• Korean Journal of Weed Science
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• v.31 no.1
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• pp.8-23
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• 2011

Weeds are one of the major constraints to crop production in organic farming systems. This paper reviews major results and techniques achieved with physical, cultural, and biological weed control and their perspectives in organic agriculture. Physical methods includes mechanical, thermal, lighting, electrocution, pneumatic, autonomous robot weeding control techniques. Cultural weed control methods includes mulching, tillage, crop rotation, cover crops and crop competition. Physical and cultural weed control techniques are especially important in organic farming crops where other weed control options are limited or not available without use of herbicides. Biological weed control includes mycoherbicides, innundative biological control, broad-spectrum biological control and allelopathy. Successful weed management in organic farming requires well managed integrated systems of mechanical control using newly developed machines, cultural control and biological control methods. Weed management decision-aid models may also needed to develop to provide greater assurance of achieving profitability and appropriate long-term weed management in organic farming in the future.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.802-811
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• 1996

Farmers need alternatives for weed control due to the desire to reduce chemicals used in farming. However, conventional mechanical cultivation cannot selectively remove weeds located in the seedline between crop plants and there are no selective heribicides for some crop/weed situations. Since hand labor is costly , an automated weed control system could be feasible. A robotic weed control system can also reduce or eliminate the need for chemicals. Currently no such system exists for removing weeds located in the seedline between crop plants. The goal of this project is to build a real-time , machine vision weed control system that can detect crop and weed locations. remove weeds and thin crop plants. In order to accomplish this objective , a real-time robotic system was developed to identify and locate outdoor plants using machine vision technology, pattern recognition techniques, knowledge-based decision theory, and robotics. The prototype weed control system is composed f a real-time computer vision system, a uniform illumination device, and a precision chemical application system. The prototype system is mounted on the UC Davis Robotic Cultivator , which finds the center of the seedline of crop plants. Field tests showed that the robotic spraying system correctly targeted simulated weeds (metal coins of 2.54 cm diameter) with an average error of 0.78 cm and the standard deviation of 0.62cm.

• Korean Journal of Environmental Agriculture
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• v.42 no.1
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• pp.63-70
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• 2023

Golden apple snails (Pomacea canaliculat) (GAS) are widely used for weed control in rice cultivation. However, concerns on the ecological risk of invasive GAS species are increasing. This study aimed to evaluate the overall impacts of GAS on weed control, abundance of aquatic animals and insects, and rice yield, in comparison with that from other biocontrol agents such as loach (Misgurnus mizolepis) and catfish (Silurus asotus), which are alternatives for biological weed control in rice paddy cultivation. Field experiments included five treatments; control, herbicide, GAS, loach, and catfish. During the rice growth, weed appearance and biological abundance were monitored, and at harvest, the rice yield was determined. Weed control efficiency was the highest for GAS treatment (100%), followed by that for herbicide (95.8%), loach (57.5%), and catfish treatments (31.7%). Insect abundance was considerably decreased in GAS treatment due to heavy weed removal, which affects the habitat of aquatic animals and insects. The amount of rice yield (unit: kg 10 a^-1) was in the order of GAS (798.9) > loach (708.1) = herbicide (700.7) > catfish (629.4) > control (496.0). Therefore, considering the weed control efficiency, biological abudance, and rice yield, loach could be a potential alternative for biological weed control in organic rice farming. However, the activity of the biocontrol agents are susceptible to environmental conditions; therefore, further studies under different conditions are essential to confirm these findings.

• Korean Journal of Weed Science
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• v.32 no.3
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• pp.273-279
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• 2012

This experiment was conducted to determine a potential effective biological weed control and/or rice young seedling injury by golden apple snail (Pomacea canaliculata) at wet hill seeded rice field. The rice seeds used were treated by iron-coating. The efficacy of weed control as affected by golden apple snail has been tested with twice applications of young golden apple snails of 12 kg (24,000 young snails, $0.5g{\pm}10%$ per young snail, 30~40 days after hatching) per ha at the same day after harrowing and applied with rate of 10 kg (20,000 young snails) per ha at 15days after seeding, respectively. The comparison of this experiment was of the conventional machine transplanted rice paddy field in terms of weed control and rice plant injury as a visual grade. The weed efficacy was of 100% similar with the conventional paddy field which was applied by systematic herbicides of pre-emergence and post-emergence chemical herbicides and there was 1~3% significant rice young seedling injury but no yield losses and grain quality due to the input of golden apple snail.

