• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.159-163
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• 2005

This study was conducted to investigate the effect of simulated acid rain (SAR) on growth and antioxidant system in french marigold (Tagetes patula L.). Plants were subjected to four levels of SAR (pH 5.6, 4.0, 3.0, 2.0) in the growth chambers for 2 weeks. SAR decreased both plant height and plant dry weight of french marigold. As the pH levels decreased from 5.6 to 2.0, the content of MDA highly increased linearly. The ratios of dehydroascorbate/ascorbate and oxidized glutathione/reduced glutathione were significantly increased with decreasing pH levels. The enzyme (superoxide dismutase, ascorbate peroxidase etc.) activities of the plant affected by SAR were increased as the pH decreased. Based on the results, SAR caused oxidative stress in french marigold and resulted in significant reduction in plant growth. Biochemical protection responses might be activated to prevent the plant from damaging effects of oxidative stress generated in SAR.

• Korean Journal of Plant Resources
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• v.20 no.4
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• pp.348-352
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• 2007

To investigate the effects of soil pH on plants, the seedlings of french marigold (Tagetes patula L.) was transplanted into the soils acidified with $H_{2}SO_{4}$ solutions (pH 5.3, 4.5, 3.9, 3.5). The level of malondialdehyde was significantly increased by soil acidification. As the pH levels decreased from 5.3 to 3.5, the contents of dehydroascorbate and oxidized glutathione of the plant were significantly increased. The antioxidative enzyme activities of the plant affected by soil acidification were increased as the pH decreased.

• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.71-78
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• 2024

Among the various environmental conditions necessary for growing crops, light is closely related to the anthesis. This study aimed to determine the optimal photoperiod affecting floral differentiation in an edible flower, marigold, to efficiently cultivate the crops in a closed-type plant factory. The experiment was conducted with photoperiods of 4, 8, 12, and 16 hours. French marigold (Tagetes patula L.) 'Durango Red' seeds were sown in polyurethane sponges, and the photoperiod treatments were applied immediately. The extent of floral differentiation was examined at 2-3 day intervals, defined as the visible appearance of flower buds at least 2 mm in size. The growth parameters such as shoot fresh weight and dry weight, height, and leaf area were measured. The optimal photoperiod was determined based on the days when the floral differentiation had occurred in 50% of the total plants. In the 4-hour treatment, proper growth and flower buds did not appear. From the 8-hour treatment, the plant grew normally, and floral differentiation occurred, however, the 8-hour treatment showed the slowest floral differentiation compared to the 12 hours treatments or more. The 12- and 16-hour treatments didn't show significant differences in floral differentiation. While the 16-hour treatment exhibited the highest results in all growth parameters, it was not significantly different from the 12-hour treatment except for shoot dry weight and leaf area. According to the results, 8 hours of photoperiod induced floral differentiation. However, more time was required for flower bud formation, and plant growth was significantly lower compared to photoperiods of 12 hours or more. Considering the energy consumption and its growth, the optimal photoperiod for marigold was 12 hours.