scholarly journals Changes in the radiation regime and photosynthesis in the crown of an apple tree when pruning for perennial wood

Author(s):  
A. G. Gurin ◽  
S. V. Rezvyakova ◽  
N. Yu. Revin

The article presents data on the study of the radiation regime and photosynthesis net productivity in the crown of an apple tree in connection with the regenerative pruning of old-aged trees. The object of the research was an apple tree of the Antonovka obyknovennaya variety, a seed stock (seedlings of cultivated varieties), planted in 1987. The test plot soil is leached chernozem. Options: 1. Established pruning (control); 2. Pruning for 5-6 year-old wood; 3. Pruning for 7-8 year-old wood. The experiment was arranged inrandomized blocks of 6 accounting trees in 3 replicates. The regenerative pruning was carried out in spring 2016. Every year damaged branches were removed in the control variant, while “wolf-like” shoots were thinned in other variants. The solar output was accounted within the daytime with the 2-hour interval from the northern and southern sides of the apple tree crown in its center, as well as under the crown at a distance of 1, 2 and 3 meters from the periphery to the center of the crown. The measurements were carried out after the growth activity cessation in the fine weather in August with a universal albedometer M-69 coming with a galvanometer GSA-1. The net productivity of leaves was determined by the method of A. S. Ovsyannikov in parallel, taking into account solar radiation. It is revealed that the regenerative pruning has a considerable impact on the performance of the solar output. The greatest arrival of solar radiation is noted on the periphery of the crown. In the treatment with pruning branches for 5-6 year-old wood, this parameter was 10.5-13.5 % higher than in the control variant. Pruning branches for 7-8 year-old wood improved lighting conditions by 27.6-31.7 % compared to the control. In the lower part of the crown, the radiation regime is less favorable for the photosynthesis process relative to the central part of the crown. Regenerative pruning increased the photosynthesis productivity significantly. In the central part of the crown, the highest parameters of the net photosynthesis productivity were observed on the periphery on the southern side when pruning for 7-8 year-old wood - 7.81 g of dry basis/m2 *day.

1982 ◽  
Vol 26 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Antonio Roberto Pereira ◽  
Eduardo Caruso Machado ◽  
Marcelo Bento Paes de Camargo

1991 ◽  
Vol 69 (2) ◽  
pp. 295-300 ◽  
Author(s):  
Ido Schechter ◽  
D. C. Elfving ◽  
J. T. A. Proctor

Trees of apple (Malus domestica Borkh.) with 'Starkspur Supreme Delicious' as the scion grafted on nine different rootstocks (Ottawa 3, M.7 EMLA, M.9 EMLA, M.26 EMLA, M.27 EMLA, M.9, MAC-9, MAC-24, OAR 1) were studied in their 8th and 9th years. Canopy seasonal development and its light interception followed by fisheye (hemispherical) photography showed that rootstock affected the amount of structural wood, the rate of canopy development, and final leaf area. However, rootstock did not affect the sigmoidal pattern of canopy development. Light interception was linearly correlated with tree dimensions and yield. Leaf net photosynthesis (Pn) of trees on dwarfing rootstocks tended to be lower than Pn rates of trees on more vigorous rootstocks. Rootstock did not affect the scion Pn response to different illumination levels. Shoot leaves, spur leaves on spurs without fruit (S − F), and spur leaves on spurs with fruit (S + F) from trees on M.26 EMLA and OAR 1 showed no differences in Pn rates. However, for both rootstocks, shoot leaves had the highest Pn rate, S + F the lowest, and S − F leaves had intermediate values. Key words: light interception, fisheye photography, leaf type.


2021 ◽  
Vol 215 (12) ◽  
pp. 59-76
Author(s):  
Anna Lyubimova ◽  
Dmitriy Eremin

