This investigation was carried out to better understand the effects of nitrogen stress on the growth and yield of tomato （Solanum lycopersicon L.）. Seeds of S. lycopersicon （Ife No. 1 variety） were collected from ...This investigation was carried out to better understand the effects of nitrogen stress on the growth and yield of tomato （Solanum lycopersicon L.）. Seeds of S. lycopersicon （Ife No. 1 variety） were collected from the Osun-State Ministry of Agriculture, Oshogbo, Nigeria and planted in analyzed top soil. The plants were grown for a period of five weeks within which they were supplied with water and kept under optimum environmental conditions that enhanced normal growth. After this period, the plants were subjected to different levels of nitrogen stress which include： plants supplied with dis- tilled water only （n）, plants supplied with complete nutrient solution （N）, plants supplied with nutrient solution in which nitrogen concentration sources was increased by a factor of 5 （N5）, and plants supplied with nutrient solution in which nitrogen concentration sources was increased by a factor of 10 （N10）. Analysis of Variance （ANOVA） results shows that there is no significant effect of stress on the growth and morphological parameters of tomato plants. However, there was a significant effect of nitrogen stress on the yield parameters. Nitrogen stress also caused an increase in the number and size of fruits produced in plants subjected with high nitrogen concentration.展开更多
Rice(Oryza sativa L.)is one of the most important cereal crops in the world.Bakanae disease is a significant rice disease widely distributed in rice-growing regions worldwide.Therefore,the present investigation aimed ...Rice(Oryza sativa L.)is one of the most important cereal crops in the world.Bakanae disease is a significant rice disease widely distributed in rice-growing regions worldwide.Therefore,the present investigation aimed to assess the optimal concentrations of paclobutrazol(PBZ)as a treatment for rice grains(cv.Sakha 108)to control bakanae disease,also evaluating its impact on grain germination,seedling growth parameters as well as disease index.Paclobutrazol concentrations had no significant impact on seed germination,regardless of whether the seeds were incubated with Fusarium fujikuroi or not.Application of PBZ,either alone or in combination with fungal pathogens,negatively impacted the rice seedlings’height.Paclobutrazol at 25,50 and 100 mg/L,combined with the fungal pathogen positively impacted root length.Paclobutrazol at 3 and 6 mg/L mitigated the adverse impact on chlorophyll pigments content in infected seedlings.The highest proline contents were achieved by 100 mg/L PBZ alone or in combination with fungal pathogens.It has been observed that the application of PBZ,either alone or in combination with a fungal pathogen,leads to the enhancement of catalase,peroxidase,and polyphenol oxidase activities.The median lethal concentration of PBZ was 0.874 mg/L;applying low concentrations of paclobutrazol effectively increased the percentage of fungal growth suppression.Application of PBZ,at higher concentrations(50 and 100 mg/L),decreased infection percentage and disease severity index(DSI)significantly.These findings suggest that PBZ can be an effective treatment for controlling bakanae disease and enhancing resistance in rice plants.展开更多
Grapevines are preferentially grown under mild to moderate water stress conditions to achieve the best compromise between wine quality and quantity.Water status detection for advanced irrigation scheduling is frequent...Grapevines are preferentially grown under mild to moderate water stress conditions to achieve the best compromise between wine quality and quantity.Water status detection for advanced irrigation scheduling is frequently done by predawn leaf water potential(ΨPD)or leaf stomata conductance(gL)measurements.However,these measurements are time and labor consuming.Therefore,the use of infrared thermography(IRT)opens up the possibility to study large population of leaves and to give an overview on the stomatal variation and their dynamics.In the present study IRT was used to identify water stress of potted grapevines.In order to define the sensitivity of IRT measurements to water stress,the IRT-based water status information were compared with simultaneously measuredΨPD and gL data.Correlations between IRT-based CWSI data on the one hand and gL andΨPD on the other showed the potential of IRT for water stress detection.However,the CWSI calculation procedure is laborious and the sensitivity of CWSI for water stress detection still needs to be improved.Therefore,further improvements are necessary in order to apply remote IRT-based systems for irrigation scheduling in the field.展开更多
