Groundnut andother crops in many regions will be prone to environmental stresses

notobserved in today’s climate. For example, wetness episodes predicted in partsof the region may lead to significant increase in groundnut rosette and otherfoliar diseases like early leaf spots, late leaf spots, rust and post-harvestaflatoxin contamination. However, those parts of the region that willexperience increased episodes of heat and drought stress will have increased incidencesof pre-harvest aflatoxin contamination. Groundnut is particularly vulnerable tobrief episodes of high temperatures >32°C to 36°C when these coincide withthe time of flowering (see Table 1.3). Therefore, in the absence of strongadaptation strategies, climate change will exacerbate food insecurity. Millionsof people in countries that have food shortages will have to give uptraditional crops as seasons become increasingly unpredictable.

Thebottom line is to ensure the development of resilient ecosystems, resilientcrops, and resilient communities (William Dar 2010). Adaptation measures towater stresses during droughts and rainfall variability, for example, plantingof drought resistant groundnut varieties, promotion of early maturing varietiesfor drought escape, and high yield varieties. Adaptation measures for heatwaves include: heat resistant cultivars; crop management (shorter season orearly maturing crops, supply irrigation, and early warning and forecast systems(Adejuwon et al. 2006; ICRISAT 2009).

ICRISATdevelops farming systems resilient to shocks, buffering crucial resources likewater and nutrients and adapting new varieties to warmer temperatures and newpest patterns. The organisation has proven innovations in crop, soil and watermanagement that can help farmers better adapt to climate change. The ICRISATrepository of genes of dryland crops like sorghum, pearl millet, pigeon pea,chickpea and groundnut are well adapted to changes in climatic regimes (WilliamDar 2010).

Table 1.3: Optimum temperature for ground growth

Descriptionof the technology or innovation

Droughttolerance: ICRISAThas groundnut varieties that are adapted to high soil and airtemperatures. For instance, we have developed 14 short-duration and 15 mediumduration groundnut cultivars released in 11 Eastern and Southern Africancountries. All the short duration cultivars escape end of season drought intheir recommended zones of adaptation.

Diseaseresistance: Diseasescause major losses in groundnut in the region. The focus of the work has beento alleviate disease constraints to groundnut productivity, mainly groundnutrosette virus, early and late leaf spots and rust. Six short duration cultivarscarry rosette resistance while three of the medium maturity varieties alsocarry rosette resistance.

Aflatoxin management: Groundnut is synonymous with aflatoxin—ahighly carcinogenic substance produced by the fungus Aspergillus flavus. As aresult, strict quality control standards have been introduced in many marketsin the developed countries to safeguard the health of consumers. Climate has asignificant effect in the development of the aflatoxin problem. ICRISAT hasdeveloped strategies, as well as production and harvesting methods aimed toreduce or eliminate aflatoxin contamination during the pre- and post-harveststages.

Climate-ready groundnut varieties released in ECA. To date, 17 improved groundnut varietieshave been released in four ECA countries (see Table 1.4).

Scaling-upapproaches

The fouraforementioned countries account for approximately half of the 3.3 millionhectares of groundnuts grown in the ECA region, impacting on the livelihoods ofmore than 6 million individuals (assumes 5.2 individuals per household).Smallholder farmers grow the crop under low input conditions, and yields varyfrom 400 to 700 kg/ha. Lack of seed of improved varieties, poor agronomicpractices, diseases and pests are considered to be some of the major factorslimiting yield in the region. The potential for increasing farmers’ yieldsthrough crop improvement, particularly biotic and abiotic stress resistance,and thus total production in the region is very high if mitigation strategiesfor adaptation to climate change are considered. New high yielding improvedvarieties will be introduced to various communities in ECA using approaches asgeographic information systems (GIS), farmer participatory variety selection(FPVS), and farmer field schools.

Table 1.4: Groundnut line bred byICRISAT and released by NARS partners as new cultivars

Groundnutis an important food and cash crop in the Eastern and Central Africa (ECA)region. Democratic Republic of Congo, Tanzania, Sudan and Uganda are the majorgroundnut producing countries. ICRISAT has released high-yielding,early-maturing and drought tolerant varieties adapted to the arid and semi-aridareas of DR Congo, Ethiopia, Tanzania and Uganda.

17groundnut varieties matching or exceeding the drought and heat thresholdslisted above are available for wide-scale promotion and adaptation in Easternand Central Africa. Two have been released in DR Congo with farmers in PVStrials with potential for release in the next two to three years. Five havealready been released in Uganda (two design appropriate seed systems for theirdelivery to smallholder farmers. Eight have been released inTanzania (five in 2009), avail seed for their large-scale adoption, and two arereleased in Ethiopia.

