flowering and fruiting of the seagrass Enhalus acoroides from multispecies seagrass meadows at two sites, Henry Lawrence and Tarmugli islands located inside the marine national parks in South Andaman Islands.  At these two locations, the average density of shoots ranged between 30.9/m2 and 18.16/m2, fruits between 5/m2 and 2.33/m2, and flowers between 6.7/m2 and 3.83/m2, whereas the mean length of the peduncles ranged from 40.59cm at Henry Lawrence to 32.44cm at Tarmugli Island.  We observed significant differences between the densities of shoots and fruits and peduncle lengths in the two sites.  The density of flowers, however, did not vary significantly.  These observations of fruiting and flowering in E. acoroides establish an important reproductive stage in the life cycle of the species and open avenues for further seagrass research in the Andaman Islands.  We describe the findings and emphasize on the need to establish a long-term phenology monitoring program for E. acoroides in the Andaman Archipelago.

Effect of waterlogging on the grain yield response of wheat to sowing date in south-western Victoria

1987 ◽  
Vol 27 (5) ◽  
pp. 661 ◽  
Author(s):  
GK McDonald ◽  
WK Gardner
Keyword(s):  
Grain Yield ◽  
Stem Elongation ◽  
Sowing Date ◽  
Kernel Weight ◽  
Early Flowering ◽  
Yield Response ◽  
Nitrogen Concentrations ◽  
The Mean ◽  
Low Levels ◽  
Western Victoria

Two experiments were conducted in 1983 and 1984 in the Hamilton district in south-western Victoria, which examined, in 1983, the interaction of cultivars of different maturity with sowing date and, in 1984, the interaction of soil waterlogging with anthesis date. In the first experiment the grain yield of Isis and Condor were not significantly (P = 0.05) affected when sowing was delayed from 18 April to 13 May despite greater DM yield at anthesis of the April sown crops (44% with Isis and 8 1 % with Condor). Early sowing resulted in early flowering and in Condor 25% fewer grains per ear. When the effect of anthesis date on grain yield was examined in 1984 at a poorly drained site (Hamilton) and a nearby better drained site (Tabor), it was found that early flowering caused yield reductions of 46 and 25%, respectively. The reduced yield at Hamilton was caused by fewer grains per ear and a lower kernel weight. Grain yield was found to be associated with the severity of waterlogging during the 30 days before anthesis. For each 1% decline in the mean air-filled porosity of the surface soil at this time, yield was reduced by 0.29 t/ha (r2 = 0.83; P< 0.05). When the soils became waterlogged, nitrogen concentrations in the plant tops declined to low levels between stem elongation and anthesis. The need to avoid waterlogging damage during stem elongation in spring may necessitate anthesis being delayed beyond the time currently recommended for the district.

scholarly journals EVALUATION OF SIMPLE HAND-HELD MECHANICAL SYSTEMS FOR HARVESTING TEA (CAMELLIA SINENSIS)

2006 ◽  
Vol 42 (2) ◽  
pp. 165-187 ◽  
Author(s):  
P. J. BURGESS ◽  
M. K. V. CARR ◽  
F. C. S. MIZAMBWA ◽  
D. J. NIXON ◽  
J. LUGUSI ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Camellia Sinensis ◽  
Step Height ◽  
Area Index ◽  
Yield Increase ◽  
Coarse Material ◽  
Terminal Bud ◽  
The Mean

