• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1493-1495
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• 1997

Cropping of head and tail ends of rod in wire Rolling Process is required to aviod roll damage, and prevent cobbles. In order to reduce the crop loss, the new crop control system for rotary shear of Wire rolling Process has been developed. Performance shows the developed system cut precisely within setting length. As a result, it is expected to increase the yield ratio of products about 0.2 percent and stabilize the operantional condition.

• International Journal of Industrial Entomology and Biomaterials
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• v.4 no.2
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• pp.133-136
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• 2002

Whitefly, Dialeuropora decempuncta (Quaintance rind Baker) (Homoptera: Aleyrodidae) has attained the major pest status in mulberry, causing 24% crop loss by sucking the leaf juice and manifesting leaf curl, chlorosis and sooty mould desease during monsoon season in West Bengal, India. The assessment of economic threshold revel is an essential component for formulating the management practices. Experiments were carried out by inoculating five different densities of whitefly viz.,10, 20, 30, 40 and 50 adults on covered mulberry plants in glass houses. From the findings, it was observed that irrespective of released density, no crop loss was observed in the initial period. But with the passing of days, the percent crop loss was increased rapidly. The linear relationship between percent crop loss and number of adults released was established to highlight the significance of economic threshold. The statistical analysis in the linear form of equation showed that initial population of 10, 20, 30, 40 and 50 whiteflies/plant causes 3%, 12%, 21%, 30% and 40% crop loss in a period of 28 days which is equivalent to 57 kg, 247 kg, 437 kg, 626 kg and 816 kg leaf/acre. Execution of management practices (spray of 0.01% monocrotophos) are economical to the farmer whenever the loss is above 247 kg/acre, but below which application of control measures is not economical. From this study, it can be inferred that the economic threshold level far whitefly is 20 individuals/plant beyond which a farmer has to take appropriate control measures.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.1
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• pp.73-82
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• 1994

This paper presents the experimental results of runoff and soil losses from sloping runoff plots under three cropping practices. Twenty-nine runoff plots having slopes of 10, 20, and 30 percent in gradient, and lengths of 10, 20 and 30 meter, respectively, were cultivated with soybean, alfalfa, and fallow conditions during 1989~1990 seasons. Crop stages were grouped based on crop canopy conditions and the cropping management factors of the Univer- sal Soil Loss Equation were derived as ratios of the soil losses to fallow conditions. The results from this study are summarized as follows : 1. Annual rainfall erosivity factor at Ichun station varied from 127 to 1336, averaging 472 and 200 in 1989. The month variations reach the peak in July, being 19& 2. Canopy cover percent for soybean that was taken by a photographic method increased sharply during 30 to 80 days after seeding and the results were used to identify periods for the six crop stages. 3. Annual average runoff rates from soybean and alfalfa plots were 35 and 16 percent of those from fallow ones, respectively. The runoff rates decreased as the crops grew. 4. Soil losses from soybean and alfalfa plots were 14 and 16 percent of those from fallow plots. And the crop coefficients were proposed for different crop stages.

• Journal of Biosystems Engineering
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• v.6 no.1
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• pp.48-59
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• 1981

The major limiting factor on the determination of combine capacity is the frequent occurence of clogging over the some parts of machine when the crop is wet in the case of Japanese self-feeding type combine. And in the case of American conventional combine having big separating parts, the great grain loss and damage occur when the machine is used for rice harvesting. This experiment was carried out to develop the new type threshing and separating equipment. Proto-type thresher which consist of a conical threshing drum and a conical separating sieve rotating around the threshing cone was constructed and tested. In the case of 800 rpm of threshing cone speed, average threshing loss was below 1 percent, separating loss was about 1 percent, grain damage was about 0.4 percent, and average total power required was about 2.6 PS. This design has some problems such as higher power required or wrapping problems under the conditions of feeding long damp straw. But, compared with the conventional combine or thresher, this machine certainly has some potentials for this approach to combine development. The crop feed rate must be increased through improvement of the feeding portion of the threshing cone. And it is required to investigate further about some parameters causing wrapping phenomena.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.1
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• pp.17-28
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• 2007

To understand the spring freezing injury symptoms during sensitive growth stage and yield loss of barley and wheat, field tests were done by using vinyl mulching and natural cold weather. The growth stage sensitive were booting, spikelet differentiation and flower organ development stages for both crops. However, barley and wheat differed in their growth responses, in that barley was less affected than wheat. For instance, barley recorded 28 percent dead ears, 10 percent dead plants and 18 percent ear degenerations while wheat recorded higher values of 59 percent, 44 percent and 44 percent, respectively. Although there were no recorded froze-resistant varieties in both barley and wheat, some showed tolerance as their yields were not affected by freezing stress. The 'Chalbori' cultivars of barley and 'Geurumil' and 'Chokwang' cultivars of wheat recorded steady yields. The yield components of barley and wheat that were greatly affected by freezing stress were the number of spike per square and the number of grain per spike. The major cause of yield loss in Suwon 259 and Kangbori was the number of spike per square but not the number of grain per spike. The study showed, however, that both the number of spike per square and the number of grain per spike were vulnerable to freezing and that which contribute much to yield loss of barley and wheat.

