ISBN 971-8676-18-X
DISEASE PROFILE OF CROPS IN USM, KABACAN, COTABATO A practical guide to diagnosing and controlling common field diseases 2nd Edition
NAOMI G TANGONAN JASMIN A PECHO ELAINE GENEVIVE G BUTARDO
Published by the Plant Pathology Research Laboratory, Crops Research Division, University of Southern Mindanao Agricultural Research Center (USMARC), University of Southern Mindanao Kabacan, Cotabato, Philippines
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Suggested citation
Tangonan NG, Pecho JA, & Butardo EGG. 2008. Disease profile of crops in USM, Kabacan, Cotabato: Cotabato: a practical practical guide to diagnosing and and controlling common field diseases. University of Southern Mindanao Agricultural Research Center (USMARC), USM, Kabacan, Cotabato, Philippines, 50pp
ISBN 971-8676-18-X 2nd Edition & 1st Printing Portions of this brochure maybe reproduced as long as acknowledgment of source is attributed to the authors and the USM Agricultural Research Center (USMARC), University of Southern Mindanao, Kabacan, Cotabato, Philippines.
Foreword This brochure is the authors’ second attempt to put under one cover a pictorial listing of the symptoms and signs of common diseases of agricultural crops grown or observed in the field and experimental areas of USM (with emphasis on fungal diseases). New additions are aspects on disease control or disease management. The approach we adopted here is to be able to help the beginner or amateur plant doctor or crop protectionist familiarize her/himself with the basics of disease diagnosis. After all, no smart decision or intervention on disease control or management may be devised without first identifying or diagnosing the cause and nature (etiology) of the plant disease based on symptoms and signs. The authors welcome your feedbacks, suggestions, and comments. Feel free to contact them at the PPRL-USMARC, USM or at telephone number (064)-248-2610, or mobile #s 0928-320-7548 (NGT), 0919-275-8671 (JAP), and 0928-264-6499 (EGGB). Email:
[email protected] [email protected] i
Acknowledgments We express our special thanks and appreciation to the late Dr Hersie C Nicor, former director of the University of Southern Mindanao Agricultural Research Center (USMARC), and the USM-based Cotabato Agriculture Resources Research and Development Consortium (CARRDEC), its current Director Dr Elizabeth D Malacad, for their full support to this project. Ms Jo-an P Pandoy for editorial assistance. Above all, to God be the glory! ii
Contents Part I Symptoms of diseases on Abaca 1 Alugba 1 Ampalaya 2 Avocado 2 Balagay/Winged Bean 2 Banana 3 Cacao 4 Citrus (Calamansi, Pomelo) 4, 5 Cassava 5 Coconut 6 Coee 6 Corn 6, 7, 8 Durian 9, 10 Eggplant 11 Gabi 11 Green Onion 12 Holy Basil 12 Jackfruit 13 Jatropha 13, 14 Kangkong 15 Langkawas 15 Lanzones 15 Lemon Grass 16 Mango 16 Mangosteen 17 Mungbean 17, 18 Oil palm 19 Okra 20 Orchid/Pakpak lawin 20 Papaya 21 Patola 22 Peanut 22, 23 Pechay 24 Pigeon Pea 24 Pineapple 24, 25 Rambutan 25 Rice 26 Rubber 27, 28, 29 Salago 30 Saluyot 30 iii
Sorghum 30 Squash 31 Sweet Pepper 31 Sweetpotato 31 Tarragon 32 Tomato 32 Ubi 33 Upo 33 Yam 33 Part II Pathogens of plant diseases Algal pathogen Cephaleuros virescens 34 Bacterial pathogens Pectobacterium Pectobacterium (Erwinia) chrysanthemi 38 chrysanthemi 38 Xanthomonas Xanthomonas campestris pv oryzae (Ishi) Dye 42 Fungal pathogens Alternaria solani 34 solani 34 Cercospora abelmoschi 34 abelmoschi 34 C. arachidicola 34 C. canescens 34 C. capsici 34 capsici 34 C. citrullina 34 C. manihos 35 C. melongena 35 C. oryzae 35 Choanephora cucubitarum 35 Colletotrichum phomoides 35 C. gloeosporioides 35 Cordana musae 35 Corcium salmonicolor 35 Corynespora cassiicola 35 Curvularia inaequalis 35 C. lunata 36 Fusarium moniliforme 36 F. oxysporum oxysp orum 36 Helminthoporium sp. 36 H. heveae 36 H. oryzae 36 H. papayae 36 H. torulosum 36
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H. turcicum 37 Hemileia vastatrix 37 vastatrix 37 Lasiodiplodia theobromae 37 Macrophoma sp 37 Mycosphaerella jiensis 37 Oidium heveae 37 Peronosclerospora Peronosclerospora philippinensis 38 Pestaloa palmarum 38 Phakopsora pachyrhizi 38 pachyrhizi 38 Phellinus noxious 38 Phomopsis ipomeae batatas 38 Phytophthora colocasiae 39 P. infestans 39 P.palmivora 39 P. parasica 39 Pseudoperonospora cubensis 39 Puccinia arachidis 39 P. polysora 40 P. sorghi 40 sorghi 40 Pyricularia grisea 40 Rhizoctonia oryzae 40 R. solani 40 solani 40 Rigidoporus lignosus 41 Scleroum rolfsii 41 Sphaceloma/Elsinoe mangifera 41 Theilaviopsis paradoxa paradoxa 41 Uslaginoidea Uslaginoidea virens 42 Nematode Rotylenchulus sp 42 Virus diseases Chloroc streak of lemon grass 16 Leaf curl mosaic of papaya 21 Mangosteen mole 17 Papaya Papaya ringspot 21 Part III How to diagnose disease of agricultural crops: a simplied approach 43
PartIV Diseasemanagement/Controlme Diseasemanagement/Controlmeasures45 asures45 References47
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Part I - Symptoms o plant diseases ABACA (Musa texlis Nee)
Leaf blight of abaca caused by Rhizoctonia solani Kuhn. solani Kuhn. Note greenish-grey to white brown margin, watersoaked spots that spread rapidly to the leaves. In severe cases sclerotial bodies may be seen.
Abaca mosaic caused by a virus. It is characterized by alternating yellow and green portions on the entire leaf area.
Abaca leaf spot caused by Deightoniella torulosa Ell. (Helminthosporium (Helminthosporium torulosum Ashby.) Its initial symptoms are tiny dot-like black spots, which when severe coalesce and become big spots and manifest a blightlike appearance. As the disease progresses, spots turn brown to almost black in advanced stages.
Abaca bunchy top caused by the banana bunchy top virus (BBTV). It is characterized by yellowing and curling of leaf blades. In severe cases, infected plants become stunted and clustering of leaves will be noted.
Eyespot of abaca caused by Fusarium moniliforme Sheldon. Its initial symptoms, are small black spots covered with yellow halos that later turn to brown and form eye- like spot appearance.
ALUGBATI (Basella (Basella rubra L.)
Leafspot of alugbati (Ceylon spinach) caused by Cercospora sp. Note Note irregular and round or spherical straw-colored necrotic spots
Leafblightofalugbaticaused by Rhizoctonia solani Kuhn. It is characterized by enlarged, irregular, brown watersoaked spots with white mycelial growth on the advancing portion of the lesion.
