TRAINING MANUAL RAPID MULTIPLICATION OF CASSAVA STEMS

Transcription

1 TRAINING MANUAL ON RAPID MULTIPLICATION OF CASSAVA STEMS International Institute of Tropical Agriculture (IITA) PMB 5320, Oyo Road, Ibadan, Nigeria Tel: , Web: 1

2 Table of content Objectives of the training manual 3 Organization of the training manual 3 Unit 1: Introduction, Importance and principles of rapid multiplication of cassava stems 4 Unit 2: Preparation of mini-stem cuttings 5 Unit 3: Methods of Sprouting and planting of cuttings in the nursery 9 Unit 4: Transplanting, field maintenance and harvesting 16 Unit 5: Storage and distribution/sales of cassava stems 18 Bibliography 21 Revision questions 22 2

3 Rapid Multiplication of Cassava Stems Objectives: This manual is to enable trainees to: explain the importance and principles of cassava rapid multiplication; prepare mini-stem cuttings; sprout mini-stem cuttings in nursery beds and polythene bags; transplant and maintain mini-stem cuttings in the field; and harvest stems and store them for distribution/sales. Expected outcome: At the end of the training, trainees should be able to produce improved cassava stems for sale using the rapid multiplication technique. Study materials Cassava plants Tools and materials to prepare mini-stem cutting Nursery beds and polythene bags Field for planting transplanted cuttings. Practical Demonstrate how to prepare land Demonstrate preparation of different stem cuttings for stem production Demonstrate how to raise cuttings in the nursery using different methods Demonstrate planting in the field Demonstrate how to harvest (ratooning) Demonstrate different methods of how to store cassava stems Structure of the Training Manual This training manual is designed to be users-friendly by simplifying the technical terms and making the manual as practical as possible. The manual is arranged in units and in sequential order so that trainees can follow systematically. Unit 1: Introduction: Importance and principles of rapid multiplication of cassava stems Unit 2: Preparation of mini-stem cuttings Unit 3: Methods of Sprouting and planting of cuttings in the nursery Unit 4: Transplanting, field maintenance and harvesting Unit 5: Storage and distribution/sales of cassava stems Bibliography Revision Questions 3

4 Unit 1: Introduction, Importance and Principles of Rapid Multiplication of Cassava Stems Introduction The production of cassava roots depends on a supply of good quality planting materials (stem cuttings). There is usually a high demand for improved varieties of cassava planting materials at the beginning of planting seasons. For example, to plant one hectare of land at a plant population of 10,000 at 1m x 1m spacing, a minimum of 2000 cassava stems of about 1 meter length are required. This means a large quantity of planting materials must be produced to meet farmers demand which makes many farmers to plant low quality and diseased-infested planting materials during the planting season. The rapid multiplication of cassava stems is therefore a worthwhile venture for those who can go into the business. Several opportunities are linked to this stem multiplication technology. Research institutes can use the technique to multiply breeder and foundation stocks of newly developed varieties rapidly for easy availability to farmers. On the other hand, farmers can multiply cassava varieties of their choice rapidly using only a few stems of such varieties. Principles of rapid multiplication of cassava stem. The term rapid multiplication describes a technique developed to overcome the low multiplication ratios in vegetative propagated crops like cassava. The multiplication ratio is the increase in planting material over what has been planted. For example, a cassava stem cutting (25 30cm long) when planted, yields about 10 stem cuttings in 12 months after planting. This means that the multiplication ratio is 1:10. In comparison, a maize plant which yields a cob with about 300 seeds has a multiplication ratio of 1: 300 (Fig. 1). This makes the rapid multiplication of cassava to be important so as to overcome the low multiplication ratio. However, whoever that wants to go into rapid multiplication of cassava business should bear in mind that production of planting materials (stems) is the major goal while production of roots is secondary. Secondly, improved varieties that are clean, healthy and disease and pest free stems must be used for multiplication so as to produce clean and healthy planting materials that will be of high demand with good prices. 4

