You may use , Click here to go to the topics page to know more about the crop. Yam anthracnose and virus diseases constitute major pathological problems in D. alata production in all yam growing regions of the world. We reviewed a total of 73 insect species associated with Dioscorea species in different parts of the world. its all about life Yam scales, mealybugs, and a few beetles cause significant losses to tubers both in the field and in storage. Information provided by https://coleacp.org. and Nicotiana benthamiana.In extracts of D. cayenensis leaves infectivity was lost after 10 min at 60 d̀C but not 55 d̀C and after dilution to 10 ‐3 but not 10 ‐2.A purification procedure is described. Flattened oval to round disc-like insect covered in waxy substance on tree branches; insects attract ants which may also be present; insect colony may also be associated with growth of sooty mold due to fungal colonization of sugary honeydew excreted by the insect, Insects have a wide host range; often tended by ants which farm them for their sugary honeydew secretions, Yam tuber infested by white scale insect (2). Various virus, bacterial and fungal diseases of yam have been reported in Nigeria since 1956. Plant disease - Plant disease - Symptoms and signs: Bacterial diseases can be grouped into four broad categories based on the extent of damage to plant tissue and the symptoms that they cause, which may include vascular wilt, necrosis, soft rot, and tumours. Wild yam has most often been prescribed by herbalists for internal use for PMS symptoms. A shoestring virus, which is transmitted mechanically and by aphids, with particles consisting of flexuous rods 600 nm in length, is known to occur in various spp. Greater and lesser yam beetles are both important pests of yams in West Africa. Today, you’ll also find topical wild yam creams that are meant to raise low progesterone levels, which can help ease PMS. Dry rot is considered as the most devastating of all the storage diseases of yam. The common symptoms are infected leaves show yellow and green patterns (called mosaics) between the veins or may show a narrow green strips bordering the veins (called vein banding). With progress in disease lesion spreads deeper (maximum up to 2 cm). d) Aphids. this is open class study site. Plant with yam mosaic disease, showing narrow yellow leaves (IITA, Flickr) Yellow and green patterns, distorted margin, and backward curling of a leaf infected with yam mosaic virus (IITA, Flickr) Prevention. (Mantell, 1980 [5]; IITA, 1993 [6]). of yam. Dry rot of yams alone causes a marked reduction in the quantity, marketable value and … It will be useful for people who smoke in their menu, as they lack vitamin A in their bodies, which can cause the development of various diseases. A shoestring virus, which is transmitted mechanically and by aphids, with particles consisting of flexuous rods 600 nm in length, is known to occur in various spp. Yam Mosaic Virus Disease: This disease is caused by an aphid-transmitted potyvirus that infects several species of Dioscorea. of yam. Diseases. Prevention. Image courtesy of agrifarming.in, PEST AND DISEASES OF YAM (Dioscorea spp. Dept. Vascular wilt results from the bacterial invasion of the plant’s vascular system. Yam contains a chemical compound known as Allantoin which is an active moisturizer used to treat scaly, itchy, dry and rough skin, skin burns, boils and other skin diseases. Yam tubers infested by nematode and white scale insect. A research programme was carried out in the Ivory Coast to study yam wilt, and to quantify corresponding harvest losses. The virus is transmitted by aphids and tubers/setts. In field and storage yams are exposed to various diseases caused by viruses, bacteria, fungi, and nematodes. Yam mosaic virus is always associated with yam mild mosaic virus, yam badnaviruses and cucumber mosaic virus in Africa making this disease more complex. Due to the losses incurred through the effect of diseases such as YAD, yam breeders and other affiliated scientists are trying to breed for plant materials with resistance to this disease. Some time the infected tubers may not show external cracking which make it difficult to diagnose. c) The taro planthopper, Tarophagus proserpina which not only transmits virus diseases, but can cause wilting and death of the plant in heavy infestations. Plant may produce few small tubers with less starch content. Can eating a diet rich in yam and palm oil prevent and ‘cure’ heart disease, stroke and type 2 diabetes? Yam mosaic virus is always associated with yam mild mosaic virus, yam badnaviruses and cucumber mosaic virus in Africa making this disease more complex. A shoestring virus, which is transmitted mechanically and by aphids with particles consisting of flexuous rods 600 nm in length, is known to occur in various species of yam. Dry rot is considered as the most devastating of all the storage diseases of yam. The disease is recorded from Fiji, Papua New