After harvest, if not using conservation tillage practices, plough in or collect and burn crop debris. The leaves of the plant present discoloration spots, and the plant has an marbled appearance. possible can significantly reduce the damage caused by the beetles. Late season spraying will prevent systemic infections and limit the. If it is not possible to avoid planting near old crops, do not plant downwind from them. Surveys, Because of the severity of this disease, unrestricted international movement of sweet potato plants, http://www.bioversityinternational.org/e-library/publications/detail/sweet-potato, During crop growth, remove plants with SPVD, especially during the first month after planting. Disadvantages of this system include the space taken up by the Napier grass; the cost and lack, Intercropping with non-host plants, such as cowpeas or cassava, will also reduce the damage. Both virus diseases cause a patchy yellowing, of leaves but in CBSD this is less intense. In wet regions, there, are three generations or cycles of the pest per year; two cycles in the drier regions. This manual includes pest and disease management options based on pesticides. In Africa, it is widespread in Ethiopia, Kenya, Malawi, Mozambique, South Africa, Swaziland and Zimbabwe. PIP Guide to Good Crop Protection Practices: for Y. Bioversity International, 1989, pp. In the sections that follow management approaches based on the use of pesticides are given. Signs of caterpillars include black frass (faecal matter) woven together by silk. KnowledgeBank/Datasheet.aspx?dsid=14918). Attractive, brightly coloured (often purple) flowering weeds. when separate downy mildew infections grow together and form a sexual stage. Check if these are available from local seed, If the measures outlined are not effective or tolerant varieties are not available, rotate groundnuts with other crops to, create a break from recycling rust from one crop to another. Epidemics occur without warning. plant parts. Leaf spots merge as leaves go yellow and die. America, South and Southeast Asia and Oceania are now thought to be incorrect. Photo: Clemson University – USDA Cooperative Extension Slide Series, and not widely available. Newly emerged leaves show yellow (or orange) and green stripes. Brown irregular leaf spots with yellow margins, expanding or joining together to cause a blight or, Mature leaves blackened during heavy rains followed. 2) has been released and adopted; for instance, it is used in over 50% of the production area in Namibia. Survival of the fungus between crops is in seed and in crop debris. Early leaf spot of groundnut (Mycosphaerella arachidis). First, it is important to remove and destroy crop residues immediately after harvest. Collecting and burning of plant remains to reduce the spread of the disease must be done on a large scale to be effective. If you see an insect on or near your beloved tomato plants, don’t rush for the nearest insecticide. BXW produces a distinctive premature ripening of, BXW can be confused with Fusarium wilt, caused by. Clean and disinfect the storage facility prior to storage. The pupae are shiny, moths are 7-17 mm long with a wingspan of 20-25 mm. Do not dry directly on the ground. They cause yield losses up to 77% and also significant post-harvest losses due to tubers, The greater yam beetle is widely distributed throughout tropical Africa, particularly in humid areas and near rivers in, West Africa. starts attacking the pod while the crop is still in the field. An alternative is to sow seed saved from. Surveys in northern Nigeria and Burkina Faso have, is widespread in East Africa and occurs in numerous countries (as well as in Asia): T. has wide distribution in Africa from north to south of the continent, but only in western Africa (Senegal, : The bean bruchid is a major post-harvest pest of most bean species. The spots expand parallel to the leaf veins and, on susceptible varieties, are light brown to grey, to 70 mm long and 4 mm wide. (http://www.cabi.org.ezproxy. The, spores (aeciospores) that develop in these cup-shaped protruding structures on the underside of the leaf infect pearl, Long distance spread is on the wind. commercial maize varieties for sale in Kenya, 117 were susceptible to MLND. (turkey berry). However, of resistant varieties and seed dressing with metalaxyl have significantly reduced the incidence of downy mildew. A combination of, Strict regional quarantine measures to ensure the availability and use of clean planting material are. and granaries, or other places the stem borer may hide. The damage caused has a negative impact on the value and, marketability of the crop and can even change some quality characteristics of the crop, including the taste. Smallholders should be advised to carefully choose plants for planting: take cuttings, only from plants without symptoms of disease during the last crop. Plant Health Australia. Around the border of the field a trap crop, such as Napier or, Sudan grass, is planted to attract or ‘pull’ the stem borer moths away from the millet. intervention is needed when a pest or disease occurs, the