scholarly journals Drought Avoidance in Katsura by Drought-induced Leaf Abscission and Rapid Refoliation

HortScience ◽  
1999 ◽  
Vol 34 (5) ◽  
pp. 871-874 ◽  
Author(s):  
Michael S. Dosmann ◽  
William R. Graves ◽  
Jeffery K. Iles

The limited use of the katsura tree (Cercidiphyllum japonicum Sieb. & Zucc.) in the landscape may be due to its reputed, but uncharacterized, intolerance of drought. We examined the responses of katsura trees subjected to episodes of drought. Container-grown trees in a greenhouse were subjected to one of three irrigation treatments, each composed of four irrigation phases. Control plants were maintained under well-hydrated conditions in each phase. Plants in the multiple-drought treatment were subjected to two drought phases, each followed by a hydration phase. Plants in the single-drought treatment were exposed to an initial drought phase followed by three hydration phases. Trees avoided drought stress by drought-induced leaf abscission. Plants in the multiple- and single-drought treatments underwent a 63% and 34% reduction in leaf dry weight and a 60% and 31% reduction in leaf surface area, respectively. After leaf abscission, trees in the single-drought treatment recovered 112% of the lost leaf dry weight within 24 days. Leaf abscission and subsequent refoliation resulted in a temporary reduction in the leaf surface area: root dry weight ratio. After relief from drought, net assimilation rate and relative growth rate were maintained at least at the rates associated with plants in the control treatment. We conclude that katsura is a drought avoider that abscises leaves to reduce transpirational water loss. Although plants are capable of refoliation after water becomes available, to maintain the greatest ornamental value in the landscape, siting of katsura should be limited to areas not prone to drought.

Symmetry ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1255 ◽  
Author(s):  
Xiaojing Yu ◽  
Cang Hui ◽  
Hardev S. Sandhu ◽  
Zhiyi Lin ◽  
Peijian Shi

Leaf surface area (A) and leaf shape have been demonstrated to be closely correlated with photosynthetic rates. The scaling relationship between leaf biomass (both dry weight and fresh weight) and A has been widely studied. However, few studies have focused on the scaling relationship between leaf shape and A. Here, using more than 3600 leaves from 12 Rosaceae species, we examined the relationships of the leaf-shape indices including the left to right side leaf surface area ratio (AR), the ratio of leaf perimeter to leaf surface area (RPA), and the ratio of leaf width to length (RWL) versus A. We also tested whether there is a scaling relationship between leaf dry weight and A, and between PRA and A. There was no significant correlation between AR and A for each of the 12 species. Leaf area was also found to be independent of RWL because leaf width remained proportional to leaf length across the 12 species. However, there was a negative correlation between RPA and A. The scaling relationship between RPA and A held for each species, and the estimated scaling exponent of RPA versus A approached −1/2; the scaling relationship between leaf dry weight and A also held for each species, and 11 out of the 12 estimated scaling exponents of leaf dry weight versus A were greater than unity. Our results indicated that leaf surface area has a strong scaling relationship with leaf perimeter and also with leaf dry weight but has no relationship with leaf symmetry or RWL. Additionally, our results showed that leaf dry weight per unit area, which is usually associated with the photosynthetic capacity of plants, increases with an increasing A because the scaling exponent of leaf dry weight versus A is greater than unity. This suggests that a large leaf surface area requires more dry mass input to support the physical structure of the leaf.


1972 ◽  
Vol 2 (2) ◽  
pp. 98-104 ◽  
Author(s):  
Philip R. Larson ◽  
J. G. Isebrands

The relationship between leaf production and wood production in two clones of Populus grown for 1 year under intensive culture was investigated. Wood weight at any one stem position was highly correlated with the cumulative leaf area above that position. About one-half the total stem weight was bark, but the bark/wood ratio decreased with increasing leaf area. Wood specific gravity in creased from stem top to stem base, with mid-stem values of about 0.35. Leaf surface area and leaf dry weight were highly correlated with leaf lamina length; the latter therefore provides an easily measured, non-destructive estimate of photosynthesizing leaf surface. Marked clonal differences existed in all parameters measured.


