scholarly journals Varietal Difference in Morphology and Photosynthetically Active Radiation Distribution in Spring Wheat Canopy.

1993 ◽  
Vol 62 (4) ◽  
pp. 554-559 ◽  
Author(s):  
Tadashi TAKAHASHI ◽  
Kimio NAKASEKO
10.12737/1361 ◽  
2013 ◽  
Vol 8 (3) ◽  
pp. 96-100
Author(s):  
Воробьева ◽  
Tatyana Vorobeva ◽  
Шашкаров ◽  
Leonid Shashkarov

This article describes the formation of leaf area, photosynthetic capacity of crops, the net photosynthetic efficiency, leaves productivity and efficiency, Coefficient of performance (COP) of photosynthetically active radiation (PAR) of spring wheat, using Nano- Gro seed treatment instead of the traditional etching, depending on the varietal characteristics o dark gray forest soils of the Nizhniy Novgorod region. The study was carried out on varieties Margarita, Marusya and Sofia. In connection with this problem, above-mentioned issues are relevant to the present day. Rising the yields of spring wheat to the level of its genetically determined potential is only possible with an increase in photosynthetic productivity of crops, primarily due to the proper selection of varieties for specific soil-climatic zones. Cropping pattern should provide the absorption of at least 2% of PAR. The main absorbing body is a leaf. Therefore the need for a crop with optimum leaf surface area. The study revealed the following, the maximum leaf area of plants of spring wheat is formed in earing seed treatment by Nano-Gro. On average, during the growing season net photosynthesis productivity of Margarita variety was 4.5-5.7 g/m2, Maroussia - 4.6-4.8 g/m2 and Sofia - 3.8-5.2 g/m2. Maximum values of net photosynthetic productivity of crops are characterized by variations in seed treatment by Nano-Gro and Margarita variety. The highest efficiency (2.46, 2.57 and 2.55 kg by 1000 units) was observed on the leaves treated by Nano-Gro and the efficiency of Coefficient of performance (COP) of photosynthetically active radiation (PAR) is 1,54-1,81 %. Margarita and Marussia were characterized by maximum values of productivity of leaf and Coefficient of performance (COP) of photosynthetically active radiation (PAR).


Author(s):  
Александр Васильевич Празукин ◽  
Юрий Константинович Фирсов ◽  
Александр Александрович Латушкин ◽  
Анна Алексеевна Чепыженко

Морские травы экологически важны, но чрезвычайно уязвимы перед антропогенными изменениями в прибрежных зонах, которые влияют на доступность света в этих экосистемах. При разной высоте Солнца над горизонтом в зондирующем режиме проводилось одновременное измерение значений температуры воды и интенсивности фотосинтетически активной радиации (IPAR) по профилю полога Zostera noltii Hornemann (высота полога 32 см.) в мелководной части Казачьей бухты (г. Севастополь, Черное море, 44°57′26″ с.ш., 33°40′33″ в.д.). Для полога Z. noltii характерен одномодальный тип вертикального распределения биомассы с максимумом (65,7 г (сухой массы) / м2) в его нижней части. Рассматривается изменение температурной стратификации и распределения IPAR по профилю растительного полога Z. noltii в течение светового дня. Seagrass is environmentally significant but extremely vulnerable in coastal areas to anthropogenic changes, which affect light availability. Simultaneous measurements of water temperature and photosynthetically active radiation (PAR) intensity in the sounding mode were taken at different solar elevation angles for the Zostera noltii Hornemann canopy (canopy height 32 cm) in shallow waters of the Cossack Bay (Sevastopol, the Black Sea, 44°57′26″ с.ш., 33°40′33″ в.д.). Z. noltii canopy is characterized by a unimodal type of biomass vertical distribution with its maximum (65,7 g (dry matter)/m2) in the lower part. Temperature stratification and IPAR distribution changes within the Z. noltii vegetation canopy profile during daylight hours are considered.


2008 ◽  
Vol 35 (10) ◽  
pp. 867 ◽  
Author(s):  
Xiping Wang ◽  
Yan Guo ◽  
Xiyong Wang ◽  
Yuntao Ma ◽  
Baoguo Li

The three-dimensional (3-D) radiation distribution model in plant canopy is pivotal for understanding and modelling plant eco-physiological processes. Diffuse and direct radiations penetrate into plant canopies in different ways and may present different intensity and wavelength composition. Sunfleck (the canopy surfaces where the direct radiation reaches) distribution in the plant canopy is usually regarded as an important index for crop development, especially under dense canopy conditions. Distributions of direct and diffuse components of photosynthetically active radiation (PAR) in maize (Zea mays L.) canopies were estimated respectively using a 3-D incident radiation model (3DIRM). The 3DIRM model was set up for computing incident radiation in crop canopies by applying a parallel-projection based submodel for direct solar radiation and a central-projection based submodel for incident diffuse radiation simulation in crop canopy. It was well assessed with a field experiment with multi-point PAR measurement in maize canopies with relative errors of 2.6, 4.5 and 2.6%, respectively, for sunfleck area ratio, diffuse PAR and total PAR. The results suggest that the 3DIRM model could be used to estimate the direct, diffuse and total PAR at any specific surface part in the 3-D canopy space. The exponential distinction model for direct, diffuse and total PAR along with leaf area index in different heights in maize canopies was also evaluated based on the 3DIRM simulation results.


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