safest and most effective options available are listed. Infected planting material appears healthy, helps to spread the disease over short distances. Green mosaic: very dark green small leaves, or light and dark green mosaic, with. High humidity favours movement of bacteria in infected plants, leading to production of a sticky ooze containing bacteria, most noticeably on stems but also from infected leaves. If possible, yams should not be planted near wet areas, along rivers, creeks, or tributaries where the beetles breed. pests, diseases, weeds, etc. Applying nitrogen, either a commercial product or manure or compost, enhances the crops tolerance to an attack. All three, chemicals are considered to be moderately hazardous and should be used carefully. This symptom is known as ‘green ear’, a distinctive feature of this disease. It can severely reduce yields by reducing, the leaves and lowering the photosynthetic activity of the plant. The ‘J’ hooks and dashes are, best seen on the underside of a leaf held against the light. Do not plant new crops next to those that have the disease. Submerge the clean trimmed suckers in a hot water bath (52 to 55°C) for 15 to 27 minutes before planting. It is particularly severe in East Africa, with, losses of 50-90% in the yield of susceptible plants. Of these, often involved in rodent population explosions. This paper sheds some light on the above two questions by (i) investigating the interactions of cowpea and sesame crop adoption with traditional grain-crops: millet, sorghum and maize, and (ii) analyzing factors that favor or discourage sesame and cowpea crop adoption among farmers in the Sahel. Apply by lightly dusting the pepper powder on cuts or other visible damage on the yam tuber surface. The eggs are very small, cylindrical and a transparent light-red colour. First symptoms with discrete spots, reddish, not. Spray more often if the first treatment is late, and. Some cultivars are, tolerant: they retain the virus but don’t develop strong symptoms. Strategies to control citrus pests include biological control, integrated pest management, and chemical control. Cases have occurred, anthracnose. The beetles leave small, round holes about 1-2 cm deep which allow secondary disease infections and cause the tubers to rot, leading to. Monitor crops. Colouring varies somewhat depending on location and season. species are present in tropical and subtropical regions worldwide. During epidemics, mature leaves of susceptible varieties rapidly turn black, a, host plant response to massive numbers of germinating spores and exposure to sunlight. Plant early to avoid the period of heavy infestation. If in doubt, send samples to a laboratory to confirm which, pathogen is present. The release in 2010 of the new red-, Uganda. problem the following season. Pupae are up to 25 mm long, and shiny, dark brown with dark patterns and the hind wings are light to greyish-brown. In Africa, management, options are limited by the lack of healthy seed programmes and access to commercial seed with, resistance to the virus, and rely mainly on cultural controls. African Journal of Biotechnology 7(25): 4706-4712. Adults lay eggs into the leafstalks (petioles). The caterpillars feed on leaves and developing grain heads, and bore into the fruiting parts of plants. Damaged spikelets can be squeezed between fingers to see if they produce red ooze (the larva or pupa. It first became widespread in the early 1990s. One option is to intercrop cowpea with other food plants to reduce the crop density and, therefore, the impact of the, disease. become leaf-like. Also lots of advice on how to grow tomatoes. The virus is widely distributed throughout East and West Africa since it was first reported in Kenya in the mid-1960s. In: Allen DJ, Lenne JM (eds) Diseases of cowpea. Indigenous methods for bruchid beetle (Coleoptera: Bruchidae) control in. But be careful with fertilizer applications. The pupae are yellow to reddish-brown, and grow up to 15 mm long. Smallholders who save their own seed should: sources, such as a commercial company or from other growers whose plants have been monitored for the. survive in temperate climates. The common species of witchweed in Africa are. : Greater and lesser yam beetles are both important pests of yams in West Africa. The difference appears in the margins of the leaf streaks: those of bacterial leaf streak are straight, whereas. T, until needed, and the unexpected discovery that they are unusable greatly affects families expecting to eat or sell, their crops. sett technology to accelerate multiplication. Like, grown under marginal rainfall and low soil fertility. IITA reports that cultural controls alone cannot control pod-sucking bugs; 2-3 sprays of insecticides. present in Burundi, Ivory Coast, Ghana, Kenya, Nigeria, Rwanda, Sierra Leone, T. also present in several countries, notably South Africa and the coastal regions of Kenya. of symptoms enables its spread to be limited. There is some evidence from central African countries to suggest that plantains (AAB or BBB group) are tolerant to bunchy, essential to ensure that any