Growth of Megathyrsus maximus cv. Mombaça as affected by grazing strategies and environmental seasonality. II. Dynamics of herbage accumulation

2021 ◽  
Vol 72 (1) ◽  
pp. 66
Author(s):  
Roberta Aparecida Carnevalli ◽  
Guilhermo Francklin de Souza Congio ◽  
André Fischer Sbrissia ◽  
Sila Carneiro da Silva
Keyword(s):  
Growth Rate ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Leaf Senescence ◽  
Accumulation Rate ◽  
Leaf Growth ◽  
Stem Elongation ◽  
Block Design ◽  
Area Index ◽  
Senescence Rate

For tropical forage grasses, leaves are the main morphological component accumulated at the beginning of regrowth, and as leaf area index increases, plants change their growth pattern, allocating more resources to stem elongation as a means of optimising light capture. We hypothesised that, for Mombaça guineagrass, stem elongation and leaf senescence rate play a major role in determining net herbage accumulation rate (NHAR) and that senescence would be the key factor driving the reduction in NHAR when regrowth is interrupted beyond the critical leaf area index, that is, when canopy light interception (LI) exceeds 95%. Treatments corresponded to all combinations of two levels of pre-grazing canopy LI during regrowth (LI95% and LIMax) and two post-grazing heights (30 and 50 cm), and were allocated to experimental units according to a randomised complete block design with four replications. Measurements were performed throughout contrasting climatic conditions during four seasons from January 2001 to February 2002. Overall, spring and the two summers were the seasons when rates of leaf appearance, leaf elongation and leaf growth rate were higher, and leaf lifespan was smaller; the inverse occurred during autumn–winter. Despite the lack of statistically significant differences in NHAR between LI treatments during some seasons of the year, the ratio of leaf growth rate to NHAR was consistently higher for LI95% than LIMax. The pre-grazing target of LI95% was also efficient for decreasing stem elongation and leaf senescence rate. Increased senescence on individual tillers was the key driver generating modifications in the patterns of variation in NHAR beyond the critical leaf area index, suggesting that there is no advantage in extending the regrowth period when the main objective is to maximise leaf growth rate or NHAR.

scholarly journals Growth and yield of wheat at different dates of sowing under chrland ecosystem of Bangladesh

2017 ◽  
Vol 14 (2) ◽  
pp. 147-154 ◽  
Author(s):  
MM Kamrozzaman ◽  
MAH Khan ◽  
S Ahmed ◽  
N Sultana
Keyword(s):  
Growth Rate ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Block Design ◽  
Grain Filling ◽  
Crop Growth ◽  
Growth And Yield ◽  
Area Index ◽  
Crop Growth Rate

An experiment was conducted at Sadipur charland under Farming System Research and Development Site, Hatgobindapur, Faridpur, during rabi season of 2012-13 and 2013-14 to study the growth and yield performance of cv. BARI Gom-24 as affected by different dates of sowing under Agro-ecological Zone-12 (AEZ-12) of Bangladesh. The experiment was laid out in randomized complete block design with six replications, comprising five different dates of sowing viz. November 5, November 15, November 25, December 5 and December 15. Results reveal that the tallest plant, leaf area index, total dry matter, and crop growth rate were observed in November 25 sown crop and leaf area index, total dry matter and crop growth rate were higher at booting, grain filling, and tillering stages of the crop. Maximum effective tillers hill-1 (3.49), spikes m-2, (311), number of grains spike-1 (42.20) and 1000-grain weight (52.10 g) were produced by November 25 sown crop exhibited the highest grain (4.30 t ha-1) and straw yield (4.94 t ha-1) as well as harvest index (46.88%) of the crop. Lowest performance was observed both in early (November 5) and late sown crop (December 15). The overall results indicated that November 25 sown crop showed better performance in respect of growth and yield of wheat under charland ecosystem of Bangladesh.J. Bangladesh Agril. Univ. 14(2): 147-154, December 2016

scholarly journals Morphogenesis and forage accumulation of Urochloa ruziziensis under nitrogen and potassium fertilization management