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AMPALAYA (Momordica charana L.)
Ampalaya leafspots caused by Cercospora citrullina Cke. appear circular circular to irregular brown with yellow halo on affected portions of the leaves.
AVOCADO (Persea (Persea americana Mill.)
BALAGAY/WINGED BEAN (Psophocarpus (Psophocarpus tetragonolobus (L.) DC)
Orange galls on leaves and fruits of balagay or winnged bean caused by Synchytrium psophocarpi DC. psophocarpi DC. 2
BANANA (Musa (Musa sapientum L.)
Sigatoka disease caused by Pseudocercospora fijiensis Morelet Zimm.(Mycosphaerella Zimm.(Mycosphaerella fijiensis Morelet) This disease causes dark spots that eventually enlarge and coalesce, causing much of the leaf area to turn yellow and brown. As the spots further increase in size, they become dark brown surrounded by a yellow hypersensitive reaction that separate spots from the normal green tissue.
Banana bunchy top virus (BBTV) disease. The symptoms may appear at any stage of banana plant growth. The leaves become bunched together towards the apex and a rosette is formed. Emerging leaves are progressively shorter, narrower, stiff or crisp and papery to the touch, and more erect than normal. The irregular, nodular, dark green dot-dash lines or streaks appear running down the leaf stalk between the leaf blade and pseudostem.
Leafspots of banana caused by Cordana musae Hoehn. musae Hoehn. appear on mature leaves. Small, irregular brown spots with yellow halo and dark-brown to black centers
Banana speckle disease caused by Cloridium musae Sta. musae Sta. showing scattered, small black spots on leaf surface.
Leafspot caused by Cordana musae Hoehn. Irregular lesions that vary in size showing necrosis or browning of leaf tissues affected.
Black spots on fruits caused by Macrophoma musae Berk. & Vogl. or Sooty mold caused by Cladosporium cladosporioides . 3
CACAO (Theobroma (Theobroma cacao L.)
Black pod rot of cacao caused by Phytophthora palmivora Butler. Infected or wilted cherelles are caused by Colletotrichum gloeosporioides Penz. gloeosporioides Penz.
Leafspot of cacao caused by Pestalotia palmarum Cke. appear as irregular, round, brown spots that in time, coalesce to develop larger lesions that may result to death of the entire leaves l eaves or even seedlings.
Leafspot caused by Colletotrichum gloeosporioides Penz. gloeosporioides Penz. Symptoms are small brown spots, irregular in shape with yellow advancing portion around the lesion. Eventually, the spots coalesce and form larger spots that sometimes cause the leaves to deform. Severe infection may lead to drying up of the leaves or death of seedling.
CALAMANSI (Citrus (Citrus madurensis Lour.)
Scab of calamansi and King Mandarin caused by Elsinoe fawcetti Bit. & Jen. (Sphaceloma (Sphaceloma fawcetti Jen.). The raised surface of the fruits become rough with a light brown color causing malformation and poor fruit quality.
Brown leafspots are scattered all over the surface of the leaves. In advanced stages, the symptoms may spread to the twigs and can cause the death of affected branches as well as the death of the grafted seedlings. The pathogen id Fusarium solani Appel solani Appel & Wr. 4
Leafspot of citrus caused by Colletotrichum gloeosporioides Penz. The spots are circular to irregular and appear as light brown with a dark brown halo.
Powdery mildew of citrus caused by Oidium tingitanium Carter. tingitanium Carter.
POMELO (Citrus (Citrus grandis L.)
Twig blight of pummelo caused by Fusarium moniliforme Sheldon. moniliforme Sheldon. It is characterized by yellowing of leaves and discoloration of the vascular tissues resulting to death of the affected twigs.
Pink disease of pummelo caused by Corticium salmonicolor B. salmonicolor B. & Br.
Leaf symptoms of a suspected virus disease showing irregular light green to yellow areas alternating with normal green areas distributed in varying intensities and patterns without any reference to veins.
Sooty molds caused by Capnodium citri Berk. & Desm.
Citrus fruit from a virus infected tree.
CASSAVA (Manihot (Manihot esculenta Crantz)
Leaf spot of cassava caused by Cercospora manihotis Henn. manihotis Henn. Note ring-like appearance on the leaf with yellow or straw-colored centers. The lesions start by a discoloration of the leaf tissues. 5
COCONUT (Cocos (Cocos nucifera L.)
Gray spot or leaf blight of coconut caused by Pestalotia palmarum Cke. palmarum Cke. The disease starts near the midrib and distal ends, brown longitudinal lesions that can cover the entire leaf surface.
Leaf blackening or sooty mols caused by Caprodium footie Berk. footie Berk. & Desm. Commonly associated with coconut mealybugs (Nipaecoccus (Nipaecoccus nipae )
COFFEE (Coea arabica L.)
Coff Coffee ee rust rust unde undern rnea eath th leaf leaf
Soot Sootyy mold mold of coff coffee ee leav leaves es
Coffee leaf rusts are circular yellow to orange spots on the affected leaves. Later, the spots become bigger and produce dust-like particles on the under-surface of the leaves. The causal pathogen isHemeleia isHemeleia vastatrix B. & Br.
CORN ( Zea Zea mays L.)
Leaf blight of corn is caused caused by Rhizoctonia solani Kuhn. solani Kuhn.
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Downy mildew of corn caused by Peronosclerospora philippinensis (Weston) Shaw continues to be the most destructive corn disease in the Philippines. It affects the yield yield potential and agronomic characteristics of corn.
Corn leaf rusts are reddish-brown colored pustules that erupt releasing spores on both sides of the leaf surface. Puccinia sorghi Schw. sorghi Schw. and P. polysora Underw. are the pathogens that cause the disease. Leafblight of corn caused by Curvularia inaequalis Boedj inaequalis Boedj
Sheath blight of corn is caused byRhizoctonia by Rhizoctonia solani Kuhn. solani Kuhn. On stems, the map-like appearance are at first ovoid and greenish-grey, later becoming grayish-white with brown margin. Spots are usually first observed at the soil line. Sclerotial bodies are formed on the affected surface.
Corn ear rot caused by Fusarium moniliforme Sheldon produces white-to-pink or salmon-colored moldy or white cottony growth on surface of infected kernels
Corn leaf blight
Northern leaf blight of corn caused by Helminthosporium turcicum Pass. It is characterized by long, elliptical, grayishgreen or tan colored lesions on the leaves.
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Symptoms infected with Fusarium stalk rot caused by Fusarium solani . It appeared as white mycelium of the stalk, cross-section showed shredding of the pith tissues starts at the nodes.
Stalks infected with the Gibberela fungus have characteristics of pink to reddish discoloration of the pith and vascular strands. Rotting commonly affects the roots, crown, and lower internodes. The breakdown and shredding of pith tissues starts at the nodes.
Bacterial leaf stripe caused by Pseudomonas rubrilineans , syn. P. avenae, Acidvorax avenae subsp. Avenae. Lesions expand along veins, producing a conspicuous striping, mainly in the youngest leaves. Stripes later dry and brown, often with shredding of the infected leaf tissue. Severe damage of the top leaves results in tassel rotting, when dead leaves enclose the tassel.
