scholarly journals Colophospermum Mopane Leaf Production and Phenology in Southern Africa's Savanna Ecosystem - A Review

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Makhado Rudzani A ◽  
Potgieter Martin J ◽  
Luus-Powell Wilmien J
Keyword(s):  
Leaf Production ◽  
Colophospermum Mopane

Growth of `Bartlett' Pear Seedlings in Response to Number of Root-lesion Nematodes and Temperature

HortScience ◽  
1990 ◽  
Vol 25 (3) ◽  
pp. 318-320
Author(s):  
J.L. Townshend
Keyword(s):  
Root Growth ◽  
Pyrus Communis ◽  
Leaf Number ◽  
Pratylenchus Penetrans ◽  
Leaf Production ◽  
Lesion Nematodes ◽  
Effects Of Temperature ◽  
Root Lesion Nematodes

The effects of temperature and root-lesion nematodes [Pratylenchus penetrans (Cobb)] on the growth of newly germinated `Bartlett' pear seedlings (Pyrus communis L.) were examined. At five temperatures from 10 to 30C, P. penetrans (five per gram of soil) did not purple the leaves. After 8 weeks, leaf number, trunk height, and top and root weights were reduced only at 25C. The number of P. penetrans in the roots were greatest at 15 and 20C. At 20C, P. penetrans (16 per gram of soil) caused the leaves of seedlings to turn purple, and, by 6 weeks after treatment, the nematodes had reduced leaf production, trunk elongation, and top and root growth.

scholarly journals Two maize cultivars of contrasting leaf size show different leaf elongation rates with identical patterns of extension dynamics and coordination

AoB Plants ◽  
2021 ◽  
Author(s):  
Tiphaine Vidal ◽  
Hafssa Aissaoui ◽  
Sabrina Rehali ◽  
Bruno Andrieu
Keyword(s):  
Genotypic Variation ◽  
Leaf Size ◽  
High Rate ◽  
Time Interval ◽  
Extension Rate ◽  
Leaf Production ◽  
Maize Cultivars ◽  
Plant Environment ◽  
The Difference ◽  
Leaf Extension

Abstract Simulating leaf development from initiation to maturity opens new possibilities to model plant–environment interactions and the plasticity of plant architecture. This study analyses the dynamics of leaf production and extension along a maize (Zea mays) shoot to assess important modelling choices. Maize plants from two cultivars originating from the same inbred line, yet differing in the length of mature leaves were used in this study. We characterised the dynamics of the blade and sheath lengths of all phytomers by dissecting plants every 2–3 days. We analysed how differences in leaf size were built up and we examined the coordination between the emergence of organs and phases of their extension. Leaf extension rates were higher in the cultivar with longer leaves than in the cultivar with shorter leaves; no differences were found in other aspects. We found that (i) first post-embryonic leaves were initiated at a markedly higher rate than upper leaves; (ii) below ear position, sheaths were initiated at a time intermediate between tip emergence and appearance, while above the ear position, sheaths were initiated at a high rate, such that the time interval between the blade and sheath initiations decreased for these leaves; and (iii) ear position also marked a change in the correlation in size between successive phytomers with little correlation of size between upper and lower leaves. Our results identified leaf extension rate as the reason for the difference in size between the two cultivars. The two cultivars shared the same pattern for the timing of initiation events, which was more complex than previously thought. The differences described here may explain some inaccuracies reported in functional-structural plant models. We speculate that genotypic variation in behaviour for leaf and sheath initiation exists, which has been little documented in former studies.

Defoliation frequency and cultivar effects on the storage and utilisation of stolon and root reserves in white clover

2000 ◽  
Vol 51 (8) ◽  
pp. 1039 ◽  
Author(s):  
A. R. Lawson ◽  
K. B. Kelly ◽  
P. W. G. Sale
Keyword(s):  
White Clover ◽  
Plant Size ◽  
Water Soluble ◽  
Cultivar Differences ◽  
Soluble Carbohydrate ◽  
Leaf Production ◽  
Plant Weight ◽  
Stolon Length ◽  
Defoliation Frequency ◽  
Leaf Appearance

