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(13(4):28-35)STUDIES ON DAMPING-OFF DISEASE OF FIBER CROPS I. Ecological Studies on Pellicularia filamentosa (Pat.) Rogers Causing Damping-off of Fiber Crops (2)
No full text1. 本研究之目的為探求P. filamentossa在黃麻引起子苗立枯型腰折病所需之土壤溫度，濕度。並於土壤內增用植物添加物及不同氮素源，觀測是否可抑制病害之發生。
2. 黃麻幼苗在土壤溫度10~35℃均可發生腰折病，23~27℃最適宜於發病，而以25℃發病最激烈。
3. 土壤濕度以10~45%含水量均可使黃麻幼苗發生腰折病。在此範圍內，含水量愈少發病愈烈、20%含水量發病最多。土壤過濕或過份乾燥，則可使麻株生理異常增加死亡。
4. 土壤中加入植物有機質可使黃麻種子減少P. filamentosa侵害，其結果尤以太陽麻稈添加物時最顯著。兩種不同氮素源，NH4NO3及Uramite各以l00ppm加入各添加物處理內，可明顯減少種子被感染及幼苗死亡，罹病程度等。若僅二種化學氮素源相比較，則速效性NH4NO3顯然比遲效性 Uramite更見效。
5. P. filamentosa菌株對黃麻精洗麻纖維素破壞能力互不相同，菌株 K2 , T 及 B2 等3菌株對纖維素破壞能力最強，次為 K3 , J , B1，及R等4菌株。菌株U則完全不具破壞能力。
1. The purpose of this study is to determine the soil temperature and moisture which are favorable to Pellicularia filamentosa causing seedling damping-off of jute. Five Kinds of mature plant materials and 2 forms of supplemental nitrogen were added in the sick soil to test the effect in reducing the disease.
2. Jute seedlings infected by P. filamentosa were found at the range of soil temperatures from 10 to 35°C. The optimum soil temperature was at 23-25-27°C.
3. Damping-off of jute seedlings generally occurred at 10-45% soil moisture, the disease becomes more severe when soil moisture was maintained at low level, parti-cularly at 20%. However, jute seedlings become dead when soil moisture was higher than 45% or lower than 10%.
4. All kinds of plant materials added in the soil were effective to prevent seed rot and pre-emergence rot, especially with the addition of crotalaria in sick soil. soluble NH4NO3 and the slowly available Uramite were also offective in reducing disease severity when they were added to provide 100 ppm of in each treatient.
5. Each isolate of P. filameitosa showed different degree of destructiveness on fiber cellulose of retted fiber of jute. Among the 12 isolates, K2, T and B2 were found to be most destructive, K3, J, B1 and R the next, and the ioslate U no harm to fiber cellulose was observed
(13(2):46-54)STUDIES ON DAMPING-OFF DISEASE OF FIBRE CROPS I. Ecological Studies on Pellicuaria filamentosa (Pat.) Rogers Causing Damping-off of Fibre Crops
No full text一、Pellicularia filamentosa之8菌株分離自一般纖維作物，6菌株分離自其他作物，其寄主範圍均相一致，惟因菌株之不同對各類作物可呈現強弱不一之病原性。
二、分離自纖維作物病株之Pellicularia filameutose 8 菌株以側定棉及黃麻不同生育狀況之感病程度差異性，結果於不同菌株間，病原性可發生差別之事實，固不待言，然棉與黃麻因生育狀態不同而感染之易否亦可發生差異。棉以苗齡愈小，罹病愈容易。黃麻則以發芽後5~15日之間罹病指數最高，過此時期，雖亦可發病，但其程度急劇降低。
三、分離自纖維作物病株之Pellicularia filameutosa 8 菌株用以測定菌絲之癒合現象（Fu-sion of hyphae）結果，各菌株之菌絲癒合之程度不盡一致。其中以菌株 K l 與 C , T 與 F K3與 K 2與 T , K 3 與 U , C 與 T , U 與 F 及 T 與 F 均可進行完全癒合現象。
四、供試Pellicularia filamentosa各菌株對纖維素之破壞能力，因不同菌株而發生差異。菌株 K 2 破壞能力最強，次為菌株 T , U P，最弱都為菌株F，僅可發生極輕微破壞現象。
1. Among 14 isolates of Pellicitlaria filamcntosa, 8 isolates were isolated from the fibre crops and 6 from other plants. They had the same host range, but the pathogenicities of these isolates were quite different on various crops.