Abstract. The purpose is to study the varietal characteristics of the photosynthetic efficiency of oats when applying fertilizers in Western Siberia. Methods. The research was carried out on an experimental field located in the northern forest-steppe of the Trans-Urals. Photosynthetic potential and net productivity of photosynthesis were determined by the Nichiporovich’s method. Results. The nature of the formation of the assimilation surface and the accumulation of biomass of oat varieties Otrada, Talisman and Foma at different levels of mineral nutrition was studied. The photosynthetic potential and the net productivity of photosynthesis are calculated. The share of the influence of weather conditions, agrophone and variety on the studied indicators is determined. The Foma variety was characterized by maximum leafiness, compared to the Talisman and Otrada. On a natural agrophone, its assimilation surface in the sweeping phase reached 36.0 ± 5.5 thousand m2, at Otrada and Talisman – 28.1 and 24.0 thousand m2 per 1 ha of sowing. A very strong variability of the leaf surface area in Otrada was revealed (Cv = 24 %). The use of mineral fertilizers enhances the development of the leaf apparatus by 44–50 % and causes competition between oat plants. A close positive correlation was revealed between the leaf area in the sweeping phase and yield (r = 0.72). The area of the assimilation surface of oats is affected by: weather conditions – 37 %; nutrition level – 30 % and variety – 25 %. It was found that the Otrada and Foma varieties have the same accumulation dynamics and form the maximum photosynthetic biomass by the sweeping phase. The nature of biomass accumulation depends on weather conditions by 39 %; on mineral fertilizers by 29 % and on the genotype of the variety by 17 %. The productivity of the studied varieties is formed by increasing the assimilation surface, rather than increasing the efficiency of photosynthesis. Scientific novelty. For the first time, the photosynthetic potential was determined and the efficiency of the net photosynthesis productivity of oat varieties of the Tyumen selection was revealed. The share of the influence of various factors in the formation of the oat crop in the conditions of the Northern Trans-Urals has been established.


Solar Energy ◽  
2004 ◽  
Author(s):  
Oleg P. Kovalev ◽  
Alexandr V. Volkov

During long-term time, the laboratory of non-traditional energetic is been busy with development and introduction of solar water heating systems for hot water supply. The systems with solar collectors of 40 m2 area have been developed and introducted. For estimation of their efficiency we should know flux density of solar radiation, proceeding to surface at the given place. However in Primorye Region at actinometrical watching only four meteostations in the Southern part are carrying out straight measurements of solar radiation flux, and the others record data which concern only solar radiation regime (the amount of solar radiation hours, relation of watching duration of solar radiation to possible duration, the amount of days without sun, etc.). We suggested the expression, which according to know data of solar radiation and cloudiness, recorded practically on all meteorological stations gives possibility to calculate for Primorye Region month sums of total radiation proceeding to horizontal surface. The comparison of estimated values with measured ones gives the error to 3...9% with regard to average many years values, and are in the range of variability of measured values for separate years. In Primorye Region more than 250 m2 of solar collectors were installed; and among them 150 m2 were developed with the laboratory, to position on 2003.11.01.   NOTE: This paper was presented at the 2004 International Solar Energy Conference and was inadvertently omitted from the 2004 ASME proceedings. The page range refers to the 2005 International Solar Energy Conference Print Proceedings, where it was subsequently published.


2020 ◽  
Vol 71 (8) ◽  
pp. 913 ◽  
Author(s):  
Eunice Kong ◽  
Yan Xiang Ow ◽  
Samantha Lai ◽  
Siti Maryam Yaakub ◽  
Peter Todd

Light and temperature are important factors affecting seagrass primary productivity. Acclimatisation to reduced light availability may affect the optimal temperature at which seagrasses photosynthesise, potentially causing synergistic effects between increasing water temperatures and decreasing light levels on coastal productivity. This study investigated the effects of reduced light availability on the morphology (leaf size, shoot density) and thermal optimal of net productivity in Halophila ovalis (R.Br.) Hook. A 12-week in situ shading experiment was conducted at Chek Jawa Wetlands, Singapore, testing high (68% shading), low (49%) and control (0%) shadings. Every 4 weeks, photosynthetic and respiration rates of H. ovalis leaves and the root–rhizome complex were measured in closed incubation chambers at temperatures from 22 to 42°C (at 4°C intervals). A fitted temperature-response model of net photosynthesis was used to estimate the thermal optimal for each shading treatment. High shading reduced shoot density (mean±s.e.) 87.06±7.86% and leaf surface area 31.72±24.74%. Net productivity (6mg O2 g–1 DW h–1) and its thermal optimal (28–30°C) were not significantly different among shading treatments throughout the experiment. Light levels appeared to have minimal influence on the thermal dependency of H. ovalis net productivity.


