Development of a hemp (Cannabis sativa L.) simulation model 4. Model description and validation

2000 ◽  
Vol 40 (3) ◽  
pp. 425 ◽  
Author(s):  
S. N. Lisson ◽  
N. J. Mendham ◽  
P. S. Carberry
Keyword(s):  
Simulation Model ◽  
Leaf Area ◽  
Biomass Production ◽  
Growth And Development ◽  
Field Trials ◽  
Model Description ◽  
Agricultural System ◽  
Independent Dataset ◽  
Systems Model ◽  
Research Activities

In studies assessing the prospects for a hemp industry, as well as in longer term research activities, the use of a hemp simulation model to complement the more traditional agronomic field trials would offer a number of potential advantages. In addition to being cost and labour intensive, field trials with hemp have political, social and security implications. With these implications in mind, a simulation model that captures the growth and development processes of hemp in response to management, genotypic, soil and climate factors, has the potential to increase research efficiency. The model could be used to assess the need, extent and nature of field trials, to help interpret field trial results, and to investigate temporal and spatial variability in selected crop responses. This paper describes a hemp crop growth and development model (APSIM-Hemp) and its validation against an independent dataset. The model was developed as a crop module within the framework of the larger systems model, Agricultural Production Systems sIMulator (APSIM), to extend the capability to encompass the agricultural system in which hemp is grown. APSIM-Hemp incorporates relationships developed in the previous papers in this series relating to pre- and post-emergent phenology and leaf area production. Other parameters relating to biomass partitioning, biomass production, water uptake and nitrogen uptake were derived from separate field studies and selected references. APSIM-Hemp adequately predicted phenology, leaf area and biomass production for the cultivar Kompolti at Forthside in north-western Tasmania, for a dataset comprised of results from trials conducted over 3 seasons and including treatments of sowing date, irrigation regime and plant density. Although performing well against this independent dataset, the performance of the model needs to be further validated over a range of other soil, climate and management conditions in order to assess its broader predictive capability. Notwithstanding these limitations, the sound basis of a model for simulating the growth and development of hemp has been developed.

scholarly journals COMPARISON OF CAMELINA SEED YIELD AND BIOMASS PRODUCTION IN CONTRASTING ENVIRONMENTS

2021 ◽  
Author(s):  
Ana Marjanovic Jeromela ◽  
◽  
Federica Zanetti ◽  
Johann Vollmann ◽  
Barbara Alberghini ◽  
...  
Keyword(s):  
Biomass Production ◽  
Seed Yield ◽  
Research Work ◽  
Field Trials ◽  
Research Activities ◽  
Camelina Seed ◽  
Breeding Groups ◽  
Common Field

The most of the research work on camelina has been carried out in northern America and continental Europe. Two breeding groups (IFVCNS and BOKU) and one group focusing on the agronomy (DISTAL) just recently started research activities focusing on the development of new genotypes more adapted for southern regions of Europe. Common field trials, with 2 camelina lines selected by IFVCNS and 6 lines selected by BOKU were established at Bologna, Italy and at Rimski Šančevi, Serbia. Newly developed camelina lines were found to be highly adapted to Bologna environment, being able to achieve sustained seed yield in spite of delayed sowing and higher temperatures during pod filling period.

scholarly journals Licorice (Glycyrrhiza glabra)—Growth and Phytochemical Compound Secretion in Degraded Lands under Drought Stress

2021 ◽  
Vol 13 (5) ◽  
pp. 2923
Author(s):  
Botir Khaitov ◽  
Munisa Urmonova ◽  
Aziz Karimov ◽  
Botirjon Sulaymonov ◽  
Kholik Allanov ◽  
...  
Keyword(s):  
Drought Stress ◽  
Water Deficit ◽  
Background Field ◽  
Field Trials ◽  
Glycyrrhiza Glabra ◽  
Agricultural System ◽  
Positive Effects ◽  
Relative Water ◽  
Moderate Drought ◽  
Four Levels