5 Maize seed can produce up to 300 seeds - 1: 300 Stem of cassava can produce 10 planting materials. 1: 10 Fig. 1: Multiplication ratio of maize and cassava 5

6 Unit 2: Preparation of Mini-stem Cuttings from Cassava Stems After the nursery and the field have been prepared for cassava stem multiplication, the next stage is the careful preparation of the mini-stem cuttings. Mini-stem cuttings are small stem pieces, each with one or more nodes depending on the portion of the stem in which the cuttings are taken. Three types of mini-stem cuttings can be produced from cassava stem. 1. The hardwood portion: These are pieces cut from the bottom of the stem (hardwood) which may have one or 2 nodes. Use of the 1-2 nodes cuttings requires selecting stems of improved varieties of choice (Fig: 2). 2 The semi-mature portion: These are pieces from the middle portion of the stem. This may have 4-6 nodes (Fig 2). 3 The tip shoot: These are pieces from the tip portion of the cassava plant which may have 6-10 nodes (Fig 2). Cuttings from the tip portion semi-mature cuttings hardwood cuttings Fig. 2: Types of mini-stem cuttings NOTE: The number of nodes on a cutting to be used is not fixed and depends on factors such as the inter-node length, stem diameter, plant age and weather conditions during and after planting. About mini-stem cuttings can be produced from a cassava plant 6

7 Tools for preparing mini-stem cuttings The hardwood portion and semi-mature mini-stem cuttings should be prepared using secateurs, hand saws or machetes (Fig. 3). The tools must be sharp to ensure that the cut ends are clean as shown in Fig: 4. Big Secateur Secateur Hand saw Cutlass Fig. 3: Tools for preparing mini-stem cuttings Badly prepared cutting Well prepared cutting Fig. 4: Example of well prepared and badly prepared cutting The tip shoots should be prepared using the secateurs or sharp knives. The leaves should be carefully stripped off leaving the youngest leaves (Fig. 5). Care should be taken not to damage the axillary buds (Fig. 6a). Each tip shoot should be placed in water immediately after preparation to prevent dehydration as shown in Fig. 6b. 7

8 Fig. 5: How to prepare tip shoot Fig. 6a: Cutting showing the axillary buds Fig. 6b: Tip shoots dipped in water Treatment of mini-stem cuttings before planting Administering preventive agrochemical treatment (a mixture of insecticide and fungicide) on the mini-stem cuttings against pests and diseases before planting is essential for good sprouting and establishment in the nursery and field. Benlate (benomyl) and Demosan have been found to be suitable broad-spectrum fungicides for treating the mini-stems against fungi. Cultural method can also be used. 8

9 For example, Neem leaf powder: 1 kg in 5 litres of water can be used. Measure out the required quantity into a container, add water and mix thoroughly. Finally, put the cuttings into the solution as in Fig. 7 and should be left in the solution for about 5 minutes before taking out to drain. Alternatively in the field, 24g of fungicide (a full match box) will be enough to treat cuttings that will fill a white polythene bag. The mini-stem cuttings can now be ready for sprouting in the nursery or planted to the field directly. Fig. 7: Treatment of mini-stem cuttings in fungicide suspension 9

10 Unit 3: Methods of Sprouting and Planting Mini-stem Cuttings in Nursery There are different methods for sprouting the mini-stem cuttings Method 1 Multi-compartment trays In this method, tray compartments are filled with loamy soil, which is well moistened and then the cuttings are planted in each of the compartment with the bud pointing upwards. The trays are kept under shade with sunshine penetration until the plants have sprouted and ready for transplanting (Fig. 8). The trays can be put in a simple dome-shaped polythene-covered structure to enhance sprouting. Fig. 8: Multi-compartment trays Method 2: Nursery Bed Another method for mini-stem cuttings sprouting is through the nursery bed. This method is good for cuttings from the middle and top parts of the stem (Semi-matured and tip shoot). A well-drained, flat site preferably near a source of water should be selected for the nursery bed. The length and width of each bed must be marked out. The width of the nursery bed should be selected so that from either side one can reach the central portion. 10