2. 8 isolates of Pellicularia filamentosa isolated from fibre crops were inoculated to different growth stages of cotton and jute, they showed different pathogeni-cites from one another. On cotton, small seedlings stage easily infected. On jute plants, high disease index was found on seedings 5 to 15 days after germination, and degree of infection was greatly reduced after this period.
3. The degrees of fusion of hyphae were different among 8 isolates obtained from the disease plant of fibre crops. However, isolates K1 and C, T and F, K2 and K3, K2 and T, K3 and U, C and T, U and F could Progress perfect fusion with each other.
4. Each isolate of Pellicularia filamntosa showed different destructive power to fiber cellulose, isolate K2 was the strongest one, isolate T, U and P the next, F and R were the weakest, the other were lower than 20% as shown in table 6
(11(4):36-48)STUDIES ON SISAL ANTHRACNOSE AND IT’S CONTROL
No full text1. 瓊麻炭疽病為臺灣瓊麻最主要病害，病原菌為 Colletotrichum agaves Cav. ，為害瓊麻老葉，使發生褐色或黑褐色病斑，葉片乾枯、縱皺、破壞纖維、使纖維帶褐色而易折斷，失去經濟利用價值。
2. 本病之發生與麻園距海之遠近無關，大都發生在有機械損傷及罹有日燒病之葉片上，發病時期為5~9月，麻田方向以向北、南之麻園發病較烈。
3. 瓊麻收割月份不同與炭疽病為害輕重有關，就罹病程度、產量、纖維等級觀之，以3月份最好，6月份次之，9月份最差。換言之，在本病盛發時期5月以前收割之麻園可使炭疽病之發生減少至最低程度。
4. 莖部施藥可撲滅本病之第1次感染原。就罹病擴大情形及罹病指數觀之，以 Sulfer 400 倍處理區最好。Granosan 1,000 倍處理區次之。
5. 田間防治試驗共使用4種殺菌劑： Granosan l,000倍，6~6式Bordeaux mixture, Ceresan Lime 及 Sanmicron E. C. 1,000倍等。 Granosan l,000 倍處理區效果最好，病斑擴大約為對照區之1/7，分級纖維比率為 91.23，高於對照區約l倍，分級後之纖維多為乙級品。其餘各藥劑處理均比對照區良好，其藥效順序為： Granosan l,000倍> 6~6 式Bordeaux mixture > Ceresan lime > Sanmicron E. C.
1. Anthracnose is the most important disease of sisal plant in Taiwan. It is caused by Colletotrichum agaves Cav. Initial symptoms show brown or brownish black spots on the old leaves of sisal plant. Then, form large spot with straw color in the center, finally the leaves dry up, lossen togather, and the fiber turned into br-own color, easy to be broken by wind. Thus, the economic value is much decreased.
2. This disease occurs only on those leaves that are injured maclinically or by sun burn, no matter how far the infested field located from seashore. The prevalent period of the disease is around May to September, and plants heavily infected are in the fields of northern and southern. Another directions correlation factor seems to be existed between the occurence period and the duration of sunshine.
3. Harvesting time is also related to the degree of disease damages. According to the severity of the affected plant, March is considered to be the best time for harvesting, and June is the next. The worst time for cutting sisal leaves is around September. Harvesting made before May may avoid the infestation of this disease to a great extent.
4. Spraying with fungicides on the left scars of the sisal stem where harbor numerous fruiting bodies of the pathogen results in good control of the disease. Among the fungicides tested Sulfer is the best one and Granosan the next.
