Fusarium wilt of bananas is caused by F. oxysporum f.sp. cubense, a common soil inhabitant. Other formae speciales attack a wide variety of other crops, including cotton, flax, tomatoes, cabbages, peas, sweet potatoes, watermelons and oil palms.;The formae speciales of Fusarium oxysporum each produce three types of asexual spores. The macroconidia (22-36 x 4-5 µm, see Wardlaw, 1961 for measurements) are produced most frequently on branched conidiophores in sporodochia on the surface of infected plant parts or in artificial culture. Macroconidia may also be produced singly in the aerial mycelium, especially in culture. The macroconidia are thin-walled with a definite foot cell and a pointed apical cell. Oval or kidney-shaped microconidia (5-7 x 2.5-3 µm) occur on short microconidiophores in the aerial mycelium and are produced in false heads. Both macroconidia and microconidia may also be formed in the xylem vessel elements of infected host plants, but the microconidia are usually more common. The fungus may be spread by macroconidia, microconidia and mycelium within the plant as well as outside the plant. Illustrations of the conidia have been published (Nelson et al., 1983).;Chlamydospores (9 x 7 µm) are thick-walled asexual spores that are usually produced singly in macroconidia or are intercalary or terminal in the hyphae. The contents are highly refractive. Chlamydospores form in dead host-plant tissue in the final stages of wilt development and also in culture. These spores can survive for an extended time in plant debris in soil.;Mutation in culture is a major problem for those working with vascular wilt isolates of F. oxysporum. The sporodochial type often mutates to a 'mycelial' type or to a 'pionnotal' type. The former has abundant aerial mycelium, but few macroconidia, whereas the latter produces little or no aerial mycelium, but abundant macroconidia. These cultures may lose virulence and the ability to produce toxins. Mutants occur more frequently if the fungus is grown on a medium that is rich in carbohydrates.
FACTSHEETS FOR FARMERS www.plantwise.orgCreated in Myanmar [Burma], June 2014 Prevention of Yellow Mosaic Virus on beans Recognize the problem Yellow specks or spots are scattered on young leaves. Newly emerging leaves have irregular green and yellow patches. Some apical leaves yellow and diseased plants are smaller and mature late. Background Yellow mosaic virus is one of the major constraints in bean production. It is difficult to control because the yellow mosaic virus is rapidly transmitted from plant to plant, and from field to field by insect vectors such as whiteflies and...
FACTSHEETS FOR FARMERS www.plantwise.orgCreated in Myanmar [Burma], June 2014 Prevention of Spotted Pod Borer on beans Recognize the problem The spotted pod borer feeds on several beans and peas apart from chickpeas. Larvae web together the bean leaves, flowers, buds and new shoots, then feed inside on these plant parts, protected by the webbing. This causes new shoots and buds to appear dry. The larvae also make holes in the pods and feed on the seeds and pods, preventing the pods from becoming fully developed. This damage to the pods and seeds, and the defoliation (leaf drop)...
FACTSHEETS FOR FARMERS www.plantwise.org Created in India , October 2013 Powdery mildew in Green gram Recognize the problem A powder appears in patches on leaves and other green parts of the plant. This powder is white but later turns a dull colour. Gradually, the powdery patches grow and become circular until they also cover the lower surface of the leaf. In severe infections, leaves turn yellow and fall early. Severely affected parts shrivel and become distorted. The disease causes forced maturity and therefore reduced crop yields. Background...
FACTSHEETS FOR FARMERS www.plantwise.org Created in Vietnam , March 2016 Mimosa diplotricha Recognize the problem Family: Fabaceae (pea family) Common names: Giant sensitive plant , creeping sensitive plant, nila grass, tropical blackberry. Vietnamese : Trinh nữ móc. Annual, biennial or evergreen, scrambling, climbing, strongly branched shrub, forming dense thickets 2 – 3 (– 6 ) m tall; woody at the base with age; stems green or purplish tinged, 4 – 5 -angled in cross-section, covered with sharp, recurved, yellowish...
