• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.2
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• pp.141-151
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• 2002

The success of sericulture industry in India is mainly attributed to the well-planned annual sericultural activity and the systematic implementation of pest preventive and control measures. The insect spectrum of silkworm and its food plants is complex and plays a major role in limiting the production of silk. Insects cause extensive damage to plant whereas predators and parasites either kill the silkworm larvae or force them to spin flimsy cocoons. Unilateral control measure against this pest is mainly based on the use of synthetic organic insecticides. Though these approaches initially paid rich dividends, the undesirable consequences soon surfaced. Insecticide induced resurgence of gall midges, leafhopper, leaf roller, secondary pest out breaks and development of pest biotypes has led to realization of Integrated Pest Management in sericulture. Various components of IPM, viz. Host plant resistance, cultural practices, biological control, chemical control and integrating them at various technological levels have been studied. Sources of host plant resistance have been identified for some of the major insect pests. High yielding mulberry variety has been propagated and their resistances towards major pests have been recorded. Cultural practices like pruning, pollarding, judicious use of nitrogen, optimum spacing and weed management have preyed to be the powerful tools in containing pests. Natural control over the pest population build- up exerted by the wide range of parasitoids, predators and pathogens has been well documented with identification of natural enemies and studies on their potential. Augmentation, through inoculation or inundative releases of parasitic arthropods, is the most direct way of increasing the numbers of these beneficials in sericulture.

• Proceedings of the Korean Society of Crop Science Conference
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• 2001.09a
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• pp.72-90
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• 2001

Environment agriculture carried out from 1999 in Daeho reclaimed saline area, located in central east cost of Choongnam Korea, resulted in dramatic reduction of amount of nitrogen fertilizer and application times and amount of pesticides. The ecological status of Daeho reclaimed saline area was considered to still very sound from the results of ecological survey on flora and fauna. However, it was desirable to adapt precision agriculture for production of high eating quality of rice and preservation of Daeho ecosystem. Especially, precise application of nitrogen and phosphorus fertilizer was recommendable for prevention of water pollution in environment rice cultivation by duck or mud snail or crab. The bioefficacy of Scirpus maritimus and Echinochloa crus-galli in paddy field of environment rice cultivation by duck or mud snail or crab in Daeho reclaimed saline area was revealed very low. Therefor, it was concluded that the pre-measures of reduction of natural weed population were necessary for successful environment agriculture. The most desirable and ideal environmentally sound agriculture in Daeho reclaimed saline area was performance of crop rotation, introduction of legume crops and green manure crops, and also, simultaneous management of crop production and animal husbandry for smooth flow of energy cycle within the closed Daeho ecosystem.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.76-81
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• 2013

This study was performed to find the effective post-emergence herbicides to control of Poa annua that has already emerged from the soil in Kentucky bluegrass. A total of 8 treatments consist of various post-emergence herbicides applied at recommended concentration or lower concentration than recommended concentration to prevent Kentucky bluegrass injury in this study. Methiozolin showed the least injury in Kentucky bluegrass during 40 days after treatments and there were no footprints by methiozolin in creeping bentgrass green during 20 days. However, Poa annua control was 60.4%, which was less than those of other 7 treatments in this study. Both of asulam sodium and iodosulfuron plus asulam sodium exhibited the higher Poa annua control of 81.7% and 82.2% respectively without serious injury in Kentucky bluegrass during 40 days, and they showed a slight footprints damage in creeping bentgrass green. On the other hand, critical Kentucky bluegrass injuries and the vivid and numerous footprints were occurred in treatments of trifloxysulfuron-sodium, foramsulfuron, rimsulfuron and flazasulfuron, even though they were applied with only 1/4 of recommended concentration. Methiozolin is available to reduce gradually Poa annua population on Kentucky bluegrass without severe turfgrass damage. Asulam sodium or iodosulfuron plus asulam sodium could be useful to remove Poa annua by spot treatment but it is prohibited to spray directly on green even spot.