5. Four kinds of fungicides: Granosan 0.1%, 6-6 Bordeaux mixture, Ceresan lime and Sanmicron E. C. 0.1% were used for field controlling experiments. Granosan was the most effective one. The expansion of lesions on sisal leaves from this treatment was about 1/7 of those from check plot, the ratio of graded fiber from treated plots is 91.23. almost double of those from check plot. The effectiveness of the fungicides may be listed below in descending order: Granosan, 6-6 Bordeaux mixture, Ceresan lime, Sanmicron
Rhizoctonia solani Kühn之形態學及誘導產生有性世代之方法
No full textRliizoctonia solani於1858年首被Kühn氏發現，其有性世代亦早於1891年即被描述，惟直到1903年Rolfs氏證明其有性世代為Corticium sp.以前，未見有連結其有性世代為同一種真菌之不同世代的報告。自玆而後，R. solanzi之有性世代即被描述為C. vagum var. solani Burt或R. solani (Prill. And Del.) Bourd and Calz。1943年後，本菌之有性世代被Rogers氏更名為Pellicukjria filamentosa (Pat.) Rogers.
本病原菌被更名為P. filamentosa曾弓―起國際間真菌學者之爭論。Donk氏經一連串之討論，並提出強烈證據，認為P. filamentosa是nomen confusum違背國際植物命名怯，是一種不合法之定名。Donk氏經重新整理並綜合異名同種，認為本病原菌之有性世代應為Thanatephorus cucurnerjs (Frank) Donk.
Donlt氏之意見受到多數真菌學者之同意。Warcup及Talbot兩氏曾強烈支待Donk氏之意見，並認為T. cucurneris是R. solanl最正確之有性世代學名。
R. solani無性世代之菌體並無特殊性。多數Rhizoctonia屬內之述菌絲性狀並無分別，且同種內之不同系統無性世代之菌體變化極大，是以R. solani被認為是混合種。Parmeter等氏曾指出Ceratobasidiurn sp.及其他R. solani之類似菌曾長期被誤涊為R. solani。T. cucurneris與Ceratobasidlum sp.之無性世代菌絲體，惟一不同處僅為菌絲細胞內細胞核之飲目。前者具多數細胞核；後者則僅含有兩個細胞核。
R.solani及其類似菌間之混亂，引起具菌學及植物病理學上嚴重紛亂。過去在缺少細胞核情形及有性世代之觀察下，關於R. solani之報告實值得懷疑並重新檢討。因此為澄清日後之混淆，發展一種可在研究室進行之簡單而容易的誘致R. solani及其類似菌類產生有性世代之方法至屬必要。
早年依據諸多學者報告，本病原菌不可能在人工培養基上產生有性世代，1924年在實驗室Muller氏首先以水球指怯培養本菌而得到有性世代，自此而後很多方法即被研究並發展之，但仍未得到最理想方怯。在這些已被知道的方法中，約可分成三類：1）琼指法，2）植物組織法，3）土壤法。
上述三種方法並不能誘致R.solani之所有系統及其類似菌類產生有性世代。蓋Rhizoctonia產生有性世代之條件，因系統不同而異，並不能以一概全。Stretton等氏曾報告，在其試驗使用之T. praticolus各菌株只可在琼脂上產生有性世代；具植物病原性之T. cucumer只能在土壤之表面產生有性世代：無植物病原性之T. cucumer則在琼脂上或上壤表面上均可產生有性世代。何以如此，原因不明。
迄至目前，控制Rhizoctonia產生有性世代之因子尚未充分瞭解。據Papavizas氏之報告，維他命、生長促進物質、植物抽出液、及許多天然或人工化合物均與本菌產生有性世代無關。某些因子如培養基質、光線、濕度、溫度和接種源則或多或少可影饗本菌產生有性世代。
綜上所述，在有把握而可供R.solani及其類似菌產生有性世代之方怯尚未發現，影響產生有性世代之因子亦未充分明瞭之前，菌絲體內細胞核數目之觀察為初步區別R. solani及其類似菌之最簡便方法。筆者並非主張真菌之鑑定，僅可依據細胞核之數目，而是在目前情形下，如以上述各種誘致產生有性世代之方法，誘導R. solani及其類似菌產生有性世代尚不可得時，惟有註明菌絲體內細胞核情形。比未註明菌絲細胞核情形就列為R. solani更清晰而正確
(17(4):51-56)罹病值物之組織隔離反應
No full textThe chain of reactions in histogenic demarcations is not initiated by the parasite iself, but by the necrosis caused by it. To his extent, demarcation reaction is non-specific, being indifferent to the particular source of the necrosis of the lesions , toxins of the parasite, orany other organic or inorganic poison.