Corn smut caused by Ustilago maydis Corda. maydis Corda. Note powdery black mass of thick-walled th ick-walled teliospores on affected area. 8
DURIAN (Durio (Durio zibethinus Murr.)
On leaves, blight is characterized by a halo of light green tissue on leaves caused caused byFusarium byFusarium sp. sp. and Rhizoctonia solani Khun. solani Khun. Fruit discoloration resulting to rot is caused by P. palmivora.
Sooty molds of durian
Durian blight
Phytophthora palmivora causing fruit rot, leafblight, and dieback diseases of durian. Symptoms Symptoms appear as watersoaked lesions with light brown center 3-5 days after infection, expands rapidly, and can completely rot an entire plant part. Patches appear on fruit surface surface as moist and damp.
P. palmivora also causes stem canker and appears as wet lesion with bark cracking, particularly on the base of the main stem near the soil and sometimes on some branches. Bark is discolored with exudate of reddish brown, resinous substance that ooze out from the surface of affected areas. Wood lesions are often very irregular in shape but are often welldefined. Infection can weaken the tree causing defoliation and death of the affected branch or dieback of the whole tree. 9
Fruit rot of durian caused by Lasiodiplodia theobromae (Pat.) Griff. & Maubl. produces grayish mycelium found behind the advancing portion of the lesion.
Vascular streak dieback (VSD) of durian caused by Oncobasidium theobromae Talbot and Keane. Staining of vascular bundles/vessels are evident followed by leaf yellowing and defoliation.
Stem canker and dieback of durian trees due toPhytophthora to Phytophthora palmivora Butler. Note various symptoms on affected trunk. 10
EGGPLANT (Solanum (Solanum melongena L.)
Fruit rot caused by Phytophthora parasitica Dastur The disease starts at any portion of the fruit. The lesions are dark-colored and sometimes covered with mycelial growth of the pathogen. Infected portions are soft and watersoaked. The lesion grows rapidly on mature fruits.
Leaf spot of eggplant caused by Cercospora melongena Welles can affect not only the leaves but also the stem, appearing watersoaked, irregularly shaped with advancing yellow halo, and scab-like brown edges. Dead tissue may tear away from the healthy tissue leaving holes on affected leaves.
Leaf blight caused by Phomopsis (Diaporthe) vexans Hartig vexans Hartig & Gratz Starts on the leaf tip and advances upward as it progresses. The lesion becomes wider and appears yellowing on the affected portion. Mycelial bodies may may be present at a closer look on dried infected potion of the leaf.
Wilt of eggplant makes the leaves turn yellow. Wilting first occurs at the terminal leaves, until the whole plant dies. It is caused by Fusarium oxysporum Schlecht. oxysporum Schlecht.
GABI/TARO (Colocasia (Colocasia esculenta (L.) Scho
Leaf blight of taro/gabi caused by Phytophthora colocasiae Rac. colocasiae Rac. showing watersoaked, dark brown to black lesions of infected leaves. Virus-like symptom of gabi (below).
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GREEN ONION ( Allium Allium cepa L.)
Sclerotium rolfsii Sacc. rolfsii Sacc. causing blight of green onion. The pathogen attacks the lower parts of the plant, turns yellow brown, wilts, until the whole plant dies. Mycelial strands and dirty white, brown fruiting bodies can be seen on the collar region or above ground part of the plant.
HOLY BASIL (Ocimum (Ocimum sanctum L.)
Leaf spot of holy basil caused by Curvularia lunata (Wakker) Boedj. Spots appear as small, yellowish brown, circular to oblong.
Leaf blight of basil caused by Virus-infected holy basil plant Fusarium moniliforme Sheldon. showing leaf curling symptom. Lesions are large, irregularly shaped, that lead to death and browning of affected tissues.
Leafspot of basil caused by Cercospora sp.
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JACKFRUIT ( Artocarpus heterophyllus Lmk.)
Dieback and bark rot of jackfruit caused by Fusarium moniliforme Sheldon. moniliforme Sheldon. It is characterized by brown, watersoaked necrotic bark along the trunk. White mycelial growth of the pathogen can also be observed extending internally into the cambium layer that as result, the affected area turns yellow, dries up, and later death of the whole tree occurs.
Fruit rot of jackfruit caused by Sclerotium rolfsii Sacc. rolfsii Sacc. Note whitish mycelia of the fungus on the affected black portions
JATROPHA JATROPHA ( Jatropha Jatropha curcas L.)
Seedling blight/ damping off caused by Choanephora sp.
Leafspot caused by Cercospora sp.
Anthracnose leafspot caused by Colletotrichum gloeosporioides Penz.
Leaf blight caused by Helminthosporium sp. Helminthosporium sp. and leafspot caused by Curvularia sp. (right)
Virus-infected leaves of Jatropha showing mottling, curling, and fan leaf symptoms. 13
Moldy rot Jatropha nuts.
Leafspot caused by Thielaviopsis (Chalara) paradoxa (Dade) Moreau
Symptoms of diseases on jatropha caused by various fungal pathogens (Curvularia, (Curvularia, Cercospora, Cercospora, and Thielaviopsis). Thielaviopsis). 14
KANGKONG/ SWAMP SWAMP CABBAGE ( Ipomoeae aquaca Forsk.)
White rust of kangkong caused by Albugo ipomoeae aquatica Sani.
LANGKAWAS ( Alpinia Alpinia galanga L.)
Leafspot of turmeric caused by Fusarium moniliforme Sheldon. Sheldon. Small circular spot appear as brown to light brown.
Rust of langkawas caused by Uromyces sp. Uromyces sp.
Leaf blight of langkawas caused by Macrophoma sp. The lesions are elongated and enlarge rapidly to cause complete yellowing resulting to death of the leaves.
LANZONES (Lansium domescum Jack)
Leaf blight caused by Fusarium moniliforme Sheldon. Early symptoms are the presence of irregular brownish lesions which enlarge and dry up. The infected leaves eventually withers and falls. In favorable condition, presence of pinkish-white, hairy growth on surface of the infected tissue were visible.
Scab on fruit.
Leaf blight of lanzones caused by Colletotrichum gloeosporioides Penz. with watersoaked lesions, brown with yellow halos from the leaf tip and margins to the entire leaf area. 15
LEMON GRASS (Cymbopogon (Cymbopogon citratus (DC) Stapf)
Virus disease of lemon grass showing lightly chlorotic streak (light green to yellowish lines) and reddish to brown dead tissues on the leaves (right).
Sudden death of lemon grass caused by Sclerotium rolfsii Sacc. indicated by maplike blight on the leaves and leaf sheaths and a white mycelial growth with sclerotial bodies of the causal causal pathogen on the base of the plant.
MANGO (Mangifera (Mangifera indica L.)
Scab disease caused by Sphaceloma/Elsinoe mangifera Bit. & Jen. on Carabao mango. Note the dry rot and cracking effect of scab and also the incidence of anthracnose fruit rot on right photo.
Carabao mango fruits showing stem-end rot disease caused by Lasiodiplodia theobromae (Pat.) Griff. & Maubl. (note broader infection of dark brown rots at stem ends).
Early and advanced symptoms of anthracnose caused by Colletotrichum gloeosporioides carabao gloeosporioides carabao mango.
