Cassava crop 1

The document involves general guideline for cassava crop production in Tanzania

1. Cassava Crop

2. INTRODUCTION Cassava ( Manihot esculenta ) is considered to be the third most important source of calories in the tropics, after rice and maize. The crop is grown mostly by low life communities especially women and the crop also is grown almost exclusively by smallholder farmers as the result it is perceived as staple food for poor people. it is one of the few staple crops that can be produced efficiently on a small scale, with no need for mechanization or purchased inputs, and in marginal areas with poor soils and unpredictable rainfall.

3. Introduction Cont…… Its production has been increasing since year 2000 for about 100 Millions tones which is influenced by great demand from Asia where they demand for cassava. This Booming demand offers millions of cassava growers in tropical countries the opportunity to intensively produce cassava, earn higher incomes and boost the food supply where it is most needed. But how question on “How local farmers choose to improve productivity” this should be of major concern to policymakers on agriculture sector (FAO, .2013)

4. BOTANICAL CLASSFICATION AND CHARACTERISTICS Botanical classification of Cassava. Kingdom: Plantae Division: Angiospermatophyta Class: Eudiocots Order: Malpighiales Family: Euphorbiaceae Genus: Manihot Species: M. esculenta Scientific name: Manihot esculenta Crantz Common name: Cassava (English name) (IITS., 2011)

5. Botanical characteristics of Cassava The cassava plant is a woody perennial shrub grown as annual , which grows from 1 m to 5 m in height. Roots: Cassava roots are tuberous, coned shape modified for starch storage covered with papery barks and pink to white homogeneous flesh encased cortex detachable rind, about 1 mm thick. The flesh ranges from bright to soft yellow

6. Botanical characteristics cont….. There are about more than 100 varieties of cassava with each distinctive color and quality adapted to different environmental conditions. Cassava tubers are very rich in starch, and contain significant quantities of calcium (50mg/100g), phosphorus (40mg/100 g) and vitamin C (25mg/100 g). However, they are low in protein and other nutrients.

7. Botanical characteristics cont….. Stems: The stem erects and radiates from the tuber and has milky latex. As the plant grows, the main stem usually divides into three branches, each of which then divides in the same way.

8. Leaves : The leaves are large and palmate (Hand- shaped) and have five to seven lobes borne on a long, slender petiole. The leaves grow only towards the end of the branches. They are dark green above and light green below

9. Flowers and fruit: Male and female flowers are arranged in loose plumes and are found on the same plant meaning the plant is Monoecious ( Protogyny ). ( FAO, .2013 ) Common Varieties in Tanzania are Makutupora, Dodoma, Mkumba and Pwani varieties (released 2012) , NDL 90/034, HBL 95/05, Kibaha, Kiroba and Mumba and other varieties are I91/00063, I91/0057, I91/0067, MM96/0876, MM96/3075B, MM96/4619, MM96/4684,MM96/5725,MM96/8233, MM96/8450, SS4, and Kachaga (a local variety showing good resistance toCMD) ( Mkamilo ,. 2005) & (IITA,.2012)

10. Note : The hardy and better able to tolerate drought and poor soil conditions than other of many crop species. It is able to be grown extremely poor, acidic soil because of its symbiotic association with the soil fungi called mycorrhizae. The crop has high productivity on the piece of land due to its ability to fast recover from lost in foliage and/ or damages caused by diseases or pests. The plant is also unusual and infamous, because both roots and leaves can somewhat be toxic when consumed. The toxic nature is resulted from the Cyanogenic glucosides (glucose + Cyanide) with produce the Hydrogen cyanide (HCN) which is potent toxin and this happens to damaged plant tissues.

11. All of Cassava varieties has the cynogenic glucose and there by one can tell if the cassava is: Sweet : When the flesh of the crop contain less concentration of the cynogenic glucose hence these types require few processing techniques before consumption. Bitter : When the flesh of the crop contain high concentration of the cynogenic glucose hence these types require extensive processing techniques to reduce the toxic compound before consumption. These techniques involves Grating, Fermenting and Sun drying, all of these techniques are aimed to damage the plant tissue hence reduce the volatile HCN. This tells the effectiveness of the processing and preparations are the ones determining the toxicity of the cassava foods. ( Alves et all,.1998)

12. CASSAVA AS AN ANNUAL CROP

13. Cassava plant has shallow root system Limited ability to survive harsh environment Has fast growth and attain early maturity Has excessive demand for nutrients Also cassava has high multiplication rate Cassava plant are susceptible to pest and disease Also has short canopy architecture Above factors proves cassava as annual crops

14. Cassava Crop Growth Stages Crop stage No. of days Observation Seedling 5-7 10-12 Adventitious roots emerges . First leaves emerges Leaf beginning and root system 30 Leaves starts to expand and + Ve Photosythesis is observed. Fibrous roots starts to grow. Maturity Up to 8 months Cassava roots are said to be matured enough to be harvested.