• Korean Journal of Weed Science
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• v.12 no.4
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• pp.352-361
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• 1992

The identification of the stoneworts, euglenoids and diatoms which were collected from paddy rice fields was conducted in 1991. In the division Charophyta. Chara braunii Gmelin was identified. Two species in the genus Euglena, 1 species in the genus Phacus and 3 species in the genus Trachelomonas were identified in the division Eugrenophyta. The total number of species identified as the diatoms was 21 species in 6 families including 5 species in the Coscinodiscaceae, 3 species in the Fragilariaceae, 1 species in the Achanthaceae, 9 species in the Naviculaceae, 1 species in the Cymbellaceae and 2 species in the Nitzschiaceae. Generally, a concentrated population of Eulgena on paddy water caused green water blooms, but the color of the water blooms at the cyst formation stage was changed to red. In soil flakes with brown tint, the diatoms belonging to the order Pennales were numerous in microscopic view.

• Weed & Turfgrass Science
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• v.6 no.1
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• pp.40-54
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• 2017

The mound grave of Korean traditional funeral culture is a unique habitat which is a Zoysiagrass lawn being sustainable in proper management. We phytosociologically described an unusual Zoysiagrass vegetation with Gueldenstaedtia verna by the Zürich-Montpellier School's method and analyzed eco-floristic characteristics. A new association, Gueldenstaedtio-Zoysietum japonicae ass. nov. hoc loco, was identified and subdivided into festucetosum ovinae, typicum, and trifolietosum repensae. The subassociations were distinguished by the difference in species composition resulting from site accessibility and lawn management method. The association was assigned as not only a regional but also a locally-limited vegetation type, which distributes on a particular microhabitat with strong continentality in the Daegu regional subdistrict of Bioclimatological division. The Zoysiagrass vegetation of Korea was considered as a continental type apparently different from the oceanic type of Zoysion japonicae (Miscanthetea sinensis, Caricetalia nervatae). Mound graves in Korea should be acknowledged as a meaningful habitat for the in-situ conservation of biodiversity and phytocoenosen, despite being a secondary grassland of Gueldenstaedtio-Zoysietum japonicae.

• Weed & Turfgrass Science
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• v.5 no.1
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• pp.29-34
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• 2016

Large patch disease in Zoysia japonica Steud. is the most destructive disease in turfgrass. For large patch management, it has been dependent on chemical controls but pesticides are harmful to soil, water and biodiversity. In this study, we evaluated 4 Streptomyces spp. strains (S2, S5, S8 and S12) which were selected in previous studies using metagenome approaches. Root colonization of the strains, large patch suppressing effect and the pathogen density change in actual golf course were investigated to evaluate biological control potential of the strains. All strains exhibited reliable root colonization ability that strains populations were higher than $6log\;cfu\;g^{-1}$ in turfgrass rhizosphere. The pathogen density, with S8 treatment, was detected average of 0.7 after a week and average of 1.2 after 4 weeks. Disease control and suppressive the pathogen population by S8 strain showed higher efficiency than other strains. S8 was applied in an actual golf course for the large patch control and pathogen density. The pathogen density in S8 treatment plot was detected below 1.6 per toothpick and lower compared with untreated plot. The results indicated that pathogen density was suppressed by S8 and the stain has great potential as a biological control agent for the large patch.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.166-172
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• 1992

The identification on blue-queen algae which were collected from paddy rice fields of the whole nation was carried out in 1991. The blue-green algae identified were 20 species in 5 families including 7 species in the Chroococcaceae. 1 species in the Chamaesiphonaceae. 1 species in the Pleurocapsaceae, 6 species in the Nostocaeae and 5 species in the Oscillatoriaceae. Among the blue-green algae, 6 species in 4 genera including Cylindrospernum, Anabaenopsis, Anabaena and Nostoc were characterized by heterocysts concerning with nitrogen fixation capacity. A concentrated population of Oscillatoria spp. induced soil flakes with blue tint in paddy rice fields. The genera. Spirulina and Oscillatoria, showed their specific motility.

