• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.20-27
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• 1996

Greenhouse experiment was carried out to investigate the specifics in growth, weed competition, and herbicide response of soybean(Glycine max) under foggy condition. Plant height and leaf stage of soybean under foggy condition were greatly increased through all growing stage comparing with non-foggy condition. At 100 days after seeding, plant height of soybean also was increased by 14％ while number of pods, number of grains per pod were reduced by 16, 24 and 23％, respectively comparing with non-foggy condition. On the other hand, plant height of soybean under foggy condition was reduced with increasing the duration of competition and this tendency was similar to non-foggy condition. Plant height was reduced by above 50-day competition. Number of pods per plant of soybean was reduced regardless of foggy condition. Among the herbicides treated, quizalofop caused slightly crop injury under foggy condition, but the other herbicides did not affect growth of soybean. Number of pods and 100-grain weight of soybean by treatment of herbicides were similar to that of the untreated control but those of soybean under foggy condition were significantly reduced. At 40 days after herbicide application, weeding efficacy (based on shoot fresh weight) of herbicides treated under foggy and non-foggy condition, released exellent data(above than 97％) in all regardless foggy condition.

• Current Research on Agriculture and Life Sciences
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• v.2
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• pp.34-41
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• 1984

This study was conducted to investigate yearly changes of weeds occurring in orchard and to evaluate an effect of continuous herbicide application on weed population in apple fields. Digitaria sanguinalis, Cephalonoplos segetum, Calystegia hederacea, Polygonum aviculare, Echinochloa crus-galli, and Portulaca oleracea were observed to be the problem weeds in orchard with yearly similar species for a three-year, showing D. sanguinalis was single dominant species for a three-year experimental period. An increase of Simpson's index from 0.22 in the first year to 0.33 in the 3 rd year was observed in the oxyfluorfen treated plot, indicating that most of the weed species were well controlled, while in the untreated plot, D. sanguinalis was relatively single dominant species showing Simpson's index, 0.56 in the 1st year and decreased to 0.32 in the 3 rd year meaning diversification of weed species, and the same trend was also observed in community dominance. Dissimilarity coefficient, 41.6, observed in the weed populations of 1st year and 2nd year, increased up to 58.8 between 1st year and 3 rd year's weed populations in the oxyfluorfen treated plot, indicating that weed community was greatly affected by oxyfluorfen treatment. Based on 3 year's dry weight oxyfluorfen treatment controlled 95 % of weeds such as $149.3g/m^2$ dry weight in the untreated control plot, with a little yearly changes of dry weight. Composition of perennial and biennial weeds was about 59% in the herbicide treated plots and 30% in the untreated control, showing a relative increase of these weeds in the treated plot. However, total dry weight of these weeds was markedly low, showing less than 5% of the untreated one. An annual, D. sanguinalis composed of 70% of total dry weight in the untreated control.

• 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.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.1-9
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• 1997

The survey of weed community in paddy field was carried out to investigate the changes of weed species on 340 fields in Kyonggi Area in 1995, that is almost same condition as sampled in 1991. The weed species observed include 3 species of grasses, 5 species of sedges and 14 species of broadleaf and other weed. Herbicide treatment system in one time treatment vs more than two time treatment was 34:66 percentage. About 25 percentage among one time treatment system was used butachlor G. Ratio of annual weed vs perennial weed was 38:62, and then perennial weed ratio was high. Major dominant weed species were Sagitaria trifolia, Eleocharis kuroguwai, Echinochloa crus-galli, Bidens tripartita and Monochoria vaginalis. Weed occurrence was decreased as order of normal soil, poorly drained soil and saline soil. Dormant weed species were S. trifolia, E. kuroguwai, E. crus-galli and B. tripartita in normal soil and were S. trifolia, E. kuroguwai, E. crus-galli and Polygonium hydropiper in poorly drained soil, and were Scirpus planiculmis, S. trifolia and E. kuroguwai in saline soil. Weed occurrence was increased with delaying the transplanting time; dominant weed species were S. trifolia, E. kuroguwai, E. crus-galli and M. vaginalis in May transplanting field and were E. kuroguwai, S. trifolia, and C. serotinus in June transplanting field. Weed occurrence was decreased as order of non-plowing transplanting field, autumn plowing and spring plowing paddy field. Dominant weed species were S. trifolia, E. kuroguwai, E. crus-galli and M. vaginalis in autumn plowing, were S. trifolia, E. kuroguwai, E. crus-galli and B. tripartita in spring plowing, and were E. crus-galli, S. hotarui and S. trifolia in non-plowing transplanting field.