The effects of defoliation frequency (2 or 6 defoliations over a 91-day period) on the reserve status and growth rate of 2 white clover cultivars, cvv. Irrigation (medium-leafed) and Haifa (large-leafed), were examined over the final 42 days of the defoliation treatments. The clover plants consisted of single stolons growing in a sand/scoria mix in an unheated glasshouse, and were fertilised weekly with a solution containing essential nutrients excluding nitrogen. More frequent defoliation reduced the leaf appearance rate, stolon elongation rate, and plant size, and increased stolon death, with all of these effects being less pronounced in Irrigation than in Haifa (18% v. 30%, 60% v. 80%, and 23% v 34%, respectively, for leaf appearance rates, stolon elongation rates, and the proportion of stolon length that died). With infrequent defoliation, the combined utilisation of starch and water-soluble carbohydrate (WSC) reserves in the first 14 days after defoliation was equivalent to 15% of the plant weight at defoliation, and to 95% of the new leaf produced during that period. Frequent defoliation reduced the reserve content and remobilisation less in Irrigation than in Haifa, with the combined mass of remobilised starch and WSC over the first 14 days after defoliation being 2.9% and 2.0% of the plant weight at defoliation, and 29% and 19% of leaf production over that period, for Irrigation and Haifa, respectively. The greater reserve mobilisation in Irrigation than in Haifa plants under frequent defoliation probably contributed to their higher growth rates and reduced stolon death. These cultivar differences with frequent defoliation suggest that Irrigation is more suited to frequent defoliation than Haifa.

The effect of ozone on cottonwood – leaf rust interactions: independence of abiotic stress, genotype, and leaf ontogeny

1987 ◽  
Vol 65 (5) ◽  
pp. 949-953 ◽  
Author(s):  
James S. Coleman ◽  
Clive G. Jones ◽  
William H. Smith
Keyword(s):  
Leaf Rust ◽  
Populus Deltoides ◽  
Leaf Age ◽  
Leaf Length ◽  
Ozone Treatment ◽  
Shoot Biomass ◽  
Leaf Ontogeny ◽  
Leaf Production ◽  
Leaf Injury ◽  
Eastern Cottonwood

The interaction of an acute ozone dose, plant genotype, and leaf ontogeny on the development of cottonwood leaf rust on eastern cottonwood (Populus deltoides Bartr.) was investigated. A rust-resistant (ST 66) and a rust-susceptible (ST 109) clone were exposed to charcoal-filtered air or were fumigated with 393 μg m−3 (0.20 ppm) ozone for 5 h. Forty hours after fumigation, leaf material of different developmental ages was inoculated with urediospores of Melampsora medusae Thum., and uredia production was measured after 10 days. Ozone fumigation of cottonwoods significantly reduced uredia production by M. medusae on both clones and all leaf ages without causing visible leaf injury or measurable changes in cottonwood height growth, leaf production, leaf length, or root/shoot biomass. Uredia production was strongly affected by ozone treatment, cottonwood genotype, and leaf age, but interactions among these three factors did not occur.

scholarly journals Continuous Lighting and High Daily Light Integral Enhance Yield and Quality of Mass-Produced Nasturtium (Tropaeolum majus L.) in Plant Factories

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1203
Author(s):  
Wenshuo Xu ◽  
Na Lu ◽  
Masao Kikuchi ◽  
Michiko Takagaki
Keyword(s):  
Secondary Metabolites ◽  
Mass Production ◽  
Physiological Stress ◽  
Growth Parameters ◽  
Leaf Production ◽  
High Productivity ◽  
Artificial Lighting ◽  
Yield And Quality ◽  
Use Efficiency ◽  
Tropaeolum Majus

Nasturtium (Tropaeolum majus L.), as a medicinal plant, has a high phenolic content in its leaves and flowers. It is often used in salads as a dietary vegetable. Attracting strong demand, it could be a good candidate crop for a plant factory with artificial lighting (PFAL) that can achieve the mass production of high-quality crops with high productivity by regulating environmental conditions such as light. In this study, two experiments were conducted to investigate the effects of continuous lighting (CL) and different daily light integrals (DLIs) under CL on the growth, secondary metabolites, and light use efficiency (LUE) of nasturtium, all of which are essential in the successful cultivation in PFALs. In Experiment 1, two lighting models, the same DLI of 17.3 mol m-2 d-1 but different light periods (24 and 16 h) with different light intensities (200 and 300 µmol m−2 s−1, respectively), were applied to nasturtium. The results showed that leaf production, secondary metabolites, and LUE were higher under the 24-h CL treatment than under the 16-h non-CL treatment. In Experiment 2, three DLI levels (17.3, 25.9, and 34.6 mol m-2 d-1) under the CL condition were applied. The results showed that the growth parameters were positively correlated with the DLI levels under CL. The lowest DLI had the highest LUE. We conclude that the mass production of nasturtium under CL in PFALs is feasible, and the yield increases as DLI increases from 17.3 to 34.6 mol m-2 d-1 under CL without causing physiological stress on plants.