15. Origin and geographical distribution Many studies indicate that cassava has multiple centres of origin; others suggest that the cultivated species originated on the southern edge of the Brazilian Amazon where it is still grown today. In year 2013 Tanzania was the 12 th largest cassava producer in the world and the 6th largest in Africa after Nigeria (top producer in the word), DRC, Ghana, Angola and Mozambique.

16. The main cassava producing areas in Tanzania are the Lake Victoria zone ( Mwanza , Mara, Kagera and Shinyanga regions), the Southern zone( Lindi and Mtwara regions and Tunduru district in Ruvuma region), the Eastern zone ( Morogoro , Tanga , Coast, Dar es Salaam) and Zanzibar (Pemba and Unguja islands) (Mkamilo &Jeremiah, .2005).

17. ECONOMIC IMPORTANCE OF CASSAVA CROP Cassava is used as staple food, as source of carbohydrate, crude protein, minerals, and vitamin Example in Tabora- Tanzania, Nigeria, Ghana, China and in Tamil Nandu- India Also used to produce alcoholic beverage . Alcoholic bevarage made from cassava include I nmpala(Mozambique, Masato (peruvian amazonia) China, Tiquira (Brazil) Culinary Sweet variety of cassava can be made into flour that is used to make bread, cakes and cookies.

18. Economic importance….. It provides employment . It also acts as the source of Income.

19.   Production Requirements for Cassava : Climatic requirements: 1) Temperature Cassava becomes more productive between 15 North and 15 South latitudes. Generally, cassava crop requires a warm, humid climate. Temperature as another factor is very important, as at about 10 °C all growth activities stops. The crop is typically grown in places which are frost-free all year round. The highest tuber production can be expected in the tropical lowlands, below an altitude of 150 m, where temperatures average 25 °C - 29 °C, but some varieties grow at altitudes of up to 1500 m from sea level (FAO, 2006).

20. 2) Water Once established, cassava can grow in places that receive just about 400 mm of average annual rainfall. But assurance for water availability for the crop ensures more productivity of the crop. . The root yields increased six fold when the quantity of water supplied by supplementary drip irrigation was equal to that of the season’s rainfall. Supplemental irrigation that increased the total water supply by 20 percent almost doubled root yields (FAO, 2013) .

21. Edaphic Factors Cassava crop is able to be grown on a wide - range of soil types but grows best on deep, free draining soils with sufficient fertility levels. It is advised that a farmer should avoid Shallow soils which may results to restriction on tuber expansion. Cassava needs a sufficiently loose-textured soil to facilitate initial root penetration and to allow for root thickening. Therefore Cassava grows best on light, sandy loams or on loamy sands which are moist, fertile and deep, but it also does well on soils ranging in texture from sands to clays and on soils of relatively low fertility with pH range about 5.5-6.5 ( University of Pretoria, .2010) .

22. Crop management planting/sowing Site selection: For selecting good site for a cassava crop production, one has to look for an area with dense vegetation cover, deep loamy soils with medium soil fertility and good drainage, and flat or gently sloping land; also examine the field history to plan for plant protection measures(James et al., 2000). Propagation: Cassava is propagated vegetatively using stem cuttings. In Selecting cuttings one has to select them from the middle stem portions, 30cm long with an average of 5–8nodes

23. Propagation cont ….. Vegetative propagule Growth begins

24. AGRONOMIC PRACTICES 1) Land preparation Ploughing : The method of land preparation depends on soil type and depth of the water table. Practice minimum tillage in sandy soil to conserve soil, organic matter, moisture, and reduce soil erosion. Prepare land to improve soil contact with stem cuttings. In shallow or hard soils, increase topsoil volume per plant for better establishment. Make ridges or mounds to reduce water logging in poorly drained soils (James et al., 2000). . Planting: Plant cassava at the correct planting time to ensure: Healthy sprouting and Good crop establishment.