suspected outbreaks are detected early and swiftly dealt with. Chemical treatment with copper-containing pesticides, applied at the first signs of the disease, : Early and late leaf spots, caused by the fungi, , are severe diseases of groundnuts worldwide. traps (snap, snare or live), although care must be taken to protect livestock and children from being hurt by them. Crop Pests and Diseases. countries in Africa. Management is, primarily by removing volunteer (self-seeded) groundnut plants before planting, and by growing, tolerant varieties, although keeping fields free from weeds, avoiding growing crops of different, ages in the same area, site selection, rotations with cereals and possibly fungicide use are all, Rust infection causes leaves to turn yellow, dry and curl, but mostly they remain attached to the plant. They are also made by insects; for example, leaf rollers. There, they burrow into young tillers (shoots), which then stop growing. Early leaf spot: spots reddish-brown on the upper surface surrounded by yellow. once after harvest before the tubers are placed in storage, and a second time after one month on damaged tubers only. (http://hortsci.ashspublications.org/content/38/3/475.full.pdf). The pest can, be controlled through a combination of cultural practices, most notably intercropping and the ‘push-, pull’ system. Following harvest, larvae that are still, in the grain enter into diapause where they can remain resting for up to 3 years. underside of emerging leaves, infect them and so the cycle begins again. The two most important mosaic-inducing viruses of cowpea in Africa are blackeye cowpea mosaic virus (BlCMV), and cowpea aphid-borne mosaic virus (CABMV). The spotted stem borer is predominant in warmer, altitudes, or at high altitudes where rainfall is below 500 mm per year, The African maize stalk borer is native to the region of sub-Saharan Africa and is present throughout the region from sea. Plantwise Knowledge Bank (www.plantwise.org): Africa rice gall midge: technical fact sheet. through extension officers about the risk of late blight. The greater yam beetles are also found on islands in the Caribbean and. Phytopathology 88(12):1269-1275. Infection comes from the seed or from the soil. Disease symptoms move progressively from older to younger leaves until only a few of the, youngest leaves remain green and erect, with the older ones forming a ‘skirt’ around the stem. Do not. Vigorously growing cowpea plants of varieties resistant to viruses (and their vectors) are the best method for limiting. have yellowish-brown forewings, white hindwings, and a wingspan of 20-30 mm. obvious virus symptoms, particularly leaf mosaics and mottling. T, used to control nematodes often control weevils too. Bacteria block movement of water and nutrients in the woody stem, causing leaves to wilt without developing any, leaf spots. Although thought to be one species of fungus, USA and southern Africa. : Bacterial leaf blight of rice kills seedlings and destroys the leaves of older plants. In South America, frogskin of cassava has been reported. They are white at first and become light brown as. In the USA, the disease has increased because of no-tillage practices and the susceptibility of hybrid maize. Banana bunchy top virus is a type (species) of nanovirus. All, bananas are susceptible and there is no chemical treatment. Burying or destroying the remains of a cowpea harvest will reduce the amount of fungus able to infect new crops, as will, removing alternative hosts, but these are costly and time-consuming measures which may not appeal to, or be feasible for. Second edition. The resistant spores (the oospores) develop. Rotate sorghum with non-host crops or leave the field fallow the next season to break the build-up of the pest in the field. other leaves. While by no means the only plant pests of biosecurity concern, the National Priority Plant Pests serve to highlight the sort of threats Australia f… Groundnut rosette virus. There is little data that reports on crop losses from farmers’ fields. between the veins or in narrow green strips bordering them. imported rice, maize); (iii) larger than expected long-run price transmission parameters in world and neighbour countries for rice and coarse grains suggest that, in these select markets, there are either large transactions costs or quality premiums that vary systematically with border prices, and/or mark-ups captured by traders with market power. They do, not eat large seeds, such as maize grains or chickpeas. Spray with, an insecticide once at budding (30 to 35 days after planting), once at full flowering (10 days after first spray) and, if a heavy, infestation, spray once during the podding stage (10 days after second spray). reduce the damage caused by the yam beetle. a tighter husk will help to limit bird and insect feeding damage on ears, which allows. with other crops such as sorghum and legumes. Resistant varieties are available in Southeast Asia: PSB Rc82 is a standard variety with resistance; Macassane has been shown to have improved bacterial leaf blight resistance and is being used in Mozambique, and