Silage corn can make good livestock feed. Anytime drought occurs during the growing season, corn grain yields will be affected. The extent of the loss will depend on stage of grow and the length of time the crop is subject to droughty conditions. During times of extended drought when grain yield potential is sever limited or nonexistent, the plants may still offer a valuable source of nutrients for livestock provided careful attention is given to how it is harvested and fed. As a rule, drought-damaged corn will have 85 to 95 percent of the feeding value of normal corn silage. Ideally, corn silage would be 60 to 70 percent moisture at harvest. Dry conditions around the state cause many corn producers to wonder about making silage from drought-damaged corn. Although silage made from drought-damaged corn is usually not as good as that made from unstress corn, drought -damaged corn can make good livestock feed. This experiment was carried out to know adaptability and forage production and quality of corn hybrid for silage at paddy field of Chonnam Province. As a result of experiment, production of silage corn reduced more than 60% compared to that of normal condition.

Drought is one of the most important types of abiotic stress that affects stability and amount of yield. This study was conducted to screen for drought tolerance at early seedling stages for 318 ecogeographically diverse wild barley (HordeumvulgareL.spp.spontaneum) diversity collection (WBDC). Considerable variation was observed for all the seedling characters examined. Seedling growth was significantly reduced by 17% polyethyleneglycol -induced osmotic stress with significant variation among accessions. Comparison of mean performance under normal and osmotic stress conditions indicated that shoot length was the most sensitive trait, followed by seedling length, seminal root number, root-shoot length ratio and root length. The mean of root-shoot length ratio, however, increased under osmotic stress. Correlation studies indicated that the root length was the most important trait, followed by shoot length and root-shoot length ratio. The accessions from the Fertile Crescent and North Africa showed more drought tolerance than those from the other geographical regions. The accessions WBDC009 (Jordan), WBDC075 (Libya), WBDC181 (Jordan), WBDC242 (Jordan) and WBDC280 (Israel) exhibited the lowest stress susceptibility index ‘S’ values. Consequently, these accessions showed tolerance to drought at the early seedling stage and are considered to be good sources of drought tolerance for cultivated barley improvement. This work was supported by a grant from Regional Subgenebank Support Program of Rural Development Administration, Republic of Korea .

애기장대의 AtSIZ3(At1g08910) 유전자에 T-DNA를 삽입한 세 종류의 변이형에 저온(4℃), 고온(37℃) 및 건조스트레스를 처리하여 유묘의 생장반응과 유전자 발현을 조사하였다. 저온과 고온처리에 의해서는 야생형과 변이형간에 유묘생장에 유의한 차이를 보이지 않았다. 야생형과 변이형 식물체에 10일간의 건조스트레스를 처리하면 야생형은 재 관수에 의해 모든 식물체가 재생하였으나 변이형은 모두 고사하였고, 10일간의 건조처리로 변이형은 야생형에 비해 유묘생장이 평균 62.9%가 억제되는 것으로 나타났다. 야생형에서 AtSIZ3 유전자는 4℃의 저온처리에서 무처리를 보다 20%정도 발현이 감소하는 반면, 37℃ 고온처리에서는 3.7배, 건조처리에서는 4.5배가 증가하였다. 이 결과로 보아 AtSIZ3 유전자는 식물의 건조내성과 밀접한 연관이 있을 것으로 판단된다.

최근에는 확률강우량을 산정할 경우 지점빈도해석의 단점을 보완한 지역빈도해석법이 자주 실무에 적용되고 있으나, 가뭄에 관련한 연구에서는 대부분 아직까지 지점자료를 이용한 가뭄분석을 실시하고 있다. 본 연구에서는 가뭄의 지역적 특성 분석을 실시하기 위하여 필요한 동질한 가뭄특성을 지닌 지역을 구분하는 연구를 수행하였다. 본 연구에서는 기상청 강우관측 지점자료 중 30년 이상의 강우자료를 보유한 58개의 관측지점을 대상으로 표준강수지수(SPI)를 산정하여 가

Experimental purpose was to evaluate growth characteristic and abscisic acid (ABA) responses against salt/drought stresses. In the shoot biomass, creeping thyme was tolerated in mild NaCl stress, ranging 0 to 100 mM, while it was severely reduced in higher salinity. Under constant drought stress, the shoot biomass of creeping thyme showed a worse value compared to that of 100 mM NaCl treatment. Chlorophyll degradation was more severe in immature leaf than mature leaf under salt and drought stresses. In salt stress, immature leaf produced much amounts of ABA compared to mature leaf and also immature leaf showed faster increase of ABA than that of mature leaf. In drought stress, immature leaf responded to stress within 24 hours by the increase of ABA, while mature leaf responded to at 72 hours. Our results recommended that the optimal salinity level of creeping thyme was 50~100 mM NaCl.

가뭄은 장시간동안 강수의 부족으로 발생하는 자연현상이며, 지역에 따라 해마다 여러 가지 피해를 발생시키고 있다. 특히 19941995년과 2001년에 발생한 가뭄은 피해가 매우 심각하였으며 중.소규모의 저수지가 바닥을 드러냈을 뿐 아니라 상당한 경제적인 손실도 발생하였다. 하지만 가뭄관리계획에 의해 저수지를 통한 최적의 물 공급방안을 제시함으로써 이러한 피해들을 최소화 시킬 수 있을 것이다. 본 연구에서는 최적의 저수지 운영을 위한 전문가시스템을 개발하

Agricultural productivity is subjected to enormous environmental constraints, particularly to salinity and drought due to their higher magnitude of adverse impacts and worldwide distribution. Silicon (Si) was found to play a favorable role in salinity and drought stress alleviation of soybean cultivar Daewonkong. All growth attributes insignificantly improved with Si nutrition. The endogenous bioactive GA1 and GA4 content increased with the application of elevated Si level both under normal and stressful condition. JA contents sharply increased with NaCl and PEG application but decreses with Si added to salt and drought stress treatments. SA level increased with NaCl and PEG and was further enhanced with Si in the salt treated plants, but reduced with the combined application of Si and PEG. The endogenous bioactive GA1 and GA4, JA and ABA content of soybean leaves were analyzed through chromatograph/mass spectrometer (GC/MS) in selected ion monitoring (SIM) mode, while SA content was quantified with HPLC.