Water deficiency restricts plant productivity, while excessive soil moisture may also have an adverse impact. In light of this background, field trials were conducted in secondary saline soil (EC 6.5 dS m−1) at the experimental station of Tashkent State Agrarian University (TSAU), Uzbekistan to determine drought tolerance of licorice (Glycyrrhiza glabra) by exposure to four levels of water deficit, namely control (70–80%), moderate (50–60%), strong (30–40%) and intense (10–20%) relative water content (WC) in the soil. The moderate drought stress exhibited positive effects on the morphological and physiological parameters of licorice, and was considered to be the most suitable water regime for licorice cultivation. Plant growth under the 50–60% WC treatment was slightly higher as compared to 70–80% WC treatment, exhibiting weak water deficit promotes licorice growth, root yield and secondary metabolite production. In particular, secondary metabolites i.e., ash, glycyrrhizic acid, extractive compounds and flavonoids, tended to increase under moderate water deficit, however further drought intensification brought a sharp decline of these values. These results contribute to the development of licorice cultivation technologies in arid regions and the most important consideration is the restoration of ecological and economical functions of the dryland agricultural system.

Yield response of restricted-tillering wheat to transient waterlogging on duplex soils

2003 ◽  
Vol 54 (10) ◽  
pp. 957 ◽  
Author(s):  
A. G. Condon ◽  
F. Giunta
Keyword(s):  
Grain Size ◽  
Biomass Production ◽  
Wheat Yield ◽  
Relative Yield ◽  
Field Trials ◽  
Growth And Yield ◽  
Yield Response ◽  
South West ◽  
Relative Extent ◽  
Before And After

Transient waterlogging during winter and spring reduces wheat yield in many parts of southern Australia. Yield reductions from waterlogging are associated with reduced production and survival of tillers, fewer and smaller fertile tillers, and smaller grain size. Under favourable conditions, wheats that have the tiller-inhibition ('tin') gene produce a lower total number of tillers but a higher proportion of large, productive tillers and larger grains than wheats without this gene. These characteristics of restricted-tillering wheat may contribute to improved yield under transient waterlogging. We compared the growth and yield of the commercial variety Bodallin and 2 Bodallin backcross derivatives containing the 'tin' gene in 8 field trials grown on shallow, duplex soils in 1995 and 1996 at 3 locations in the south-west of Western Australia. Trials were sown at standard (1995) and standard and high (1996) seeding rates. Trial-mean yield ranged from 0.5 to 4.7 t/ha, depending on the occurrence and severity of waterlogging before anthesis and of soil water deficit before and after anthesis. Grain yield of the restricted-tillering (RT) lines averaged only c. 80% of Bodallin. At all sites and seeding rates the RT lines had fewer spikes per m2 (45% fewer, on average) but averaged 44% more grains per spike. In 1996 only, grain weight of the RT lines was 6% greater than of Bodallin. There was no evidence that the relative yield of the RT lines was greater at waterlogged sites than at other sites. Waterlogging reduced the number of fertile spikes of RT lines and of Bodallin to the same relative extent and differences in grains per spike and grain size had little effect on relative yields. Even though harvest index of the RT lines was slightly elevated in some environments, biomass production of the RT lines was low in all environments. We conclude that wheats with the 'tin' gene are unlikely to have a yield advantage under transient waterlogging unless their biomass production can match that of more freely tillering wheats.

Low temperature effects on the growth of evening primrose (Oenothera spp.) rosettes

2004 ◽  
Vol 52 (1) ◽  
pp. 19-28
Author(s):  
A. F. Fieldsend
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Relative Growth Rate ◽  
Relative Rate ◽  
Field Trials ◽  
Effect Of Temperature ◽  
Relative Growth ◽  
Evening Primrose ◽  
Intermittent Exposure ◽  
Environment Experiment

In field crops of evening primrose (Oenothera spp.) the post-winter growth of rosettes is slow to re-start. The effect of temperature on the growth of rosettes was assessed in a controlled environment experiment. Relative growth rate was positively correlated with temperature, but in apparent contrast to the results from field trials, the rosettes grew at constant temperatures as low as 6.5ºC. However, following transfer to warmer temperatures an increase in relative growth rate did not occur until 7-10 days later, whilst a change to a cooler environment caused an immediate reduction in relative growth rate. Thus, it seems likely that growth is inhibited by intermittent exposure to temperatures of 0°C or below. Partitioning of biomass between root and shoot was independent of temperature, but at 6.5ºC the relative rate of leaf area increase was very low. Consequently, the specific leaf area was lower in rosettes growing at lower temperatures.