25. Select good cassava varieties for planting, look for varieties which Grow fast, Give good yields, Tolerate major diseases and pests, Mature early, Give high root yields (fresh and dry) and which Meet end-users quality characteristics high dry matter, good mealiness, good ground storability and which are well adapted to your area; the variety should also bulk early and be easy to process. Select healthy cassava stem cuttings, choose disease free cassava plants as sources of planting materials; use stem cuttings taken from the middle, brown portions of the stem and free of stem-borne pests and diseases. plant cassava stem cuttings properly consider the type of soil; prepare ridges and mounds in areas where soil gets waterlogged; use minimum tillage in sandy soil; plant cassava stem cuttings vertically in sandy soil; plant cassava stem cuttings at an angle in loamy soil; plant cassava stem cuttings 1 meter apart from each other insole cropping; and in cassava intercrops make sure there is enough space for the plants (James et al., 2000).

26. Spacing : Distances between cassava plants mainly depend on the variety and on the cropping system. In Pure stands (with no intercropping), a recommended spacing is 1.0 m * 0.9 m. When the crop is intercropped, Interplant with a cover crop of beans or groundnuts at a spacing of 50cm * 20cm. The spacing is recommended to be 1.0 m * 4.0 m. This combination of crops gives maximum yields of both cassava and bean or groundnuts.(James et al., 2000).

27.   Fertilizer Requirements A soil test should always be done to determine fertilizer types and rates but if not done then the following recommendations for fertilizing should be followed: a) NPK fertilizer with the relative ratio as (12:24:12) is to be applied at the rate of 336 kg/ha at 6 weeks after planting and followed with 16:8:24 at 16 weeks after planting b) Average quantities to be applied should be one full hand (85gm-113gm) of fertilizer per each plant at each application.

28. c) The fertilizer should be placed about 15cm to 45cm from the base of the stem in drill holes. Drilled holes should be 10cm to 15cm in depth. Placing fertilizer into the drilled holes reduces fertilizer loss through water runoff. d) it was found that fertilizing plants 16 weeks after planting enhances tuber bulking hence increase productivity. (FAO,. 2006).

29. Gap filling and Pruning Gap filling to those stem cuttings to the cutting failed to grow between 2 to 3 weeks. Pruning of the plants should be done about 9 months after planting when using high densities or if growth is excessive. Note that pruning can create wound entries for pests and pathogens, and can spread them from one plot to another by way of the cutting instrument and workers’ clothing. Dip cutting instruments in a detergent solution between plots to destroy bacterial and viral pathogens on the surface.

30. Weeding, Pests & Diseases and Their Managements. Weed control (WEEDING) Ensure adequate control of weeds pre-emergence by ploughing and harrowing the soil or applying pre-emergence herbicides before planting and post emergence with herbicide applications, inter-row weeders or regular manual weeding intensively in first three months after planting (Vegetative phase of the crop ) until leaves form a canopy and weed growth is suppressed because the leaves canopy will reduce the growth of weeds by shading them. (FAO, 2006)

31. Pests control Most of the times insect pests are not a huge threat to cassava crop production but still one needs to have a very close attention. The most notable Pests in Cassava include; The cassava mealybug, Phenacoccus manihoti. occurs on cassava leaves, shoot tips, petioles, and stems easily said as on growing points of the plant. Cassava mealybug damage symptoms include shortened internode lengths, compression of terminal leaves together into “bunchy tops”, distortion of stem portions, defoliation, and “candlestick” appearance of shoot tip, this is because they affect the growing points hence leads to stunt growth. The insects survive on cassava stems and leaves and are easily carried to new fields in this way.