2020 ◽  
Vol 75 (4) ◽  
Author(s):  
GRIGORIY DEMYDAS ◽  
MAXIM ZAKHLEBAEV ◽  
IVAN SHUVAR ◽  
HALINA LIPIŃSKA ◽  
TERESA WYŁUPEK

The study objective was to analyze the formation of the leaf surface of white melilot (Melilotus albus) cultivated in pure sowing and mixes with annual cereals, with varying seeding rates for this species and varying fertilization levels. White melilot was sown in pure sowing and mixes with maize, millet, Sudan grass, and sorghum, with four seeding rates (16, 18, 20, and 22 kg ha–1). Four doses of fertilization with NPK were used in the investigations (0 – control treatment without fertilization, N45P45K45, N60P60K60, and N60P90K90). The leaves’ surface was assessed through scanning on the 30th, 40th, and 50th day after the germination of white melilot and in the period of its readiness for mowing (64th day). White melilot leaves were separated from the stems and placed in a transparent folder with a 25 cm calibration square, then scanned with a flatbed scanner in black-and-white mode. The obtained image was analyzed in Areas software, the built-in analytical tools of which were used to determine the area of the scanned leaves. After determining each plant’s leaf surface, the mean for each variant of the experiment was calculated, and then, using the concentration of plants per 1 m2, the mean M. albus leaf surface per hectare was obtained. The investigations demonstrated that the surface of white melilot leaves varied depending on the mix’s component, the seeding rate for this species, and the fertilization doses. Depending on the seeding rate (16, 18, 20, and 22 kg ha–1), one plant’s mean leaf surface area was as follows: 0.014115, 0.013955, 0.013824, and 0.013654 m2. The smallest M. albus leaf surface area per hectare was recorded in treatments without components (pure sowing) and with the highest seeding rate for this species’ seeds. The significantly the largest leaf surface area was observed in treatments where M. albus was sown in 16 kg ha–1, in a mix with Sudan grass and maize. Millet was the component with the strongest negative effect on this parameter, with each of the M. albus seeding rates used. Typically, the studied species’ leaf surface area was successively decreasing by 2 to 11% as the seeding rate increased. When mineral fertilizers were introduced, the species under study's leaf surface area was increasing by 7 to 16% as the fertilization rate increased. Considering the mean values for the study period, the largest area of white melilot leaves (in the period of readiness for cutting) was recorded in a mixed treatment of white melilot with Sudan grass, i.e., 52.3 thousand m2 ha–1 with fertilization of N60P90K90 and seeding rate of 16 kg ha–1.


2021 ◽  
Vol 6 (1) ◽  
pp. 1-10
Author(s):  
Reginawanti Hindersah ◽  
Agusthinus Marthin Kalay ◽  
Henry Kesaulya ◽  
Cucu Suherman

Abstract Nutmeg is important for national and community revenue mainly in Maluku Province where nutmeg seedlings are grown in low-fertility soil without fertilizer. A greenhouse experiment was performed to evaluate the response of nutmeg seedlings following the application of two different biofertilizer concortia. The experimental design was completely randomized block design, which tested the combination treatments of two rates and the application methods of biofertilizer concortium. The rates of “bacillus biofertilizer” was 0.15 and 0.3%, while the rates of “mixed biofertilizer” was 0.5 and 1.0%. Both biofertilizer were inoculated by foliar spray and soil application. The results verified that at 24 weeks after inoculation, biofertilizers increased the seedling growth traits which included plant height, shoot dry weight, leaf surface area, root number, and root dry weight over the control. Soil application by 1% of “mixed biofertilizer” consists of nitrogen-fixing bacteria and phosphate-solubilizing microbes resulted in better seedlings performance. However, the highest plant height was demonstrated by seedlings treated with 0.3% “bacillus biofertilizer” composed of phosphate solubilizing Bacillus. Biofertilizer inoculation also enhanced soil microbes and leaf surface area but did not change the root-to-shoot ratio of the seedlings. The results showed that biofertilizer inoculation improves the growth of nutmeg seedlings.