Pink disease caused by Corticium salminocolor B. salminocolor B. & Br. attacks the trunks, twigs, and branches on mango. It may appear typically as spider-like structure covering the infected surface. It turns thick, smooth, and pink in color during rainy season. 16
Anthracnose on leaves caused by Colletotrichum gleoesporioides.
MANGOSTEEN (Garcinia (Garcinia mangostana L.)
Leaf spot of mangosteen (Alternaria (Alternaria sp.) occurs as small, dark necrotic spots.
Seedling wilt of mangosteen predisposed by sun scalding. When sectioned, brown to black color on the root system of infected seedlings are apparent. Virus-infected mangosteen tree showing mottling of the leaves (alternate light and dark green areas color). Symptoms characterized by mosaic, stunted growth reduced leaf size, shortened internodes, and erect, stiff leaves.
Virus disease of mangosteen. Note chlorosis and reduced width size of leaves.
MUNGBEAN/ STRING BEAN (Phaseolus aureus Roxb./Vigna Roxb./Vigna radiata (L.) Wilczek) Leaf spots of mungbean are irregular shapes with tan centers. Lesions increase in size and coalesce until the greater part of the leaf infected. The disease is caused by Cercospora canescens Ell. & Mart. Powdery mildew of beans caused by Erysiphe polygoni DC. polygoni DC.
Rust of string beans caused by Phakopsora pachyrhizi.Syd. pachyrhizi.Syd. The lesions are small, reddish in color and surrounded by yellowed leaf tissue.
Virus-infected string beans.
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Samples of legumes showing symptoms of leafspots, blights, leaf curling, and insect damage. 18
OIL PALM (Elaeis (Elaeis guineensis Jacq.)
Anthracnose of oil palm caused by Colletotrichum gloeosporioides Penz.
Leafspot of oil palm caused by Pestalotia palmarum Cke. palmarum Cke.
Rachis blight of oil palm caused by Thielaviopsis (Chalara) paradoxa (Dade) Moreau
Leafblight of oil palm caused by Curvularia lunata (Wak.) Boedj.
Leafspot of oil palm caused by Fusarium moniliforme Sheldon. moniliforme Sheldon.
Heart rot of oil palm caused by Pectobacterium chrysanthemi Burk. chrysanthemi Burk.
Stem/ bud rot of oil palm caused by Rhizoctonia solani Kuhn. solani Kuhn.
Basal trunk rot caused by Ganoderma lucidum Karst. lucidum Karst.
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OKRA (Hibiscus (Hibiscus esculentus L.)
Leaf spot or leaf mold (lower left) l eft) of okra caused byCercospora by Cercospora abelmoschi Chupp abelmoschi Chupp & Sher. looks like a combination of black and purplish, small spots on the upper surface of the leaves. Mycelia (grayish to black) or threadlike structures of the causal pathogen can be seen on the undersurface of the leaf.
Severe moldy rot on okra showing entire fruit covered with fungal growth.
ORCHID / PAKPAK LAWIN ( Asplinium Asplinium nidus Linn.)
Leaf blight on pakpak lawin.
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Black spot of orchid.
PAPAYA (Carica (Carica papaya L.)
Leaf curl mosaic virus of papaya showing irregular reduction and malformation of pale green leaves. In advanced stage, plants appear mottled, distorted, wrinkled, and the edges curl downward
Leafblight of papaya caused by Phytophthora parasitica Dast.
Papaya ringspot virus-infected tree.
Crown rot of papaya caused by Pectobacterium carotovora subsp. atroseptica (Van Hall) Dye . It is one of the most widespread and destructive diseases of papaya that infects fruits, leaves, petioles, and causes wilting and rotting of the growing point resulting to decapitation and toppling over the shoot.
Leafspot of papaya caused by Helminthosporium papayae Sydow. papayae Sydow. It is characterized by a small brown with a yellow halo lesion.
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Virus-infected papaya and fruit rot.
PATOLA (Lua cylindrical Auct. NonRoem.)
Leaf blight and fruit rot on papaya.
PEANUT ( Arachis Arachis hypogaea L.)
Wilted and stem rot of peanut showing severe infection of Sclerotium rolfsii Sacc. and exhibit symptom of decline
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Symptoms of early leafspot of peanut (Cercospora (Cercospora arachidicola Hori.) observed.
Peanut rust (Puccinia (Puccinia arachidis Speg.) arachidis Speg.)
Symptoms of leafblight of peanut (Fusariumn oxyporum Schlecht.) observed.
Root rot of peanut caused by nematode, Rotylenchulus sp. Rotylenchulus sp. Leaf rust of peanut caused by Puccinia arachidis Speg. arachidis Speg.
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PECHAY (Brassica (Brassica pekinensis (Lour.) Rup.)
Wilt of pechay caused by Fusarium oxysporum showing water-soaked infected part (crown) and whitish growth of causal pathogen
PIGEON PEA/KADYOS (Cajanus cajan (L.) Huth.)
Leaf spot of pigeon pea caused by Cercospora canescens Ell. & Mart. appears as small brown, with a yellow halo.
Leaf blight of pigeon pea starts from the leaf margin and later spreads to the entire leaf.
PINEAPPLE ( Ananas Ananas comosus (L.) Merr.)
Phytophthora heart rot
Wilt caused by Fusarium
Bacterial heart rot
Butt rot caused by Pectobacterium chrysanthemi
Nematode-infected crown of pineapple.
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Pineapple plants showing various degrees of root rot caused by Pythium spp. Pythium spp.
RAMBUTAN (Nephelium (Nephelium lappaceum L.)
Pink disease caused by Corticium salmonicolor B. & Br. attacks the trunks, twigs, and branches of rambutan. The disease may appear typically as spider-like structure covering the infected surface. It turns thick, smooth, and pink in color during rainy season. The infected plant parts dry-up.
Algal spot caused by Cephaleuros virescens attacking virescens attacking the upper portion of leaves. The lesions forming more or less circular spots on the leaf.
Leaf blight of rambutan caused by Colletotrichum gloeosporioides Penz. gloeosporioides Penz. infects the leaf margin and eventually advances until brown colored lesion developed.
Vascular streak dieback of rambutan caused by Oncobasidium theobromae theobromae T. T. & K. Staining is evident when the affected twigs are detached and cut up. 25
RICE (Oryza sava L.)
Symptoms consist of brown, dark, circular to oval spots that vary in size. Spots on seedlings may become numerous. It caused by Helminthosporium oryzae B. oryzae B. de Haan.
Bacterial leaf blight (Xanthomonas (Xanthomonas campestris pv oryzae (Ishi.) Dye). The first symptom of the disease are water soaked lesions on the edges of the leaf blades near the leaf tip. The lesions expand and turn yellowish and eventually become grayish-white. In severe cases, it leads to panicle blight.
Panicle blight appear at heading during grain fill, small clusters of panicles do not fill out, and turn over because they are unfilled.