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.103-111
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• 2011

Monochoria vaginalis var. plantaginea (Pontederiaceae) is one of the most problematic weed in the rice field in Korea. Tanysphyrus (Tanysphyroides) major was selected as a potential biological control agent for M. vaginalis. Continuous rearing of T. (T.) major was carried out from 2006 to 2007, and its morphological characteristics and ecological characteristics were investigated. This species has a single generation per year, over-wintering as an adult stage. The emergence of adults starts in later June and last until September. These observations indicate that T. (T.) major takes $22{\pm}0.7$ days to develop from egg to adulthood. Host specificity test showed that finally selected this species was suitable candidates for the biological control of M. vaginalis var. plantaginea since it showed negative host specificity against major 60 test crops.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.15-18
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• 2003

Contemporary biological control system includes the use of fungi to control weeds in agricultural ecosystems and forests. Fungal pathogens of weeds that are highly virulent and specific to target weeds, and able to be produced massively by artificial culture could be applied like chemical herbicides over the weeds.(중략)

• Korean Journal of Organic Agriculture
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• v.6 no.2
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• pp.127-140
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• 1998

Organic farming excludes any use of the herbicide. The present paper reviews what can be done for effective weed control with existing weed control technology by farmers crop-ping paddy rice, field crops, vegetables, and fruit trees. If condition of the crop-land-al-lows diversified rotational use of the paddy land as paddy and upland field would minimize weed problem. Practising this is limited in acreage due to extremely limited governmental investment to the land for the purpose. Secondly, rotation of crops in the upland field breaking life cycles of various weeds adapted to each crop should reduce the weed problem. This is also limited as only a few crops are making the farmer profitable. In addition climate and tolerance of crops to high and low temperature. Monsoon rains and poor drainage restrict the freedom of choice. For any crop land year-round multiple cropping in denser planting shall lessen the weed problem, this multiple cropping practiced by 1960s has been abandoned due to laborshortage and increased production cost. Deep flooding the rice is impractical at present in Korean. Mulching crop with transparent, black , or combinated polyethylene sheet, hs been in-creasingly used. Progresses in development and use of mulch with allelopathic crop residues. inexpensive paper mulch, allelopathic crop residues, inexpensive paper mulch, allelopathic crop cultivar development, recently developed ex-perimental weeding machinaries, flamers, microbial herbicides, biological control organisms, soil sterilization techniques have been critically reviewed for their adoption into existing in-tegrated weeding system. Unfortunately, information on cost-benifit, and labor-benefit, for the various methods above mentioned are lacking. Urgent need for the research on rational weeding in organic farming, and herbicide low-input farming is emphasized.

• Weed & Turfgrass Science
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• v.3 no.4
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• pp.354-361
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• 2014

This study was conducted to investigate whether several composted liquid manures (CLMs) are useful for biological control of large patch on zoysiagrass and investigate the chemical and biological factors to suppress large patch in soil treated with CLMs. The CLMs were produced at 4 different facilities for livestock excretion treatments located in Korea. Field experiments were carried out at 5 golf courses located near each facility. CLM and Chemical fertilizer (CF: water soluble fertilizer, 20-20-20) were applied four and three times with N at $12g\;m^{-2}$ per year, respectively. There was significant increase of concentration of K, Na, and Cu of soil treated with CLM compared to CF treatment. Among experimental plots, CN and GG2 plot sites were shown significant higher effect of biological control 80% and 50% respectively against large patch disease. The number of bacteria, Actinomycetes, and fungi in soil at these sites significantly increased and fluorescein diacetate hydrolytic activity was enhanced, while the soil was treated with CLM. The results of this study demonstrated that CLM application has effect on soil to suppress large patch and reduce the use of fungicide in environment-friendly turf management.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.405-416
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• 2019

Weeds are a serious problem in crop production. Use of synthetic herbicides is rapidly increasing in weed management worldwide including Korea. Herbicide application reduces the time spent on weed control. However, the evolution of resistance to herbicides in weeds has become widespread as a natural response to selection pressure imposed by agricultural management activities. If an herbicide with the same mechanisms of action is used repeatedly and intensively, it can rapidly select for a weed biotype that shifts toward difficult-to-control becoming a more tolerant weed and lead to the evolution of herbicideresistant weeds. Moreover, agricultural and biological factors have an important role in the development of herbicide-resistant weed populations. Mitigating the evolution of herbicide resistance in weeds relies on reducing selection through the diversification of weed control techniques. The resistance management of weeds in the future will strongly depend on intensive cropping systems. The current situation of intensive cropping systems with their heavy reliance on the efficacy of chemical weed control will not lead to significant containment of this problem. Therefore, management strategies need to overcome the further spread of herbicide resistance in weeds in Korean crop production. This review presents the current information on herbicide resistance in Korea and factors controlling the development of herbicide resistant weeds.

• The Korean Journal of Mycology
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• v.51 no.3
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• pp.245-249
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• 2023

Prickly lettuce (Lactuca serriola), an invasive annual plant, poses a significant threat to the agricultural systems of many countries, including Korea. In 2020, leaf blight symptoms were observed in the prickly lettuce populations of various farms across Korea. Detailed morphological and molecular sequence analyses revealed that the disease was caused by the fungus, Curvularia intermedia. A pathogenicity test confirmed that the fungus can cause the same symptoms in healthy prickly lettuce, thereby fulfilling Koch's postulates. To the best of our knowledge, this is the first report of C. intermedia causing leaf blight on L. serriola in Korea, suggesting its potential as a biocontrol agent for this weed. However, further investigations are necessary to determine its ecological impact to prevent any non-target effects.