• International Journal of Industrial Entomology and Biomaterials
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• v.38 no.2
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• pp.31-37
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• 2019

Silkworm larval mortality specifically during spinning stage leading to non-spinning with specific morphological symptoms was frequently complained by sericulturists in Karnataka, India during 2015. Survey was conducted and information collected through questionnaire from the identified farmers who faced the problem of non-spinning in both traditional and non-traditional areas of Karnataka. Survey results indicate that the problem is specific to the silkworm crop of those farmers' who shifted from other crops of agriculture/ horticulture/olericulture/ floriculture to Sericulture. Silkworm rearing performance of the batches fed with these leaves confirmed that the pesticide sprayed to the crops previous to mulberry, remain in the soil and when mulberry plantation is taken up in these gardens, the pesticide is absorbed by the roots of mulberry plants and transported to the leaves. Silkworms that feed on these mulberry leaves, grow and ripen normally but during spinning stage, larvae die with external symptoms like regurgitation, body shrinkage, rectal protrusion later become hook shaped leading to non-spinning or partial metamorphosis into pupa and death or spin flimsy cocoons. Larval mortality ranged from a minimum of twenty five percent to a maximum of hundred percent. The problem was noticed from the first harvest of leaves and lasted for a maximum period of 36 months. Cocoon crop loss depends on the concentration, duration and type of pesticides used previously for other crops.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.4
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• pp.81-85
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• 1980

Field experiment was conducted to determine the optimum harvesting time in winter rape (Brassica napus L.) by investigating the percent oil, 1, 000 seed weight, seed yield, dehiscent pod ratio and oil yield at 46, 50, 54, 58, 62, 66 and 70 days after flowering. Variation of all characters with days after flowering could be explained significantly by second degree polynomial equations. Percent oil and 1, 000 seed weight increased until 62 days after flowering and thereafter these traits decreased, while seed yield increased to 58 days after flowering and thereafter this trait decreased. This controversy was due to the drastic increase in dehiscent pods beyond 58 days after flowering which brought loss in seed yield. These results suggest that optimum harvesting time is 58 days after flowering and it should not be later than 60 days after flowering.

• Korean Journal of Medicinal Crop Science
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• v.16 no.3
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• pp.188-191
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• 2008

Poncirus trifoliata Rafinesque has been used as the immature fruit of the trifoliate orange tree. This study was carried out to investigate the quality change of Poncirus trifoliata Rafinesque depending on packing materials (vacuum packing, PP (polypropylene) packing, gunny sack packing), storage places and storage periods up to 12 months. The change of loss on drying content, content of poncirin were measured during the 12 months. As a result, the loss on drying content was decreased rapidly in gunny sack packing after storage of 12 months at room temperature. The content of poncirin was decreased generally according to storage conditions and its average loss percent was 38.8%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.27 no.4
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• pp.291-295
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• 1982

The biosphere of the earth is not only about to overpass the limit to meet the food demand of the world but also the stability of its food production has been also jeopardized by the disasters and pests, especially by the unpredictable weather disasters. In addition the agricultural and industrial pollution against biosphere aggravates the unstability of agricultural production and constitutes a threat in securing the food of the world. In Korea the yield level of crops has been greatly enhanced by the improved agrotechnologies and varietal improvement, but the yield variability due to unfavorable weather events and pests remained unchanged with the change in time. Among weather-related disasters the drought and flood damages has occurred most frequently and impacted most greatly on the agricultural production and its stability. During last decade (1970-l980) the rice production experienced the average annual loss of 0.544 million metric ton which was composed of 0.21 million M/T by climatic disaster, 0.21 million M/T by disease and 0.12 million M/T by insects, and the annual loss of upland crop production from climatic disasters amounted to 0.06 million metric tons. Especially in 1980, the global climatic disasters due to cold or hot temperature endangered the agricultural production all over the world and also the rice production of Korea recorded the unprecedented yield reduction of about 30 percent due to cool summer weather. Nowadays, the unusual weather conditions are prevaling throughout the world, and agro-meteologists predict that the unpredictable cool summer and drought will often attack the rice and other crops in 1980's. To meet the coming weather unstability and to secure the stable crop production, multilateral efforts should be rendered. Therefore, the Korea Society of Crop Science, which commemorates the 20th anniversary of its founding, prepared the symposium on Meteological Stress in Crop Production and its Countermeasures to discuss the decrease in agricultural production due to weather-related disasters and to devise the multilateral counter-measures against the unfavorable weather events.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.147-156
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• 1981

Most of the currently available rice threshers in Korea are of head-feeding type originally developed for threshing paddy at grain moisture content of 15 to 17% on wet basis. And prevailing rice harvesting system is swathing or cutting and bundling upright rice crop at a maturity stage of grain moisture content of ca. 28 to 20%, followed by transient natural drying in the field and threshing at grain moisture content of about 17%. The system often allows rather high field loss of rice both quantitatively and qualitatively. These necessitate use of a preharvest desiccant, and diquat has been registered recently as a rice desiccant. Aim of the present study is to determine the best time and rate of diquat application and to evaluate its utility as a rice desiccant under its optimal usage conditions in Korea. Diquat was not so effective for japonica rice varieties while it was very effective for the new varieties bred from indica x japonica crosses. The best time of application was the period from 2 days before to 3 days after physiological maturity of grain (moisture content of 28% w.b.) and the optimal rate was about 330g of diquat ion/ha. Applying diquat at the right time and rate dropped grain moisture to 15 to 16% (w.b.) within a week after treatment in contrast to that of 20 to 24% in untreated rice. Desiccation of rice crop with diquat resulted in 10 to 15% increase in grain resistance to shattering and significant reduction in percent green rice. However, there was no reduction in milled rice yield and percent whole kernel and was no change in the percent chalky rice and percent tinted rice. Diquat use appears highly desirable, if there is no residue problem which has not been studied in the present study.