2021 ◽  
Vol 280 ◽  
pp. 06009
Author(s):  
Vasyl Lopushniak ◽  
Нalyna Hrytsuliak ◽  
Mykhailo Gumentyk ◽  
Mykola Kharytonov ◽  
Bazena Barchak ◽  
...  

The case study to determine the peculiarities of Miscanthus giganteus aboveground biomass formation depending on sewage sludge and composts rate carried out in the Precarpathian region of Ivano- Frankivsk province on sod-podzolic soils. The largest area of the leaf surface of miscanthus is formed in the trials where fresh sewage sludge was applied in the rate of 20 - 40 t/ha. The leaf surface area increases from 19 up to 24.0 cm2/plant, and the yield of raw mass of plants at the level of 23.5 - 25.1 t/ha due to increasing rates of sewage sludge application. The highest indicators of net photosynthesis productivity were found in the period of intensive growth, which amounted to 7.78 g/m²/day and in the maturation period of 7.56 g/m²/day in the trial SS - 40 t/ha + N10P14K58. The amount of dry mass of miscanthus plants significantly depends on the height of the shoot and the leaf surface area of the plants. The use of compost based on sewage sludge and straw in a ratio of 3: 1 at a rate of 30 t/ha contributes to the dry weight of miscanthus plants at the level of 15 t/ha.


1985 ◽  
Vol 3 (3) ◽  
pp. 142-146
Author(s):  
Daniel K. Struve

Rooted cuttings of Betula nigra ‘Heritage’ originating from short shoots were either staked and lateral shoots pruned to a 3 node length or were unstaked and unpruned. One hundred and twenty-five days following propagation, the pruned and staked plants had higher net assimilation rates and lower leaf area ratios than unstaked and unpruned plants. No differences in relative growth rates, total dry weight, root/shoot ratios or shoot length were observed between control and treated plants. Pruned and staked plants had, relative to unstaked and unpruned, less leaf surface area composed of fewer but larger leaves which produced more grams of dry weight per cm2 leaf surface area per day. Pruning and staking maximized economically important dry matter production without reducing total dry weight. Plants originating from long shoots had greater root, shoot and total dry weights, and required less staking to produce upright growth than plants originating from short shoots. By exploiting the beneficial topophysis growth of long shoots, nursery productivity can be increased.


2017 ◽  
Vol 23 (2) ◽  
Author(s):  
NAVALSINGH J. TODAWAT

Sooty mould diseases of Tress from Aurangabad district were surveyed. During the survey of tress, 5 species were found infected by fungal pathogens causing sooty mould diseases. Disease is easily identifiable by the presence of a black, velvety growth covering the leaf surface area. The fungus produces mycelium which is superficial and dark grows on the flowers, leaf, stem and sometime on fruits also. The severity of disease depends on the honeydew secretions by insects. The diseases were found to be caused by 5 species of fungi viz. Capnodium anonae, C. ramosum, Capnodium sp., Meliola bangalorensis and Meliola ranganthii.