Groundnutis essentially a woman’s crop in ECA. Enhancing the income generating potentialof the crop through its increased yields is therefore enhancing women’s statusin society. Most cultural practices in groundnuts are done by women. Womenspend significant amount of time harvesting and shelling. Village levelprocessing is also mainly by women. Women’s engagement in Participatory VarietySelection (PVS) and value chain development will be key to increase productivityand equitable benefits sharing (nutrition and incomes). The ICRISAT work onbunch type cultivars would make harvesting easier and introduction of handoperated mechanical shellers would release women’s time to do other importantwork for their families.

Name and address of the organisation:

International Crops Research Institutefor the Semi-Arid Tropics (ICRISAT);

P. O. Box 1096,

Lilongwe, Malawi.

Tel: +265-1707057 /067;

Fax: +265-1707298,

Mobile: +265-888203858

Country: Malawi

Name and address of presenter:

Dr Emmanuel S Monyo;

Principal Scientist (Breeding), and Dr  Sam Njoroge  (Associate  Scientist);

P. O. Box 1096;

Lilongwe, Malawi.

Telephone: +265 1707057/067

Fax: +265 1707298

Mobile: +265 888 203858

Email: e.monyo@cgiar.org

Country: Malawi

Nameand address of key partners:

Dr Omari Mponda;

Naliendele Research Institute;

P. O. Box 509;

Mtwara, Tanzania.

Tel: +255-232333836

Fax: +255-232333922

Mobile:+255-784471813

Email: mpondaomari@hotmail.com

Country: Tanzania

Mr Kalule Okello David;

National Semi-Arid Resources and ResearchInstitute (NaSSARRI);

P. O. Box Soroti, Uganda;

Email: kod143@gmail.com;

Tel: +256 712 858768

Mobile: +256 753 858768

Country: Uganda

Dr Idumbo Kasele;

c/o INERA, 13 Avenue de Cliniques,Kinshasa;

Gombé, Democratic Republic of Congo;

Tel: +243 817888810

Mobile: +243 814083823

Email: idumbo2@yahoo.com

Country: Democratic Republic of Congo

ICRISAThas employed several strategies to promote wide-scale adoption of groundnutsvarieties released in the eastern and southern Africa region. These include:Improvement of the adaptive capacity of smallholder farmers from diverse partsof the region to sustainable use of technologies that the targeted populationdepend upon and do so under changing biophysical and socio-economic conditions.The strategies are discussed in the following sections.

1.    Geographicinformation systems: Thisapproach uses climate characteristics of the crop/ variety during the growingseason, based on the notion that areas of suitability are those with the sameclimatic characteristics. It uses these characteristics of the sites where thetechnology was tested and released, and extrapolates to identify larger areasof potential adaptation in the country for which the technology is released.This is further extrapolated to similar agro-ecological zones of the regiontaking the understanding that zones of adaptation do not follow countryboundaries. This approach facilitates matching the requirements of the crop andthe characteristics of the environment for successful transfer of new varietiesto farmers’ fields across the ECA region.

2.    Farmerfield schools: Farmerfield schools is a participatory extension approach based on innovativelearning, which employs non-formal adult learning through experimenting withnew technologies. Coherent farmer groups are established with the aim offacilitating research and extension of new improved technologies, establish,articulate farmer needs, and graduate farmers from dependence on externalsupport. Ultimately farmers evaluate and adapt new technologies to their localconditions.

3.    Farmerparticipatory variety selection through the mother-baby trials approach: This technique increases farmerparticipation in technology evaluation employing a trial linked design thatprovides researchers with tools to quality feedback from farmers. It is a goodcommunication and learning tool and generates swift results because spontaneousadoption begins during experimentation. The methodology helps identify the mostsuitable technologies and disseminating them quickly.

Researchable challenges, opportunities and approaches toaddress groundnut production constraints under a changing climate.

ICRISAT has had 28 years of physical presence in Easternand Southern Africa, having established regional offices in Zimbabwe a hasoffices in Kenya, Malawi, Mozambique an in the region provides for closerinteraction with national agricultural research systems (NARS) for technologydevelopment and dissemination. Excellent working relationships have beenestablished with the two sub-regional organisations (SROs), SADC/FANR inSouthern Africa, and ASARECA in Eastern and Central Africa. Malawi provides anatural screening environment for key biotic and abiotic constraints. Thefollowing are some of the challenges, opportunities and strategies that canaddress each of the major constraints in a changing climate.