Exotic Pest Alert: Giant African snail April 2015 Primefact 1394 1st edition Plant Biosecurity and Product Integrity, Orange Giant African snail (Achatina fulica) is an exotic plant pest not established on Australia’s mainland This snail is a serious threat to Australia’s environment If found it must be reported promptly to the Exotic Plant Pest Hotline 1800 084 881 Giant African snail Giant African snail (GAS) is one of the world’s largest and most damaging land snails. Giant African snail prefers warm tropical conditions. It can survive temperatures lower...
‘Best Bet’ IPM strategy Decision making for insect management in grain crops (ipmworkshops.com.au) Last revised October 2014 Winter pulse pests – Southern region Post harvest, pre‐sowing Establishment ‐vegetative Flowering ‐maturity Aphid vectors and virus source Control green bridge (in fallows) Sow virus‐free seed Sowing into standing stubble may reduce aphid landing. Assess riskof aphid outbreak. High risk when: warm, mild conditions abundant weed hosts nearby food sources e.g. clover/medic Aim to close canopy and minimise gaps to outcompete ...
06/15 CONTENTS This bulletin is a companion to SARE’s Cover Crop Topic Room, an online collection of select, mostly SARE-based resources on cover crops. Information is available at www.SARE.org/Cover-Crops on the following topics: Selection and ManageMent econoMicS eStabliShMent no-till Soil and Fertility ManageMent Water ManageMent PeSt ManageMent croP rotationS MiScellaneouS SARE’s Topic Rooms contain dozens of publications, videos and other educational materials on a wide range of topics, including local food systems, high tunnels, small ruminants and more. Visit...
SYMPTOMS AND DETECTION | VARIETAL RESISTANCE OR TOLERANCE | MANAGEMENT OF NEMATODES | TESTING FOR ROOT-LESION NEMATODES WESTERN SEPTEMBER 2018 SECTION 8 NEMATODE MANAGEMENT BARLEY 1 NEMAtoDE MANAgEMENt seCtIon 8 BARLEY WESTERN JUNE 2017 Nematode management Root-lesion nemtodes (RLN; Pratylenchus spp.) are microscopic, worm-like animals that extract nutrients from plants, causing yield loss. 1 Root-lesion nematodes are found over 5.74 million hectares (or ~65%) of the cropping area of WA and populations potentially limit yield in at least 40% of these infested paddocks...
CHOOSING A VARIETY | VARIETAL PERFORMANCE AND RATINGS YIELD | PLANTING SEED QUALITY | FUTURE BREEDING DIRECTIONS WESTERN SEPTEMBER 2018 SECTION 2 PRE-PLANTING CHICKPEA1 Pre-PLantInG seCtIon 2 CHICKPEAS February 2017 Pre-planting Key messages • In variety choice, consider yield and adaptation to the area, disease resistance, grain quality, marketability and proximity to receival point. • Be aware of the specific management needs for the variety chosen through its variety management package (VMP). 1 • Kabuli chickpea provides a very profitable cropping option to Western...
ROOT-LESION NEMATODE (RLN) | NEMATODES AND CROWN ROT WESTERN SEPTEMBER 2018 SECTION 8 NEMATODE MANAGEMENT CHICKPEA1 neMatoDe ManaGeMent seCtIon 8 CHICKPEAS February 2017 nematode management Key messages • Nematodes are common soil pests that feed on the roots of a wide range of crop plants in all agricultural areas of Western Australia, irrespective of soil type and rainfall. • Root-lesion nematodes are found over 5.74 million ha (or ~65%) of the cropping area of Western Australia (WA). Populations potentially limit yield in at least 40% of these infested paddocks. • The...
CROP OVERVIEW | PRODUCTS AND USES | MARKET | FABA BEAN RESEARCH WESTERN NOVEMBER 2017 SECTION A INTRODUCTION FABA BEANxiv INtRODUCtION IntroduCtIon FABA BEANS NOVEMBER 2017 Introduction A.1 Crop overview A.1.1 the role of pulses in farming systems In WA, faba beans is a niche crop and production currently stands at around 6,000 tonnes (DAFWA). Vicia faba minor is grown under broadscale farming conditions in WA. In modern farming systems pulses have a role that is far greater than the traditional ones of ‘nitrogen fixation’ and ‘disease break’. They can be a cash crop in their...
