• Korean Journal of Weed Science
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• v.17 no.3
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• pp.281-287
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• 1997

Growth and anatomical responses of rice and barnyardgrass(Echinochloa crus-galli) to oxyfluorfen were examined under various growing conditions in a greenhouse. With foliar application at 0.08kg ai/ha 7 days after seeding or transplanting, oxyfluorfen completely reduced the shoot and root growth of barnyardgrass under all growing conditions. However, oxyfluorfen reduced the growth of direct seeded and transplanted rice by 0~64% and 0~12%, respectively. Phytotoxic effect on rice growth, with respect to plant height and shoot fresh weight, was more pronounced under water(53~63%) than under dry-condition(16~33%), and in broadcast-seeded(34~62%) than in drill-seeded rice(16~33%). Anatomical changes of epidermal and vascular bundle sheath cells of rice leaves were not induced by oxyfluorfen, but mesophyll cells were partially ruptured and total leaf thickness was reduced. Oxyfluorfen, however, constricted and ruptured mesophyll and vascular bundle sheath cells and severely reduced leaf thickness of barnyardgrass under all growing conditions examined. These anatomical changes were more severe under dry- than under water-seeded condition.

• Korean Journal of Weed Science
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• v.14 no.2
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• pp.144-155
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• 1994

Scanning electron micrography and Transmission electron micrography studies were performed on the surfaces of stem(coleoptiles) of rice and barnyardgrass under various cropping patterns at 5 days after seeding or transplanting. Stem surfaces of rice under dry condition possessed rodlet-like epicuticular waxes, trichomes, stomata and cork cell layer in both broadcast and drilled rice while barnyardgrass had only thread-like epicuticular waxes, but trichomes, stomata and cork cell layers were not found. However, rice under water condition has no rodlet-like waxes, stomata and cork cells, and barnyardgrass was similar to that under dry condition. On the other hand, those on stems of 8-day and 25-day transplanted rice were well arranged and developed compared with those of direct seeded rice. Electron micrography showed significant difference in thickness of outer epidermal cell walls of rice and barnyardgrass under dry, water and transplanting condition. Thickness of outer epidermal cell was greater in transplanted rice, dry direct seeded rice, water-direct seeded rice and barnyardgrass in descending order.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.1
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• pp.77-86
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• 1980

Asking to change the cropping patterns to save the labor and capitals in paddy rice cultivation, the study was intended to know the weed problems under the various possible cultural systems; namely, direct seeding (in broadcast and row), machine transplanting and hand transplanting. Under the conditions as weedy check plots, paddy yields were significantly variated among cropping systems, and the functions of panicle No. and spikelet No. to the yield were neglected, among others. However, the yield and yield components were narrowed among cropping systems, and the function of spikelets number per area was comparatively improved to the others.