Leaf and shealth blight. The disease caused by Rhizoctonia oryzae Ryker oryzae Ryker & Gooch or R. solani Kuhn solani Kuhn starts from the basal leaf sheaths as water soaked spots with light brown or straw-colored center and reddish border. These lesions usually develop just below the leaf collar as oval to elliptical, green-gray spots
Dark brown to black spots are often large enough to cover entire grain. Affected grains may be poorly filled and chalky. It is also caused by Helminthosporium oryzae B. de Haan (Cochliobolus (Cochliobolus miyabeanus False smut. Spore balls are found in place of grain or around the grain and reduce the quality of the produce. The spores are greenish on Drechs.). outside and yellow orange inside. Disease incidence maybe seen at postflowering to ripening stage of the crop. It is caused byUstilaginoidea byUstilaginoidea virens Tak. virens Tak.
Narrow brown leaf spot on leaves and upper leaf sheaths include short, or long linear lesions that become numerous as the plant approaches maturity. It is caused by Cercospora oryzae Miyake (Sphaerulina (Sphaerulina oryzina Hara). 26
Leaf blast caused by Pyricularia grisea (Cooke) Sacc. (P. (P. oryzae Cav). oryzae Cav). It can cause cause serious losses to susceptible varieties. Depending on the part of the plant affected, the disease is often called leaf blast, rotten neck, or panicle blast. The center of the spot is usually gray and the margin brown or reddish-brown.
IRPT rating scale used in the assessment of Rhizoctonia leaf and sheath blight of 15 rices, 0 means of infection.
RUBBER (Hevea (Hevea brasiliensis (Muell.) Arg.
Bird’s eye spot caused by Helminthosporium heveae Petch. Anthracnose leafspot and leafblight caused by Colletotrichum gloesporioides Penz.
Powdery mildew caused by Oidium heveae Stein. heveae Stein.
Leaf and seedling blight and Leafblight caused by P. palmivora and wilt caused by Fusarium Rhizoctonia. solani Khun. solani Khun. oxysporum f. sp. vasinfectum Snyd. & Hans.
Leafspot/Leaf fall caused by Corynespora cassiicola (Berk and Curt) 27
Seedling blight of rubber.
Powdery mildew of rubber.
Seedling blight caused by Phytophthora palmivora Butler.
Knob-gall of rubber.
Black stripe, stem canker, and bark splitting due to P. Palmivora. Palmivora.
Pink disease caused by Corticium salmonicolor B. salmonicolor B. & Br.
Knob gall and stem bleeding caused by Lasiodiplodia theobromae (Pat.) theobromae (Pat.) Griff. & Maubl. 28
White and brown rot diseases caused by Rigidoporus lignosus Imazeki lignosus Imazeki and Phellinus noxious Cunn. noxious Cunn.
Root damage due to white and brown root rots caused by Rigidoporus lignosus and lignosus and Phellinus noxius .
Leafspot and leafblight on rubber.
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SALAGO (Wikstroemia (Wikstroemia lanceolata L.)
Stem and leaf blight of salago caused by Rhizoctonia solani Kuhn, solani Kuhn, resulting to death of the affected leaves and twigs.
SALUYOT / JUTE (Corchorus (Corchorus olitorius L.)
Leafspots caused by Cercospora corchori Saw., corchori Saw., Colletotrichum sp., Curvularia sp., and Helminthosporium sp Helminthosporium sp
SORGHUM (Sorghum (Sorghum bicolor (L.) bicolor (L.) Moench.
Leaf and sheath blight of sorghum caused by Rhizoctonia solani Khun solani Khun first appear as small, purplish, long irregular spots. Cloudy and humid conditions favor the pathogen to abundantly grow its mycelia that colonize the sheath causing it to bend, dry, and die.
Rust of sorghum caused by Puccinia sorghi Schw. or P. pupurea Cke. showing small, orange to brown spots on the leaves. Spots coalesce forming raised lesions filled with rust uredospores.
Black/tar spot spot of sorghum caused caused by Phyllachora sorghi v. Hoehnel. Leaf spot of sorghum caused Curvularia sp. 30
SQUASH (Cucurbita (Cucurbita maxima Dcne.)
Squash can be infected by viruses at any stage of growth. When infected, the leaves turn yellow, and show abnormal growth. Infected fruits reveal patterns of white blotches interspersed with dark green spots that are raised into conspicuous blisters.
SWEET PEPPER (Capsicum (Capsicum annuum L.)
Fusarium oxysporum (Schlecht.) oxysporum (Schlecht.) Snyder & Hansen causes wilt of sweet pepper and infects the roots and vascular tissues (causing its discoloration) leading to death of the plant.
Brown leaf spot caused by Cercospora capsici Heald and Wolf. It infects on surface of the leaves with grayish centers scattered all over the leaf area.
Spots are circular to irregular, enlarge with age, the center becomes light brown with dark margins. Later, the necrotic necrotic tissues drop off leaving a shot-hole effect. The disease is due to Cercospora capsisi Heald capsisi Heald & Wolf.
Bacterial fruit rot of sweet pepper caused by Erwinia carotovora (Jones) Bergy et al.
SWEETPOTATO (Ipomoea (Ipomoea batatas (L. Lam.)
Gray leaf spot of sweet potato caused by Phomopsis ipomeae batatas ipomeae batatas Pun. (Phyllosticta (Phyllosticta batatas ),), is either angular or circular with a brown halo and light brown necrotic lesion at the center where pycnidia or fruiting bodies may be seen. 31
TARRAGON ( Artemisia Artemisia dracunculus L)
Stem blight of tarragon caused by Sclerotium rolfsi i.i. Sclerotial bodies may be seen in severe cases (above).
Leaf curling of tarragon caused by a virus.
TOMATO (Lycopersic (Lycopersicon on esculentum Mill.)
Leaf blight of tomato caused by Alternaria solani Jones. solani Jones. & Grout (left).
Fruit rot of tomato caused by Phytophthora infestans de Bary, it is characterized by watersoaked brown lesions that later increase in size until the whole fruit rots. Note cottony mycelial growth (right).
Leaf blight of tomato caused by Rhizoctonia solani. 32
Sclerotium rolfsii causing fruit rot of tomato.
Fruit rot of tomato caused by Colletotrichum phomoides Chester.
UBI (Dioscorea (Dioscorea alata L.)
Infected portion is clearly defined, it spreads rapidly over the leaf lamina, collapses, and turns brown. It is caused by Colletotrichum gloeoprioides.
UPO (Lagenaria (Lagenaria leucantha (Duch.) Rusby)
Brown and circular specks lesions of upo, the centers become light in color. The pathogen is Colletotrichum lagenarium Ell. lagenarium Ell. & Halst.
Downy mildew symptoms appear angular yellow on the leaves on the upper side and purplish mildew on the lower side. The causal pathogen is Pseudoperonospora cubensis Rostow. cubensis Rostow.
Typical symptom of mosaic virus disease of upo or bottle gourd. The leaves have irregular pale green with dark green spots scattered. In advanced stage, plants appear mottled, distorted, wrinkled, and the edges curl, downward.
Postharvest disease of upo caused by Fusarium sp. Symptom starts from peduncle which later advances as the disease progresses.
YAM (Dioscorea (Dioscorea alata L.)