2019 ◽  
Vol 40 (4) ◽  
pp. 1605
Author(s):  
Karla Rodrigues de Lima ◽  
Carlos Augusto Brandão de Carvalho ◽  
Flavio Henrique Vidal Azevedo ◽  
Fabio Prudêncio de Campos ◽  
Aline Barros da Silva ◽  
...  
Keyword(s):  
Growth Rate ◽  
Accumulation Rate ◽  
Leaf Growth ◽  
Stem Elongation ◽  
Block Design ◽  
Elongation Rate ◽  
Repeated Measurements ◽  
Positive Form ◽  
Potassium Fertilization ◽  
Appearance Rate

The objective of this study was to evaluate the effect of nitrogen and potassium fertilization on the morphogenetic and structural characteristics and production of Urochloa ruziziensis in two summer seasons (summer 1, 2010–2011and summer 2, 2011–2012) and the autumn and spring of 2011. A randomized complete block design with four treatments (0, 120, 240, and 360 kg ha-1 year-1 of N and K2O) and five replications was used, with repeated measurements in each season, in a split plot arrangement. The treatments were allocated to the plots and the seasons of the year to the subplots. The phyllochron (PHY),leaf appearance rate (LAR), leaf elongation rate (LER), stem elongation rate (SER), tiller population density (TPD), tiller appearance rate (TAR), tiller mortality rate (TMR), leaf growth rate (LGR), stem growth rate (SGR), senescence rate (SR), forage accumulation rate (FAR), and leaf accumulation rate (LAR) of Urochloa ruziziensis were evaluated. There was a positive quadratic effect for the PHY and ELR, with maximum values of 4.3 days leaf-1 and 0.43 cm tiller-1 day-1, respectively. While the SER increased linearly (0.0012 cm day-1 kg-1 of N and K2O) during summer 2. The TPD, TAR, and TMR increased linearly (averages of 1.53 tillers m-2, 0.04% and 0.02% per kg of N and K2O, respectively) with nitrogen and potassium fertilization during spring and both summer seasons. The LGR, SGR, and SR also increased linearly with N and K2O application rates during summer 2 (0.2809, 0.0082, and 0.0411 kg DM ha-1 day-1, per kg of N and K2O, respectively), while the FAR and LAR increased in a quadratic positive form (maximum values of 175 and 129 kg dry matter (DM) ha-1, corresponding to 294 and 237 kg ha-1 of N and K2O, respectively) during summer 2. Urochloa ruziziensis is a forage plant with a high DM production capacity during the summer and a high seasonal forage production.

scholarly journals PENGARUH WARNA NAUNGAN PLASTIK DAN DOSIS PUPUK ORGANIK KOMPOS TERHADAP PERTUMBUHAN BAWANG MERAH (Allium ascalonicum L.)

2018 ◽  
Vol 16 (2) ◽  
pp. 129
Author(s):  
Iskandar Umari ◽  
Wiwit Widarti ◽  
Insan Wijaya ◽  
Hudaini Hasbi
Keyword(s):  
Growth Rate ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Block Design ◽  
Organic Fertilizer ◽  
Fertilizer Application ◽  
Transparent Plastic ◽  
Area Index ◽  
Randomized Block Design ◽  
Treatment Dose

The aim of the research was to study the effect of calors plastic shade and dosage organic fertilizer and the interaction on the growth analyze of Shallots. The experiment was conducted in experiment field of Agriculture Faculty, University Muhammadiyah of Jember.The experiment was arranged in Randomized Block Design consisted of 4 x 3 factorial treatments with three replications. The first factor were 3 levels of Transparent Plastic Shelter, i.e.: clear, blue, and red. The second factor were 4 levels of compost organic fertilizer application, i.e.: 15, 20, 25 and 30 t/ha. The results showed a significant interaction between the color shade of plastic and a dose of organic fertilizer on the parameters of leaf area age 60 days after planting and leaf area index age 60 days after planting, treatment shade of blue with organic fertilizer 30 tons / ha showed the best effect on leaf area and treatment shade of blue with dosages of 25 tons / ha showed the best effect on leaf area index. Use of shade of blue give the best effect on leaf area age 60 hst and shade of red gives the best effect on the growth rate of plants. The treatment dose of organic fertilizer 25 tons / ha gives the best effect on leaf area index age of 60 days after planting, the rate of plant growth, and relative growth rate, and treatment with a dose of fertilizer 30 ton / ha.

