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
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.
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.