scholarly journals Restoring the Soils of Nauru: Plants as Tools for Ecological Recovery

2021 ◽  
Author(s):  
◽  
Alexander Feary
Keyword(s):  
Biomass Production ◽  
Soil Type ◽  
Biomass Productivity ◽  
Well Being ◽  
Field Trials ◽  
Small Degree ◽  
Tissue Type ◽  
Soil Restoration ◽  
Landscape Degradation ◽  
Germination Success

<p>The restoration of Nauru’s mined areas is fundamental to the future wellbeing of the people and ecosystems of Nauru. Extensive open cast phosphate mining on Nauru over the last 100 years has led to soil losses and landscape degradation to the extent that over 70% of this South-Western Pacific island state is now uninhabitable and almost all productive land has been lost. Significant landscape degradation has occurred and as a consequence the soils that remain are insufficient in volume and quality to achieve the Government’s restoration goals which support the long-term development of Nauru and the well-being of its people. The aim of this research is to evaluate aspects of cover-crop use as a means for soil restoration in Nauru. This research evaluates biomass production, phytoremediation potential, and germination success for a range of species in Nauruan soils. Field trials exploring biomass production and cadmium phytoextraction were performed, as was an experiment assessing the effects of cadmium on germination success. It was found that, in the circumstances assessed, biomass productivity was significantly determined by species, mulch use, soil type, and to a small degree – cadmium. Phytoextraction was significantly determined by tissue type. Germination success was not determined by soil cadmium, but soil type was a significant factor.</p>

scholarly journals Hybrid tea-roses under controlled light conditions. I. The effect of the level of irradiance on the growth and development of seedlings.

1978 ◽  
Vol 26 (1) ◽  
pp. 119-127
Author(s):  
D.P. de Vries ◽  
L. Smeets
Keyword(s):  
Light Intensity ◽  
Leaf Area ◽  
Growth And Development ◽  
Day Length ◽  
Light Conditions ◽  
Flower Bud ◽  
Juvenile Period ◽  
Low Light ◽  
Bud Formation ◽  
Flower Bud Abortion

As a basis for breeding cvs adapted to flowering in winter light conditions, the growth of hybrid tea rose seedlings under controlled conditions was studied. Irradiance varied from 4-24 W/m2, day length was 8 h, temperature 21 deg C. Like cvs, the seedlings sometimes aborted the flower bud at low light intensity. With increasing irradiances, the following phenomena were observed: the juvenile period of the seedlings shortened; plants were longer at bud formation, at first flowering and at flower bud abortion; leaf area and the number of petals increased. Leaf number was constant at all irradiances. Flowering seedlings were smaller at bud formation, but taller at actual flowering than blind ones. Blind seedlings had fewer leaves with a smaller area. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals PENDUGAAN POTENSI PRODUKSI GANDUM (Triticum aestivum L.) DI SULAWESI UTARA DENGAN MENGGUNAKAN PERANGKAT LUNAK SHIERARY WHEAT VERSI 2.0

EUGENIA ◽  
2011 ◽  
Vol 17 (1) ◽  
pp. 60
Author(s):  
Johannes E. X. Rogi ◽  
Siska J. Frans
Keyword(s):  
Simulation Model ◽  
Growth And Development ◽  
Field Capacity ◽  
Triticum Aestivum L ◽  
High Yield ◽  
Nitrogenous Fertilizer ◽  
North Sulawesi ◽  
Hypothetical Data ◽  
Total Input ◽  
Input Model

