• Korean Journal of Weed Science
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• v.14 no.3
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• pp.223-227
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• 1994

Basis for differential response of rice and E. crus-galli to cyhalofop-butyl ester (R-butyl 2-(4-(4-cyano-2-fluoro-phenoxy)phenoxy)propionate) was anatomically compared. Cell division in the growing point of E. crus-galli was severely inhibited by the herbicide, leading to malformation and irregular arrangement of cells. The inhibitory symptom of rice by cyhalofop-butyl ester appeared to be very similiar to that of E. crus-galli although its injury was negligible in rice when applied at the rate of 180ppm.

• Korean Journal of Weed Science
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• v.16 no.3
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• pp.176-180
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• 1996

In order to estabilish a labour-saved and environmental protected paddy rice system in Southern Korea, new system, called no-tillage paddy system, was proposed and investigated from 1988 to 1996. Under the no-tillage paddy system, occurrence pattern, control value and regrowth of water foxtail each treatment(herbicides and application dates), and occurrence of volunteer rice plant in application dates of herbicide were investigated. The growth of water-foxtil was markedly increased from middle of May and no. of tillers and dry weight of water-foxtail increased up to 3rd crop year in no-tillage. Glyphosate application for control of water-foxtail was 20 days before transplanting. And when the soil under the no-tillage paddy system in May 1 and May 10 application of herbicide machine-transplanted with 8-day-old seedlings missing hills were increased compared to April 20 and early growth stages of machine transplanted of rice in April 20 applications of herbicide showed increased plant height, no. of tillers of rice, occurrence of volunteer rice plants from the shattered seeds were 1,600plants/10a and decreased in May 10 compared to April 20 and May 1.

• Weed & Turfgrass Science
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• v.2 no.3
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• pp.322-326
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• 2013

This study was tried to control the weedy rice using minimum tillage direct seeding of rice on dry paddy. Minimum tillage direct seeding on dry paddy is tilled with 4 cm in width at 27 cm intervals by 1-shaped rotary blade. Using this cultivation method can control weedy rice effectively by minimizing the soil disturbance. In this study, weedy rice was firstly emerged at April 28 in 2012. After 11 days emergence rate of weedy rice at May 9 was 61.9%. At this time rice was sown and then herbicides was treated at 10 and 15 days after sowing. When herbicides was treated at 10 days after sowing the control effect was 89-96%, and when treated at 15 days the control effect was 97-99%. However emergence of weedy rice differ according to the year and year. It was thought to be affected by April average temperature and total precipitation. So, for effective weedy rice control and stable rice yield, it was considered that irrigation at April 15-20 to induce the emergence of weedy rice is required.

• Korean Journal of Weed Science
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• v.31 no.4
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• pp.401-404
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• 2011

Bromobutide, a paddy field herbicide, can effectively control annual and perennial weeds. It has an excellent weeding effect especially against Monochoria vaginalis and Scirpus juncoides etc. When it is mixed with other herbicides controlling weed spectrum and application timing can be broaden. Bromobutide has stable weeding effects regardless of field and weather conditions, and there is almost no phyototoxic effects to rice.

• Proceedings of the Korean Society for Information Management Conference
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• 2000.08a
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• pp.129-132
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• 2000

GIS(Geographic Information System) tool has been applied to determine a spatial difference of weed population density in paddy field and it has introduced to rice yield difference among counties as well as to rice blast in Korea. There was highly difference between sampling sites in terms of spatial analysis which may imply to be able to apply this tool for the precesion agriculture in the 21 century.

• Proceedings of the Korean Society of Crop Science Conference
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• 1989.05a
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• pp.16-17
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• 1989

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.4
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• pp.437-443
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• 1995

Concerns on use of excess amount of chemical fertilizier and pesticide in current farming system turns both of the producer and consumer of agricultural products to an organic farming which use a less chemicals and more natural manure. Rice-duck farming system is one of the strategy to meet the purpose and this experiment was carried out to find the effect of the rice-duck farming system on the quality and yields of rice. 20day-old rice seedling were mechanically transplanted in sandy-loam paddy field and 21 day-old ducks were raised from 3 weeks after transplanting with population of 30 heads per 10a. The plots were consists of reduce fertilizer(70%) with and without duck-raising. The conventional fertilizer treatment without duck-raising was used as check. The results obtained are summarized as follows. The weeds population of test plots which were raised with duck for 3 consecutive years was less than that of test plots without duck-raising, though a speciffic population of Echinochola crusgallis were increased. The weed control effect was higer in duck-raising than in check at the maximum tillering stage but, not at later stages of rice plant. It was found that the small animals and insects inhibiting in the rice field were reduced by duck-treatment, however, there were also damages of grass leaf roller at booting stage in the plots of duck-raising. In rice-duck plot, dark green leaf color were found: 41.8 of SPAD value than 38.6 of SPAD in check plot. Higher root activity and surface soil oxidation were also observed in rice-duck plot than check plot. 3% of the increase in yield was observed by duck-treatment. However, the expected increase of the palatability wsa not observed. This may be due to the unfavorable weather conditions during the rice growing in this expriment.