Leafblight of yam (ubi)
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Part II - Signs (pathogens) o plant diseases
Alternaria solani Jones solani Jones & Grout
Cercospora abelmoschi Chup abelmoschi Chup & Sher
Cercospora capsici Heald capsici Heald & Wolf
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Cephaleuros virescens Kunze virescens Kunze
Cercospora arachidicola Hori
Cercospora canescens Ell canescens Ell & Mart
Cercospora citrullina Cke
Cercospora manihotis Henn manihotis Henn
Cercospora melongena Welles
Cercospora oryzae Miyake oryzae Miyake
Choanephora cucubitarum Thaxter cucubitarum Thaxter
Colletotrichum phomoides Chester phomoides Chester
Colletotrichum gloeosporioides Penz gloeosporioides Penz
Cordana musae Hoehn musae Hoehn
Corticium salmonicolor B. salmonicolor B. & Br.
Curvularia inaequalis Boedj inaequalis Boedj
Corynespora cassiicola (Berk& Curt) Wei
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Fusarium moniliforme Sheldon moniliforme Sheldon Curvularia lunata (Wakker) Boedj
Helminthosporium sp Helminthosporium sp Fusarium oxysporum (Schlecht) oxysporum (Schlecht) Snyder & Hansen
Helminthosporium oryzae B oryzae B de Haan
Helminthosporium heveae Petch heveae Petch
Helminthosporium torulosum Ashby torulosum Ashby Helminthosporium papayae Sydow papayae Sydow 36
Helminthosporium turcicum Pass turcicum Pass
Hemileia vastatrix B. vastatrix B. & Br.
Lasiodiplodia theobromae (Pat) theobromae (Pat) Griff & Maubl
Macrophoma sp
Mycosphaerella (Para/Pseudocercospora) fijiensis Morelet fijiensis Morelet Oidium heveae Stein heveae Stein 37
Pectobacterium chrysanthemi Burk chrysanthemi Burk
Peronosclerospora philippinensis (Weston) philippinensis (Weston) Shaw
Pestalotia palmarum Cke palmarum Cke Phakopsora pachyrhizi Sydow pachyrhizi Sydow
Phellinus noxious Cunn noxious Cunn
Phomopsis ipomeae batatas Pun batatas Pun
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Phytophthora colocasiae Rac colocasiae Rac Phytophthora infestans de infestans de Bary
Phytophthora palmivora Butler Phytophthora parasitica Dastur
Pseudoporonospora cubensis Rostow cubensis Rostow
Puccinia arachidis Speg arachidis Speg 39
Puccinia polysora Underw
Puccinia sorghi Schw sorghi Schw or P purpurea Cke
Pyricularia grisea (Cooke) Sacc (P (P oryzae Cav) oryzae Cav) Puccinia sorghi Schw sorghi Schw or P pupurea Cke
Rhizoctonia oryzae Ryker oryzae Ryker & Gooch or R solani Kuhn solani Kuhn
Rhizoctonia solani Kuhn solani Kuhn 40
Rigidoporus lignosus Imazeki lignosus Imazeki
Sclerotium rolfsii Sacc rolfsii Sacc
Sphaceloma/ Elsinoe mangifera Bit & Jen
Theilaviopsis (Chalara) paradoxa (Dade) Moreau
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Ustilaginoidea virens Tak virens Tak
Xanthomonas campestris pv campestris pv oryzae (Ishi) oryzae (Ishi) Dye
Nematode
Rotylenchulus sp Rotylenchulus sp 42
Part III - How to diagnose diseases o agricultural crops: a simplifed approach Diseases lower crop yields
Diseases attacking agricultural crops are constraints to bigger yields. Field and postharvest diseases lower both the quality and quantity of all food crops, feed grains, and fibers. Some examples of diseases that limit yields are downy mildew and stalk rot of corn, tungro, blights and blast of rice, head molds of sorghum, rust of coffee, peanut, and soybean, virus diseases of legumes and vegetables, and bunchy top of abaca, wilt and damping- off seedlings, sigatoka leaf spot and moko wilt of banana, pod rot of cacao, root- knot galls of ramie, eggplant, tomato, citrus, pink disease and black stripe of rubber.The list goes on… Diagnosis through eld symptoms
The most practical approach to diagnoses of crops is by means of their field symptoms. This means taking a look at their appearance. Any apparent abnormality in the plant/plant part (caused by disease- causing organism called pathogen) when compared to its healthy counter part is a good starting point. This should not be confused, however, with certain disorders in plants which may be due to nonliving factors or physiological deficiencies in soil nutrients (e.g. lack of fertilizers such as NPK and/ or other elements). Some common symptoms of diseases
Stunting A diseased crop may be stunted with stiff leaves and yellowish or dark color coupled with an overgrowth of tiller of leaves, thus a bushy and dwarf appearance. Wilting, Galling Soilborne microorganisms that attack the roots of crops enter and plug the vascular tissues in the stem thereby causing wilt. This can differentiated from ordinary wilting (caused by moisture- temperature stress) by the presence of brownish or dark color in the tissues when the stem is cut across or lengthwise. Meanwhile, solanaceous crops are easy prey to invasion of cysts or root- knot galls due nematodes and bacterial infection (Agrobacterium tumefaciens is a common cause of crown gall). Twisting, Wrinkling These symptoms are usually indicative of a virus disease. In some cases, they lead to “ witches’ broom” with the leaves and shoots arising from a common point. Leaf surfaces may develop depressions and protruded tissues or tumors and the damage aggravated by insects. Overall size is greatly reduced. Chlorosis, Necrosis Infection begins with the appearance of small chlorotic spots of lesions on leaves, leaf sheaths, and stem. These may also be recognized as streaks, stripes, or blights with irregular, water soaked, and enlarged map - like zonations. The loss of chlorophyll (green color) creates a clear contrast with the healthy tissues.
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For virus symptoms, mottling and mosaic patterns are evidenced by distinct borders alongside darker shades on the affected part of the latter. Severe chlorosis may lead to necrosis or the eventual death of tissues. At times this is characterized by what looks like a cottony or powdery outgrowths as in mildews caused by fungi or by some rough encrustations as in rusts, smuts, and scabs. Soft and hard/dry rots Stored and transported fleshy and non fleshy fruits, vegetables, pods, berries, nuts, and grains are favorite targets of postharvest microorganisms. Soft rots are usually due to bacteria and characterized by a slimy feel and a strong foul odor, while hard and dry rots are possibly due to fungi, oftentimes covered with dry spores with a distinct moldy or mushroom-like odor. Important Reminders
It must be borne in mind that many diseases caused by bacteria, fungi, nematodes, and viruses may show similar symptoms. In such a case, further laboratory (microscopic) observation of the physiological and cultural characteristics of the host pathogen are needed. Ideally, this will also require that the organism be tested for pathogenicity or its ability to cause disease using Koch’s K och’s Postulates or rules of pathogenicity.