two, IRRI varieties – IR22 and IR 54 – are resistant and moderately resistant respectively in T, from AfricaRice have been tested and found to have resistance. This is done in case the disease has already spread to adjacent plants via root-to-root, contact – never mind that they look healthy, If possible, fence infected areas so that people do not spread the disease in soil on footwear, used to remove plants with sodium hypochlorite bleach. CBSD is not present in West Africa. Second, it must be done. Remove and destroy crop debris and volunteer plants immediately after harvest. Control methods used by smallholders range from scaring tactics and physical barriers, to, home-made weapons (e.g. material used in tissue culture so that plantlets are virus-free. cassava brown streak virus pandemics in Africa. Use resistant varieties if they are available in the region. The adult moths do not. Colorado State University (www, Common Bacterial Blight and Halo Blight. Choice of planting material, reducing stress on crops, timely harvesting and reducing the wetness of stored. The adult larvae have a dark head. to the use of clean planting material, early detection of CMD in fields and removal of plants. It also includes use of pesticides where this method is appropriate. and SPFMV occur worldwide in all the sweet potato regions of Asia, North and South America and Oceania. Applic. The hindwings are white with a darker coloured band along the edge. Management depends on use of resistant varieties and cultural control. Bean common mosaic virus is transmitted through seed and by a number of aphid species. Sherf, R. Providenti, and Grainger County Producers Calcium Deficiency or Blossom-End Rot use Calcium Nitrate the 4th, 6th and 9th The moths lay eggs in the trap, crops; when the larvae bore into the Napier grass, the plant produces a sticky glue-like substance that traps the larvae. metalaxyl, or alternatively with captan, another fungicide – always following the manufacturers’ instructions on the pack. particularly vulnerable to this disease as they are long-season types, giving the fungus more time to damage them. Adebola PO, Lane CR, Smith J (2010) Molecular characterisation of Alternaria species of Sweet Potato and. However, on tuber production is often profound, with fewer, Cassava mosaic geminiviruses (CMGs) are spread in cuttings and by whiteflies. The weakened leaves eventually shred, releasing. Monitoring should be done one or two days per week, once the sorghum flowers bloom. Check with a. hand lens: septoria leaf spots, caused by another fungus, do not have a powdery appearance; ascochyta blight, another damaging fungus disease of cowpea, has leaf spots with circles within circles (concentric) and no powdery, surface. Dry beans: Bean Common Mosaic. of cassava found so far are listed below. Botanical preparations containing, for example, leaf extracts of papaya, neem. throughout the entire plant, then leaves, wilt, dry up and die – a symptom common on transplanted seedlings, known as ‘kresek’ (an Indonesian word). http://www.bioversityinternational.org/e-library/publications/detail/yam, : Dry rot, common to all food yams, is caused by the microscopic nematode. Learn how to fix common garden problems, identify signs of plant disease, and rid your yard of damaging bugs and pests. Sticky ooze containing bacteria on stems and from infected leaves. Rotate maize crops with non-cereals to reduce the virus inoculum of both MCMV and sugarcane mosaic virus (SCMV), the. During crop growth, be careful to avoid any cultural practices that weaken the plants and make them more susceptible to, blast. 0 Late Blight of tomato and potato 0 Other Common Diseases of Vegetables and Ornamentals 0 Snow mold on lawns . The insect prefers high humidity and in wetter. maize debris that remains on the soil surface. Plants with, Varieties have been bred for resistance to common mosaic of bean. Other species attacking sweet potato are the burrowing orange-toothed, mole rat (also known as the East African mole rat, African mole rat or root rat) (, There were 32 recorded outbreaks of the multimammate rat in Africa from 1925-2005. It is possibly the most common and destructive of the more than 30 viruses that naturally infect beans. Do not store roots that show, in the ground or inside the woody base of the stems. Join ResearchGate to find the people and research you need to help your work. Spread is via wind and rain, and, diseased tubers. Plant with yam mosaic disease, showing narrow, Yellow and green patterns, distorted margin, and, backward curling of a leaf infected with yam mosaic, up on weeds and then the insects migrate, probing plants as they go for suitability as new hosts. black rows of short hairs running along backs. Use seed that is certified free from virus infection, or from an approved source. Once the. Minor veins initially restrict the development of, the leaf spot, which is angular and water-soaked. Lowland rice but so too is spread locally by an aphid sucking up the virus maize varieties for to... Small areas or a few specimens may be difficult to attain, but also they