• 제목/요약/키워드: agricultural period

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꽃감염 위험기간 중의 강우가 충남지역 과수 화상병 발병에 미치는 영향 (Effect of Rainfall During the Blossom Infection Risk Period on the Outbreak of Fire Blight Disease in Chungnam province)

  • 김병련;김윤정;원미경;주정일;유준명;이용환
    • 한국농림기상학회지
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    • 제25권4호
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    • pp.302-310
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    • 2023
  • 과수의 개화기 꽃감염 위험기간 중의 강우가 화상병의 발병에 어느 정도 영향을 주었는지 조사하였다. 2015년부터 시작된 충남지역의 과수 화상병 발병 기간 중에서 2020년부터 2022년의 발병 규모가 가장 크게 변화하였는데, 2020년에는 63개 과원에서 발병하였고, 2021년에는 170 과원으로 크게 증가하였으나, 2022년에 46개 과원으로 감소하였다. 2022년에는 발병과원의 발병 나무 가지에 형성된 궤양증상이 감소하였고, 이것은 개화기 건조한 날씨에 의한 것으로 평가 되었다. 즉, 꽃감염 위험기간 중의 강우 여부 및 누적 강수량에 따라 그 해의 화상병 발병은 증가하거나 감소하였다. 이러한 경향은 사과와 배가 재배되는 조사지역 모두에서 유사한 경향이었고, 꽃감염 위험시기의 기상환경 중 강우는 월동 궤양으로부터 활성화된 병원균의 전반과 꽃 감염에 큰 영향을 주었으며, 특히 꽃감염 위험경보가 시작되는 초기 3일간의 강수량은 발병 규모를 결정하는 요인으로 확인되었다.

EFFECT OF FEEDING PATTERN ON DIURNAL VARIATION IN FAECAL CHROMIC LEVEL WHEN USING CONTROLLED RELEASE DEVICES IN SHEEP

  • Lee, G.J.;Mortimer, S.I.
    • Asian-Australasian Journal of Animal Sciences
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    • 제4권1호
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    • pp.79-83
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    • 1991
  • Diurnal variation in faecal chromic oxide levels was estimated from 4 hourly faecal sampling of 56 wethers allotted to one of six different feeding patterns. Sampling occurred on days 6 and 7 (Period 1) after a controlled release device was administered, and was repeated on days 14 and 15 (Period 2) following re-randomisation of the wethers to the feeding patterns. Increasing the frequency of feeding tended to be associated with higher faecal chromic oxide levels (p < 0.05), particularly in wethers fed thrice daily at 8 hour intervals. There was no interaction between feeding pattern and period, sampling day or time within-day. There were significant period x time within-day (p < 0.05) and day x time within-day (p < 0.001) interactions, indicating that variation in faecal chromic oxide between sample times was not consistent. This implies that sampling at any time of day is unlikely to result in a biased estimate of pasture intake, providing sufficient samples are collected. Significant period (p < 0.001) and period x day (p < 0.01) effects were associated with slow faecal chromic oxide equilibration in period 1. Equilibration did not occur until after day 7, indicating a need for caution when commencing sampling.

Effect of Pregnancy on Lactation Milk Value in Dairy Buffaloes

  • Khan, Sarzamin;Qureshi, Muhammad Subhan;Ahmad, Nazir;Amjed, Muhammad;Durrani, Fazali Raziq;Younas, Muhammad
    • Asian-Australasian Journal of Animal Sciences
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    • 제21권4호
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    • pp.523-531
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    • 2008
  • Buffalo are a major source of milk production, contributing 12.1% in the World and 38.0% in Asia. The buffaloes are kept under peri-urban farming systems to produce milk for urban populations. Breeding is delayed in these herds to get more economic benefit because farmers believe that the pregnancy decreases milk production. The lactation milk value has been studied in this paper as an economic indicator. Complete milk yield records of 3,304 buffaloes was collected from a group of state farms. Economic traits including lactation yield, lactation length, calving interval (CI), dry period and milk yield per day of calving interval (MYPDCI) were derived from the data. The animals were grouped according to parity number (1-3), service period (G1 to G4, conceiving during <150, 150-200, 200-300 and >300 days post calving) and yield levels (HMY>2,500; MMY 2,001-2,500; and LMY 1,500-2,000 liters/ lactation). To study the effect of pregnancy on milk composition a research trial was conducted at a medium size private dairy farm, using forty lactating buffaloes of three yield levels and four service period groups, as described already. Milk was sampled on alternate weeks and analyzed for fat and protein contents (%). For quantifying the value of milk produced during a lactation period, the value corrected milk (VCM) was determined and converted to lactation milk value (LMV). Group means were compared for varicous parameters. Highest milk yield ($2,836.50{\pm}15.68$ liters/lactation) was recorded in the HMY animals of G4 group while lowest milk yield of $1,657.04{\pm}8.34$ liters/lactation was found in LMY of G1. Lactation was significantly increased with the extending of service period. The shortest dry period was recorded in HMY, parity 1, G1 animals and the longest in parity 2, MMY, G4.The CI was shortest in HMY, parity 1, and G1 animals and longest in LMY, parity 3, G4 buffaloes. The HMY, parity 2, G1 buffaloes showed the highest MYPDCI and the lowest value was recorded ($6.53{\pm}0.17$ vs. $2.76{\pm}0.04$ liter/day) for LMY, parity 1, G4 buffaloes. The VCM decreased with the delayed conception. This decreasing trend was higher in respect of the total yield but decrease in the VCM was smaller due to the increasing levels of fat and protein in the milk. The gap between the various production classes was reduced based on the VCM as compared with the yield per day of CI. LMV showed a consistent decline with extending service period in all three production groups. The study suggests that CI increased with delayed conception, showing a consistent trend in the low, moderate and high yielding buffaloes. There was a coherent declining pattern of milk yield with delaying conception, associated with prolonged CI. An animal conceiving at a later stage of lactation showed a decline in financial returns of 24 to 27% compared with those conceiving earlier.

