• Title/Summary/Keyword: days to emergence

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Devloping Chcory for Forage Crop by New Technology (새로운 기법에 의한 치코리 (Cichorium intybus L.) 의 사료화에 관한 연구)

  • 허삼남;박홍석
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.15 no.4
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    • pp.265-273
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    • 1995
  • Seeds of chicory were collected and selected with good germination, emergence and productivity. To develop chicory as a new forage crop seeds were primed with polyethylene glycol (PEG 6000) and coated with some chemicals, and tested in laboratory and field. The results obtained are summarized as follows: 1. Among the seed lines collected, PUlgAH, PU21TH, PU37CH and PU30TK were germinated more quickly and took less time for germination than the others. 2. PUI8AH was the best in emergence and growth although PU21TH showed superior germinative ability among the lines collected. 3. Chicory seeds primed with 20~25% PEG solution for three days at $10^{\circ}C$, or the seeds treated with 25% PEG solution at $15^{\circ}C$ regardless the treatment period showed good germination performances. 4. Osmotic priming with PEG accelerated the germination of chicory, but not in the field. 5. Coated seeds geminated more slowly in Petridishes but showed superior emergence and growth to those of primed or untreated seeds. Treatment 3 showed the best performances in pot experiment. 6. Coated seeds showed remarkable increase in establishment and dry matter yield especially in sod sowing compared to the other sowing method. 7. Most nutrient contents except iron and manganese of chicory were much higher than those of mixed pasture .

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Germination and Growth Characteristics of Tannin Containing Forage Crops (탄닌 함유 사초식물의 발아 및 생육특성)

  • 허삼남;이성운;최순호;차장옥
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.21 no.4
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    • pp.211-216
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    • 2001
  • In an effort to investigate the germination and growth characteristics of tannin containing forage crops (such as chicory, birdsfoot trefoil, Lotus pedunculatus, sulla, lespedeza, crownvetch, sainfoin), germinativity, seedling vigor, and productivity were studied. Although the cumulative germination percentage (CGP) of chicory and birdsfoot trefoil was low, the germination rate(GR) and days to reach 50% of final germination(Gt50) were excellent. Crownvetch, lespedeza and sainfoin showed poor germination. Chicory seeds were light but the rate of emergence and establishment were high. Seeds of Lotus pedunculatus and birdsfoot trefoil were also small, but their rates of emergence and establishment were quite good. On the other hand, seeds of sainfoin and crownvetch were heavy but their emergence and establishment rate were very low. Lespedeza was the best in getting over the hot summer, and crownvetch also survived well during summer. Chicory was good in productivity and early growing but its persistence was not good. In case of birdsfoot trefoil and Lotus pedunculatus their early growing were slow but their productivity and persistence were fairly well. Lespedeza, crownvetch, and sainfoin showed poor growth in Korea. Based on the results of this study it can be concluded that chicory would be better to use as short term high productive forage crop, and Lotus pedunculatus and birdsfoot trefoil could be used as continuous functional forage crops in Korea. (Key words : Tannin. Germination. Chicory. Birdsfoot trefoil, Lotus pedunculatus)

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A Study on the Improvement of the Collection Traps of the Pine Gall Midge (Thecodiplosis japonensis Uchida et Inouye) II. Effects of Temperature by the Treatment of the Collection Traps on the Fluctuation of Emergence (솔잎혹파리 발생예찰을 위한 우화기구 개발에 관한 연구 II. 우화기구별온도효과가 우화소장에 미치는 영향)

  • Oh M.H.;Woo K.S.;Shim J.W.
    • Korean journal of applied entomology
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    • v.18 no.3 s.40
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    • pp.127-132
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    • 1979
  • This experiments were performed to investigate the temperature effects, which caused by the various types of collecting trap treatments, during the overwintering period of pine gall midge larvae, on the peak adult emergence time. And the following results were obtained. 1) The maximum temperatures inside of the collection traps were significantly different each other, and the vinyl cage showed the highest degree which highering $15^{\circ}C$, and standard cage, cage-50 and funnel trap highering $3-12^{\circ}C$ in monthly average comparing to control. 2) There was no significant difference among the treatment in minimum temperatures, during the overwintering periods of larvae. 9) The peak adult emergence time were May 15 in vinyl cage plot which shortened 20 days and both standard cage and cage-50 shortened 14 day than that of control. 4) The funnel type trap treatment delayed 6 days of the peak adult emergence comparing to control, in spite of the treatment showing higher maximum and cumulative temperatures than the control plot. 5) The decadal maximum temperatures of middle part of December and March were significantly correlated with the shortening of the peak adult emergence date.