Over an eight-year period, harvesting methods based on simple mechanical aids (blade and shear) were evaluated against hand harvesting on mature morphologically contrasting tea clones in Southern Tanzania. The effects of shear step height (5–32 mm) and the harvest interval (1.8–4.2 phyllochrons) were also examined. Except in the year following pruning, large annual yields (5.7–7.9 t dry tea ha−1) were obtained by hand harvesting at intervals of two phyllochrons. For clones K35 (large shoots) and T207 (small shoots), the mean harvested shoot weights were equivalent to three unfurled leaves and a terminal bud. The proportions of broken shoots (40–48 %) and coarse material (4–6 %) were both relatively high. Using a blade resulted in similar yields to hand harvesting from K35 but larger yields from T207 (+13 %). The yield increase from clone T207 was associated with the harvest of more shoots and heavier shoots, smaller increases in canopy height, and a higher proportion (7–9 %) of coarse material compared to hand harvesting. On bushes, which had been harvested by hand for two years following pruning, using flat shears (no step) supported on the tea canopy resulted, over a three year period, in yields 8–14 % less than those obtained by hand harvesting and, for clone K35, a reduction in the leaf area index to below 5. The development of a larger leaf area index is made possible by adding a step to the shear. However, since annual yields were reduced by 40–50 kg ha−1 per mm increase in step height, the step should be the minimum necessary to maintain long-term bush productivity. As mean shoot weights following shear harvesting were about 13 % below those obtained by hand harvesting, there is scope, when using shears, to extend the harvest interval from 2 to 2.5 phyllochrons.

scholarly journals Effect of Dates and Methods of Sowing With and Without Hydropriming on Growth,Phenology and Yield of Sorghum under Semi arid conditions of Eritrea

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Berhane Teklesenbet Negassi ◽  
Woldeamlak Araia ◽  
Nitya Nand Angiras
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Growth Parameters ◽  
Seed Priming ◽  
Area Index ◽  
Agricultural College ◽  
Sowing Dates ◽  
Significant Difference ◽  
Level Of Significance ◽  
Direct Sowing

A study was carried out at the research farm of Hamelmalo Agricultural College during summer 2015 to study the effect of dates and methods of sowing with and without hydro-priming on growth, development and yield of sorghum. The experiment consisted of 2 factors- three dates of sowing viz.  D0 (Sowing before the onset of first summer rain, June 30), D1 (Sowing with the onset of first summer rains, July 7) and D2 (Sowing after the onset of summer rains, July 14) and three methods of sowing viz. SP (Direct sowing with hydro seed priming), TR (Transplanting) and DS (Direct sowing without hydro seed priming). The experiment was conducted in split plot design with 4 replications by keeping dates of sowing in the main plots and methods of sowing in the sub plots. The data on growth parameters, crop phenology, yield components and yield were recorded. The data was analysed using GENSTAT software and inferences were drawn by using LSD at 5% level of significance. Sowing methods significantly affected leaf area and leaf area index but sowing dates and their interaction with sowing methods did not show significant difference. Stand count, plant height, phenological parameters, thousand grain weight, grain and biomass yield were significantly affected by the sowing dates and methods but no significant difference in their interaction on all the parameters except in stand count and phenological parameters. Sowing before the onset of first summer rains (D0) resulted in significantly highest grain yield. Among the sowing methods, transplanting resulted in significantly higher grain yield seconded by direct sowing with hydro seed priming. Transplanting is less profitable and practicable as it is more laborious and difficult to apply in larger areas. 

scholarly journals Examining the latent period of Septoria tritici blotch in a field trial of winter wheat

2004 ◽  
Vol 57 ◽  
pp. 116-120 ◽  
Author(s):  
T. Armour ◽  
S.L.H. Viljanen-Rollinson ◽  
S.F. Chng ◽  
R.C. Butler ◽  
P.D. Jamieson ◽  
...  
Keyword(s):  
New Zealand ◽  
Latent Period ◽  
Environmental Conditions ◽  
Wheat Cultivar ◽  
Flag Leaf ◽  
Sowing Date ◽  
Septoria Tritici ◽  
Sowing Dates ◽  
Forecasting System ◽  
The Mean

The wheat cultivar Consort was artificially inoculated with Septoria tritici in an experiment to determine the latent period of the pathogen in New Zealand Three individual leaf layers (leaf three leaf two or the flag leaf) were inoculated over three sowing dates to provide a range of different environmental conditions following inoculation The mean latent period was 21 to 27 days (291372C days) The length of the latent period increased slightly with delays in sowing date The implications for producing a simple forecasting system to assist farmers with timing of fungicide applications are discussed

