Root and tubers crops

Brief

Root and tuber crop programme conducts research on tuber crops (mainly cassava) and root crops (mainly Sweetpotato). Cassava (Manihot esculenta Crantz), is the world’s most widely grown starch storage root crop and has high potential to alleviate food shortages and energy deficiencies in Kenya. Sweetpotato (Ipomoea batutus (l) Lam) is one of the most important staple food crops consumed in Kenya and plays a significant role not only as a food security crop but also as a potential commercial crop. The activities of the programme include collection, evaluation and maintenance of germplasm and breeding varieties that address the production and utilisation constraints for both sweetpotato and cassava.

Constraints

Some of its production constraints of cassava (Manihot esculenta Crantz) include lack of high yielding varieties, susceptibility to cassava brown streak disease (CBSD), and cassava mosaic disease (CMD), as well as low dry mass content (DMC), high cyanide content and unavailability of clean and timely planting materials. On the other hand, sweetpotato is one of the most important staple food crops consumed in Kenya. Its production constraints include bioticconstraints such as pests (sweetpotato weevil, weeds, nematodes) and diseases (virus, alternaria blight, bacterial wilt, fusarium wilt), abiotic contraints (water stress, soil nutrition deficiencies and floods) and socioeconomic constraints mainly lack of appropriate varieties, clean timely seeds, poor processing and marketing.

Some cassava pests and diseases

 

Cassava Mosaic Disease (CMD)

Cassava Brown Streak Mosaic Virus (CBS)

3837

Whiteflies on cassava NAARI

Cassava Bacterial Blight (CBB)

Mealy bags and leaf aphids (vectors for CMD /CBS

Some Sweetpotato pests and diseases and their control

 

 

(a)

 

(b)

 

Control

  

·       Breeding resistance sweetpotato varieties.

·       Use of clean planting materials   

 

  

Root nematodes (a)Root necrosis and (b) distortion and Internal necrosis

  

 

(a)

 

 

(b)

 

Sweetpotato weevil (SPW) can cause upto 90% yield loss. It is controlled by:

·       Dipping planting materials into the systematic pesticide solution

·       Spraying the vines in the field

·       Use of biological control agents

·       Use of resistant varieties

·       Use of deep rooting cultivars

·       Use of clean planting materials,

·       Timely planting and harvesting

·       Flooding with water,

·       Earthing the bases,

·       Supplementary irrigation in case of drought

·       mulching

·       Removal of root residues,

·       Removing infected roots during peace meal harvesting

·       Removing volunteer and wild relative weeds

·       Practicing crop rotation

·       Burying residues below 15 cm

·       Intercropping sweetpotato with other crops e.g coriander

·       Establishing guard rows round the Sweetpotato crop to prevent migrating weevils.

  

(a)SPW larvae and (b) SPW adult

  

Image result for sweetpotato weevil photos

 

  

SPW damages

  

 

(b)

(a)

Image result for Sweetpotato virus disease photosFingerprinting_100 Best bet 90 DAP 317

 

 

SPVD is a combination of SPFMV and SPCSV which may result to yield losses upto 90%. It is controlled through

·       Spraying against aphids and white flies

·       Avoiding recycling planting materials

·       Using clean planting material

·       Crop rotation

·       Removal of volunteer plants and crop residues

·       Timely planting and prompt harvesting

·       Removal of alternate, wild hosts

 

  

(a)SPVD infected and (b) uninfected sweetpotato

  

 

Objectives

 

Variety development for cassava focuses on breeding for

·       Disease resistance mainly includes Cassava mosaic disease (CMD) caused by a Begomovirus, Cassava brown streak virus disease (CBSD) caused by Ipomovirus, and Bacterial blight caused by Xanthomonas campestris pv. Manihotis,

·       Pest resistance which includemites, mealy bugs, thrips  and white flies,

·       High yield, high dry matter, low cyanide content and high starch content.

·       Processing and value addition, mechanization and marketing quality traits.

