Maryam Chavoushi; Khosrow Manoochehri Kalantari; Mohamad Javad Arvin
Abstract
Salinity stress is one of the main limiting factors for optimum agricultural productivity of safflower, Carthamus tinctorius L., in arid and semi-arid regions. It could leads to significant changes in plant biochemical, physiological, and growth traits. Salinity induced endogenous rise in jasmonic acid ...
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Salinity stress is one of the main limiting factors for optimum agricultural productivity of safflower, Carthamus tinctorius L., in arid and semi-arid regions. It could leads to significant changes in plant biochemical, physiological, and growth traits. Salinity induced endogenous rise in jasmonic acid and its methyl esters (MeJA) has been reported. In the present study, effects of salinity stress (6 and 12 ds m-1) and the exogenous application of MeJA (0.1 and 0.5 mM) on the leaf number, shoot fresh weight, shoot length, chlorophyll a/b, soluble sugar, proline, and malondialdehyde (MDA) contents were investigated in two safflower varieties (Isfahan and IL111). Salinity stress negatively affected the growth of both varieties. Lipid peroxidation was not observed in Isfahan variety, but it significantly increased in the salinity resistant safflower, IL111. Soluble sugar and proline as the important osmoprotectants and free radical scavengers were elevated by salinity stress. Exogenous application of MeJA to the salinity stress-imposed plants slightly improved the growth due to inductions in the rate of photosynthesis; however, MeJA application impaired the growth of non-stressed plants because of induction of stomatal closure and as a result reduced photosynthesis.
David Kiprono Rutto; Elizabeth Omami; Julius Ochuodho; Lucas Ngode
Abstract
Production of Mrenda (Corchorus olitorius) in Kenya has been low due to various reasons, such as poor agronomic practices like incorrect fertilizer rates. Observations from the Mrenda growing areas showed that there is high unmet demand for crop in local market and even for export. This is due to yields ...
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Production of Mrenda (Corchorus olitorius) in Kenya has been low due to various reasons, such as poor agronomic practices like incorrect fertilizer rates. Observations from the Mrenda growing areas showed that there is high unmet demand for crop in local market and even for export. This is due to yields being low, 2-4 tons/ha as compared to expected yield of 5-8 tons/ha. Therefore, the main objective of this study was to discern effect of Nitrogen fertilizer on growth and yield of Mrenda (Corchorus olitorius) morphotypes. Seed samples were planted at two sites of University of Eldoret and Kenya Agriculture and Livestock Research Organization, Kitale using Randomly Complete Block Design with three replicates and three levels of nitrate (Calcium nitrate) fertilizer. Five plants were tagged and the following traits were recorded: plant height, number of branching at main stem, number of pods and fresh leaf yield. Results showed highest N fertilizer rates had most effect exhibited by Morphotypes GT and BT on plants height; plant branching; pods number per plant and yield weight per plant respectively. Use of no N fertilizer caused lowest plant height, branching at main stem, pods and leaf weight per plant by Morphotypes GT and BT. It is concluded that Mrenda is N loving plant as it enhanced its growth when high amount of Nitrogen fertilizer was applied. It is recommended farmers use high N fertilizer for Mrenda production.