11 Dig up the soil with a mattock or hoe and with a spade or hoe, the bed can be raised with the soil between two beds as in Fig. 9. Fig. 9: Preparation of raised beds The top of the bed must be flattened using a rake or fork. The height of the bed must be about 30 cm (Fig. 10). Fig. 10: How to flatten the nursery bed Method 3: Use of black polythene bags filled with soil The third method of sprouting the mini-stem cuttings is the use of perforated polyethylene bags filled with good quality soil. The black polythene bags are perforated at the sides and bottom to allow good drainage (Fig. 11). The planting procedure in this method is similar to the nursery bed 11

12 Fig. 11: Sprouting of mini-stem in black polythene bags filled with soil. Method 4: Use of transparent polythene bags Another important method of sprouting mini-stem cuttings is sprouting in the white polythene bags without soil. The hardwood and semi-mature mini-stem cuttings that have been treated with fungicides as described in Fig.6 are placed directly into a perforated polythene bags as in Fig. 12. The high humidity and temperature in the polythene bags promote rapid and uniform sprouting. Fig. 12: Treated mini-stem cuttings placed in polythene bag The bags should be tied with a piece of string leaving about one-third of the total space empty for aeration as in Fig. 13. Various sizes of bags can be used as long as there is space for aeration. 12

13 Fig.13: Bags containing mini-stem cuttings being tied The bags containing the mini-stem cuttings should be kept in a shaded area or under the roof as in Fig. 14. Fig.14: Bags containing mini-stem cuttings kept under shade Mini-stem cuttings sprout in 3-5 days. However, some varieties may require a few days more. Sprouted mini-stem cuttings from this method can be planted directly into the field after 7-10 days. Fig.15: Sprouted mini-stem cuttings ready for planting in the field 13

14 The use of white transparent polythene bag method has some advantages over the previous 3 methods discussed in that: It does not require transplanting It does not require soil transportation, planting and maintenance The labour required is low The method is quick and inexpensive The method is convenient Cuttings can be stored for few days before planting Bags can easily be carried by hand Cuttings can be used for mechanical planting. Note: 1 This method is only suitable for hardwood and semi-mature mini-stem cuttings because the tip shoot portion cannot survive under this method because of the high temperature in the bag. 2 For practical purpose and technicality involved in sprouting in the nursery, it is advisable that farmers use this method for rapid multiplication of cassava. Planting and Maintenance of cuttings in the nursery Hardwood mini-stem cuttings should be planted horizontally at a spacing of 10 cm x 10 cm at a depth of 4 6 cm as in Fig. 16. Cuttings should not be planted too close to the surface so that they will not be exposed and be dehydrated. Fig. 16: Cuttings planted at 10 x10 cm in the nursery The cuttings should be placed so that the two adjacent nodes are on the right and left sides as in Fig

15 Fig. 17: Right way to place cutting nodes in the soil Semi-mature cuttings should be planted vertically at also a spacing of 10 cm x 10 cm with two-thirds of the cuttings and the old ends buried in the soil as in Fig. 18. Fig. 18: Planting of semi-mature cuttings The tip shoot mini-stem cuttings should be planted the same way as semi-mature mini-stem cuttings at a spacing of 10 cm x 10 cm as in Fig. 19. Fig. 19: Planting of the tip shoot mini-stem cuttings 15

16 Nursery Maintenance The following steps must be carried out when cuttings are in the nursery. Water immediately after planting Water twice a day Label the beds including name of the variety Weed regularly Cover exposed cuttings during watering Tip shoots are sensitive, water lightly 3 times daily. Fig. 20: Watering of mini-stem cuttings in the nursery 16