1971 ◽  
Vol 22 (1) ◽  
pp. 11 ◽  
Author(s):  
DW Puckridge ◽  
DA Ratkowsky

The photosynthesis of two cultivars of wheat at three densities of sowing was measured during the growing season of 1968. When the data were plotted as carbon dioxide uptake versus leaf area index (LAI) (leaf laminae and green stem) for a fixed value of solar radiation, it was found that all of the data could be fitted by a single curve, irrespective of variety, sowing density, or time of season when the measurements were made. Since the curve was of continuously decreasing slope, the carbon dioxide uptake per unit LAI was highest for the low values of LAI and was reduced with the increased light interception at high LAI. For a solar radiation of 0.6 cal/cm2/min the approximate maximum net photosynthesis was 4.5 g CO2/m2/hr for an LAI of 6. A mathematical model for photosynthesis was found to give good prediction of carbon dioxide uptake versus solar radiation for most of the period of measurement. For each plot, a rectangular hyperbola was fitted to the data. When the parameters of the model were subsequently plotted as a function of LAI, then within a given variety, it was found that lines of common slope but differing intercepts could be drawn through the points for different sowing densities. From these fitted lines together with the measured values of LAI and respiration, carbon dioxide uptake was then predicted as a function of solar radiation by employing the rectangular hyperbola model. Good agreement between predicted and measured values of photosynthesis was obtained.


Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1216
Author(s):  
Sławomir Świerczyński ◽  
Agnieszka Antonowicz ◽  
Joanna Bykowska

The article describes an experiment conducted on maiden apple trees of selected cultivars growing in a nursery. The aim of the study was to investigate how the foliar application of four biostimulants (Aminoplant 0.4%, Biamino Plant 0.2%, Bispeed 0.2% and Fylloton 0.4%) and two fertilisers (Basfoliar 6-12-6 and Basfoliar 12-4-6+S both at a concentration of 0.5%) affected the growth of the trees cultivated with the mineral fertilisation reduced by half. The plants were sprayed with the preparations and fertilisers four times at three-week intervals, between late May and late July. Selected parameters of the plants’ physiological processes were also assessed: net photosynthetic rate (Pn), transpiration rate (E), stomatal conductance (C) and intracellular CO2 (I). The foliar application of all the biostimulants and fertilisers significantly improved the growth of the maiden apple trees. The lowest values of the plant growth parameters were noted in the control combination, which was treated with a full dose of mineral fertiliser. The foliar spraying of the apple trees particularly improved the total length and number of side shoots and the fresh weight of maiden apple trees. The apple tree cultivars differed in their growth parameters, and the influence of individual foliar treatments was not conclusive. The foliar application of selected preparations intensified the leaf transpiration coefficient and the internal concentration of carbon dioxide, but it did not increase the net photosynthesis intensity or stomatal conductance.


2020 ◽  
pp. 34-37
Author(s):  
Tatyana Yakovlevna Prakhova ◽  
Anna Nikolaevna Kshnikatkina ◽  
Galina Viktorovna Ilyina ◽  
Batyr Zainullinovich Shagiev

The results of studying the parameters of photosynthetic activity of oilseeds (false flax, Abyssinian crumbe and white mustard) are presented. So, in the phase of the rosette, the assimilation surface was 11.2-21.8 thousand m2 per hectare. The smallest leaf area of  11.2 thousand m2 per hectare  was formed in the Abyssinian crambe agrocenosis. During the budding phase, the leaf area of  the crambe doubled and amounted to 22.3 thousand m2 per hectare. The leaf surface of all studied oilseeds reaches its maximum value in the flowering phase - 42.4-52.1 thousand m2 per hectare. In white mustard, the minimum leaf area was in the rosette phase - 21.8 thousand m2 per hectare, the maximum - in the flowering phase - 44.2 thousand m2 per hectare. Then the total assimilation surface decreased by 29.5% and amounted to 31.2 thousand m2 per hectare. The value of photosynthetic potential   ranged from 1594 to 1964 thousand m2 × day per hectare. The maximum value of photosynthetic potential was in Abyssinian crambe - 1964 thousand m2 × day per hectare, the minimum one - in false flax - 1594 thousand m2 × day per hectare. The high productivity of photosynthesis was in Abyssinian crambe (2.52 g / m2 × day). White mustard and false flax are characterized by slightly lower parameters of the net productivity of photosynthesis - 2.07 and 1.98 g / m2 × day, respectively. A longer period of the assimilation surface of false flax, white mustard and Abyssinian crambe plants provides high net photosynthesis productivity - 1.98-2.52 g / m2 × day and, as a result, high potential productivity up to 2.11-3.05 t / ha.


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