M. rahmnpourazar; jalal tabatabaei; Sahebali Bolandnazar
Abstract
Nitrate is an essential component for plants and vegetables are of the most important source of nitrate for human being. It is estimated that vegetables provide 92 % of nitrate for human nutrition. The positive and negative effects of elevated root zone CO2 on growth and yield of some plants have been ...
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Nitrate is an essential component for plants and vegetables are of the most important source of nitrate for human being. It is estimated that vegetables provide 92 % of nitrate for human nutrition. The positive and negative effects of elevated root zone CO2 on growth and yield of some plants have been reported. This study has been conducted in order to examine the effect of root zone CO2 on growth and nitrate accumulation in lettuce. The experiment was conducted as a completely randomized design with four levels of CO2 (0, 200, 400 and 600 ml per minute) and with five replication on two cultivars of lettuce (Sativa and Capitata). The study performed in floating system and aeration was supplied by air pump. The results showed that injection of CO2 had significant effect on the fresh and dry weight of leaves, stems and roots of plants. By increasing the concentration of CO2 fresh and dry weight of leaves, stems and roots increased in both cultivars. Photosynthesis efficiency increased in both cultivars in the treatment of 400 ml/min root zone CO2. The influence root zone CO2 significantly decreased nitrate content in leaves of lettuce. Nitrate concentration in the leaves of lettuce was decreased by injection of root zone CO2 in L.sativa. var. Capitata in the treatment of 400 ml/min and in L.sativa. var Sativa in the treatment 600 ml/min. respectively by 27% and 47.6%. With increasing input root zone CO2 increased activity of nitrate reductase enzyme in both cultivars that showed highest content in treatment 400 ml/min.
G. Chenarani; Mahmoud Shour; Ali Tehranifar; S.H. Nemati; Gholam Hossein Davarynejad
Abstract
CO2 enrichment in greenhouse is a suitable way which reduces production time, better growth vigor and also higher plant quality. The main aim of this study was to find out the effects of artificial CO2 enrichment under different light levels on rooting of the ornamental foliage Codiaeum variegatum. The ...
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CO2 enrichment in greenhouse is a suitable way which reduces production time, better growth vigor and also higher plant quality. The main aim of this study was to find out the effects of artificial CO2 enrichment under different light levels on rooting of the ornamental foliage Codiaeum variegatum. The experiment was planned as a split plot based on a completely randomized design. CO2 was considered as the main plots (380 as control, 750 and 1050 ppm) and these light intensities as the sub plots (10000 as control, 12000 and 14000 Lux) were used. Results showed a significant increase on measured traits with elevating levels of CO2 and light. Highest measured values of different traits were observed at 12000 Lux light intensity and 750 ppm CO2 enrichment. Light intensity × CO2 interaction had a significant effect on leaf length, leaf number, root quality, root volume, root length (P≤0.01) and rooting percentage at (P≤0.05). Spad chlorophyll unit was not noticeably significant. Rooting and plant growth generally raised along with both light intensity and CO2 elevation.