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Part IV- Disease management/Control measures A combination of two or more methods or an integrated approach in disease management and control is the most useful tool to combat diseases of crops. If the damage is limited to certain parts of the crop (localized and has not spread) at its early stage and severity is not extensive, the disease may be controlled. Similarly, if a population shows only an isolated and negligible number of infected plants, control is recommended. One has the option to control or manage diseases in many ways. Through any of the following methods done singly or a combination of any two or all methods methods in an integrated approach, approach, to wit: Cultural (intercropping, proper plant density, weeding, off-barring, hilling-up, trap cropping, irrigation, modify cropping practices). When a disease attacks the crop, the cropping pattern used may be modified or altered by using an entirely different one. An example is crop rotation – planting another crop in sequence. Say soybean after rice, peanut after corn, mungbean after sorghum. The temporary absence of the main crop prevents the build- up of pathogens that would otherwise be favored in the next cropping season. Intercropping or strip cropping- is another strategy that can be done to prevent the spread of the pathogens. Intercrops, therefore, act as trap crops preventing further spread of the disease. Other cultural practices that may be done are: fallowing the field (temporary absence of any crop), intermittent flooding or irrigation, weeding and cultivation, deep- plowing the soil to expose the micro organisms under the sun, and burning all field trash or debris within and in the immediate parameter of the area. Furthermore, applying the needed fertilizers will not easily predispose the crops to diseases. Mechanical (rouging, pruning, etc) A practical way of controlling diseases is by rouging or removing diseased plants and pruning or cutting infected parts and burning them immediately. Physical (solar radiation, smudging, light traps for pathogen-carrying pathogen-carrying insects) Chemical (spraying, swabbing, drenching pesticides) - The judicious use of the appropriate pesticide/s may be the last choice to be considered. Your local agrochemical dealer has adequate supplies of pesticides for all types of crop diseases. Specific instructions on the product label must be strictly followed in terms of how much quantity is needed and how to apply the particular fungicide. Organic-based formulations applied as sprays, swabs, or soil drench (fermented teas from agriwastes of plants and plant parts like fruit peels, cobs, legume pods, bagasse, straw, or animal wastes like earthworm vermicasts, manures, manures, etc)
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Use of biocontrol agents and biopescides
• antagonists (nonpathogenic (nonpathogenic or nontarget microorganisms microorganisms like bacteria, fungi, fungi, mild strain viruses for cross protection, predators or friendly insects, etc). • botanicals (plants (plants with pesticidal pesticidal properties: fungicidal, bactericidal, bactericidal, nematicidal, nematicidal, insecticidal, viricidal) Use of resistant varieties or cultivars - When and if resistant varieties are available these are highly recommended. In addition, they must be certified and disease- free planting materials. However, it must be pointed out that proper field management is still necessary to ensure maximum yields.
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References
Alejandro FR, Tangonan NG, Malacad WB, Escalante WB, & Miral PR. 1990. Thirteen outstanding sorghums developed at USMARC-USM, Kabacan, Cotabato. USM CA Res. Journal 1:223-228 Ayob JT & Tangonan NG. 2000. Identification and chemical control of two pathogens of salago (Wikstroemia lanceolata L.). USM CA Res Journal 11 (1): 82-91 Balmores LM, Jover EM, & Tangonan NG. 1992. Etiology of rubber stem bleeding at USMARC. The USM CA Res Journal 3: 53-57 Cahatian PO & Tangonan NG. 2009. Pests and Diseases of Jatropha and their Management, CHED-funded, USM, Kabacan, Cotabato ISBN 978-971-8676-28-8, 67 pp Brochure Dela Torre AC Jr & Tangonan NG. 2008. Efficacy of Jatropha extracts against Cordana musae causing leafspot of Cardava banana. USM R & D Journal 16 (1):89-97 Godoy JC & Tangonan NG. 1990. Efficacy of six fungicides against brown rot gummosis of calamansi (Citrus (Citrus madurensis ).). USM CA Res. Journal 1:120-124 Manalo JO & Tangonan NG. 1992. Fungicides for the control of stem canker of cocoa caused by Phytophthora palmivora Butler. Plant Protection Paper No. 112 IN Cocoa Pests and Diseases Management in Southeast Asia and Australia, FAO Via delle Terme di Caracalla, Rome, Italy (Book Chapter), pp 153-155 Marcelino JP & Tangonan NG. 2008. Diseases of oil palm (Elaeis (Elaeis guineensis ) in six municipalities of Sultan Kudarat Province, Philippines. J Nature Studies 7 (2):49-56 Mondero NA, Evangelista RB, Tangonan NG, & Baltazar RB. 1991. Identification of castor bean (Ricinus communis ) diseases. USM CA Res. Journal 2:61-64 Nitafan JH, Tandigan IC, & Tangonan NG. 1991. Some variations in three isolates of Phytophthora palmivora Butler causing black pod rot in cacao. USM CA Res. Journal 2:74-88 Noble IC Jr, Silvestre JC, & Tangonan NG. 1990. Incidence and chemical control of pink disease of citrus caused by Corticium salmonicolor B. salmonicolor B. & Br. USM CA Res. Journal 1:174-181 Pedrajas AE & Tangonan NG. 1989. Incidence and infectivity of Physoderma brown spot of corn at USMARC-USM, Kabacan, Cotabato. Philipp. J. Crop Sci. 14:89, Abstr Ramos MA & Naomi G Tangonan. 2009. Identification of diseases of passion fruit (Passiflora ( Passiflora edulis F. edulis F. flavicarpa Deg.) in selected municipalities of North and South Cotabato, Philippines. USM R & D Journal 17(1):127-133
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Sollorin LB & Tangonan NG. 1990. Trichoderma sp as biological control against Sclerotium rolfsii causing rolfsii causing damping-off in cotton (Gossypium (Gossypium hirsutum L.) hirsutum L.) seedlings. USM CA Res. Journal 1:181-185 Tangonan NG. 2007. Diseases of rubber in the Philippines In Rubber Manual for Smallholders in the Philippines by EA Alcala 1st Edition, USM-Philippine Rubber Board, Inc. (PRBI), Book S. No.1, pp 39-42 Tangonan NG. 2006. Diseases of Rubber (Hevea ( Hevea brasiliensis ) in the Philippines: control and screening for resistance, International Rubber Research Development Board (IRRDB) and Rubber Research Institute of Vietnam (RRIV), Proceedings of the International Natural Rubber Conference (INRC), The Legend Hotel, Ho Chi Minh City, Vietnam, November 13-17, 2006 Tangonan NG. 2006. Incidence, host range, and control of white root rot disease of rubber in the Philippines, Proceedings of the International Workshop on White Root Rot Disease of Hevea Rubber (Country Report), November November 28-29, 2006, 2006, Salatiga, Indonesia, Indonesia, Indonesian Rubber Rubber Research Institute and the International Rubber Research and Development Board, pp 42-56, ISBN 978-979-25-3284-5 978-979-25-3284-5 Tangonan NG. 2005. Some updates on diseases of rubber in the Philippines and their control, Proceedings of the 1st International Rubber Conference and Centennial Celebration, November 22-24, 2005, Waterfront Hotel, Davao City Tangonan NG & Alojado