올챙고랭이(Scirpus juncoides Roxb.)의 生態的 特性에 관한 硏究 = Ecological variations of scirpus juncoides roxb

국문 초록 (Abstract)

最近에 優占度가 높아가고 있는 논 雜草種 올챙고랭이(Scirpus juncoides Roxb.)의 休眠, 發生, 競合, 再生, 繁殖에 관한 生態特性을 把握하기 위하여 一連의 試驗을 遂行한 結果를 要約하면 다음과 같다.
種實의 休眠打破를 위한 貯藏條件을 논 2cm 깊이 埋沒處理에서, 貯藏溫度는 5℃에서 休眠覺醒效果가 가장 높았다. 發芽床의 條件은 폿트보다 PETRI dish 置床에서 發芽率이 높았으며, 休眠覺醒에 필요한 所要日數에 10∼60일이었다. 熟度別 休眠性程度는 完熱 및 中熟狀態의 種實보다는 未熟狀態의 種實(綠色)이 休眠性이 낮아서 發芽所要日數가 짧았고, 休眠覺醒劑處理效果는 藥劑의 濃度가 높을수록 覺醒效果가 컸었으며 역시 完熱보다 未熱種子에서 效果的이었다.
種實의 發芽特性을 檢討한 結果, 發芽適溫은 25∼35℃였고, 休眠이 打破된 種實의 發芽率은 暗狀態에서 10%, 光條件下에서는 50%이상의 發芽率을 보였으며, 透明 및 黃色필름下에서 發芽促進效果가 높았다. 酸素濃度는 低酸素條件(0∼5%)에서, pH는 5.7, 水分은 1cm 水深에서, 履土深은 1∼1.5cm에서 效果的이었다.
株基部의 出芽適溫은 20∼25℃였고, 遮光에 의해 出芽가 促進되는 경향이었으며, 履土深은 0.5∼1.0cm깊이에서 出芽가 良好하였다.
競合特性 벼와의 種間競合이나 單獨個體群으로서의 競命特性으로 볼 때 올챙고랭이는 바람하늘직이, 올방개, 골풀과 함께 生長特性은 크더라도 벼에 대한 競合力은 크지 않은 雜草群으로 分類가 되었다. 올챙고랭이의 種內競合密度는 벼 立苗存無에 따라 폿트당 10株∼15株부터 시작되었고, 벼에 의한 競合은 草長보다 莖數나 乾物重에서 크게 나타났으며, 肥料 性分別 樣相은 燐酸이나 加理質보다는 窒素成分의 施用量 增大로 競合이 甚하였다. 水分條件은 밭 條件에 가까울수록 벼보다는 올챙고랭이가 生育이 유리하였으며, 光競合力은 單植보다 混植에서 벼보다 優位性을 보였다.
刈取를 通한 防除時期를 探索한 結果 再生力은 刈取期까지의 生長量이 클수록 컸었고 年間總生産量에 있어서는 5월 15일경의 刈取에서 가장 再生能力이 커지는 傾向이었다.
實生에 의한 後代繁殖力은 0∼2cm 水深에서, 出穗期의 適溫은 25℃, 光條件은 10% 程度의 遮光下 또는 透明 및 黃色光下에서 促進되는 傾向이었고, 土壤物理性은 粘土比 75%의 水準에서 向上되는 結果를 나타내었다. 이상의 試驗 및 結果를 通하여 올챙고랭이의 發生과 生育 및 繁殖이 最近의 水稻栽培法 變異에 편승하여 優占化하고 있음을 알 수 있었다. 또한 올챙고랭이는 벼에 대한 競合被害를 極甚하게 끼치는 雜草種은 아니지만 時期와 場所에 따라 單獨群으로 激發할 可能性이 있기 때문에 除草劑間의 混用, 體系處理 혹은 藥劑와 栽培管理法間의 合理的인 連繫處理에 의하여 防除토록 하는 것이 바람직한 것으로 判斷되었다.

다국어 초록 (Multilingual Abstract)

Bulrush(Scirpus juncoides Roxb.) as a paddy weed plant may be widely distributed in the southern regions in the near future, and it seems that the weed plants forces farmers to pay extra cost for controlling the weed in most paddy fields. To investigate the adatability and environmental factors of bulrush, a series of experiments ; the developenemt and germination, regrowth capacity of propagation, the classification into similar ecotype, and the intra-and inter-specific competitions to rice, were carried out at the Experimental Farm of the Chonnam National University and Suncheon National University in 1983-1986.