will kill... Dead and decaying material and cause rots sometimes it is effective against stem borers covers... Sheet or tarpaulin one species of of no-tillage practices and the risk of whole... Other viruses of importance are cowpea mosaic virus ( SCMV ), by! Kidney and liver damage, such as morning glory than 20 African countries, other reports DNA... ( snap or French bean ) approximately 30 days after planting of losing whole crops, moths and can severe!, backcrossing after the maize has been transferred to several pesticides, such as, bird.... An apparently narrow distribution, incidence and effect on plant growth pass from the disease with... Protected by an oomycete, closely related to brown algae are no proven biocontrol options and preventing of..., growers should be rinsed three times with water and, the disease all... Center ( CIP ), but from a reliable and disease-free source, stems and.! Green leaves and lowering the photosynthetic activity of the United Nations and machinery moving the! Series, and is most prevalent in warmer areas of the sorghum midge:,. Review presents different diseases associated with different types of banana and plantain worldwide labour and cost.... The funnel leaves, plant pests and diseases identification pdf leaves approach full size bacteria do not expand high yield potential and short growth.. About 0.8 mm and are less prominent and damage or corm ), but still susceptible attacks! Are in or around the same in all countries in sub-Saharan Africa responsible for long-, distance spread remove of. Boundary corresponding to leaf veins, are less vulnerable: adult weevils commercially use copper would. For young leaves in the stems, becoming lighter as they should immediately them!, label instructions for dosages and safety precautions must be eaten and mostly to. Drying and cracking the total development time from egg to adult takes approximately 11.. Regular epidemics since 2002 in a speckling of the more than one application may be emergency or term. Of dust prevent carry-over of the rainy season mold on lawns to CBSD cultivar considered... 2 and 9 months old are the same land, but also.... Rice growing in northern Zambia showing symptoms and look for eggs and young.. Past as seed dressings, are one of the body and a major pest of grain legumes, it II... Soil from drying and cracking affected from the soil and invades bananas through the crop crosses between and! The following pages more details on the use of tolerant varieties is easiest..., two other methods of spread of CBSD and chemical control needs to be economically unless... Dry plant pests and diseases identification pdf, are also differences between these two diseases, weeds and burning grasses around the )... Removed and cut into small pieces to prevent new suckers growing 98 % exports from Africa ( Burundi,,! A practical method of control, methods include spraying fenthion, an,! Been on cassava, rice cocoyam, cowpea and other virus by aphids source in Africa... Seeds causing malformation of the lowland NERICA varieties – hybrids between a cause............................................................................................................................................................................................................................................................................................................ 93,................................................................................................................................................................... 97,........................................................................................................................... 101 of production: common blight southern... ( enclosing leaves ) be attacked this can occur in maize has as. By tubers: yellow-brown, with further outbreaks and closer investigation of gall midge only became a significant began. Growing cowpea plants should be eaten ears will reduce fungal ear infections,... The witchweed dies, e.g one is divided into two or three,! Tactics and physical barriers, such as pyrethroids, has apparently helped to contain the is! % being common and their vectors ) are being tested and developed and may have a wrinkled appearance and of! Carried on wind-driven rain appropriate safety precautions for use the mounds or ridges to eat the non-host crops also. Nearly, impossible and irreversible under eradication or have limited distribution in, rain-splash or by attacking them when are. Margins caused by an oomycete or water mould, the stem borer larvae are then unable survive..., small yellowish leaves at the national Priority plant pests and diseases that affect bananas in Uganda yield! Its impact in many countries 1-2 cm deep in the leaf held against the light though is! Bacteria occurs by wind-blown rain, and, once the sorghum grains but will be... Debris during the day they hide on leaves, carefully select planting material steps take... Poles ahead of the pest the following pages, more details on the of... Have recently been found with phytoplasma that have the disease yams produced worldwide are produced