• The Plant Pathology Journal
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• v.29 no.3
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• pp.260-273
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• 2013

The incidence and distribution of Tobacco mosaic virus (TMV) and related tobamoviruses was determined using an enzyme-linked immunosorbent assay on 1,926 symptomatic horticultural crops and 107 asymptomatic weed samples collected from 78 highly infected fields in the major horticultural crop-producing areas in 17 provinces throughout Iran. The results were confirmed by host range studies and reverse transcription-polymerase chain reaction. The overall incidence of infection by these viruses in symptomatic plants was 11.3%. The coat protein (CP) gene sequences of a number of isolates were determined and disclosed to be a high identity (up to 100%) among the Iranian isolates. Phylogenetic analysis of all known TMV CP genes showed three clades on the basis of nucleotide sequences with all Iranian isolates distinctly clustered in clade II. Analysis using the complete CP amino acid sequence showed one clade with two subgroups, IA and IB, with Iranian isolates in both subgroups. The nucleotide diversity within each subgroup was very low, but higher between the two clades. No correlation was found between genetic distance and geographical origin or host species of isolation. Statistical analyses suggested a negative selection and demonstrated the occurrence of gene flow from the isolates in other clades to the Iranian population.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.268-268
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• 2022

Protein is a major nutrient of food and has long been studied for nutritional and utility value. Among them, rice protein is attracting attention because of its hypoallergenic characteristics and nutritional value. Mutant DM225 with increased protein content was selected by EMS treatment on the weed rice Dharial. QTL analysis of Protein content was carried out using BC₂F₂ populations derived from a cross between "Hanareum2" as a recurrent parent and "DM225" as a donor parent. The protein content of populations was between 5~11%, with an average of 7.7%. To identify QTLs related to Protein content, 117 KASP markers(polymorphic ratio: 15%) showing polymorphisms between the parents were genotyped for the BC₂F₂ population. One QTL was detected between markers SK07 06 and SK07_10 on chromosome 7(LOD: 28.1). This QTL explained 71.4% of the phenotypic variance for Protein content. This QTL will be useful for protein-related rice breeding program.

• Journal of Ecology and Environment
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• v.47 no.4
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• pp.250-260
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• 2023

Background: Crabgrass (Digitaria ciliaris, Poaceae) is a globally distributed weed, including in Afro-Eurasia, America, and Australia. As a highly gregarious plant, crabgrass is an important habitat for a diverse array of insects, and a potential habitat for agricultural pests. To compare the insect communities associated with the crabgrass community, insects were sampled using sweep sampling (100 sweeps per sample) at five sites, including Daejeon (Daejeon and Gap rivers), Anseong, Namhae, and Inje, with a focus on the Daejeon River. Results: A total of 5,888 individual insects belonging to eight orders, 42 families, and 115 species were collected from the five sites. Both the number of species and individuals of Hemiptera were the highest at all of the sites. In the present study, 73% of the insect population fed on D. ciliaris as a host plant. The dominant species in the D. ciliaris community was Laodelphax striatellus (Delphacidae), being ubiquitous at all the sites which showed a high abundance of rice pests in the communities and the suitability of D. ciliaris as an alternative host plant for them. The Shannon-Wiener diversity index was highest in Inje on 17 September (2.88), and the Chao1-bc diversity index was highest in the Gap River on 5 September (80). The sampling efficiency of 100 sweep samples (sample coverage) was calculated to be as high as 90%. The results of the samples taken from September to November in the Daejeon River showed that the number of species and individuals decreased gradually over time, and the number of dominant species decreased sharply between September and October. Similarity analysis indicated that sampling dates that were closer together yielded sampled assemblages with higher faunal similarity. In addition, in each sampling, the difference in the minimum temperature during the two-week period prior to sampling and faunal similarities were negatively correlated. Conclusions: This study provides foundational data that could enhance our understanding of insect diversity in D. ciliaris. The data can facilitate ecological conservation and management of Korean grasslands generally, as well as identification of potential pests that may disperse from D. ciliaris communities to nearby farmland.