Author(s):  
M. G. Markova ◽  
E. N. Somova

Work on going through the adaptation stage of rooted micro-stalks comes down to searching for new growth regulators and studying the influence of external conditions, which include, among other things, light effects. The data of 2018-2019 on the effect of growth regulators Siliplant, EcoFus and experimental LED phytoradiators on the adaptation of rooted micro-stalks of garden strawberries (Fragaria x ananassa duch) in vivo are presented. The object of research is rooted micro-stalks of garden strawberries of the Korona variety. It was revealed that, at the adaptation stage of rooted micro-stalks of strawberries, the most effective was the treatment of plants by spraying with Siliplant at a concentration of 1.0 ml/l and the combined treatment with Siliplant and EcoFus at concentrations of 0.5 ml/l: regardless of lighting, the survival rate averaged 99.4 - 99.7%, the leaf surface area increased significantly from 291.85 mm2 to 334.4 mm2. The number of normally developed leaves of strawberry microplants increased significantly after treatment with all preparations from 3.5 to 6.0, 5.8 and 6.5 pcs/plant, and a significant increase in the height of strawberry rosettes was facilitated by treatment with Siliplant and Siliplant together with EcoFus. Regardless of growth regulators, the most effective was the experimental LED phyto-irradiator with a changing spectrum, which contributed to an increase in leaf surface area, height of rosettes and the number of normally developed leaves in strawberry microplants. When illuminated with a flashing phytoradiator, these indicators are lower than in the control version, but not significantly. By the end of the rooting stage, all microplants of garden strawberries corresponded to GOST R 54051-2010.


2021 ◽  
Author(s):  
Noa Ligot ◽  
Benoît Pereira ◽  
Patrick Bogaert ◽  
Guillaume Lobet ◽  
Pierre Delmelle

<p>Volcanic ashfall negatively affects crops, causing major economic losses and jeopardising the livelihood of farmers in developing countries where agriculture is at volcanic risk. Ash on plant foliage reduces the amount of incident light, thereby limiting photosynthesis and plant yield. An excessive ash load may also result in mechanical plant damages, such as defoliation and breakage of the stem and twigs. Characterising crop vulnerability to ashfall is critical to conduct a comprehensive volcanic risk analysis. This is normally done by describing the relationship between the ash deposit thickness and the corresponding reduction in crop yield, i.e. a fragility function. However, ash depth measured on the ground surface is a crude proxy of ash retention on plant foliage as this metrics neglects other factors, such as ash particle size, leaf pubescence and condition of humidity at leaf surfaces, which are likely to influence the amount of ash that stays on leaves.</p><p>Here we report the results of greenhouse experiments in which we measured the percentage of leaf surface area covered by ash particles for one hairy leaf plant (tomato, Solanum lycopersicum L.) and one hairless leaf plant (chilli pepper, Capsicum annuum L.) exposed to simulated ashfalls. We tested six particle size ranges (≤ 90, 90-125, 125-250, 250-500, 500-1000, 1000-2000 µm) and two conditions of humidity at leaf surfaces, i.e. dry and wet. Each treatment consisted of 15 replicates. The tomato and chilli pepper plants exposed to ash were at the seven- and eight-leaf stage, respectively. An ash load of ~570 g m<sup>-2 </sup>was applied to each plant using a homemade ashfall simulator. We estimated the leaf surface area covered by ash from pictures taken before and immediately after the simulated ashfall. The ImageJ software was used for image processing and analysis.</p><p>Our results show that leaf coverage by ash increases with decreasing particle size. Exposure of tomato and chilli pepper to ash ≤ 90 μm always led to ~90% coverage of the leaf surface area. For coarser particles sizes (i.e. between 125 and 500 µm) and dry condition at leaf surfaces, a significantly higher percentage (on average 29 and 16%) of the leaf surface area was covered by ash in the case of tomato compared to chilli pepper, highlighting the influence of leaf pubescence on ash retention. In addition, for particle sizes between 90 and 500 µm, wetting of the leaf surfaces prior to ashfall enhanced the ash cover by 19 ± 5% and 34 ± 11% for tomato and chilli pepper, respectively.</p><p>These findings highlight that ash deposit thickness alone cannot describe the hazard intensity accurately. A thin deposit of fine ash (≤ 90 µm) will likely cover the entire leaf surface area, thereby eliciting a disproportionate effect on plant foliage compared to a thicker but coarser deposit. Similarly, for a same ash depth, leaf pubescence and humid conditions at the leaf surfaces will enhance ash retention, thereby increasing the likelihood of damage. Our study will contribute to improve the reliability of crop fragility functions used in volcanic risk assessment.</p>


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