Groundnutrosette disease

The groundnut rosette disease is endemic to groundnutgrowing countries of sub- Saharan Africa and its off-shore islands such asMadagascar. Epidemics of groundnut rosette disease in African countries oftensignificantly reduce groundnut production and cripple the rural economy. Thedisease epidemic has totally destroyed the crops in several countries insub-Saharan Africa on several occasions. In 1975 an epidemic in northernNigeria destroyed approximately 0.7 million ha of groundnut, estimated at thecost of US$250 million (Yayock et al. 1976). In 1980s it was established thatgroundnut rosette disease had a complex etiology involving three agents (Murantet.al 1988): 1) Groundnut rosette assistor luteovirus (GRAV); 2) Groundnutrosette umbravirus (GRV); and 3) Satellite RNA of GRV (Sat RNA). Resistance torosette was first discovered in groundnut landraces originating from BurkinaFaso and Cote d’Ivoire as early as 1954. Since then more sources of resistancehave been identified in germplasm, but none of these lines have resistance toGRAV, which is one of the components of the disease cycle. The resistanceidentified from West Africa is governed by two independent recessive genes, andhas formed the basis for rosette resistance breeding programmes throughoutAfrica. Currently, several resistant varieties in ECA: ICG 12991, ICGV-SM90704, ICGV-SM 99566 and ICGV-SM 93535 (Uganda), ICGVSM 99555, ICGV-SM 99557,ICGV-SM 01711, and ICGV-SM 01721 (Tanzania) have been released. With harmonisedseed regulations in the SADC region, these varieties can also be adapted intosimilar agro-ecologies in DR Congo. Others are currently in advanced testingand the programme has segregating populations from F2 to F6 generations withthe objective of developing improved GRD-resistant breeding lines, and tocombine GRD and vector resistance.

Recommendation for addressing thegroundnut rosette disease challenge

Researchpriorities for rosette should therefore centre around characterisation of thesources of resistance and knowledge of the alternative hosts includingintegrated pest management (IPM) of the aphid vector. Though several sources ofresistance have been identified in both wild and cultivated groundnuts, thesesources have not been characterised and therefore very little is known aboutthe diversity of the observed resistance. Once this is known then incorporationinto adapted high-yielding varieties will be the next step while additionalefforts are directed at identifying more sources of resistance and thealternative hosts. Field screening trials in Malawi have clearly separatedgenotypes resistant to one of the virus components in the disease complex,while others appear to be resistant to the aphid vector (ICG 12991 forexample). This finding provides opportunity for development of genetic markersavailing a simpler screening methodology to identify aphid and virus resistancein lines thereby accelerating breeding progress. It is important to develop geneticmarkers for the two independent recessive genes that govern resistance towardsgroundnut rosette virus as well as markers for the single recessive vectorresistant gene.

GRAV isthe main component involved in aphid transmission. It is not certain how onlyGRAV affects the plant system and productivity. Therefore, GRAV resistance willprovide additional defence and will be particularly helpful in situations wherevery high aphid infestation results in late infection in some branches inresistant genotypes. As seasons get shorter and drought episodes increase, thiswill likely favour mass multiplication of the aphid vector resulting in higherinfestation and even breaking down of resistance. Identification of combinedresistance to GRAV, GRV and its sat RNA is considered vital to broadening thegenetic base of rosette resistance in groundnut.

Leafdiseases

Earlyleaf spot (ELS) disease, caused by the fungus Cercospora arachidis, and late leaf spot (LLS) disease caused byfungus Cercosporidium personatum, arethe major destructive disease of groundnuts worldwide (Smith et al. 1992).Problems related to leaf spot diseases cause nearly complete defoliation andyield losses of up to 50% or more. The leaf spot disease epidemics are affectedby weather patterns such as hot and wet conditions (Shew et al. 1988).

Recommendationfor addressing foliar leaf diseases

Breedingfor resistance is one of the best means of reducing crop yield losses and it isa strategy particularly well suited to help smallholder farmers, who generallylack financial resources, to use chemical control methods. Screening andbreeding of acceptable varieties with resistance to early leaf spot has beenextensively performed in Malawi. Breeding populations ranging from F2 to F7generations are available; some of which carry multiple resistances (ELSrosette combined). Currently we have improved early-maturing ELS-resistantvarieties, like ICGV-SM 95713, 95714, 95740 and 9574 that have consistentlyoutperformed JL 24 in yield. In Malawi, the kernel yield of these ELS-resistantvarieties increased by 23%, to 43% compared to JL 24 across 15 locations.Similarly in Mozambique yields of the ELS-resistant varieties increased byabout 50% compared to the local variety Natal Common. However, ELS resistanceis usually associated with poor grain qualities. The programme is thereforefocusing on the development of new ELS-resistant varieties combining bothagronomic and quality superiority over the known acceptable controls. Based onthe results obtained on components of resistance to early leaf spot (incubationperiod, infection frequency, lesion diameter, and defoliation) by the ESAprogramme, suitable parents have been chosen to generate different filialgenerations for inheritance study and transfer of resistance. Knowledge of thecomponents of resistance inherent in elite varieties is essential in matchingcultivars to their probable zones of adaptation.