1. Dormancy-breaking Conditions
The germination were ranged from 2 to 60 percent in even natural conditions, and especially the effect of dormancy-breaking was highest at storage of 2 cm soil depth in paddy soil. The germination percentage were higher in PETRI dish than in pot conditions. The dormancybreaking at low temperature storage(5℃) was most effective and high temperature storage(25℃) was ineffective to break dormancy. The vsriations in dormancy-breaking affected by storage duration were not large, but short storage duration(10-60 days) showed a little increase of germination percentage. The average required days for germination were negatively correlated with germination percentage, and the germination were decreased by high dormancy. The dormancy-breaking for immature seeds by germination promoters was easier than for moderately and completely mature seeds. The effect of dormancy-breaking was enhanced by higher concentration if chemicals, and the rates were highest in paddy-field pre-treatment conditions. The enhancement of germination rate by chemicals was significantly more effective in green seeds than in brown and black seeds, and black seeds was effective only in paddy-field condition.
2. Seed Germination/Basal Emergence
The optimal temperature for seed germination was 25 to 35℃, and the germination was about 10% at 20℃. The optimal temperature for basal emergence was from 20 to 25℃ and 20 to 30℃ in terms of continuous increment and higher emergence rates, respectively. In the light intensity, the germination rates were 10 and 50% in dark and light conditions, raspectively. The germination were increased by light intensity with 2 to llKLux, but the effect of light intensity was not significantly different. On the different levels of shading, 95% shading plot showed the best emergence rate for the overwintered basals. The quality of light was siginificantly affected the seed germination rates. The germination were the most effective under the clear and yellow film than any other photo-selective materials. The emergence rates of overwintered basals were more effective under clear and blue film under red filter. On the soil pH, both seed germination and basal emergence rates were best at soil pH 5.5 which was critical point. The shoots developed from 3 gram basals showed the greatest numbers and rapidest shooting speed than any other sizes, and the germination was 75% at O₂concentration 15∼20%. In case of water level, the seed germination at 1cm water depth was most enhasnced, and the water depths of -5 to 10cm were in second place. The rates were significantly decreased at -10cm water depth. The basal had better emergence at lower or deeper water depths than the seeds. The seed germination was best at 1 to 1.5cm molding depth, but no germination was observed at 5cm depth. The emergence of basals was best at 0.5 to 1.0cm molding depth, and the rates at 3 to 5cm depths were significantly decreased.
3. Competitional Classification of Weed Species around Bulrush
A series of assessments on the competition ability in space and dry matter production(nutrient depletion) of respective weed species and paddy rice, and the data were used to compute that phenotypic similarity by Single-Link-Clustering method. Both growth response of weed species in mono-and under the paddy rice standing was very similar(□ 0.969), but the reduction rate as affected by paddy rice standing was negatively correlated with the ability in space-competition(□ 0.513). Dendrogram of 10 weed species based on the phenotypic similarity computed in 4 characters in mono- and under the paddy rice standing was also similar, as Echinochloa crus-galli, Ludwigia prostrata, Cyperus serotinus, and Scirpus maritimus in I-group, Eleocharis Kuro-quwei, Scirpus juncoides in II-group, and Juncus effusus, Potamogeton distinctus in III-group, respectively. Also, that of paddy rice to 10 weed species showed Fimbristyllis miliaceae, Scirpus juncoides, Eleo-charis Kuroguwei, Scirpus maritimus, and Juncus effusus in I-group, and Ludwigia prostrata, Potamogeton distinctus, Monochoria vaginalis in II-group, respectively. The integrated dendrogram by the above two data indicate the I-group with Fimbristylis miliaceae, Scirpus juncoides, Eleocharis kuroguwei and Juncus effusus as higher growth response with realtively lower competition ability to paddy rice, II-group with Cyperus serotinus, Potamogeton distinctus and Ludwigia prostrata as higher both in growth and competition and the last, III-group with Monocho-ria vaginalis, and Scirpus maritimus as lower growth but higher competition, respectively.