 

Variety development for sweetpotato comprises breeding for:

·       Disease resistance such as sweet potato virus disease (SPVD), bacterial wilt, alternaria blight and fusarium wilt,

·       Pest resistance such as sweetpotato weevil and root nematodes,

·       Processing quality, high beta caroteine and Iron and Zinc (biofortification), and value addition  for products such as bread, biscuits and cake, mechanization and market quality,

·       Dual purpose varieties (both for human food and animal feed)

·       Drought tolerance, high yield, soil factors adaptation.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Technologies (varieties)

 

IMG_20170711_102046

 

 

·       Variety: 990005 (Katuni)

·       Yield: 45 t/ha

·       Resistant to cassava brown streak and mosaic diseases

·       Tolerant to cassava mites

·       Highly tolerant to drought

·       Variety: Kabode (Naspot 10),

·       Maturity: 4-5 months

·       Yield: 16-20t/ha

·       Moderate resistance to sweetpoato virus disease,

·       drymatter: 30.5%,

·       High vitamin A content.

 

Sweetpotato varieties

 

Variety

Region for optimal production

Duration to Maturity

Yield

 

Special attributes

Suitable areas for planting

 Kenspot-4

1700-2300

 6-7

72 bags/acre

OFSP, High dry matter (30.4); high beta carotene (3.08); and average acceptability (3.2)

Western Kenya, Nyanza and Eastern and central  Kenya

Kenspot-5

1700-2100

 6-7

60bags/acre

OFSP, High beta carotene (4.7); moderate dry matter (25.9) and moderate acceptability (3.0)

Western Kenya, Nyanza and Eastern and central  Kenya

Vitaa

1200-1800

4-5

60 bags/acre

OFSP, Purple skin, 25.8% dry matter

Western Kenya, Nyanza, Bomet,  Trans nzoia

Kabode

1200-1800

4-5

64 bags/acre

OFSP, Purple skin, deep orange fleshed, 27.5%dry matter

Western Kenya, Nyanza and Eastern and central  Kenya

NASPOT-1 (Double-Double)

 

3-4 months

63 bags/acre

Dual purpose variety-roots for human consumption and vines for livestock. Farmers are able to harvest the vines at 75 days and both roots and vines at 150 days. Moderately resistance to SPVD

Western Kenya, Nyanza and Eastern and central  Kenya

Cuny

 

4-5 months

64 bags/acre

High dry matter content and yellow fleshed, has average level of sugars. Tolerant to altanaria. High consumer acceptance rating

Western Kenya, Nyanza and Eastern and central  Kenya

Namnyekera

 

4-5 months

70 bags/acre

Yellow-fleshed with high consumer acceptance rating, moderately resistance to weevil attack due to its deep rooting characteristics, resistance to alternaria

Western Kenya, Nyanza and Eastern and central  Kenya

Kemb 10

1000-1800 m ASL

3-4 months

60 bags/acre

Yellow fleshed roots, Sweet taste when Boiled or roasted

Western Kenya, Nyanza and Eastern and central  Kenya

SPK 013

1200-1900 m ASL

4-5 months

72 bags/acre

White fleshed, very high dry matter, very good taste, tolerant to virus diseases. Dual purpose, 40 t/ha of vines

Western Kenya, Nyanza and Eastern and central  Kenya

Mugande

1000-1700 m ASL

4-5 months

80 bags/acre

Red skinned and white-fleshed, High DM, good taste,  good root shape (dual purposew)

All over the country

SPK 004 (Kakamega 4)

1000-1900

3-4 months

60 bags/acre

Pink skin, orange-fleshed, Contains beta carotene, Tolerant to viruses and drought, high consumer acceptability. Processed into flour for making various products. Widely adopted.

Western Kenya, Nyanza and Eastern and central  Kenya

K117

1200 - 1600

5 - 6

60 bags/acre

Orange fleshed, high DM and dual purpose Boiling, roasting processed into flour for making various products.

Western Kenya, Nyanza and Eastern and central  Kenya

Mwavuli

1200 - 1800

4 - 5

88 bags/acre

High root yield, high DM, high vine production, dual purpose. Boiling, roasting

Western Kenya, Nyanza and Eastern and central  Kenya

KSP 047

Makueni, Taita taveta

3-4 months

25t/ha

Dry matter is 24%, light orange fleshed and high beta caroteine content

Suitable for warm semi arid areas,

800-1000 m.a.s.l.

KSP 072

Machakos, Muranga, Kiambu, Kirinyaga, Embu, and Meru counties

3-4 months

22t/ha

Dry matter 25%, Light orange fleshed, high beta caroteine content

Suitable in warm, semi arid areas, 200-2000 m.a.sl

KSP 0084

 

3-4 months

22t/ha

Dry matter 25%, orange fleshed and high beta carotene content, dual purpose

Warm semi-arid areas, 600-1800masl, Coffee zones and lower areas.