Calacarus carinatus (purple tea mite).

2021 ◽  
Author(s):  
Claire Beverley
Keyword(s):  
Leaf Production ◽  
The Usa ◽  
Tea Leaf

Abstract C. carinatus is a mite native to Asia. It is now also present in Africa, Europe, the USA and Australia. It usually attacks camellias and can reduce tea leaf production. In Kenya, C. carinatus has resulted in loss of capital due to the reduction in tea leaf production.

scholarly journals Profitability of betel leaf (Piper betle L.) cultivation in some selected sites of Bangladesh

2015 ◽  
Vol 40 (3) ◽  
pp. 409-420 ◽  
Author(s):  
QMS Islam ◽  
MA Matin ◽  
MA Rashid ◽  
MS Hoq ◽  
Moniruzzaman
Keyword(s):  
Easy Access ◽  
High Price ◽  
Piper Betle ◽  
Cost Ratio ◽  
Leaf Production ◽  
Benefit Cost Ratio ◽  
Betel Leaf ◽  
High Initial Cost ◽  
Rot Disease ◽  
Benefit Cost

The study was conducted in four betel leaf growing areas, namely Barisal, Chittagong, Rajshahi and Kustia district during 2013-14 to assess the cultivation practices, physical productivity, profitability, and to explore the constraints to betel leaf cultivation. The study has been designed to investigate the economics of betel leaf production considering intensive cultivated areas for recent information in Bangladesh. From each district, two upazilas were selected considering the concentration of betel leaf growers and easy access. Also from each upazila, two blocks and from each block 20 farmers were selected with the consultation of Upazila Agriculture Officer and Sub Assistant Agriculture Officer. The study revealed that betel leaf cultivation was profitable in the study areas, although BCR in the first and second years was below one which was due to high initial cost. The highest yield and gross return of betel leaf cultivation were in the fifth year. The benefit cost ratio was found highest in 6-10 year followed by 5th and 11-15 year. The benefit cost ratio at 12%, 15% and 20% rate of interest were 1.27, 1.25 and 1.21 respectively. Internal rate of return (IRR) was calculated 62% in current situation, IRR 37% was found by 10% decrease of return and 39% by 10% increase of cost. The problems like leaf rot disease, high price of boroj materials, low price of betel leaf, high price of oilcake, etc. were facing by the betel leaf farmers.Bangladesh J. Agril. Res. 40(3): 409-420, September 2015

scholarly journals Effect of sowing density and nitrogen top-dress fertilisation on growth and yield of chia (Salvia hispanica L.) in a Mediterranean environment: first results

2015 ◽  
Vol 10 (3) ◽  
pp. 163 ◽  
Author(s):  
Rocco Bochicchio ◽  
Roberta Rossi ◽  
Rosanna Labella ◽  
Giovanni Bitella ◽  
Michele Perniola ◽  
...  
Keyword(s):  
Southern Italy ◽  
Plant Density ◽  
Fruit Production ◽  
Growth And Yield ◽  
Leaf Production ◽  
Salvia Hispanica ◽  
Area Index ◽  
First Results ◽  
Salvia Hispanica L ◽  
Set Up

The demand for sources of nutraceuticals has led to the rediscovery and diffusion of traditional crops such as chia (<em>Salvia hispanica</em> L.), whose leaves and fruits are rich in W3 fatty acids and anti-oxidants. Chia originates in Central America but it is rapidly expanding to new areas. A field experiment conducted at Atella in Basilicata (Southern Italy) was set up to test the response of chia to N top-dress fertilisation (0 and 20 kg ha<sup>–1</sup>) and to sowing density (D1=125, D2=25, D3=8 and D4=4 plants m<sup>–2</sup>) in a split-plot design with three replications. First results show maximum leaf area index values up to 7.1 and fresh vegetative biomass production at early flowering ranging between 50.87 (D4) and 59.71 (D1) t ha<sup>–1</sup>. Yield increased with plant density: a significantly (P&lt;0.01) higher production (398 kg ha<sup>–1</sup>) was reached in D1. N top-dressing had a detrimental effect on yield and corresponded to higher lodging and lower maturation percentage of seeds, though non-significant. Based on our first results it seems worthwhile to continue agronomical trials for chia in herbaceous systems of southern Italy for leaf production based on traditional genotypes, while fruit production might be pursued by adopting high sowing density and the search for longer-day genotypes.