The adverse effects of salinity and drought on soybean cultivar Hwangkeumkong were also investigated. Endogenous bioactive gibberellins GA1 and GA4, jasmonic acid (JA), abscisic acid (ABA) and salicylic acid (SA) content and pertinent changes in response to basic and double NaCl (70 mM & 140 mM) and PEG (8% & 16%) were examined. We found that plant growth and yield components significantly reduced with the application of NaCl and PEG during pre-flowering and post-flowering growth periods. The endogenous bioactive GA1 and GA4content decreased under elevated salt and drought stress. However, an insignificant increase in GA4level was noted with 8% PEG, applied during post-flowering growth stage. JA levels significantly increased with NaCl and PEG applications, but declined with elevated PEG applied during post-flowering period. SA level drastically reduced with NaCl, while insignificantly reduced with PEG. Endogenous ABA contents of leaves increased with elevated NaCl and PEG application. The endogenous bioactive GA1 and GA4, JA and ABA content of soybean leaves were analyzed through chromatograph/ mass spectrometer (GC/MS) in selected ion monitoring (SIM) mode, while SAcontent was quantified with HPLC.

Jatropha (Jatropha curcas L.) is a shrub or tree belonging the genus Euphorbiaceae and is cultivated in a tropical regions including South America, South-East Asia, India and Africa. Jatropha possibly is adapted to grow in a wide range of environments for producing non-edible oils. The objective of the study is to determine effect of salt and drought on plant growth characteristics. Treatments are thus followed, 100 and 200 mM NaCl and 5 and 10% PEG. Various physiological parameters such leaf length and width, stomatal conductance, chlorophyll fluorescence and gene expression were investigated. The results showed that from 2 days onwards, 100 and 200mM NaCl treatments were significantly suppressed leaf length, width, and stomatal conductance, but 5% and 10% PEG treatments showed a similar trend of control plants. Gene expression of JcACBP of the 100 mM NaCl was slightly decreased compred to those of other treatments. These results indicate that 100 and 200 mM NaCl treatments significantly showed negative response, but 5 and 10% PEG treatments improved plant growth and development of Jatropha.

Brassica napus L. (Brassicaceae), is one of major oilseed crops commonly cultivated cereal-growing areas after the rice harvest in Asia countries, has recently focused much attention as its seed is the primary source for bio-diesels. In rapeseed growing regions of South Korea, typical double-cropping regions are constantly or periodically received with poorly drained soil condition or encountered dried soil condition during the reproductive stage. This study was conducted on rapeseed plants subjected to both waterlogging and drought conditions for 4 days to investigate responses in physiological characteristics, fatty acid compositions and yield performances at reproductive stage. The treatments were thus as follows: (1) control normally irrigated, (2) waterlogging treatment were flooded by placing their pots inside larger plastic pots filled with tap water with a 2-cm water layer over soil surface, (3) drought treatment was not irrigated. For recovery period, rapeseed plants subjected to waterlogging for 4 days were drained after waterlogging, and irrigated daily as control. Drought treatment after recovery period was irrigated daily as control. Rate of photosynthesis and stomatal conductance of waterlogging and drought treated plants significantly decreased within 4 days. For recovery period, stomatal conductance and photosynthetic rate of the waterlogged and drought treated plants occurred level similar to that of the controls by 2 days after recovery period. Fatty acid compositions of the both waterlogging and drought treated plants did not affect, but yield performances of the waterlogging treatment significantly decreased. These results suggest that both waterlogging and drought conditions for 4 days did not influence fatty acid compositions, but affected yield performance at final harvest.

장기지속 가뭄에 대한 많은 연구는 과거 기록 자료에 제한을 받아왔다. 장기지속가뭄과 관련된 연구의 애로점은 분석을 위한 많은 가뭄 사상을 얻는데 필요한 장기간의 과거 수문자료의 기록이 부족하다는데 있다. 이와 같은 어려움을 극복하기 위해 근래의 연구방법중 하나는 합성유량자료 계열을 이용하는 것이다. 과거 관측 자료의 추계학적 특성에 근거하여 수문시나리오를 개발하는 것으로, 방법론은 분석에 필요한 다양한 수문사상이 포함될 수 있도록 희망하는 수문자료계열을

본 연구는 가뭄시 제한급수를 할 경우 이에 대한 소비자의 지불의사를 추정코자 하였다. 7대 특 광역시와 32개 가뭄상습지역에 거주하는 일반인을 대상으로 가정용수 수요패턴과 가뭄을 고려한 가정용수의 가치를 추정하였다. 조사결과 상대적으로 부유한 특 광역시 주민들은 수돗물의 수량보다는 수질을 더 중요하게 생각하였고 상습가뭄지역의 주민들은 수질도 중요하지만 수량의 중요성을 강조하고 있다. 지불의사 추정을 위한 설문은 양분선택형과 개방형을 혼합하였고, 모형은