The defensive reactions classified by Gäumann include three groups and six different kinds. Here, hisstogenic demarcations are one kind of protection which is effected by means of the antitoxic reaction; their aim is not to prevent infecton, but to prevent disease.
植物對疾病之防禦反應一向被認為是因為病原體在植物體內之進展而引起之對該病原菌本身之一種或多或少具有持殊性之抗禦作用。Gäumann曾將植物之防禦反應，據防禦對象分成3種，另按防禦反應之類型分成6種。本文論述之組織隔離反應（Histogenic demarcation reaction）即為該氏依據反應類型而分類之一種。
組織隔離反應是寄主植物因抵制從病原菌或植物腐爛細胞所產生之異化物質而產生的保護植物自身的一種防禦反應，所以與其他類型之植物防禦反應不能混為一談。
梨、桃等許多植物之穿孔病為植物組織隔離反應的典型例子。這種防禦反應不僅可發生在葉片，亦可發生在根、莖等部位。然而因發生部位之不同而反應過程及結果亦稍有差異。以Clasterosporium carpophilum引起之櫻桃穿孔病為例，當葉片被病原菌侵染後4至8日間，組織防禦反應開始發生。距離被侵染之腐敗斑點約20個細胞處的健全細胞，圍成一狹帶，並稍膨脹，這些細胞互相擠集，細胞間隙及葉綠體消失，原生質濃縮，細胞核增大，而具活性。當病情擴展時，在病斑四週的已成熟之細胞再次恢復分裂，此極活潑之細胞分裂，透過維管束，而將導管擠在週綠，另方面這些隔阻組織，中止營養分從健全組織進入病斑內，終使腐敗之罹病斑點脫落。
罹病植物之組織隔離反應具有兩大特性，是抗毒質反應，亦是植物體之自動反應。因為這種組織隔離反應是緣賴病原菌引起腐爛而導致，並非病原菌自身所引起，所以這種組織隔離反應並無特殊性，不論何種腐爛病斑內之物質，寄生菌產生之毒質，或是有機或無機物所發生之結果均無差異性。基於上述原因，植物組織隔離反應乃是植物抗禦有毒物質而產生之保護自身健康之反應，其目的不在防止病原體（菌）之侵染，而在於防止疾病之擴展
Experiments in Controlling the Damping-off Disease of Kenaf
No full text纖維作物腰折病，據過去之經驗，均發生於幼功期，民國50年發現本病可為害鐘麻成株，迨民國51年，已普遍在鐘麻產區--雲林、嘉義、臺南諸縣犯獗為害，發病率平均為10-83%，死亡率為5.4-43%，形成嚴重缺株，影響鐘麻單位面積產量至鉅。
Various fiber crops including jute, kenaf flax and Thai kenaf (Paw Keo) are generally attacked by damping-off disease during the seedling stage. Although effective control methods were lacking the disease has never caused a serious loss. This is probably due to the use of an excess amount of seeds at the time of seeding, which undoubtedly makes the loss of seedlings escaping notice. The disease was not found until 1961 that it is capable of affecting kenaf plants which have reached 1.5 meter high. Now the disease is widely distributed throughout the kenaf growing area in Taiwan. It occurs on the plants higher than 70cm. resulting a serious reduction of plant standing and becomes one of the most important diseases of kenaf
(25(2):134-140)STUDIES ON SEED TRANSMISSION OF FLAX FUSARIUM WILT AND ITS CONTROL WITH SEED TREATMENT
No full text亞麻立枯病病原菌雖係土壤傳播真菌，但也可經由種子而萬播。採收自罹病亞麻田之種子質輕、不飽滿而略扁平、表面有皺紋、無光澤、千粒重為2.3~3.0g，依發病程度而異；反之健全田之種子較重、飽滿、黑褐色、表面平滑、有光澤、千粒重為3.6g。種子攜帶病原菌之比率為0.42~6.00%，與田間亞麻罹病率成正相關。病原菌亦可侵入種皮內，其比率為0.02~0.1%。以發病亞麻田（發病率26~50%）採收之種子播種會引起萌前腐敗，亦可導致發生幼苗立枯病，前者達15.7%，後者為7.6%。
亞麻種子以50% Benlate W. P., Benlate T-20, 50%Vitavax-Thi-ram W. P., 50% Bavistin W. P.等0.5~0.1%（依重量計算）行拌種處理，可有效防止病原菌之蔓延，但因亞麻種子表面有膠質，遇水黏結成團，處理工作不易進行。故採用Dowfumo MC-2 1.5 lbs/22.32m3行燻蒸處理，為既有效又經濟之方法。