• Korean Journal of Weed Science
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• v.4 no.1
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• pp.79-87
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• 1984

Herbicidal effects of alachlor to peanuts were observed under different formulations (granule containing 5.0% a.i. and emulsifiable concentrate containing 43.7% a.i.) and levels (granule with 3 and 6kg/l0a and emulsion with 300㏄/l0a) with the transparent polyethylene (P.E.) film mulching. Formulations and levels of alachlor did not affect emergence ratio, time of emergence and flowering, and early growth of peanuts such as the number of leaves and branches, length of branches; and shoot dry weight at 20 and 40 days after planting, but early growth was enhanced by P.E. film mulching. At harvest, weed dry weight was positively correlated with length of branches, but negatively correlated with the number of branches and shoot dry weight. Acalyphu australis and Chenopodium album were not effectively controlled by the application of alachlor and growth of C. album was retarded under P.E. film mulching. Portulaca oleracea and Digitaria sanguinalis were effectively controlled by alachlor, but they were not affected by P.E. film mulching. At harvest, D. sanguinalis, A. australis, and Echinochloa crus galli were predominant weeds in all treatments; persistence of alachlor may not be long enough to control even sensitive weeds to alachlor such as D, sanguinalis in the field of peanuts of which canopy development was relatively slow. Weed dry weight at harvest was negatively correlated with the number of pods and grain yield of peanuts. Among the yield components only the number of nods per plant was positively correlated with grain yield. Hana weeding after July 1 increased grain yield of Peanuts even in alchlor applied plots.

• Korean Journal of Organic Agriculture
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• v.19 no.2
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• pp.255-272
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• 2011

This work studied the growth and yield of green crops, changes of mineral composition in greenhouse soil and green crops, and infection with wintering green crops cultivation in greenhouse field. At 74 days after seeding of wintering green crops, dry matter was 710kg/10a in rye, 530kg/10a in barley, 230kg/10a in hairy vetch, and 240kg/10a in bean or weeds. Total nitrogen content in green crops was 4.5% in pea and hairy vetch, and 3~4% in barley and rye. $P_2O_5$, CaO, and MgO contents in all green crops were about 1.0%, and $K_2O$ content was the highest level by 4~5% among macro elements. Total nitrogen fixing content in shoot green crops uptaken from soil was 22.1kg/10a in rye, 20.6kg/10a in barley, 10.6kg/10a in hairy vetch, and 9.6kg/10a in pea and giant chickweed. $P_2O_5$ fixing content in shoot green crops uptaken from soil was 8.4kg/10a in rye, 6.3kg/10a in barley, and 2.3 kg/10a in hairy vetch and pea. $K_2O$ fixing content in shoot green crops uptaken from soil was 28kg/10a in rye, 24.7kg/10a in barley, and 11kg/10a in hairy vetch and pea. CaO fixing content in shoot green crops uptaken from soil was 2~3kg/ 10a in all green crops, and MgO fixing content was 1.7~2.6kg/10a in all green crops. Pepper growth in no-tillage was not a significant difference at all green manure crops. The number of fruit and fruit weight were higher in control, pea, hairy vetch and harvest barley than rye and barley. Soil mineral compositions in wintering green crops increased at pH, organic matter, CEC compared with control. Soil chemical compositions were stable level at green crops cultivation according as decreases of EC, available phosphoric acid, Ca, and Mg contents. After no-tillage by green manure crops, pH in soils was higher in green manure crops than control. EC content in soils was lower in green manure crops than control, and was remarkably low level in barley harvest. Organic matter content in soils increased in hairy vetch and barley green manure but decreased by 35% in barley harvest. Total nitrogen and avaliable $P_2O_4$ content in soils remarkably increased but was not a significant difference at all green manure crops. Cation (K, Ca, and Mg) content in soils decreased by 15~20% in K, 2~11% in Ca, and 3~6% in Mg at rye, barley and pea compared with control.

• Korean Journal of Weed Science
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• v.11 no.2
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• pp.128-136
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• 1991