KSP0154

Coffee zones (Kiambu, Muranga, Nyeri, Machakos, Embu

3-4 months,

23 t/ha

Light orange fleshed, and average beta caroteine content

Good for coffee zones, Kiambu, Muranga, Nyeri, Machakos, and Embu, 800-1800m.a.s.l.

 

 

Cassava varieties

 

Variety

Attribute

Katsuhanzala

(990132)

Matures in 8-10 Month, its root flesh colour is cream with dry matter of 29%; used for home consumption or industrial purposes; Wide adaptation from the coffee zone to the coastal region; yield 36.7t/ha. Resistance to stress, Tolerant to cassava brown streak disease, High yielding, high dry matter, low in cyanogenic potential (HCN) and early maturing

 

Kasukari

(990127)

Matures in 8-10 Month, its root flesh colour is cream with dry matter of 24%; used for home consumption or industrial purposes;  Wide adaptation from the coffee zone to the coastal region; yield 34.4 t/ha. Resistance to stress, tolerant to cassava brown streak disease, High yielding, high dry matter, low in cyanogenic potential (HCN) and early maturing

Katune

(990005)

Matures in 8-10 Month, its root flesh colour is cream with dry matter of 30%; used for home consumption or industrial purposes; wide adaptation from the coffee zone to the coastal region; yield 36.7t/ha. Resistance to stress, Tolerant to cassava brown streak disease, High yielding, high dry matter, low in cyanogenic potential (HCN) and early maturing.

KME-2

Matures in 8-10 Month, its root flesh colour is cream with dry matter of 30%; used for home consumption or industrial purposes; wide adaptation from the coffee zone to the coastal region; yield 45t/ha. Resistant to cassava mosaic disease and moisture stress, Tolerant to cassava mites, High yielding, high dry matter, low in cyanogenic potential (HCN) and early maturing.It is sweet, less fibrous.Production altitude ranges 25-1500 masl.

KME-3

Matures in 8-10 months, its root flesh colour is cream with dry matter of 29%; used for home consumption or industrial purposes; wide adaptation from the coffee zone to the coastal region; yield 40t/ha. Resistant to cassava mosaic disease; tolerant to cassava mites; Highly tolerant to drought; Sweet in upper Makueni, Lower Machakos. Muranga, Kiambu, Kirinyaga, Embu and Meru counties and Does well in all semi arid areas, low in cyanogenic potential (HCN) and early maturing.It is sweet, less fibrous.Production altitude ranges 200-2000 masl.

 

KME-4

Matures in 8-10 Month, its root flesh colour is cream with dry matter of 30%; used for home consumption or industrial purposes; wide adaptation from the coffee zone to the coastal region; yield 438t/ha. It is resistant to cassava mosaic disease; tolerant to cassava mites; highly tolerant to drought; Sweet in Taita Taveta county and does well in semi arid areas. Low in cyanogenic potential (HCN) and early maturing.It is sweet, less fibrous.Production altitude ranges 200-2000 masl.

Muchericheri

Matures in 16 to 18 months, yield 20-28 t/ha, sweet, has deep red leaf stalks, tolerant to cassava mosaic and scales, low cyanide, production altitude 25-1750 masl.

EX-Ndovu

Green stem turning purple green, yield 40t/ha, tolerant to mosaic and scales

 

 

 

Publications

1.     Kivuva, B. M., Francis John Musembi, Peter Onyango Owenga and Edward Mare Muya. January 2016. Sweetpotato Handbook. ISBN. 978-9966-30-034-8.

2.     B. B. Mdenye, J. M. Kinama, F. M., Olubayo, B. M. Kivuva, J. W. Muthomi. 2016. Effect of Storage Methods on Carbohydrate and Moisture of Cassava Planting Materials. Journal of Agricultural Science; Vol. 8, No. 12; 2016 ISSN 1916-9752 E-ISSN 1916-9760. Published by Canadian Center of Science and Education. doi:10.5539/jas.v8n12p100 URL: http://dx.doi.org/10.5539/jas.v8n12p100.