scholarly journals Phenological relationships between two insect galls and their host plants: Aspidosperma australe and A. spruceanum (Apocynaceae)

2010 ◽  
Vol 24 (3) ◽  
pp. 727-733 ◽  
Author(s):  
Priscila Tolentino Campos ◽  
Maria Cecília Dias Costa ◽  
Rosy Mary dos Santos Isaias ◽  
Ana Sílvia Franco Pinheiro Moreira ◽  
Denis Coelho de Oliveira ◽  
...  
Keyword(s):  
Comparative Studies ◽  
Host Plants ◽  
Neotropical Region ◽  
Good Strategy ◽  
Insect Galls ◽  
Leaf Production ◽  
Maximum Percentage ◽  
Phenological Synchrony ◽  
One Year ◽  
Gall Induction

Although gall diversity in the Neotropical region is immense, comparative studies on the phenology of host plants and their galls are scarce. Gall systems generally require high levels of phenological synchrony between the associated organisms. The relationships between the phenology of two leaf galls induced by an unidentified Cecidomyiidae in Aspidosperma spruceanum Benth. ex Müell. Arg. and by Pseudophacopteron sp. in A. australe Müell. Arg. were investigated. The investigation was performed on ten individuals per species in 15-day intervals taking into consideration the percentage of galled leaves. In a one-year study, three distinct phenophases for the leaf galls and four phenophases for host plants were observed. The maximum percentage of leaf galls (80%) on A. australe occurred just after the peak of leaf sprouting. In A. spruceanum, the percentage of leaf galls was always over 50%, which can be related to continuous leaf production and gall induction in this species. In both species, developing galls were observed over the entire year, indicating multivoltinism. The ability to induce galls at young and mature sites seems to be a good strategy for galling species survivorship.

scholarly journals EFFECT OF CRUDE OIL ON THE DEVELOPMENT OF WHITE MANGROVE SEEDLINGS (Avicennia germinans) IN THE NIGER DELTA, NIGERIA

2008 ◽  
Vol 30 (70/72) ◽  
Author(s):  
A. C. Chindah ◽  
S. A. Braide ◽  
J. O. Amakiri ◽  
J. Onokurhefe
Keyword(s):  
Crude Oil ◽  
Human Life ◽  
T Test ◽  
Avicennia Germinans ◽  
Growth Responses ◽  
Leaf Production ◽  
Wilcoxon Sign Rank ◽  
Mangrove Seedlings ◽  
Growth Attributes ◽  
The Impact

Crude oil is a complex hydrogen whose introduction into the may be hazardous to aquatic and human life, and consequently a threat to natural resources. The severity of the impact of crude oil depends on a variety of factors, including characteristics of the oil itself, natural conditions, such as water temperature and weather, and the sensitivities of receiving or biota. Consequently, various types of biological resources such as mangrove seedlings have different sensitivities to oil spills. The long term persistence of oil in the environment may cause defoliation and possibly death. Recruitment of seedlings into the oiled area may also be affected. This study is designed to evaluate the acute and chronic effects of crude oil (Bonny Light) on the growth performance of mangrove seedlings in a laboratory condition; monitoring critical plant growth attributes such as stem height and diameter, leaf length, width and numbers of leaves (leaf production), senescence and seedlings survival, for sixteen weeks. The study revealed that the mangrove seedlings responded differently in growth attributes with varying treatment. Evidence of crude oil effects were remarkably demonstrated between control and acute (Wilcoxon sign –rank t-test (1.0) > P (0.29)0.05 and chronic (Wilcoxon sign – rank, t-test (1.0) > p (0.47)0.05. The mangrove critical growth responses by mangrove seedlings as a result of the treatments were further explained by the cluster and correspondence analyses.

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