This experiment was conducted to evaluate the effect of plant growth regulators, dichlorprop and MCPB on the reduced effect of fruit drop and fruit quality before and after storage in apples. Dichlorprop was tested with dilution of 1000 at 30, 40, 50 days before harvesting, and MCPB with dilution of 4000 at 15, 25, 35 days before harvesting. The results are summarized as follows : Percentage of fruit drop was appeared to the notable reduction as compared with the untreated control when regulators was applied with dilution of 1000 at 30 days before harvesting by dichlorprop and with dilution of 4000 at 35 days before harvesting by MCPB. Degree of fruit colour showed to the remarkable promotion at all the treatment of 30, 40, 50 days before harvesting by dichlorprop as compared with the untreated control. Sugar contents in flesh was increased a little at the treatment of 30 days before harvesting by dichlorprop, but acid contents in flesh was reduced at all the treatment of 30, 40, 50 days before harvesting by dichloroprop and at 15, 25, 35 days before harvesting by MCPB. Passed firmness of fruit after storage was maintained at the treatment with dilution of 4000 at 35 days before harvesting. Therefore, it was repressed a softening of fruit, but by dichlorprop treatment at 30, 40, 50 days before harvesting, fruit firmmess was appeared to reduce according to the passage of storage period. Amount of ethylene evolution after storage was showed to reduce at all the treatment by early treated time of dichoroprop and MCPB, but carbon dioxide increased at treatment conditions such as the front. Accordingly, these relationship showed to be contrary each other.

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.236-240
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• 2016

Weeding measures is an important issue for cereal crop because weed is superior to crops in early growth stage and there are not many herbicides applicable to cereal crop. Since the concern about well-being and eco-environmental products are increasing, cultivation with polyvinyl chloride (PVC) is needed. Five treatments included as weed-free, control (not remove weed) and covering with polyvinyl chloride removed 20, 30, 40 DAS (day after seeding). At removing PVC, plant height did not differ depending on the growth stage. However, weed-free plot by weed competition were somewhat short. And, removing PVC accelerated the earlier by 2-3 day than weed-free plot. Soil moisture which removed from the control was higher than 20, 30, 40 DAS and weed-free, and it was kept low by evaporation. The chlorophyll meter of weed-free plot was 34.3, 30 DAS was 40.6 at heading time. Weed-free showed that increased in weed population $300.8g\;m^{-2}$. Weed control value of 20 DAS, 30 DAS, 40 DAS were 86.5%, 84.0% and 74.8%, respectively. In 30 DAS, yield of foxtail millet according to treatment of removing PVC were $355kg\;10a^{-1}$. At weed competition early in 30 DAS, the removing PVC was good for control. Thus, 30 DAS was judged to be suitable.

• Korean Journal of Weed Science
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• v.9 no.2
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• pp.97-102
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• 1989

1. IAA showed no significant growth of root primordia and then lateral root emerged at 2 days after IAA treatment. BA treatment, however, strongly inhibited the formation of root primordia and a few lateral roots, if any, emerged about 5 days after treatment. 2. Treatment of BA and Indol-B on the water retaining ability sampled 1, 3, 5 days after chemical treatment was apparent on the soybean sprouts sampled 5 days after treatment while the difference among the treatments was negligible when sampled 1 and 3 days after treatment. 3. BA stimulated ABA content in the hypocotyl while inhibited ABA content in the root of soybean sprouts. ABA may relate with water retaining ability. 4. Soaking the soybean seeds to several seed disinfectant chemical solution had no effect on the growth and elongation of soybean sprouts. 5. It can be recommended that container of soybean sprouts should be shut tight during growing period except irrigation because the ethylene accumulation in the container may stimulate hypocotyl swelling and inhibit length of soybean sprouts.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.200-208
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• 2010

The objectives of this study were to evaluate no-tillage cover crop cropping systems for organic farming in paddy. The experiment was performed at Ihyeon series (silt loam: 9.1% sand, 73.0% silt and 17.9% clay) which affected by different management practices. Planthopper population per 20 plant was significantly higher 65.3 for conventional tillage with chemical compounds (control) compared with 3.4~9.6 for no-tillage treatments (without rice straw or green manure, amended with rice straw, hairy vetch, rape, rye, and Chinese milk vetch). Also, disease severity of sheath blight was significantly higher 10.5% for control compared to 0.7~2.9% for no-tillage treatments. Four weed species, namely Monochoria vaginalis, Ludwigia prostrata, Rotala indica, and Aneilema keisak occurred in no-tillage paddy, whereas Monochoria vaginalis occurred in control only. The pH, available phosphate, and microbial biomass C in paddy were steeply decreased in response to submerging, but increased at first heading stage. Soil $NH_4$-N content at first heading stage was significantly higher in no-tillage treatments compared with control. The grain yield was significantly higher in 4.30 Mg $ha^{-1}$ for control than other treatments. Meanwhile, rice productivity was significantly higher in 2.69 Mg $ha^{-1}$ for no-tillage amended with Chinese milk vetch compared to other no-tillage treatments. The number of panicle per plant, grain number perpanicle, and percent ripened grain were highly related for increasing the yield of rice. These results show that Chinese milk vetch was optimum cover crop for organic farming in no-tillage paddy.