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Methods of Estimating Growing Degree Days to Predict Growth Duration in Maize (옥수수의 생육기간 예측을 위한 Growing Degree Days의 계산방법)

  • Jong, Seung-Keun;Lee, Suk-Soon;Park, Keun-Yong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.31 no.2
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    • pp.186-194
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    • 1986
  • In an attempt to find better ways to relate growth with temperature and to estimate maturity differences in corn (Zea mays L.), various formulas of computing Growing Degree Days (GDD) were evaluated. Utilizing data from 17 plantings of a single cross, Suweon 19, over a 3 year period, 24 different methods of computing GDD were compared for their ability to reduce variations over different plantings. The best equation was to compute GDD with a base temperature of 10$^{\circ}C$ and an optimum of 30$^{\circ}C$. The excess temperature above 30$^{\circ}C$ was subtracted to account for high temperature stress. GDDs required for emergence and silking of Suweon 19 were 64${\pm}$12$^{\circ}$ and 794${\pm}$19$^{\circ}$, respectively. Based on these GDD values, emergence and silking dates could be estimated with a variation less than 3 days. The observed and estimated number of days from planting to emergence and silking were not significantly different.

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Developmental Ecology of Persimmon Fruit Moth, Stathmopoda masinissa Meyrick (Lepidoptera: Stathmopodidae) (감꼭지나방 (나비목: 감꼭지나방과)의 발육생태)

  • 박은철;박형진;김길하;김정하
    • Korean journal of applied entomology
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    • v.40 no.1
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    • pp.41-43
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    • 2001
  • Persimmon fruit moth, Stathmopoda masinissa, collected from roadside persimmon trees planted as shade trees in yeongdong area was used to investigate their developmental ecology under laboratory conditions; $25\pm$ $1^{\circ}C$, 16L : 8D and 85% RH. Developmental periods for eggs, larvae, and pupae were 7.4, 34.8 and 15.5 days, respectively. The duration for each larval instar from the 1st to the 5th was 3.5, 4.2, 5.2, 6.5 and 15.4 days, respectively, and the head capsule width of corresponding stage was 0.20, 0.40, 0.65, 0.87 and 1.07 mm. Rates of pupation and emergence were 68.0 and 59.9%, respectively. Longevity of adult males was 6.2 days while that of females was 10.1 days. Average fecundity was 25.4 eggs.

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Effect of Priming and Preimbibition on Germination of Zoysiagrass Seeds (Priming과 침지처리가 들잔디의 종자발아에 미치는 영향)

  • 김태일;구자형
    • Asian Journal of Turfgrass Science
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    • v.8 no.1
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    • pp.1-11
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    • 1994
  • Studies were conducted to evaluate the effect of priming and preimbibition on gerraination of unscarified and KOH-scarified zoysiagrass (Zoysia japonica Steud.) seeds, respectively. Germi-nation percentages at 35˚C of seeds primed in $KNO_3$ and Ca($NO_3$)$_2$ were significantly higher than that of untreated seeds. The optimum conditions for priming unscarified seeds were in aerated $KNO_3$ solution at O4 M for 4 days at 20˚C. No additional benefit of $GA_3$ on increasing germination was not found in seed priming with solution of $KNO_3$ + $GA_3$ or in seeds preimbibed with $GA_3$ after priming. Scarified seeds preimbibed with distilled water(DW) for 4 days at 20˚C germinated higher and with fewer days to 50% of total germination(T 50) than untreated seeds. Preimbibition with $GA_3$ solution at 50 ppm for 4 days at 5, 10, 15 and 20˚C enabled up to 97% of seeds to germinate and reduced days to T 50 about 1.1 to 1.2 days at 35˚C Especially, seeds preimbibed with $GA^2$˚$_3_2_1$$\times$ had greatly higher germination and lower T 50 than untreated or DW-preimbibibed seeds at 30˚C, which is inadequate to germination in general. Preimbibed seed performance was unchanged after storage at room temperature for 50 days. Seeds preimbibed with GA $_3$ had higher rate of seedling emergence and faster growth of shoot than untreated seeds after sowing at 30˚C in growing medium in growth chamber.