AB. 2006. Bio-efficacy evaluation of Organica on the incidence of major pests and diseases of tissue-cultured cooking Cardava banana, http://organica.walkertaiwan.com/banana_ph2006 Tangonan NG & Butardo EGG. 2005. Control of Phytophthora black stripe disease of rubber in Matalam, Cotabato. Journal of Tropical Plant Pathology 41:70-76 Tangonan NG, Pecho JA, & Butardo EGG. 2007. Disease Profile of Crops in USM, Kabacan, Cotabato, USM, Kabacan, Cotabato ISBN 971-8676-18-X, 971-8676-18-X, 31 pp Brochure Tangonan NG, Pecho JA, & Butardo EGG. 2008. Technoguide on Diseases of Rubber and their Control, DA-BAR-funded, USM, Kabacan, Cotabato ISBN 971-8676-17-1,53 pp Brochure Tangonan NG, Evangelista CC, & Ruano CP. 2005. Development of integrated pest and disease management for citrus. USM R & D Journal 13(2):219-248 Tangonan NG & Solilap VE. 2003. Sclerotium rolfsii causing fruit rot of jackfruit (Artocarpus (Artocarpus heterophyllus L.). heterophyllus L.). Journal of Tropical Plant Pathology 39:70-72 Tangonan NG. 2003. Cacao diseases and their management, Description and Management in Cacao Production Technology Manual, SUCCESS-Alliance Philippines Project, ACDI-VOCA, Cocoa Foundation of the Philippines-USAID-NAFC-DA, pp 53-68 48
Tangonan NG & Escopalao VM. 2002. Rhizoctonia disease of salago (Wikstroemia (Wikstroemia lanceolata L.) in the Philippines and and its control. Journal of Tropical Plant Pathology 38:9-15 Tangonan NG. 2002. Common fungal diseases of rubber (Hevea (Hevea brasiliensis Muell. brasiliensis Muell. Arg.) in the Philippines I. Incidence and symptomatology. USM R & D Journal 10(2):11-20 Tangonan NG. 2002. New records of fungal plant diseases in Cotabato, Mindanao, Philippines USM R & D Journal 10(2):194-197 Tangonan NG. 2000. Host index of plant diseases in the Philippines: current status. Review Article. Annual Report of the Research Center for Pathogenic Fungi and Microbial Toxicoses, Division of Ultrastructure and Function, Department of Molecular Function), Chiba University, Chiba 260-8673, Japan, pp 71-74 Tangonan NG. 1999. Host Index of Plant Diseases in the Philippines 3rd Edition, 408 pp, ISBN 971-9081-04-X, DA-PhilRice-USM, Maligaya, Maligaya, Muñoz, Nueva Ecija & USM, Kabacan, Cotabato Tangonan NG & Escopalao VM. 1999. Leaf blight disease of coffee caused by Rhizoctonia solani Kuhn. solani Kuhn. Philipp. J. Crop Sci. 24(1): 28, Abstr Tangonan NG & Cuambot FD. 1998. Rhizoctonia solani causing solani causing leaf blight of durian. Philippine Phytophathology 33(2): 130-133 Tangonan NG & Cuambot FD. 1998. Leaf blight of lanzones: 1st report. USM R & D Journal 6(1 & 2): 121-123 Tangonan NG. 1997. Anthracnose leafspot of alugbati (Basella ( Basella rubra L.) caused by Colletottrichum gloeosporioides Penz. USM CA Res Journal 8(2):196-197 Tangonan NG, Sebastian FA, & Cuambot FD. 1996. Phytopathological note: etiology of white root rot of rubber. USM R & D Journal 4(1): 9-12 Tangonan NG & Natoc EH. 1994. Studies on biological control of plant diseases in the University of Southern Mindanao, Kabacan, Cotabato, Philippines: 1978-1994. USM R & D Journal 2(1): 189-200 Tangonan NG. 1994. New foliar disease on peanut at USMARC noted. USM CA Res. Journal 4(2):214 Tangonan NG, Miral PR, Evangelista RB, & Garcia AV. 1993. Phytopathological note: incidence of knob gall disease in immature rubber. USM CA Res Journal 4(1): 135-138 Tangonan NG. 1992. A review of the University of Southern Mindanao’s primary scientific publications: 1968-1991. USM CA Res. Journal 3: 88-104
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Tangonan NG & Dalmacio SC. 1992. Diseases of sorghum in the Philippines. In Sorghum and Millets Diseases: A Second World Review, ICRISAT pp. 35-40, India. Tangonan NG, Rondon RB, Punzalan F, Atienzar AL, Miral PR, & Arguelles JA. 1991. Effect of paclobutrazol (Cultar 25 SC) on disease and yield of calamansi (Citrus ( Citrus madurensis ).). USM CA Res. Journal 2:48-58 Tangonan NG, Torreon FA, & Silvestre JC. 1990. Citrus dieback disease at USM, Kabacan, Cotabato: incidence and identification of its causal pathogens. Philipp. J. Crop Sci. 15:823, Abstr Tangonan NG & Sanico PG. 1988. Disease incidence in jute accessions at SMARC-USM, Kabacan, Cotabato. Philippine Phytopathology 24:17, Abstr Tangonan NG & Quimio TH. 1986. Etiology of sorghum stalk rot complex in Mindanao. Philippine Phytopathology 21: 20-27 Tuyan JM and Tangonan NG. 2005. Agronomic and disease profile of industrial crops at PICRIUSM, Lumayong, Kabacan, Cotabato. USM CA Res Journal 16(1&2):117-123 Valencia DE, Jover EM, & Tangonan NG. 1992. Efficacy of Isoprothiolane for the control of rubber stem bleeding. Proc. 1st. PPS-SMD Conv. Nov. 11-12, 1991, Villa Victoria, Davao City, pp. 29-34
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About the authors NGT currently the Vice President for Research and Extension, is University Professor of USM and Scientist 1 (of the Scientific Career System, Department of Science and Technology) who has been working closely with JAP and EGGB (Research Assistants in the Plant Pathology Research Lab, USMARC) for some years now. They work as a team in crop protection and plant disease R & D, trainings and seminar-workshops seminar-workshops among farmers, technicians, students, and have presented their outputs in local, national, and international scientific conferences. Their team-up has brought them to different places in the country and along the way have been blessed with new friendships and clientele not to mention some local and regional awards (e.g., Best Paper and Best Poster). They hope this brochure may spark a new or continuing interest in the field of plant pathology and pave the way to a broader and more comprehensive publication on plant diseases in the future; more importantly, that this guide will help the beginner learn basic disease diagnosis, a key factor crucial to devising effective control measures or management interventions for better crop yields and higher profits.
The UniVERSitY oF SoUtHERn MindAnAo The University of Southern Mindanao (USM) is a state university created by virtue of Presidenal Decree No. 1312 dated March 13, 1978 which eected its conversion from the former Mindanao Instute of Technology Technology (MIT), then a state college established by virtue of Republic Act No. 763 on June 20, 1952. As a state university, its highes6 governing and policy making body is the Board of Regents with the Commissioner of Commission on Higher Educaon Department (CHED) as Chairman. The University President administers the Instuon. Campus Site
The University main campus lies on a 1,024-hectare land grant situated in the Municipality of Kabacan, Cotabato (Region XII), Philippines. It is 0.6 kilometer north of the naonal highway connecng the cies of Cotabato and Davao, about 10 kilometers from the juncon of the Makilala-TacurongMakilala-TacurongGeneral Santos Road and about 3 kilometers kilometers from from the juncon of the Cotabato-Davao Sayre Highway. Vision Quality and relevant educaon for its clientele to be globally compeve, culture sensive and morally responsive human resources for development.
Mission To accelerate the socio-economic development, promote harmony among the diverse cultures in Southern Philippines, and improve the quality of life through instrucon, research, extension and producon. Core Values Goodness Responsiveness Excellence Asseron of Right and truth