4. Competition ecological Study
In the characteristics of intra-specific competition according to bulrush density, the intra-specific competition in plant height began at 5 and 15% per pot in mixed culture and bulrush monoculture, respectively. The intra-specific competition in the shoot began at 5 plants per pot in both mixed cultur and bulrush monoculture. The competition in dry matter weight began at 15 plants per pot in monoculture, and at 10 plants in mixed culture. On the rice density, the plant height, and numbers of shoot and dry matter weight in rice were rapidly increased up to 2.6, 2.5 and 2.5 plants per pot, respectively. And then the increments were slow. The critical inter-specific competition of bulrush with rice was 2.5 to 3 plants per pot in their traits of rice, and especially the number of shoots and dry matter weights per pot showed significant decrements. In the different transplanting time in rice, the plant heights in both rice and bulrush elongated longer in mixed culture than in monoculture. The plant height of bulrush became shoter but the height of rice longer with late transplanting. The ratio of shoot number in rice to the number in bulrush was about 1:3 in all plots, and shoot numbers became less by late transplanting. The dry matter weight in both species were decreased by late transplanting, and the decrements were more prominent in bulrush than in rice. The plant height, shoot numbers and dry matter weight in both bulrush and rice were increased by high level of nitrogen fertilizer and especially the dry matter weights in both species were sharply increased by high level of nitrogen fertilizer. The plant height, dry matter weight in rice, and shoot, and dry matter weight in bulrush were increased by high level of phosphorus fertilizer. The deficient symptom diappeared with change of low level into high level phosphorus in rice. The plant height, dry matter weight and shoot numbers in rice and bulrush were increased by high level of potassium fertilizer. In the inter-specific competition in bulrush according to various water levels, the plant heights in both species elongated longer with deep water levels, and the plant height and dry matter weight in bulrush were more sharply decreased than in rice by deep water levels. The shoot numbers and dry matter weight were critically dropped above 6-8cm water level. In case of the shoot numbers for light source, in both species were more decresaed in mixed culture than each monoculture. The exserted shoot length and weight in bulrush were larger than in rice. The shaded shoot dry weight was more decreased in mixed culture than in each monoculture. The exserted shoot length and weitght in bulrush were larger than in rice. The shaded shoot dry weight was more decreased in mixed culture than in each monoculture, and the decrement was larger in bulrush than in rice.
5. Regrowth by Seasonal Mowing
The number of regrown shoots per plant for 2 weeks after mowing were sharply increased in response to late mowing until June 6, and then the increments were slow. The number of regrown shoots for July 30 were many with early mowing until May 14, and then the numbers were rapidly decreased. The plant height regrown for 2 weeks after mowing was increased until May 14, and then decreased. The plant height regrown for July 30 was not sensitive to mowing time and the development was linerarly shown. The fresh weight regrown for July 30 was only increased by late mowing. The regrowth rate of shoots for 2 weeks after mowing was much higher than untreated control and the ratio was decreased with late mowing and the ratio to untreated for control for July 30 was decreased up to 50% by late mowing. The regrowth rate of plant height for 2 weeks after mowing was rapidly decreased, but slowly decreased for July 30 mowing. The regrowgh rate of fresh weight was higher until May 22, and then rapidly decreased by late mowing. The decreasing tendency for 2 weeks after mowing was more prominent them for July 30. The annual regrowth rates in shoots and plant height were slowly decreased, but the decreasing rate in fresh weight was rapidly done until May 15, and then decrement became up to 30% by late mowing.
6. Reproductive Growth
In case of water condition the dry matter weight per plant was highest at 0cm flooding depth, and was decreased at above 2cm flooding dephs. The shoot and spikes per pot development best at flooding depths of 0 and 2cm, but did not worst at -5cm or above 4cm flooding depths. The dry matter weight of shoots was linarly increased, but the weight of roots was sharply decreased according to high temperature after flower initation. The shoots and spikes per pot developed more effectively at 25℃ than at 35 or 15℃. The number of shoot and spike per pot were decreased according to higher shading. The effects of shading of 25-45% were not significantly small. The natural white and yellow spectra were the most effective to increase dry matter weight, shoots and spikes per pot. The dry matter weights of shoot and root per plant were not significantly different among at 50 and 75% clay. The number of shoots were best and continuously increased at 75% clay, and the increments at 0 and 100% clays showed the lag period at early stage. The pattern of spikes was similar to shoots with less difference in various clay compositions. The dry matter weight per plant in paddy field to upland fields was basically similar. The numbers of shoot and spike were increased in response to increased fertilizer levels up to 20kg per 10a of each component.