32. Vertebrates pest of cassava Red legged sqirrel( Akande 1976) Giant African rat

33. Diseases Cassava Mosaic Disease (CMD) Cassava mosaic disease is caused by a virus which occurs inside cassava stems and this the most feared disease in the cassava production because it leads to the reduction and deformation of leaves structure hence reduce photosynthetic efficiency hence growth. Symptoms of cassava mosaic disease damage are patches of normal green leaf color mixed with light green and yellow chlorotic areas in a mosaic pattern

34. Cassava Anthracnose Disease (CAD) Cassava anthracnose disease is caused by a fungus which occurs on the surface of cassava stems. The disease damage symptoms are cankers (“sores”) on the stem and bases of leaf petioles. The disease reduces the sprouting ability of stem cuttings. ( Fokunang et al., 2000)

35. Cassava Bud Necrosis Cassava bud necrosis is caused by a fungus which grows on the surface of cassava stems covering the axilliary buds or the “eyes” of stem cuttings. The affected buds die, and the sprouting ability of stem cuttings is reduced. (James et al., 2000)

36. Cassava Brown Streak virus Disease It was first identified in 1936 in Tanzania, and has spread to other coastal areas of East Africa. CBSD is characterized by severe chlorosis and necrosis on infected leaves, giving them a yellowish, mottled appearance. ( Ntawuruhunga & Legg,. 2007 )

37.   General Pest and Disease control Select healthy planting material. Treat cuttings with pesticides and fungicides before planting, and the plants during the growth stage when necessary. Rogue and burn diseased plants regularly during the growth season (if it does not compromise the survival of a specific accession). After harvest, destroy discarded stems and roots that have disease symptoms or pest contamination The use of IPM The use of Natural enemies.

38. Harvesting Harvest as soon as the tubers are mature. Optimum time for harvesting varies according to the variety, climate and soil factors. Harvest early maturing varieties between 8–12 months after planting. Harvest full season varieties between 12 and18 months after planting. In cold environments, harvesting can be delayed until 18 and 24 months after planting. If the tubers are left in the ground, the starch content increases with age until, at a certain point, lignifications takes place, causing the tubers to become tough and woody and making it more difficult to prepare them for consumption and other uses. Yields may also vary depending on variety, soil type and management practices. Average yields are 10 –30 tons/ha. Cassava harvesting may be done piece-meal (one by one) or can be by uprooting whole plants. A stick or hoe may be used to remove the tubers.

39. ONE TO ONE HARVESTING UPROOTING THE WHOLE PLANT

40. Post-Harvest Operations Some of the Harvested tubers must be delivered to the processing plant within 48 hours to prevent deterioration. Roots can be processed into granulated flour, or into high quality cassava flour which can be used as a substitute for some of the maize flour for Ugali cooking in Tanzania, wheat flour in bread and confectionary. In Thailand and China, root starch goes into food products, plywood, paper and textiles, and is used as feedstock for production of sweeteners, fructose, and alcohol and fuel ethanol. Two recent cassava mutations have starch properties that are highly valued by industry. Fresh cassava roots were stored in straw-lined trenches for periods of up to 12 months (Booth and Coursey , 1994)

41. Marketing of Cassava Cassava crops after being harvested are commonly to be consumed in livelihood level but since it cannot be stored for long time then mostly they are sold as fast foods or are transported to the nearest marketing places where there will be assured demand of the crop. If the small scale farmer wishes to store them for long time then they are advised to reduce water contents in them by drying them.

42. MARKETING PLACES

43. Referrences De Vries , J. and G. Toenniessen (2001) Securing the Harvest. Biotechnology, Breeding and Seed Systems for African Crops. CABIPublishing , NewYork . James, B., Yaninek , J., Tumanteh , A., Maroya,N ., Dixon, A., Salawu , R Kwarteng,J .(2000) Starting a Cassava Farm: IPM Field Guide for Extension N.M., Kanju , E., Kulembeka , H., Tollano , S.M., Massawe , M.H. & Masumba , E. 1999. Food Security and Crop Diversification in SADC countries: The Role of Cassava and Sweet Potato. Proceedings of the SARRNET Scientific Workshop, Lusaka,Zambia , 17-19 August 1998 MKAMILO G.S. & JEREMIAH S.C. (2005). Current status of cassava improvement programme in Tanzania African Crop Science Conference Proceedings, Vol. 7. pp. 1311-1314 Pheneas Ntawuruhunga ; James Legg (May 2007). "New Spread of Cassava Brown Streak Virus Disease and its Implications for the Movement of Cassava Germplasm in the East and Central African Region" (PDF).

44. Fokunang , C.N., C.N. Akem , T. Ikotun and A.G.O. Dixon, 2000. Germplasm evaluation of cassava genotypes for resistance to anthracnose, bacterial blight and mosaic diseases and their effects on yield. Genet. Resour . Crop Evol ., 47: 63-71. IITA http://www.isaaa.org/kc/cropbiotechupdate/article/default.asp?ID=9138