• Journal of Life Science
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• v.13 no.1
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• pp.9-14
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• 2003

Seed germinability might be highly related to seedling establishment. The experiments were carried out to evaluate the effect of presowing treatments of aging, priming, $GA_3$ , prechilling and water imbibition, different temperatures and light quality during germination on germination of gourd (Lagenaria siceraria Standl.) seeds. Aging treatment with different temperatures and periods was done by the accelerated aging method. Priming using KNO$_3$ and $GA_3$ treatment for 24 hours were done at 100 mM and at 0.01 mM before a week prechilling. The germination tests using a week prechilled seeds were done at 10, 20 and $30^{\circ}C$ on the condition of darkness, and also with blue, red, far-red light and darkness as light quality treatments. FR-yongjadaemok and FR-kunghap were used as test cultivars and their daily germination rates were measured at treatment levels. Germination rates were reduced in the seeds aged at $45^{\circ}C$ for 6 days. Prechilling showed the highest and fastest rate among the four presowing treatments but the two other presowing treatments had similar or less rates than water imbibition. Prechilling done before sowing enhanced the low vigor seeds, and accelerated the germination of cv. FR-kunghap at 20 to $30^{\circ}C$ and with blue, red light or darkness during germination although far-red light inhibited their germination.

• Korean Journal of Environmental Agriculture
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• v.20 no.3
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• pp.180-185
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• 2001

Control effects of phosphorous acid were investigated on Phytophthora blight of red pepper plants in greenhouse and field. In vitro test, the mycelial growth of Phytophthora capsici was inhibited by the phosphorous acid more than 97% at 1,000 ${\mu}g$ and 10,000 ${\mu}g$ a.i./mL in the liquid and solid culture, respectively. At concentration of 10 ${\mu}g$ a.i./mL of phosphorous acid, in the liquid culture the mycelial growth of P. capsici was inhibited 46.2%, however inhibited only 4.9% on the soild culture. Zoosporangial formation was also inhibited 89.1% by phosphorous acid at 100 ${\mu}g$ a.i./mL. Phosphorous acid affected more zoosporangial formation of P. capsici than its mycelial growth. At the concentrations of 10,000, 1,000 and 100 ${\mu}g$ a.i./mL of phosphorous acid, germination of zoosporangia was inhibited 100, 84.3 and 44.2%, respectively. Mycelial growth and zoosporangial formation of P. capsici were little affected at the concentration of 10 ${\mu}g$ a.i./mL of phosphorous acid. Cermination of zoosporangia was also little affected at this concentration, however growth of the germ tubes was inhibited and the abnormal mycelial growth was observed. Phosphorous acid suppressed the incidence of Phytophthora blight of red pepper plants up to $77.0{\sim}62.0%$, in greenhouse. Phosphorous acid suppressed the incidence of Phytophthora blight of red pepper plants up to 54.0% at the conventional culture in field. Treatments of phosphorous acid increased up to 113% in height, 135% in number of fruit, and 129% in weight of fruit.