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Improvement of Rice Seedling Emergence by Seed Coating Materials in Direct Seeding into Flooded Paddy Soil (벼 담수토중직파재배시 종자분의 재료에 따른 입모향상 효과)

  • 원종건;최충돈;이외현;이상철;김칠용;최부술
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.3
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    • pp.286-291
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    • 1997
  • This experiment was carried out to improve seedling emergence and establishment in paddy rice sown into puddled soil. Rice seed were coated with CaO$_2$, KNO$_3$ and acid sulphate soil. When coated seeds with CaO$_2$, KNO$_3$ and acid sulphate soil were sown into puddled soil, soil redox potential was increased and the period of oxidizing was longer in KNO$_3$ than that of any other soils. pH was higher in control than that of coated seeds with CaO$_2$, KNO$_3$ and acid sulphate soil. It seems that the coated seeds oxidize soil locally, thus prohibit soil reduction. Seedling emergence was improved by seed coating materials. Emergence date was 8 days after seeding(DAS) in CaO$_2$, 14 DAS in acid sulphate soil, 21 DAS in KNO$_3$ coated seed and 20 DAS in uncoated seed, respectively. Emergence rate was highest in CaO$_2$ coated seed(80%) followed by acid sulphate soil coated seed(61%), while control(46%) and KNO$_3$(42%) were very poor. This result would be interpreted as the difference in oxidizing power among coating agents ; CaO$_2$ and acid sulphate soil may oxidize weakly and shortly while KNO$_3$ may oxidize soil strongly and persistantly. Our results suggested that local oxidizing around rice seed sown into puddled soil enhanced seedling emergence and also found a possibility to promote seedling emergence with acid soil.

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Immature Development, Longevity and Fecundity of the Larval Parasitoid, Meteorus pulchricornis (Wesmael) (Hymenoptera: Braconidae), on Tobacco Cutworm

  • Hwang, Seok-Jo;Byeon, Young-Woong;Lee, Seol-Mae;Kim, Jeong-Hwan;Choi, Man-Young;Kim, Sung-Hyun;Kim, Nam-Jeong;Park, Hae-Chul;Lee, Young-Bo;Lee, Sang-Beom;Lee, Jong-Wook
    • International Journal of Industrial Entomology and Biomaterials
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    • v.21 no.2
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    • pp.180-183
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    • 2010
  • This study was performed to investigate the temperature-dependent development, longevity and oviposition of an indigenous larval parasitoid, Meteorus pulchricornis, on tobacco cutworm, Spodoptera litura. M. pulchricornis were reared at nine constant temperatures between 15 and $35^{\circ}C$. The developmental times of each three developmental stage decreased from 38.7 to 16.3 d between 15 and $30^{\circ}C$. However, M. pulchricornis showed longer developmental time at $32.5^{\circ}C$ (9.5, 7.7 and 17.2 days for each three developmental stage) than at $30^{\circ}C$ (8.9, 7.3 and 16.3 days for each three developmental stage). Immature M. pulchricornis could not develop any more at $35^{\circ}C$. The lower developmental threshold estimated by linear regression equation for the egg to cocoon, cocoon to adult emergence and egg to adult emergence were 5.1, 4.6 and $4.5^{\circ}C$. The thermal constant for each of the three stages were 217.2, 176.2 and 403.8 degree-days, respectively. When no food or 50% honey solution as a food source is provided for M. pulchricornis, the parasitoid survived for 8.3 and 55.9 days at $25^{\circ}C$, respectively. M. pulchricornis females laid 5.2 eggs daily and total of 131.6 eggs at $25^{\circ}C$ until it died. Peak age-specific fecundity was observed on $14^{th}$ day (9.6 cocoons) after parasitoid emergence and gradually decreased thereafter.