The demand of wheat increases yearly in Indonesia. Therefore, Indonesia has imported wheat fromoverseas. Agronomically, wheat could be cultivated in Indonesia. Simulation model using ShieraryWheat ver 2.2 software developed by Handoko (1992) will be used in this studi. This software has beenvalidated by Rogi (1996) in several areas in Indonesia. This model has daily resolution which explainsinteraction between growth and development of wheat. Model inputs include weather elements such asradiation, temperature, humidity, wind and rainfall. Soil physical field capacity (water condition in thesoil), characteristic such as field capacity, wilt permanent point, and evaporation together with pH, totalnitrogen were incorporated in the model. Agronomical inputs such as irrigation, nitrogenous fertilizer,ground water and total nitrogen were used as hypothetical data. The research was aiming to assessthe best location and time for cultivated wheat ini North Sulawesi. The result showed that planted timein August had potential high yield followed by January, March, April, May, and Septemnber respectively.The suitable lacations for cultivated wheat in North Sulawesi were Tondano, Langowan, Tompaso,Tompaso Baru, and Kotamobagu. The best potential high yield was found in areas which had optimal ofair temperature and rainfall.Keywords : Wheat, Agronomically, Simulation model, Shierary Wheat Ver 2.0 ABSTRAKKebutuhan gandum yang terus meningkat setiap tahun di Indonesia dipenuhi dengan cara mengimpor,padahal secara agronomis gandum saat ini dapat dibudidayakan di daerah tropis dengan produksi yanglebih tinggi dan waktu panen yang lebih pendek. Penentuan daerah-daerah pengembangan Gandum diIndonesia seperti di Provinsi Sulawesi Utara penting untuk dilakukan dengan menggunakan modelsimulasi. Perangkat lunak Shierary Wheat Ver 2.0 yang dikembangkan Handoko tahun 1992 diMelbourne Australia dan divalidasi oleh Rogi (1996) dan telah dikalibrasi pada berbagai tempat diIndonesia. Model ini mempunyai resolusi harian yang menjelaskan proses interaksi antaraperkembangan dan pertumbuhan tanaman gandum. Input model terdiri dari unsur-unsur cuaca beruparadiasi matahari, suhu udara, kelembaban udara, kecepatan angin, dan curah hujan, sedangkan sifatfisik tanah (kapasitas lapang, titik layu permanen dan parameter evaporasi), serta sifat kimia tanah (pH,nitrogen total). Input agronomis berupa irigasi, pupuk nitrogen, kondisi awal berupa kadar air tanah dannitrogen total menggunakan data asumsi. Sehingga penelitian ini bertujuan untuk mendapatkan waktudan lokasi tanam yang terbaik untuk Tanam Gandum di Sulawesi Utara. Hasil penelitian mendapatkanbahwa Waktu tanam 1 Agustus mempunyai potensi hasil paling baik kemudian berturut-turut Januari,Maret, April, Mei dan September dengan lokasi yang sesuai adalah Tondano, Langowan, Tompaso,Tompaso Baru, dan Kotamobagu.

scholarly journals Effects of nitrogen on development and growth of the leaves of vegetables. 3. Appearance and expansion growth of leaves of spinach

1995 ◽  
Vol 43 (2) ◽  
pp. 247-260
Author(s):  
H. Biemond
Keyword(s):  
Leaf Area ◽  
Leaf Size ◽  
Field Trials ◽  
Leaf Expansion ◽  
Mature Leaf ◽  
Leaf Emergence ◽  
Number Of Leaves ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Main Factor

In a series of greenhouse and field trials, spinach cv. Trias plants were supplied with different amounts of N fertilizer in various split applications. Rates of leaf emergence and expansion were recorded, as well as final leaf size. The rate of leaf appearance varied between 0.16 and 0.57/day across experiments, but was hardly affected by N treatment. The rate of leaf expansion and mature leaf area increased with leaf number, reaching maximum values at leaf pair 3+4 or 5+6 and decreasing subsequently. Both characteristics were positively correlated with N supply. The duration of expansion was not influenced by N treatments and varied between 15 and 30 days in most experiments. The rate of leaf expansion was the main factor determining mature leaf size. Specific leaf area over all green leaves slowly decreased with time in most experiments and was around 300 cmsuperscript 2/g. As the differences in the number of leaves were small, the differences in total green leaf area per plant resulted from differences in the areas of individual mature leaves.

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