Guinea, New Caledonia, Niue, Samoa, Solomon Islands, Tonga, and Vanuatu. Monitoring. Hosts. Preventive methods, ... Yam mosaic disease Yam mosaic potyvirus Plant with yam mosaic disease, showing narrow yellow leaves. The data currently available do not enable determination of the damage that parasitic fungi cause to yam. At later stage the rot become light and dark brown to black in color and tubers may show external cracks. There is no above ground symptom with yam nematode infestation. For maximum yield, the yams require a humid tropical environment, with an annual rainfall over 1500 mm distributed uniformly throughout the growing season. Leaves and shoots of the yam will blacken and die, resulting in stunted, small, deformed harvests. Yam (Dioscorea spp.) Yam is infested by 48 species when the crop is in the field, and after harvest (i.e. stem basal canker (F. Protozoan diseases in animals pdfyam diseases and control pdf Cassava Diseases Prevention and Control to Ensure Food The virus is transmitted by aphids and tubers/setts. Given wild yam’s hormone-like effects, it’s no surprise that it can have benefits for fertility. of Plant Pathology) Pegus, J.E. Save my name, email, and website in this browser for the next time I comment. The pest which affects the plant are nematodes such as root-knot (Meloidogyne spp.) Severe infestation may leads to tuber shrivel. Shumei Hua, Zhihua Chen, Lihong Li, Kuan-Hung Lin, Yangwen Zhang, Jieyu Yang, Shi-Peng Chen, Differences in immunity between pathogen-resistant and -susceptible yam cultivars reveal insights into disease prevention underlying ethylene supplementation, Journal of Plant Biochemistry and Biotechnology, 10.1007/s13562-020-00582-9, (2020). ), which this site functions with internal linking marked in colours. Pests and diseases of yam and their control methods Pests of Yam Yam tuber pests makes holes on tubers, resulting in low tuber marketability. 4.5 Other Diseases and Pests. The adult beetles burrow into the soil and feed on the tubers. The actual yield loss is estimated up to 27 to 55 %. Different species of yams are grown in the "yam zone"of West Africa. The leaves turn yellow in color. Direct Control. It may cause up to 40% loss in yield. Anthracnose: It is one of the most severe yam diseases, in particular among the species Dioscorea alata. Abstract Various virus, bacterial and fungal diseases of yam have been reported in Nigeria since 1956. The virus is transmitted by aphids and tubers/setts. Initially this dry rot is of cream and light yellow lesions appear just below the outer skin without any external symptom. Their growth and dormant phases correspond respectively to the wet season and the dry season. The complexities in their epidemiology necessitate the use of integrated approaches in their management. Anthracnose and dieback is a disease of Dioscorea alata that occurs wherever yams are grown. Spauld. Disease is reported in West Africa , … Even though it won't effect yield sometimes foliage cause poor growth and tubers may show delay in germination or even stopped. There are many strains of Colletrotrichum … Yam crops face pressure from a range of insect pests and fungal and viral diseases, as well as nematode. How to Control the spread of yam pest: Apply insecticide like BHC at planting to avoid disease spreading around Dust yam sett with aldrin dust Practice crop rotation to control disease spread Dry rot of yams alone causes a marked reduction in the quantity, marketable value and edible portions of tubers and those reductions are more severe in stored yams. May Enhance Fertility. A wide range of nematodes are associated with yam, but only two ‘types’ are of concern: root-knot nematodes (Meloidogyne spp. , Fusariwn oxysporwn and F. Solani), root rot (F. Oxysporwn and Pythiwn sp. Yam diseases can be controlled by several integrated control practices. The infected plants are stunted with poor growth. Studies on diseases of cassava and yam in Trinidad [1988] Rajnauth, G. (Ministry of Food Production, Marine Exploitation, Forestry and the Environment, Centeno (Trinidad and Tobago). Yam mosaic virus, Yam mosaic virus and Yam mild mosaic potyvirus, Cucumovirus, Dioscorea bacilliform virus, Potexvirus Dioscorea latent virus. It causes black necrotic spots on the leaves which develop along the veins. Tubers and feeder roots are galled. The major disease affecting Dioscorea cayenensis in the Ivory Coast is caused by a virus which was transmitted by mechanical inoculation to some Dioscorea spp. Pre-harvest and post-harvest tuber rot may result in storage loss of 25%. Nearly 47% of all yam tubers on sale in Nigerian markets were infested with S. bradys (Bridge, 1973) and both dry rot and wet rot diseases of tubers have been observed in all Nigerian yam barns and markets sampled (Adesiyan and Odihirin, 1977). Yam anthracnose is a fungal infection that can impact your yam plants in any geographic region. 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