17 Unit 4: Transplanting, Field Maintenance and Harvesting Transplanting Mini-stem cuttings are usually kept in the nursery for 4-6 weeks before transplanting. Cuttings should be transplanted into a well prepared field at a spacing of either 100 cm x 50 cm or 50 cm x50 cm. The soil around each plant should be firmed and the field should be labelled indicating variety, date of planting and other information necessary. A water logged fields should however be avoided to prevent low establishment due to poor aeration and root development. Field Maintenance There is a need for proper field maintenance after transplanting for production of strong and healthy plants. Weeds should be controlled during the first 10 weeks either by using hoe or apply herbicides. Any missing stands should be filled to ensure good plant stand and good canopy. Fertilizer should be applied where necessary. Harvesting If the cassava rapid multiplication field is well maintained, stems should be ready for harvesting in 6-7 months after transplanting. Since the objective of rapid multiplication is to produce stems, the cassava plant should not be uprooted to harvest the roots. However, instead, cut from hardwood portion of the stems leaving at least cm above the ground after ensuring that the stems are physiologically mature and free of diseases and pests as in Fig. 21. Fig. 21: Cassava stem cut at height of 25 cm The practice of leaving stumps standing after cutting the stem is known as ratooning. Several shoots may sprout from each stump, but leave only three or four shoots. Cut another set of stems again 6 months later. Harvesting of stems could take up to three times. It is necessary to apply fertilizer after cutting the first stems so as to have vigorous growth of new stems and the stems could be ready for harvest after 6 months later. The recommendation is that as many as 3 sets of stems could be harvested from ratooned fields. After this, the roots 17

18 could be uprooted and the field replanted. This means, farmers could make a lot of income every 6 months from sale of planting materials. The number of sets that can be harvested is influenced by several factors such as variety, soil type and fertility, weed control and field maintenance. After harvest, the stems should be tied in bundles. The general practice is to tie in bundles of 50 stems at 1m long for sale. Stems should be handled carefully when harvesting, transporting and loading to avoid bruising as bruised buds may not develop into shoots. One hectare planted with improved variety can give an average of bundles of cassava stem at a time. In all, about 1000 bundles of cassava stems or more can be obtained from the same unit area within a farming year. Fig. 22: Cassava stems tied in bundles 18

19 UNIT 5: Storage and Distribution/Sales of Stems Cassava cuttings cannot be stored for a long time because stems dehydrate (lose water) and can be attacked by insects and diseases. Storage of cassava stems can be done up to 8 weeks using 3 methods. 1 The bundles of 50 cassava stems each of 1 m long can be stored in an upright position (bud facing up) in a well ventilated shed (Fig.23) or under a tree providing good shade (Fig 24). The base of the stems must be inserted in the soil and watered. Fig. 23: Stored stems under a well ventilated shed Fig. 24: Stems stored under tree shade 2 The tied bundles of cassava stem are inserted in the soil in a well shaded area standing in an upright position such that they lean on a strong support which has been tied horizontally between two trees (Fig. 25). The soil should be watered to keep the base of the stems moist. 19

20 Fig.25: Stems leaning on support tied horizontally between two trees 3 Stem bundles can be stored horizontally under a well developed tree shade as in Fig Fig. 26: Stems stored horizontally under a well developed tree shade Rules for storing cassava stems Avoid direct sunlight and hot or cold wind Ensure that buds face upwards when stored vertically Store only mature stems from healthy cassava plants Long stems store better than short one Distribution and sales Distribution of cassava stems requires special efforts especially when they are to be distributed to local farmers. Some farmers may be able to collect stems at sources of supply. However, many farmers lack transport or are not aware of the existence of superior varieties. For those to be distributed by government farms, they can be distributed through the following channels: Government or donor-assisted agricultural projects Strategically located multiplication centres 20

21 Private and mission agricultural projects School farming projects Agricultural meetings, training courses, farmers field days and agricultural shows Demonstration plots Multi-location and on-farm trials Farmer-to-farmer. For commercial production of cassava stems, total plot harvest is the usual practice among production entrepreneurs. The stems are loaded in big vehicles to the points of use in large scale production of cassava farms as shown in Figs. 27 and Fig. 28. Fig. 27: Loading of stems to be delivered Fig.28: Lorry load of cassava stems for sale 21