• Korean Journal of Weed Science
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• v.16 no.4
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• pp.337-345
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• 1996

This study was conducted to investigate the protox activity, the PPIX accumulation and the activity of antioxidative enzymes of the oxyfluorfen-tolerant and -susceptible rice cultivars by oxyfluorfen and oxytluorfen-similar herbicides treatment. When treated with acifluorfen, bifenox or oxadiazon, the oxyfluorfen-tolerant rice cultivars showed less decreased in fresh weight than the susceptible rice cultivars. The inhibition of protox activity was in the order of acifluorfen > oxyfluorfen > bifenox > oxadiazon, and the PPIX accumulation was in the sequence of oxadiazon > acifluorfen > oxyfluorfen > bifenox. The inhibition of protox activity and the PPIX accumulation by the herbicide was greater in the susceptible rice cultivars than in the tolerant rice cultivars. The effect inhibiting the decrease of chlorophyll content resulting from the treatment of GC, tetrapyrrole biosynthesis inhibitor, was in the order of oxyfluorfen > acifluorfen > bifenox > oxadiazon, and the tolerant rice cultivar had more than the susceptible rice cultivar. In the treatment of DPE and oxadiazon, the activities of MDAR, POX and GR was higher in the tolerant rice cultivar than in the susceptible rice cultivar, and in the case of POX isozyme the activities of main D and E bands increased in the tolerant rice cultivars at tested herbicides but they didn't in the susceptible rice cultivar.

• Korean Journal of Weed Science
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• v.14 no.1
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• pp.62-70
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• 1994

This study was conducted to find out if there are some differences in germination, growth and morphological characteristics between rice(Oryza saliva) and barnyardgrass(Echinochloa crus-galli) under various cropping patterns and to abtain the fundamental information on weed control method in direct seeded rice. Rice was broadcast on soil-surface(Broadcast rice), drill seeded in soil(Drilled rice) and barnyardgrass was drill seeded in soil(Barnyardgrass) under dry(Dry condition) and water direct seeded condition(Water condition). Also rice was transplanted with 8-day seedlings(8 -day-old seedling) and 25-day seedlings(25-*day-old seedling) under transplanting condition(Transplanting condition) At 1, 2, 3, 5, 7, 10, 15 and 20 days after seeding or transplanting(DAS/T), plants were harvested to examine their germination, growth and morphology. The major results were as follows ; Until 5 DAS/T growth of rice and barnyardgrass were well established under dry condition but under water condition growth of shoots was mainly elongated. At 20 DAS/T barnyardgrass had greater plant height and shoot fresh weight than rice under direct seeded condition, while plant height and shoot fresh weight of rice was greater than those of barnyardgrass under transplanting condition. Root length of barnyardgrass was greater under the dry, drilled, direct seeded conditions than that of rice under the water, broadcast, transplanting condition, respectively. And root fresh weight of rice under direct seeded condition was similar to that of barnyardgrass but that of rice under transplanting condition was significantly greater than that of barnyardgrass. Barnyardgrass only formed mesocotyls and its length increased with increased depth of seeding. Leaf stage and leaf area of barnyardgrass was greater under the dry, drilled than those of rice under water, broadcast conditions, respectively, while those of rice was greater than those of barnyardgrass under transplanting condition. Chlorophyll contents were higher in barnyardgrass, dry direct seeded rice, transplanted rice, water direct seeded rice in descending order.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.1
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• pp.73-78
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• 2017

This study was conducted to elucidate the effects of mulching materials on root growth characteristics and weed occurrence of Platycodon grandiflorum transplants (3 years old) in organic farming. After transplanting, roots were mulched with one of three mulching materials (biodegradable film, sawdust, or rice husks) or a control (no mulching). The average root diameter of all mulching groups was 28.1 mm, which was 5.1 mm thicker than the no-mulching treatment. Roots with the biodegradable film treatment were the thickest at 30.9 mm. Root length was the shortest, 22.0 cm, with rice husk mulching. The number of rootlets was the highest with film mulching (36.0 rootlets/root) and the lowest with no mulching. For root fresh weight, which directly affects yield, the average of treated and untreated roots was 100 and 56 g/root, respectively. The highest fresh weight was in the biodegradable film plot (130 g/root). The mulching treatment groups showed a weed inhibition effect compared with the no-mulching treatment. The dominant weeds with the no-mulching treatment were Setaria viridis and Digitaria ciliaris, and that with the mulching treatment was Setaria viridis. Average annual weed occurrence across all treatments was 72%. Weed occurrence was the highest with the no-mulching treatment ($125weeds/m^2$), and there were no weeds with the biodegradable film treatment.