FUNGAL DISEASE MANAGEMENT STRATEGIES | SYMPTOM SORTER | CHOCOLATE SPOT | ASCOCHYTA BLIGHT | SCLEROTINIA STEM ROT | BOTRYTIS GREY MOULD | ROOT ROTS | RUST | RHIZOCTONIA BARE PATCH | VIRUSES | SAMPLE PREPARATION FOR DISEASED PLANT SPECIMENS WESTERN NOVEMBER 2017 SECTION 9 DISEASES FABA BEAN 1 DISEASES seCtIon 9 FABA BEANS WESTERN NOVEMBER 2017 Diseases Key messages • Chocolate spot (Botrytis fabae) can cause extensive losses and is the major disease of faba beans in WA. • In central and southern areas of WA use varieties that are at least moderately...
TEMPERATURE | FROST | WATERLOGGING AND FLOODING | DROUGHT WESTERN NOVEMBER 2017 SECTION 14 ENVIRONMENTAL ISSUES FABA BEAN 1 ENVIRONMENtAl ISSUES seCtIon 14 FABA BEANS WESTERN NOVEMBER 2017 Environmental issues Key messages • Frost damage is not always obvious and crops should be checked 5–7 days after a suspected frost. • Faba beans have a medium tolerance to frost due to their thick pod walls. • Faba beans are the pulse most tolerant to waterlogging. • Disease resistance is especially important in drought-prone areas. 14.1 temperature Temperature, daylight, day length...
PLANNING/PADDOCK PREPARATION PRE-PLANTING PLANTING PLANT GROWTH AND PHYSIOLOGY NUTRITION AND FERTILISER WEED CONTROL INSECT CONTROL NEMATODE MANAGEMENT DISEASES PLANT GROWTH REGULATORS AND CANOPY MANAGEMENT CROP DESICCATION AND SPRAY OUT HARVEST STORAGE ENVIRONMENTAL ISSUES MARKETING CURRENT AND PAST RESEARCH WESTERN FIELD PEAS AUGUST 2017 GROWNOTES ™DISCLAIMER: Any recommendations, suggestions or opinions contained in this publicati\ on do not necessarily represent the policy or views of the Grains Research and Development Corporation (GRDC). No person should act on t\ he basis of...
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Banana;The various symptoms of Fusarium wilt on banana are described and well illustrated by Ploetz and Pegg (1999).;The first external symptoms of Fusarium wilt on bananas is a faint off-green to pale-yellow streak or patch at the base of the petiole of one of the two oldest leaves. The disease can then progress in different ways. The older leaves can yellow, beginning with patches at the leaf margin. Yellowing progresses from the older to the younger leaves until only the recently unfurled or partially unfurled centre leaf remains erect and green. This process may take from 1 to 3 weeks in cultivar 'Gros Michel'. Often the yellow leaves remain erect for 1-2 weeks or some may collapse at the petiole and hang down the pseudostem. In contrast to this 'yellow syndrome', leaves may remain completely green except for a petiole streak or patch but collapse as a result of buckling of the petiole. The leaves fall, the oldest first, until they hang about the plant like a skirt. Eventually, all leaves on infected plants fall down and dry up. The youngest are the last to fall and often stand unusually erect.;Splitting of the base of the pseudostem is another symptom as is necrosis of the emerging heart leaf. Other symptoms include irregular, pale margins on new leaves and the wrinkling and distortion of the lamina. Internodes may also shorten (Stover, 1962, 1972, Jones, 1994, Moore et al., 1995).;The characteristic internal symptom of Fusarium wilt is vascular discoloration. This varies from one or two strands in the oldest and outermost pseudostem leaf sheaths in the early stages of disease to heavy discoloration throughout the pseudostem and fruit stalk in the later disease stages. Discoloration varies from pale yellow in the early stages to dark red or almost black in later stages. The discoloration is most pronounced in the rhizome in the area of dense vascularization where the stele joins the cortex. When symptoms first appear, a small or large portion of the rhizome may be infected. Eventually, almost the entire differentiated vascular system is invaded. The infection may or may not pass into young budding suckers or mature 'daughter' suckers. Where it does, discoloration of vascular strands may be visible in the excised sucker. Usually, suckers less than 1.5 m tall and ca. 4 months old do not show external symptoms. Where wilt is epidemic and spreading rapidly, suckers are usually infected and seldom grow to produce fruit. Above- and below-ground parts of affected plants eventually rot and die.;Fusarium wilt was reported to occur on banana cultivars of the 'Mutika-Lujugira' (AAA genome) subgroup in East Africa above 1400 m. Internal symptoms were much less extensive than those described above and external symptoms more subtle, comprising thin pseudostems and small fingers. Nevertheless, symptomatic plants were recognized by smallholders and were rogued. These mild symptoms were initially believed to be indicative of an attack on a plant whose defences have been weakened as a result of cooler conditions or other predisposing factors at altitude (Ploetz et al., 1994). Given the importance of this banana group, also referred to locally as ÔEast African highland bananasÕ, to local trade and as a staple food, further investigation was merited. This revealed that the disorder also affected non-indigenous banana types, including Cavendish and Bluggoe (which were not affected by Fusarium wilt) and was related to abnormal soil nutrient levels and farm management practice. Discoloration similar to that caused by F. oxysporum f.sp. cubense was observed in vascular tissues of affected plants. Fusarium pallidoroseum (syn. Fusarium semitectum) was consistently isolated from such tissues but found to be non-pathogenic. F. oxysporum was not recovered (Kangire and Rutherford, 2001, Rutherford, 2006).