Although flax wilt pathogen, Fusarium oxysporum f. sp. lini, is a well known soil-borne fungus, it can also be transmitted by seeds. Seeds harvested from diseased flax fields are lighter, yellowish to dark brown, rough and dull, weight per thousand seeds varied from 2.3 to 3.0 g depending upon the percentage of wilt flax in the field. On the other hand, seeds from healthy flax fields are heavier, dark brown, smooth and shining, weight per thousand seeds is 3.6 g. Seeds from diseased fields carried F. oxysporum f. sp. lini with the rates varied from 0.42 to 6.00%, proportioned with the severity of flax wilt. However, wilt pathogen was detected not only on the seed but also in the seed. There were 0.02-0.10% of seeds found to carry the pathogen inside the seedcoat. Sowing of seeds from moderately diseased field (26-50% of flax wilt) resulted 15.7% of preemergence rot and 7.6% of seedling wilt.
Slurry-overcoating of flax seeds with Benlate, Benlate T-20, Vitavax-Thiram, or Bavistin at the rate of 0.5-1.0% by weight was effective in controlling seedling wilt and increasing stands. However, because of flax seeds are covered with a layer of gelatinous substance and are adhering in mass when wet, slurry-overcoating is not a good method for flax seed treatment. Fumigation with Dowfume MC-2 at the rate of 1.5 lbs/22.32 cu m for 14 hr during the storage period in a compact warehouse is recommended
(26(3):216-223)STUDIES ON FUSARIAL WILT AND ROOT DISEASE COMPLEXES OF ASPARAGUS IN TAIWAN
No full text調查本省苗栗、彰化、嘉義及屏東等四縣主要蘆筍栽培鄉鎮共11,201處（每處01公頃）蘆筍田，發現根部病害周年發生率達1.8～5.2％。全部罹病株中Fusarium oxysporum f. sp. asparagi引起之立枯病約佔46％，F. moniliforme引起之根腐病約17％，餘為其他病原菌如F. solani, Rhizoctonia solani及Pythium sp.等所引起。土壤種類對根部病害之發生有很大的影響，周年平均發病率壤土為.％，砂壤土為.％，壤砂土及砂土為5.2％。
以F. oxysporum f . sp. asparagi與F . moniliforme 兩種病原菌探討土壤溫度及濕度與發病之關係，發現兩者均以土壤溫度25℃發病最嚴重，但土壤濕度則前者以21% MHC ，後者以26% MHC 最易發病。F. oxysporum f. sp. asparagi在中性（PH7）土壤，F. moniliforme 以略偏酸性（PH6）土壤較適於發病。
A survey on fusarial wilt and other root diseases of asparagus was carried out from 11,201 fields located at 4 different asparagus growing prefectures in Taiwan in 1975. It was found that annual average of wilt and root diseases reached as high as 1.8-5.2%. Among diseased plants fourty six percent were proved to be incited by Fusarium oxysporum f. sp. asparagi, 17% by F. moniliforme, and the rest of them by F. solani, Rhizoctonia solani and Pythiurn sp. The soil type of asparagus field was proved to be closely related to the severity of root diseases; those of loam soil showed 2.4% of disease, sandy loam 3.6%, but loamy sand and sand 5.2%.