Physiological determinants of storage root yield in three cassava genotypes under different nitrogen supply

2017 ◽  
Vol 155 (6) ◽  
pp. 978-992 ◽  
Author(s):  
K. PHUNTUPAN ◽  
P. BANTERNG
Keyword(s):  
Growth Rate ◽  
Leaf Area ◽  
Leaf Growth ◽  
Block Design ◽  
Dry Weight ◽  
N Fertilizer ◽  
Storage Root ◽  
Root Yield ◽  
Area Index ◽  
Root Dry Weight

SUMMARYPhysiological traits can be used to improve the efficiency of selecting suitable genotypes to grow under nitrogen (N) limitation. The objective of the current study was to investigate the relationship between physiological characteristics and storage root yield of three cassava genotypes under three rates of N fertilizer. The experiments were conducted from 2014 to 2016 at farm fields in Thailand. A split-plot randomized complete block design with four replications was used. Three different rates of N fertilizer, i.e., 46·9, 90·0 and 133·2 kg N/ha and three cassava genotypes, Rayong 9, Rayong 11 and Kasetsart 50, were used. Kasetsart 50 had the highest mean performance for most crop traits. Growth rate of stem (SGR), storage root (SRGR) and crop (CGR) during 180–210 days after planting (DAP) and leaf area index (LAI) at 120 DAP were related to storage root dry weight for all three rates of N fertilizer. Storage root growth during 90–120 DAP, CGR during 180–210 DAP and specific leaf area (SLA) at 210 DAP contributed most to storage root dry weight of the three genotypes grown at 46·9 kg N/ha, while the combination of SRGR during 90–120 DAP, SRGR during 180–210 DAP, LAI at 210 DAP and SLA at 210 DAP was best for N fertilizer at 90·0 kg N/ha and the combination of leaf growth rate (LGR) during 180–210 DAP and LAI at 210 DAP was best for N fertilizer at 133·2 kg N/ha.

scholarly journals Performance of Chia on Different Sowing Dates: Characteristics of Growth Rate, Leaf Area Index, Shoot Dry Matter Partitioning and Grain Yield

2019 ◽  
Vol 11 (9) ◽  
pp. 252
Author(s):  
Patrícia Carine Hüller Goergen ◽  
Isabel Lago ◽  
Angelica Durigon ◽  
Gabriel Felipe Maboni Roth ◽  
Lúcio Gabriel Scheffel ◽  
...  
Keyword(s):  
Growth Rate ◽  
Plant Growth ◽  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Dry Matter ◽  
Block Design ◽  
Area Index ◽  
Sowing Dates ◽  
Physiological Indexes

The objective of this study was to comparatively determine the characteristics of growth rate, leaf area index, shoot dry mass partitioning and grain yield of chia plants (Salvia hispanica L.) on different sowing dates. A field experiment was conducted in the crop year of 2016/2017 in five sowing dates (09/22/16, 10/28/16, 01/03/17, 02/08/17 and 03/24/17) with a randomized complete block design and four replicates. Plant growth was determined through field samplings to determine the dry matter mass and leaf area performed every 15 days. The following physiological indexes were calculated: relative growth rate, absolute growth rate, net assimilation rate, leaf area ratio, specific leaf area and leaf mass ratio. To weekly evaluate plant height, ten plants per plot were marked after emergence, and the final height was considered when plants reached physiological maturity. A useful area of 2.10 m² per plot was collected for evaluating grain yield. The physiological indexes indicated that at earlier sowing dates there is a greater plant growth, either in shoot dry matter mass, height and leaf area index. The leaf area index of branches is progressively increased with plant development and contributes significantly to total leaf area index of chia plants in all studied sowing dates. The main stem represents between 60 and 70% of the shoot dry matter accumulated in the early sowing dates, and between 40 and 50% in late sowing. The best sowing date in terms of grain yield is 01/03/17.