F. oxysporum f.sp. cubense is one of around 100 formae speciales (special forms) of F. oxysporum which cause vascular wilts of flowering plants (Gerlach and Nirenberg, 1982). Hosts of the various formae speciales are usually restricted to a limited and related set of taxa. As currently defined, F. oxysporum f.sp. cubense affects the following species in the order Zingiberales: in the family Musaceae, Musa acuminata, M. balbisiana, M. schizocarpa and M. textilis, and in the family Heliconeaceae, Heliconia caribaea, H. chartacea, H. crassa, H. collinsiana, H. latispatha, H. mariae, H. rostrata and H. vellerigera (Stover, 1962, Waite, 1963). Additional hosts include hybrids between M. acuminata and M. balbisiana, and M. acuminata and M. schizocarpa.;F. oxysporum f.sp. cubense may survive as a parasite of non-host weed species. Three species of grass (Paspalum fasciculatum, Panicum purpurascens [ Brachiaria mutica ] and Ixophorus unisetus) and Commelina diffusa have been implicated (Waite and Dunlap, 1953).
G. sepium forms a small to medium-sized, thornless, deciduous, single- or multiple-stemmed tree;2-15 m and occasionally 20 m tall, and 5-30 cm and occasionally 1 m in stem diameter, with an open rounded crown, often greatly modified by lopping. The bark on young branches is smooth, grey-brown or pale whitish grey with raised pale brown lenticels, becoming fissured on boles. The leaves are alternate or sometimes sub-opposite, pinnate, 15-35 cm long, with slender, yellow-green, finely hairy rachis, an odd terminal leaflet, and 6-24 opposite (except in upper part of rachis) leaflets per leaf. Leaflets are narrowly elliptic to elliptic, rarely broadly elliptic, usually pointed at tips, 4.4-8.3 cm long, 1.7-4.8 cm wide, larger towards tip of the leaf, with characteristic dark purplish tannin patches scattered, especially on lower surface. The flowers are borne on erect, 2-15 cm long racemes arising from leaf axils, or on leafless nodes of older stems with almost synchronous maturation of 30-100 flowers on a single inflorescence. The flowers are typical of Papilionoid legumes, borne on short 5-11 mm long slender pedicels, 2 cm long, with a five-lobed campanulate (bell-shaped) calyx and a typical pea-shaped whitish-pink or purple corolla with five strongly unequal petals. The standard petal is light pink, or pink with a deep yellow basal blotch, and the blade is reflexed at 180¡ when the flower is fully open. The wing and keel petals are also usually pink. There are 10 whitish stamens, 9 united into a tube and one free. The pods are 10-17 cm long and 1.4-2.2 cm wide, strongly compressed, green sometimes tinged maroon and fleshy unripe, drying mid yellow-brown when ripe, and opening explosively when dry with the pod valves twisting into tight spirals after dehiscence. There are 3-10 lenticular, round or elliptic, yellow-brown, darker orange-brown when mature, seeds per pod, 8.5-11.5 mm in diameter.