文摘This investigation was carried out to better understand the effects of nitrogen stress on the growth and yield of tomato （Solanum lycopersicon L.）. Seeds of S. lycopersicon （Ife No. 1 variety） were collected from the Osun-State Ministry of Agriculture, Oshogbo, Nigeria and planted in analyzed top soil. The plants were grown for a period of five weeks within which they were supplied with water and kept under optimum environmental conditions that enhanced normal growth. After this period, the plants were subjected to different levels of nitrogen stress which include： plants supplied with dis- tilled water only （n）, plants supplied with complete nutrient solution （N）, plants supplied with nutrient solution in which nitrogen concentration sources was increased by a factor of 5 （N5）, and plants supplied with nutrient solution in which nitrogen concentration sources was increased by a factor of 10 （N10）. Analysis of Variance （ANOVA） results shows that there is no significant effect of stress on the growth and morphological parameters of tomato plants. However, there was a significant effect of nitrogen stress on the yield parameters. Nitrogen stress also caused an increase in the number and size of fruits produced in plants subjected with high nitrogen concentration.
基金supported and funded by Deanship of Scientific Research,Vice Presidency for Graduate Studies and Scientific Research,King Faisal University,Saudi Arabia(KFU241897).
文摘Rice(Oryza sativa L.)is one of the most important cereal crops in the world.Bakanae disease is a significant rice disease widely distributed in rice-growing regions worldwide.Therefore,the present investigation aimed to assess the optimal concentrations of paclobutrazol(PBZ)as a treatment for rice grains(cv.Sakha 108)to control bakanae disease,also evaluating its impact on grain germination,seedling growth parameters as well as disease index.Paclobutrazol concentrations had no significant impact on seed germination,regardless of whether the seeds were incubated with Fusarium fujikuroi or not.Application of PBZ,either alone or in combination with fungal pathogens,negatively impacted the rice seedlings’height.Paclobutrazol at 25,50 and 100 mg/L,combined with the fungal pathogen positively impacted root length.Paclobutrazol at 3 and 6 mg/L mitigated the adverse impact on chlorophyll pigments content in infected seedlings.The highest proline contents were achieved by 100 mg/L PBZ alone or in combination with fungal pathogens.It has been observed that the application of PBZ,either alone or in combination with a fungal pathogen,leads to the enhancement of catalase,peroxidase,and polyphenol oxidase activities.The median lethal concentration of PBZ was 0.874 mg/L;applying low concentrations of paclobutrazol effectively increased the percentage of fungal growth suppression.Application of PBZ,at higher concentrations(50 and 100 mg/L),decreased infection percentage and disease severity index(DSI)significantly.These findings suggest that PBZ can be an effective treatment for controlling bakanae disease and enhancing resistance in rice plants.
文摘Grapevines are preferentially grown under mild to moderate water stress conditions to achieve the best compromise between wine quality and quantity.Water status detection for advanced irrigation scheduling is frequently done by predawn leaf water potential(ΨPD)or leaf stomata conductance(gL)measurements.However,these measurements are time and labor consuming.Therefore,the use of infrared thermography(IRT)opens up the possibility to study large population of leaves and to give an overview on the stomatal variation and their dynamics.In the present study IRT was used to identify water stress of potted grapevines.In order to define the sensitivity of IRT measurements to water stress,the IRT-based water status information were compared with simultaneously measuredΨPD and gL data.Correlations between IRT-based CWSI data on the one hand and gL andΨPD on the other showed the potential of IRT for water stress detection.However,the CWSI calculation procedure is laborious and the sensitivity of CWSI for water stress detection still needs to be improved.Therefore,further improvements are necessary in order to apply remote IRT-based systems for irrigation scheduling in the field.