scholarly journals Influence of Spiral Nematodes (Scutellonema spp.) on Maize Performance and Growth under Natural Field Infestation in Mwea, Kenya

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Samuel Maina ◽  
Rossa Nyoike Ng’endo
Keyword(s):  
Food Security ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Management Practices ◽  
Block Design ◽  
Negative Relationship ◽  
Stress Factors ◽  
Area Index ◽  
Number Of Leaves

Maize (Zea mays L.) is a significant food security crop in Kenya and it serves as the main source of nutrition and calories among the small-holder farmers. The overall maize yields per hectare have been fluctuating in the past few years posing a great risk to food security. Among the stress factors associated with maize yield loss include plant-feeding nematodes. In this regard, this study was conducted to evaluate the impacts of plant-parasitic nematodes specifically Scutellonema spp. under field conditions on maize performance in Mwea, Kenya. The field trials were laid out in a randomized complete block design with each treatment comprising of four replicates. The treatments included maize plots without nematicide (MPWN) and control plots treated with nematicide. The experiments were conducted in two trials. Soil samples were taken at a 0–20 cm depth at monthly intervals during 2018–2019. During the two trials, MPWN recorded significantly lower plant height and number of leaves per plant. Correlation analysis revealed a significant negative relationship between Scutellonema abundance with leaf area index, plant height, and number of functional leaves in MPWN during the 2019 trial. This implies that high population of Scutellonema perhaps has the potential to affect leaf area index, plant height, number of leaves per plant, which are aspects that in turn influence maize productivity. Therefore, holistic sustainable management practices to control Scutellonema spp. in maize fields such as use of organic amendments, resistant maize cultivars, and antagonistic organisms are crucial in order to alleviate negative impacts linked to Scutellonema infestation.

scholarly journals Effect Of Planting Geometry On Growth Of Rice Varieties

2017 ◽  
Vol 5 (4) ◽  
pp. 423-429 ◽  
Author(s):  
Mohan Mahato ◽  
Bishnu Bilas Adhikari
Keyword(s):  
Growth Rate ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Dry Matter ◽  
Dry Matter Accumulation ◽  
Rice Varieties ◽  
Area Index ◽  
Crop Growth Rate ◽  
Planting Geometry

A field experiment was conducted under humid subtropical agro-climatic condition of Nepal during rainy season of 2014. The experiment was laid out in to two factor Randomized Complete Block Design with  three replications consisting three drought tolerant rice varieties (Sukhadhan-4, Sukhadhan-5 and Radha-4) and four planting geometry (15 cm × 10 cm, 15 cm × 15 cm, 20 cm × 15 cm and 20 cm × 20 cm). The results revealed that the highest plant height and maximum leaf area index was recorded in planting geometry 15 cm × 10 cm in all growth stages. Whereas, planting geometry 20 cm × 15 cm produced the maximum number of tiller m-2 in all growth stage.  While planting geometry 20 cm × 15 cm and 20 cm × 20 cm produced statistically similar crop growth rate and dry matter accumulation in all stage of growth. Regarding the varieties, Sukhadhan- 4 showed highest plant height up to 75 DAT and plant height was statistically similar to Radha - 4 in 60 and 75 DAT. But maximum number of tiller m-2, leaf area index, crop growth rate and dry matter accumulation were recorded in Sukhadhan – 5 varieties. Int. J. Appl. Sci. Biotechnol. Vol 5(4): 423-429

scholarly journals Evaluation of the growth and quality of lettuce (Lactuca sativa L.) in a closed recirculating hydroponic system