COMPARISON OF INBRED AND HYBRID CORN GRAIN YIELD MEASURED AT EQUAL LEAF AREA INDEX

1972 ◽  
Vol 52 (3) ◽  
pp. 315-319 ◽  
Author(s):  
D. J. MAJOR ◽  
R. B. HUNTER ◽  
L. W. KANNENBERG ◽  
T. B. DAYNARD ◽  
J. W. TANNER
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Density ◽  
Area Index ◽  
Wide Range ◽  
The Mean ◽  
Common Plant ◽  
Single Cross Hybrids ◽  
Corn Grain

Grain yield of 44 single crosses and their component inbreds of corn (Zea mays L.) was determined over a wide range of plant populations. Yield was determined for inbreds and single cross hybrids at unit intervals of leaf area index (LAI) of 1–4. Mean inbred yield was no greater than 60% of the mean hybrid yield, regardless of whether yields were compared at a common plant density or LAI. Optimum LAI (LAI where grain yield was at its maximum) was higher for the hybrids than for the inbreds.

The influence of pre- and post-anthesis periods on yields of winter barley varieties in southern Spain

1982 ◽  
Vol 99 (3) ◽  
pp. 521-523 ◽  
Author(s):  
J. M. Ramos ◽  
L. F. Garcia Del Moral ◽  
L. Recalde
Keyword(s):  
Grain Yield ◽  
Leaf Area ◽  
Environmental Conditions ◽  
Grain Filling ◽  
Winter Barley ◽  
Southern Spain ◽  
Yield Variation ◽  
Leaf Area Duration

SUMMARYSix varieties of winter barley were grown during the years 1979, 1980 and 1981 in Granada (southern Spain). Grain yield variation in the 3 years studied was a function of the pre-anthesis period (especially as a determinant of number of ears/m2). In comparison leaf area duration and grain: leaf ratio from anthesis to ripening had far less influence on grain yield variation. Though these findings contrast with the generally accepted view, they can be explained by environmental conditions prevailing in southern Spain during grain filling.

scholarly journals Influence of sowing date and irrigation on the growth and yield of pinto beans (Phaseolus vulgaris) in a sub-humid temperate environment

2000 ◽  
Vol 134 (1) ◽  
pp. 33-43 ◽  
Author(s):  
H. K. DAPAAH ◽  
B. A. McKENZIE ◽  
G. D. HILL
Keyword(s):  
Phaseolus Vulgaris ◽  
Leaf Area ◽  
Seed Yield ◽  
Sowing Date ◽  
Growth And Yield ◽  
Sowing Dates ◽  
Irrigated Crops ◽  
Pinto Beans ◽  
Pod Growth

The growth and yield of pinto beans (Phaseolus vulgaris L.) cv. Othello in response to a total of six sowing dates (from October to December) and irrigation was examined over two seasons in Canterbury, New Zealand. In 1994/95, two irrigation treatments (nil and full) were combined with two sowing dates (27 October and 24 November). In 1995/96, Othello was examined under two irrigation treatments (nil and full) and four sowing dates (1 November, 15 November, 29 November and 13 December). The total rainfall for the two seasons was 50% and 60% of the long-term average, respectively. The mean temperatures for the seasons were similar to the long-term average. Both irrigation and sowing date had a marked effect on growth and seed yield. Averaged over both seasons, seed yield for fully irrigated crops was 337 g/m2, c. 50% higher than the yield of unirrigated crops. The irrigated crops yielded more than the unirrigated crops because they attained greater canopy closure, intercepting 84–95% of incident radiation. They also had on the average 47% higher leaf area duration (LAD), 72% higher maximum leaf area index (LAI) and greater utilization coefficient. The mid- to late November-sown crops yielded more than the late October to early November and December-sown crops because the leaf area of the former increased most rapidly, achieved a higher maximum LAI and LAD and consequently intercepted more photosynthetically active radiation (PAR). They also had faster pod growth rates and 26% of stored assimilates contributed to pod growth compared with 13% in late October to early November and 5% in December-sown crops. The results showed that pinto beans can grow and yield well in Canterbury, and that a yield advantage could be obtained when sown in mid- to late November and with irrigation.

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