22 Bibliography Ajayi, M.T., Banmeke, T.O.A., Omoregbee, F.E. and Edeoghon, C.O. (2007) Extension Guide for Growing Cassava and Rapid Production of Quality Cassava Planting Materials. In Erhabor, P.O., Azaiki, S.S. and Ingawa, S.A. (Eds), Cassava the White Gold Initiative Publication Co., Benin City, pp Ekwe, K. C. Cassava Stem Multiplication Technology: A Viable Option for Industry Development? National Root Crops Research Institute (NRCRI) Umudike, Nigeria. International Institute of Tropical Agriculture (1990). Cassava in Tropical Africa. A reference Manual. IITA, Ibadan, Nigeria. 176 pp. Odedina, S.A. and Adebayo, K. (2012). Commercial production of cassava in the Humid Tropics. Livelihood Support and Development Centre, Abeokuta, Nigeria, 137 pp. Otoo, J.A, (1996). Rapid Multiplication of Cassava. IITA Research Guide 51. Seesahai, A. and Ousman, M. Cassava Production: A Farmer s Guide to Selecting High Quality Planting Material, Module

23 Revision Questions 1 Why is rapid multiplication of cassava stems important? 2 What is the definition of multiplication ratio? 3 What is the main principle of rapid multiplication of cassava stems? 4 What are mini-stem cuttings? 5 What are the three main types of mini-stem cuttings? 6 What are the main tools used in preparing mini-stem cuttings? 7 Why should the tools be sharp before using them? 8 What are the methods of sprouting mini-stem cuttings before planting in the field? 9 How should the mini-stem cuttings be planted in the nursery? 10 Why is it necessary to treat some mini-stem cuttings before planting? 11 What is the planting distance in the nursery? 12 How long should the mini-stem cuttings stay in the nursery before transplanting? 13 What are the advantages of sprouting mini-stem cuttings in the white polythene bags without soil? 14 How long does it take to take the mini-stem cuttings sprouted in the white transparent polythene bags to the field? 15 How long does it take to harvest stems in rapid multiplication field? 16 What is the name of the stump left after harvesting cassava stem? 17 Why is this stump left after harvesting? 18 How should cassava stems be placed during storage? 19 What are the methods of storing cassava stems? 20 Why should care be taken when transporting cassava stems? 21 How long should cassava stems be stored? 22 In what ways can cassava stems be distributed? 23

24 ABOUT IITA YOUTH AGRIPRENEURS (IYA) The IITA Youth Agripreneurs (IYA) is a group of 35 members made up of 16 males and 19 females from various disciplines such as History, Computer Science, Quantity Surveying, Statistics, Biochemistry, Mass Media, Economics, Soil Science, Agronomy, and Crop Breeding. The group began with reorientation to prompt a change in mindset about agriculture in the youth. Despite limited knowledge of agriculture and agribusiness at the commencement of the program, the youths were able to gather great understanding and knowledge of agripreneurship through training both on and off the field. IYA uses science-driven improvements in agriculture to make a distinctive contribution to solutions of the challenges faced in agriculture and agribusiness and also offer consultancy services on best bet agronomic practices of the following crops: Cassava stem multiplication, cassava root production, Maize and soybean seed production, plantain and banana sucker multiplication, vegetable production, fishery and livestock (production of fingerlings to table size) and also into the value addition of some of this crops. Entrepreneurship skill set is also not left out such as: ICT in agribusiness, marketing, record keeping, M&E, business development, etc. The goal of IYA is engaging youths in productive market-oriented agriculture, agribusiness and service provision. IYA directly engages youth to use linkages along the value chains from production to processing, marketing, and ultimately to industrial and domestic consumption. IYA s initial focus was production and distribution of quality seeds and has expanded to value addition leading to production of cassava bread, soymilk, and tidbit snacks, service delivery in capacity building and consultancies. The group also diversified into vegetable production, catfish farming and pig raising for low fat pork. Currently the IYA concept is expanded to more countries and new groups have been established in DR Congo, Kenya, Tanzania, Uganda and Zambia 24