Inoculum Sources to Generate High Mechanical Transmission of Barley yellow mosaic virus

  • Jonson, Gilda;Kim, Yang-Kil;Kim, Mi-Jung;Park, Jong-Chul;Hyun, Jong-Nae;Kim, Jung-Gon
    • The Plant Pathology Journal
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    • 제23권2호
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    • pp.103-105
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    • 2007
  • Mechanical transmission of barley seedlings with barley yellow mosaic virus (BaYMV) is generally inefficient and is the major constraint for testing cultivar resistance to the virus. To explore mechanical transmission, BaYMV-infected barley plants were grown at different conditions and used as inoculum sources to seedlings of susceptible barley cultivar Baegdong. Extracts prepared from BaYMV-infected Baegdong plants at 47, 53, 74, and 90 days after symptom appearance (DASA) and grown at 10 and $12^{\circ}C$ gave 10, 30, 68 and 76% infection, respectively on inoculated susceptible barley cv. Baegdong seedlings. While Jinyangbori, another susceptible cultivar obtained 95% infection rate inoculated with extracts from 90 DASA disease source and grown at $10/12^{\circ}C$. However, low infection rates were obtained when the virus sources were grown in a greenhouse at $15-18^{\circ}C$. Our results indicate that longer incubation period and lower temperature are required for virus accumulation and stability.

우리나라 서남해안 간척지 및 간석지 토양의 입단분포 (Soil Aggregate Distribution in Reclaimed Tidelands and Tidelands of Southwest Coastal Area of Korea)

  • 손재권;최진규;황선아;박봉주;조재영
    • 농촌계획
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    • 제11권4호
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    • pp.93-98
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    • 2005
  • A aggregate size distribution of soils is an important in successful crop production in reclaimed tidelands. The aggregate size distribution for this study were determined of 0.1mm, 0.25mm, 0.5mm, 1.0mm, and 2.0mm by wet sieving method. Agricultural activity, period of reclamation showed significant effects on aggregate size distribution in reclaimed tidelands. Aggregate MWD was greater in SS and KH(above 1.0m) than in YSG, GHD, SMG, and DH(below 0.5mm) reclaimed tidelands and tidelands. The percentage of aggregates less than < 2mm for SMG, GHD, and SM reclaimed tidelands and tidelands were ranged 8.9%, 36.7%, and 38.0%, respectively. The percentage of > 0.1mm aggregates for SMG, GHD, and SM reclaimed tidelands were ranged 9.0%, 26.0%, and 48.9%, respectively. Results indicated that aggregate size distribution of reclaimed tidelands and tidelands under various agricultural systems vary with reclamation period and soil type.

영농기와 비영농기에 강우에 의해 논으로 유입되는 질소공급량 분석 (The Analysis of Nitrogen Supply Amount in Paddy Fields by Rainfall During Cropping and Non-Cropping Period)

  • 최동호;최순군;허승오;홍성창;김민경
    • 한국농공학회논문집
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    • 제60권3호
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    • pp.107-112
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    • 2018
  • In this study, we conducted to analyze and quantify the amount of nitrogen supply into the rice paddies from the rainfall during cropping and non-crop periods. Rainfall monitoring conducted 85 times from June 2015 to December 2017. Nitrogen supply of cropping season ranged from 5.37 to 7.70 kg/ha, while non-cropping season were supplied from 3.97 to 4.42 kg/ha. The supply of T-N in the crop period was more than 60% of the total supply. And as a result of analyzing the correlation between the characteristics of rainfall and the supply amount, nitrogen concentrations in rainfall were decreased with increasing rainfall, but the supply amount was increased. Therefore, efforts should be made to increase the rainfall utilization and to increase the nitrogen supply of crops by increasing rainfall storage through drainage management.