2017 ◽  
Vol 35 (2) ◽  
pp. 216-222 ◽  
Author(s):  
Rafael David Fraile-Robayo ◽  
Javier Giovanni Álvarez-Herrera ◽  
Andrea Johana Reyes M. ◽  
Omar Ferney Álvarez-Herrera ◽  
Ana Lucía Fraile-Robayo
Keyword(s):  
Growth Rate ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Calcium Nitrate ◽  
Potassium Nitrate ◽  
Area Index ◽  
Hydroponic System ◽  
Physiological Variables ◽  
Over Time

The production of lettuce in hydroponic systems with a recirculating nutrient solution has been growing, so it is necessary to evaluate the growth and quality of production under this system. Two harvest cycles were evaluated, comparing the behavior of physiological variables and growth rates on lettuce plants in a hydroponic system with a plastic cover. Lettuce plants were planted at 30 days after germination in an NFT hydroponic system. Nutrient solutions were prepared with sources of potassium nitrate, calcium nitrate, urea phosphate, magnesium sulfate and a source of minor nutrifeed. The second cycle had the highest total dry mass and leaf area index (LAI) at 43 days after transplant (dat). The relative growth rate (RGR) declined over time. The absolute growth rate (AGR) presented a sigmoid behavior as a gaussian bell shape; the leaf area index (LAI) increased until 43 dat, with the second cycle presenting the highest value; the net assimilation rate (NAR) decreased over time, with the second cycle having the highest value at 22 dat. The chlorophyll content for this variety was low, with a yellow pigmentation in the plant. The stomatal conductance (SC) in the two cycles at transplant time presented low values caused by the stress leaded by an imbalance in the pH of the solution, when the plants adapted to the system, this value increased.

A simulation model of kenaf for assisting fibre industry planning in northern Australia. III. Model description and validation

1992 ◽  
Vol 43 (7) ◽  
pp. 1527 ◽  
Author(s):  
PS Carberry ◽  
RC Muchow
Keyword(s):  
Leaf Area Index ◽  
Soil Water ◽  
Leaf Area ◽  
Leaf Growth ◽  
Biomass Accumulation ◽  
Fibre Industry ◽  
Model Description ◽  
Northern Australia ◽  
Area Index ◽  
Extractable Soil

NTKENAF (Version 1.1) is a computer model which simulates the growth of kenaf (Hibiscus cannabinus L.) under rainfed conditions in tropical Australia. In daily time-steps, the model simulates the phenology, leaf area development, biomass accumulation and partitioning, soil water balance and dry matter yields of kenaf plants based on climatic and management inputs. The model assumes adequate nutrition and no effect of pests and diseases. The model uses daily maximum and minimum temperature, solar radiation and rainfall. The duration from sowing to flowering is predicted using temperature and photoperiod. Leaf growth is described as a function of node production (as determined by temperature), leaf area per node and leaf area senescence. Potential daily biomass is predicted from leaf area index, the light extinction coefficient and radiation use efficiency, and partitioned to the economic stem yield. Soil evaporation is predicted using a two-stage evaporation model, and plant transpiration is predicted from the daily biomass accumulation, a transpiration efficiency coefficient and predicted daily vapour pressure deficit. Plant extractable soil water is dependent on the available soil water range for each depth increment, the extraction front velocity, and the extent of water extraction at each depth. Daily transpiration and leaf growth are decreased below potential values once the fraction of available soil water declines below a threshold value. NTKENAF V1.1 has been validated against observed data from kenaf experiments conducted at two sites (lat. 13�48'S. and 14�28'S.) in northern Australia. The predictive accuracy of the model was good over a range in above-ground biomass up to 25 000 kg ha-1 (n = 40, r2 = 0.94, root mean square deviation = 1716 kg ha-1). Validations were also undertaken for predictions of the core and bark stem components, leaf area index and plant extractable soil water contents. The development of NTKENAF has provided a tool which can greatly aid assessment of the feasibility of a fibre industry based on kenaf in northern Australia.

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