Effect of air humidity in dark period on growth, transpiration, nutrient uptake and dry matter production in cucumber young plants
2003
Sakiyama, H. (Chiba-ken. Agricultural Experiment Station (Japan)) | Dan, K. | Imada, S. | Udagawa, Y.
Summary In order to clear the effects of air humidity in dark period, four relative humidity levels, 99,80,60 and 40% were investigated in cucumber young plants. 1. Plant height and fresh weight were maximum at R.H.99%, which increased in dark period. Fresh and dry weight of leaves and stems increased maximally at R.H.99%. Dry matter content of leaves was lower at R.H.99%. 2. Although transpiration rate per fresh weight in dark period increased with lower humidity within the range, R.H.40-99%, which in light period was almost same. 3. The amount of absorption of P, K, Ca, and Mg per increased fresh weight was higher at R. H.60-80%, and which was significantly lower at R. H. 99%. It was closely related with uptake of nutrient solution and transpiration. 4. The Relative growth rate of dry weight was not affected by relative humidity in dark period. The net assimilation rate was almost equal over R.H.60%. 5. From results described above, relative humidity in dark period had no effect on dry matter production, but had effected shape, growth, transpiration and nutrient uptake in cucumber young plants.
Показать больше [+] Меньше [-]