Although the optimum soil temperatures for disease incidence of both F. oxysporum sp. asparagi and F. moniliforme were at 25°C, the former was more prevalent if soil water holding capacity was at 21% with soil pH at 7, and the latter was more favorable at 26 % of water holding capacity with a soil pH around 6
(10(3):39-52)A COMPARATIVE STUDY OF ANTHRACNOSE DISEASE ON THAI KENAF(PAW KEO) AND JUTE
No full text1. 本研究之目的在探求泰國麻炭疽病菌之生理性狀及感染途徑，並與黃麻炭疽病菌（Collet-trichum corchorum）作一比較，冀能確定泰國麻炭疽病菌之名稱。
2. 泰國麻炭疽病菌與黃麻炭疽病菌之分生胞子堆、分生子梗及分生胞子之形態、色澤、大小比較結果，非常類似，未能發現可資鑑別之差異。
3.就培養性狀與分生胞子發芽條件比較結果，兩者截然異趣，其為不同菌之事實，已可認定。
4.泰國麻炭疽病菌於任何一種培養基上之生長，均顯然迅速，以泰國麻種子瓊脂上之生長最速，次為黃麻種子瓊脂，但就菌絲之生長密度、分生胞子形成量言，則馬鈴薯蔗糖瓊脂最佳。又蔗糖濃度以 8~10%之間，碳素源以Dextrose及Sucrose，氮素源以NH4N03 ( 250 mg.）最適合菌絲之生長及分生胞子之形成。
5. 泰國麻炭疽病菌之生長溫度範圍為 10~40oC之間， 28oC為最適宜之生長溫度。酸鹼度以 pH 5.5~7.5之間生長最佳， pH3.5~9.5之間均可生長。螢光處理結果，雖亦可促進胞子之形成，但並不顯著。
6. 分生胞子之發芽以蒸餾水加黃麻莖組識之發芽率聶高，洋蔥蔗糖瓊脂及蒸餾水加泰國麻莖組識次之。發芽溫度以 26~28oC較20oC及30oC適合。
7. 泰國麻炭疽病之感染途徑與黃麻炭疽病相同，分種子、土壤、成株地上部3種感染方法。同時對黃麻亦有高度致病性，病徵與黃麻炭疽病相同。
Thai kenaf (Hibiscus sabdariffa L. Var altissima) is a new fiber crop introduced from Thailand in 1957. It has been found that the Thai kenaf is susceptible to anthrax-cnose and its injury tends to become serious throughout the growing areas.
Since the symptom of this disease and the morphology of its pathogen such as the forms of acervulus, setae, conidiophore and conidium are very similar to those of jute anthracnose. Physiological aspects of the two pathogenes were compared to determine whether they differ from each other or not.
It was found that the pathogen of Thai kenaf anthracnose grew more faster on the culture than that from jute. The types and colours of colonies were affected by the different media. On the potato-sucrose agar, for example, brownish, encountered colonies covered with white mycelia were obtained. Such difference was not observed in the case of jute anthracnose.
The optimum temperature of each pathogen was 28°C. for Thai kenaf anthracnose, and 30°C. for jute anthracnose. Both pathogenes obtained better growth at pH value
6-7. However, the former seemed to prefer Alkali region to Acid region, while the latter showed to have a preference for acidity.
A majority of the conidia of Thai kenaf anthracnose germinated on distilled water containing jute stem tissue. On the other hand, superior gemination of the conidia was found if jute anthracnose was provided with onion-sucrose agar.
Inoculation tests revealed that the infestation of Thai kenaf anthracnose might occur either by the means of seed infection, soil infection and plant infectIon. The pathogen was also able to infect jute, and caused the symptom which like the jute anthracnose.
On the basis of these results, it is appropriate to conclude that the pathogene of Thai kenaf anthracnose might differ from that of jute anthracnose in some extent. Because two pathogenes can be easily distinguished as the mentioned characteristics are compared. Apparently a further study is necessary in order to determine whether the differentiation of Thai kenaf anthracnose is caused by the organism other than Colletotrichum corchorum Ikata et Tanaka., or merely due to its physiological variation
(Special Publication of TARI No. 24)Proceedings Of A Symposium On Grape Industry Research And Development
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