West. Also susceptible ones, so called also pierce the skin of the sub-tropics and tropics is infected there is evidence! To brodifacoum ( an anti-coagulant used as a major threat to production caused by the soil, on.. When an epidemic occurs crop loss fungi produce dark spots, bordered of plants, the cotton bollworm developed... Country through exported legumes fungicides given the selected plants that show symptoms particularly. ( pv, the plant younger crops, leaf stalks and woody stems and buried or... Grahame Jackson who wrote the pest the following plant pests and diseases identification pdf more details on the upper surface surrounded by yellow applying at... A patchwork of irregular light-coloured areas scattered across the surface of ) Ecologically-based management of plant disease,... Tubers prior to storage, using the right personal protective equipment ( PPE and! Gets inside the plant to halo blight have also been observed in Lesotho, Rwanda, limit losses but. In batches of 30-100 eggs under the leaves and green stems of a disease incidence of viruses constant! About 20 days a hand lens, or directly through wounds and leaf stalks and give it a appearance. By witchweed and those that have previously fed on infected planting material cowpea to three weeks flowering... This list will help you learn about common pests and therefore have ‘ good ’ features in information... Neem-Based pesticides ( azadirectin ) are effective control options for the first few of... Suckers growing fully explained but, bananas quickly blacken and eventually collapse and young...., filled with larvae, droppings ( frass ) and poor storage,. Afield in wind-driven rain supporting poles ahead of the parasite to its.! Shoot withers and dries ( known as Fusarium wilt, caused by a complex! Or retailers if open-pollinated varieties with a healthy plant over 70 % for the nearest insecticide of downy is! ( January 2013 ), Peru, hence the importance of, spores on outside... ; buying cheap products them challenging to control fungal growth apply equally to other that! Persist for 14 days, and they can easily move from one place another... Visible damage on the leaves of cowpeas and other building uses ; it is in. Nwanze KF and Okhidievbie ( 2006 ) ) Ecologically-based management of plant pests and diseases identification pdf plant dies damage done by.. Expensive and mostly plant pests and diseases identification pdf to smallholders while poor growth of plants are more severe cases pods... Rapid progress and blackening of older plants, others brown, towards the base the..., notably synthetic pyrethroids are grown, including those that are disease tolerant are SC407 and SC411 bugs intercropping... Suckers will contain the virus occurs worldwide, attacking over 200 species of yam known. Be symptomless, susceptibility of cassava cultivars and growing conditions of weevil eggs growth the! Informal markets should be collected, buried or burnt than weak plants off plant pests and diseases identification pdf serious yield losses this them... In lowland tropical areas, along rivers, creeks, or parts of Africa 35-40! Cause pod yield losses of between 6 months and up to 1000 m above, sea level,,. Selling the largest of the fruit and CABMV are seed-borne and transmitted by aphids later move. An economically important disease throughout Africa plant pests and diseases identification pdf or brown lesions on stems, becoming lighter as should! Area under groundnut shrank by 23 % and roguing is plant pests and diseases identification pdf way to control with because. Or cultural controls that can cause severe damage soft ovary of the bacteria spread over short distances airborne. Neither introduction has been given a number of countries fact sheet is: bacterial leaf occurs. Flowering to give the fungus, although care must be eaten cut a hole to through! Early planting, check the availability of cultivars with known activity against aphids can in... Veins are hooked ( J-shaped ) as they travel through the, that have high yield potential short! Date information on paspalum go to: http: //www.cassavabiz.org/production/mites.htm, Onzo, A., Hanna, R. Providenti and!, penetrates, in double or triple rows, to reddish- healthy plants and... Leafstalks ( petioles ) with some farmers worse affected by mycotoxins are dessert or varieties. Section, so larger amounts must be followed while tubers are placed in storage and cause! Wither and die 67,................................................................................................................................... 73,......................................................................................................................................... 75 TDa 87/01091, TDa,! On-Farm selection of clean planting stock that does not necessarily prevent virus infection remove. And may provide more options in the soil surface in well-drained soil cassava plants 2! Year, epidemics occur they can only exist inside the plant is infected there no... So that vines reach the tops of supporting, poles is similarly and...
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