목차 (Table of Contents)

• 抄錄 = 1
• 緖言 = 3
• 謝辭 = 5
• I. 硏究史 = 6
• II. 올챙고랭이 種實의 休眠打破條件에 관한 硏究 = 12
• 材料 및 方法 = 12
• 結果 및 考察 = 14
• 試驗 1. 圃場貯藏條件에 따른 種實의 休眠覺醒 差異 = 14
• 試驗 2. 溫度別 貯藏條件에 따른 種實의 休眠覺醒 差異 = 15
• 試驗 3. 稔實經過가 다른 種實의 休眠覺醒 差異 = 19
• 摘要 = 22
• III. 올챙고랭이의 種子發芽 및 越冬株基部의 出芽生態에 관한 硏究 = 24
• 材料 및 方法 = 24
• 結果 및 考察 = 28
• 試驗 1. 溫度條件에 따른 發生量 差異 = 28
• 試驗 2. 光量(光有無 및 照度差)에 따른 發生量 差異 = 31
• 試驗 3. 光質(Spectrum)에 따른 發生量 差異 = 32
• 試驗 4. 土壤酸度에 따른 發生量 差異 = 34
• 試驗 5. 株基部 重量에 따른 發生量 差異 = 36
• 試驗 6. 酸素 濃度에 따른 發生量 差異 = 37
• 試驗 7. 水深에 따른 發生量 差異 = 38
• 試驗 8. 覆土深에 따른 發生量 差異 = 39
• 摘要 = 41
• IV. 올챙고랭이와 主要 논 雜草種의 벼 競合 生態的 分類 = 42
• 材料 및 方法 = 42
• 結果 및 考察 = 44
• 1. 草種別 競合特性에 의한 分類 = 44
• 2. 벼의 雜草競合特性에 의한 分類 = 47
• 3. 綜合 分類 = 49
• 摘要 = 50
• V. 올챙고랭이의 競合生態에 관한 硏究 = 51
• 材料 및 方法 = 52
• 結果 및 考察 = 54
• 試驗 1. 種內 및 種間競合特性 = 54
• 1. 올챙고랭이 種內競合 = 54
• 2. 벼에 의한 올챙고랭이 種間競合 = 55
• 3. 벼 作期에 따른 올챙고랭이의 種間競合 = 56
• 4. 올챙고랭이 密度 變動에 의한 벼와의 種間競合 = 58
• 試驗 2. 肥料成分別 種間競合特性 = 59
• 1. 窒素 反應 = 60
• 2. 燐酸 反應 = 60
• 3. 加里 反應 = 62
• 試驗 3. 水深에 따른 種間競合特性 = 62
• 試驗 4. 光制限에 따른 種間競合特性 = 63
• 摘要 = 64
• VI. 올챙고랭이의 刈取에 따른 再生力에 관한 硏究 = 66
• 材料 및 方法 = 66
• 結果 및 考察 = 68
• 1. 莖數의 再生 = 68
• 2. 草長의 再生 = 69
• 3. 再生長生體重 = 70
• 4. 再生長率의 變動 = 71
• 摘要 = 74
• VII. 올챙고랭이 種實 및 越冬株基部의 繁殖生長에 관한 硏究 = 76
• 材料 및 方法 = 76
• 結果 및 考察 = 79
• 試驗 1. 水深에 따른 繁殖量의 差異 = 79
• 試驗 2. 出穗期의 溫度條件에 따른 繁殖量의 差異 = 81
• 試驗 3. 遮光(照度)에 따른 繁殖量의 差異 = 83
• 試驗 4. 光質(Spectrum)에 따른 繁殖量의 差異 = 84
• 試驗 5. 土壤物理性에 따른 繁殖量의 差異 = 86
• 試驗 6. 施肥量에 따른 繁殖量의 差異 = 89
• 摘要 = 90
• VIII. 綜合考察 = 92
• 1. 올챙고랭이의 發生 및 優占化 = 93
• 2. 올챙고랭이의 競合性 = 94
• 3. 올챙고랭이의 後代繁殖 = 96
• 4. 올챙고랭이의 防除技術 探索 = 97
• 引用文獻 = 99
• Summary = 112