3.     Kivuva, B. M., Stephen M. Githiri, George C. Yencho & Julia Sibiya. 2015. Screening sweetpotato genotypes for tolerance to drought stress. Field Crops Research; Final version published online: 23-NOV-2014, Full bibliographic details: Field Crops Research (2015), pp. 11-22. DOI information: 10.1016/j.fcr.2014.10.018. http://authors.elsevier.com/a/1Q4eQ1M2tUyyrs

4.     Kivuva, B. M., Stephen M. Githiri, George C. Yencho & Julia Sibiya 2014. Combining ability and heterosis for yield and drought tolerance traits under managed drought stress in sweetpotato. Euphytica http://www.springer.com/home?SGWID=0-0-1003-0-0&aqId=2714195&download=1&checkval=cfd5c257532709a5fe658bbd6f401a0d

5.     Kivuva, B. M., Francis J. Musembi, Stephen M. Githiri, Craig G. Yencho, Julia Sibiya, 2014. Assessment of production constraints and farmers’ preferences for sweetpotato genotypes. Journal of Plant Breeding and Genetics, 2(01): 15-29. http://escijournals.net/index.php/JPBG/article/view/524/389

6.     Kivuva, B. M., Stephen M. Githiri, George C. Yencho & Julia Sibiya. 2014. Genotype x environment interaction for storage root yield in sweetpotato under managed drought stress conditions. Journal of Agricultural Science.  6:41-56. http://www.ccsenet.org/journal/index.php/jas/article/view/33268/22188

7.     Kivuva, B. M., Mburu M. W.K., Maina, J.M., Murdoch, A.J. 2014. The effects of planting density and weeding regime on maize light and water use. Journal of Agricultural Science, accepted for publication in august 2014.

8.     Kivuva, B. M., Maina, J. M., Mburu, W.M.K., Murdock, A.J., Njuguna J.M., Mwangi, D.M. 2012: The effects of planting density and weeding regimes on maize as a food and fodder crop. East Africa Agriculture and Forestry Journal. 78 (2), 63-74.

9.     Kivuva, B. M., Stephen M. Githiri, George C. Yencho & Julia Sibiya, 2014.  Breeding Sweetpotato (Ipomoea batatas [L.] Lam.) for Drought Tolerance in Kenya.  A thesis submitted in partial fulfilment of the requirements of the degree of Doctor of Philosophy (PhD) in Plant Breeding African Centre for Crop Improvement (ACCI) School of Agricultural, Earth and Environmental Sciences University of KwaZulu-Natal Pietermaritzburg Republic of South Africa November 2013.  http://www.acci.org.za/resources/documents/page_docs/docs/benjamin-kivuva.pdf

10.Joseph Kamau, Rob Melis, Mark Laing, Paul Shanahan,  Jon Derera, Kahiu Ngugi and Yusuf Migwa, 2016. Farmers’ Perceptions of Production Constraints and Preferences  in Cassava Grown in Semi-Arid Areas of Kenya  . International Journal of Current Microbiology and Applied Sciences . ISSN: 2319-7706Volume 5 Number 3(2016) pp. 844-859 : http://dx.doi.org/10.20546/ijcmas.2016.503.098

11.  Kivuva, B.M., S.M. Githiri, G. C. Yencho, J. Sibiya, 2013. Mitigating negative drought effects on sweetpotato productivity through tolerant cultivars in Kenya, APA 2013 abstract:http://sweetpotatoknowledge.org/germplasm/breeding/2013-sweetpotato-breeders-meeting/day-3/pres01-kivuva-mitigating-negative-drought-effects-20130425.pdf.

 

 

Projects

Tittle

Donor

Start

End

Achievements

Ongoing

 

 

 

 

Dissemination of Sweetpotato Technologies

KOPIA Sweetpotato

July 2015

June 2018

Technologies on fertilizer use, maintaining clean seed for Sweetpotato and planting density being disseminated

 

Breeding dual purpose Sweetpotato varieties

 

CIP- SASHA

July 2015

 

June 2018

Already evaluated NPT first season

Completed

 

 

 

 

Enhancing sweetpotato production in Kenya through development and promotion of appropriate technologies project, funded by South Korean government. 

 

KOPIA Sweetpotato

July 2012

 

June 2015

Technologies on fertilizer use, maintaining clean seed for Sweetpotato and planting density validated

Sweetpotato hand book published

Conventional improvement of farmer prefered early bulking cassava varieties for cassava brown streak resistance

AGRA CASSAVA 2010 PASS 052 NCE

 

July 2015

June 2016

Three varieties released

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