Effects of Seed Treatment with Several Systemic Insecticides to Rice, Barley and Soybean (수도, 대맥 및 대두에 대한 침투성살충제의 종자분의처리효과)

  • Choi Seung Yoon
    • Korean journal of applied entomology
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    • v.12 no.3
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    • pp.115-120
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    • 1973
  • An experiment was carried out to investigate possible use of several systemic insecticides as seed treatment to control some insect pests of rice, barley and soybean. The insecticides were impregnated with active carbon dust and $2\%$ water solution of methyl cellulose as skicker. The seeds were dressed with the insecticides: Fussol (Monofluoroacetamide), Dimethoate (0, 0-dimethyl-S-(N-methyl carbamoylmethyl) phosphorodithioate), Metasystox (0, 0-dimethyl 0-2 ethylthioethyl phosphorodithioate), Dimecron (0, 0-dimethyl (diethylamide-1-chlorocrotonyl) Phosphate). The seeds were treated at the rate of $4\%$ by grain weight. Effects of seed treatments with systemic insecticides on the seed germination and insecticidal effectiveness were tested. Fer rice, no seed germination was observed in Fussol treatment. Dimethoate, Metasystox and Dimecron showed a slight reduction in germination when seeds were sown 1 day after treatment, but they showed gradual reduction in germination when seeds were sown 20 and 45 days after treatment. Especially Diriethoate treatment showed significant reduction in germination after 20 and 45 days of storage. All the insecticides reduced seedling stands of barley somewhat. No plant emergence was observed in Fussol treatments after 25 and :to days of storage. In case of the 40 days of storge in barley seed treated with Dimethoate, Hetasystox and Dimecron there was no gignificant reduction in plant emergence except Fussol treatment. Dimethoate was highly toxic to the soybean seed viability. However, there was no significant reduction in the soybean germination after 1 day of storage. in Fussol, Metasystox and Dimecron treatments After 25 days of storag in Fussol and Dimethoate treatments, no plant emergence was observed, and there was $13.3\%$ emergence in Metasystox treatment, and $93.0\%$ emergence in Dimecron treatment. Dimethoate treatment in rice seed(variety Suwon # 82) showed $90\%$ mortality at the twentieth day and $33.3\%$ at the thirtieth day after sowing against the green rice leafhopper, Nephotettix cincticeps But no visible effectiveness was observed in Metasystox and Dimecron treatments. Dimethoate treatment in barley seed resulted in low population density of aphids. Rhopalosiphum spp. Final observation on the number of eggs per plant was made at the fiftieth day after sowing; 2 in Dimethoate, 4 in Fussol, 6 in Metasystox, 7 in Dimecron, and 13 in check plots. All the insecticides tested resulted in good insecticidal effectiveness against the aphids, Aulocorthum solani on soybean plant at the ninth day infestation after sowing. Dimethote, Metasystox, and Dimecron treated soybean plants was still effective in controlling the aphids to the eighteenth day infestation.

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Effects of Sublethal Concentration of Insecticides On the Pupal Duration, Emergence, Adult Longevity and Oviposition of Tobacco Cutworm, Spodoptera litura (Fab.) (Lepidoptera : Noctuidae) (담배거세미나방의 유충에 처리된 살충제 아치사농도가 용기간, 우화율, 성충수명 및 산란에 미치는 영향)

  • 배순도;김현주;홍연규;조현제
    • Korean journal of applied entomology
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    • v.43 no.2
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    • pp.175-180
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    • 2004
  • This study was conducted to determine the effect of sublethal concentrations ($LC_{10}$ and $LC_{30}$) of insecticides on pupal duration, emergence, adult longevity and oviposition of tobacco cutworm, Spodoptera litura Fabricius, when 3rd instar larva of tobacco cutworm was treated with insecticides of chlorpyrifos, ethofenprox, chlorfenapyr-bifenthrin and hexaflumuron-chlorpyrifos . Pupal duration of female and male were 6.9 days and 8.0 days at untreatment, and were 7.2 to 7.6 days and 8.3 to 8.6 days at insecticide treatment, respectively. Thus pupal duration at the insecticide treatment was slightly longer than that at the untreatment, and that of the males was slightly longer than that of the females even though significant difference between sublethal concentrations and among insecticides was not observed. Percent mergence was 88% at untreatment and ranged from 79% to 95%, in particular which showed above 91% treated with chlorfenapyr-bifenthrin and ethofenprox, at insecticide treatment. Adult longevity was 7.7 days and 7.9 days for female and male at untreatment respectively, and 7.1 to 8.4 days for female and 7.7 days to 9.0 days for male at treatment. There was a significant difference between insecticides and sublethal concentrations of insecticides except showed the longest adult longevity at hexaflumuron-chlolfyrifos treatment. Total number of eggs laid were less at treatment (778-948) than that (1,010) at untreatment regardless of sublethal concentrations of insecticides. Accordingly the pupal duration and oviposition of tobacco cutworm were affected at the insecticide treatment of sublethal concentration.