Aflatoxinand market quality

Confectionarynuts are eaten or consumed directly. The greatest challenge to the growth ofthis market worldwide is aflatoxin contamination. Research efforts to reduceaflatoxin contamination in groundnuts should therefore be prioritised. Thevalue of a resistant source depends upon the level and stability of itsresistance. Resistance to pod infection has been reported to be highly variableand of a low level. In vitro seed colonisation by A. flavus (IVSCAF) is notabsolute and only a few lines (J 11, PI 337394 F, and PI 337409) have shownstable resistance. Finally, resistance levels to aflatoxin production in theknown sources is relatively low.

Recommendationto address the aflatoxin contamination and market quality challenge Geneticresistance though very important should be looked at as a component in theintegrated management of the aflatoxin problem. There are three types ofresistance to aflatoxin- producing fungi: resistance to pod infection (podwall), resistance to seed invasion and colonisation (seed coat), and resistanceto aflatoxin production (cotyledons). There are already known sources ofresistances to all the types reported above. Facilities for screening againstseed invasion and colonisation are available at the Chitedze Research Station.Pod strength and resistance to cracking as well as colonisation by the fungican be significantly affected by episodes of droughts and wetness, depending onwhat stages of the crop’s development these occurs. The confectionary groundnutmarket seems to be governed by consumers preference for taste, grain colour,size, shelf life of marketed products and industrial specifications forparticular size and shape of necessity this demands that efforts be directedtowards breeding and selection for oil content and quality, particularly, lowoil content to reduce problems of rancidity, and high oleic / linoleic ratios,which favour long shelf life.

Successin these areas will require strong partnerships between the internationalagricultural research centres (IARCs), SROs and national research and extensionservices with a range of other partners including NGOs, farmers’ organisations,the private sector, universities, policy makers, and donor agencies.

Drought

Thelargest area under groundnuts production in the ECA region lies in the arid andsemi-arid tropics, characterised by short and erratic rainfall season. Shortduration varieties would be more suitable for these areas but the region stilllacks enough suitable varieties. There are several reasons why short durationvarieties are not popular among farmers in the vast ECA region. These include:

1)     Lackof an adequate number of released varieties matching the available length ofgrowing period.

2)     Sourcesof foliar disease resistance in the early maturity germplasm are very rarewhereas in the region, in general, both E

3)     Lackof appropriate screening facilities for drought research—particularly end ofseason drought—which is most serious in ECA.

4)      Problem of sprouting due to lack ofdormancy in the few available short duration accessions.

The confounding constraint of lack of sources of resistanceto foliar diseases in the early germplasm is now partly addressed with theavailability of ELS and Rosette resistance sources.

Recommendationsto address the drought challenge

The ICRISAT strategy to address thevariety needs of the region will therefore be to target varieties that willreach physiological maturity within 90–100 days for the large part of ECA. Veryshort season germplasm accessions from Bolivia have been identified which reachphysiological maturity within 70 days in Bolivia. It is important to introducesome of these accessions to the region, study their maturity patterns, andidentify some of these that can be useful for the region farmers’ needs. In ourquest to address the drought constraint in groundnut, there is need to developgenotypes that can use the limited available water efficiently in order toenhance groundnut productivity in ECA. In physiological model, pod yield isassociated with transpiration (T), transpiration efficiency (TE) and harvestindex (HI) all of which have a significant bearing on climate. However, some ofthese traits are not easy to measure in large populations under fieldconditions. A search for easily measurable surrogate traits for TE led tospecific leaf area (SLA) and then, on to SPAD Chlorophyll Meter readings, whichcan be used for rapid assessment of SLA and specific leaf nitrogen (also asurrogate measure of TE in groundnut). Water-use efficiency (WUE) is correlatedwith specific leaf area (SLA), which is an easily measurable trait. To improveSLA and in turn WUE and HI, understanding the genetic systems that controlexpression of these traits is essential to choosing an efficient breedingprocedure. There is therefore need to study the mode of inheritance of thesetraits. For ESA, in the absence of facilities like rainout shelters and lineirrigation system in many NARS programmes ICRISAT rely on screening undernatural dryland conditions. The ICRISAT location, Ngabu, in Malawi, provides anexcellent natural environment because the season is short (90 days) hence acombination of planting time will ensure good end-of-season stress for thecrop. Finally, genetic resistance to dormancy is available. This willnecessitate combining drought resistance/tolerance or escape with dormancy, soas to avoid the problems of seed sprouting in the soil in case of fewaccidental showers at the end of the season.

Adejuwon JO. 2006. Food security,climate variability and climate change in Sub Saharan West Africa. Assessmentsof Impacts and Adaptations to Climate Change (AIACC), Project No. AF 23 A FinalReport, AIACC Project Office, Washington, DC, USA.

Challinor AJ. 2009. Assessing cropgenetic resources for adaptation using ensemble climate and crop yieldforecasting. IOP Conference Series. Earth and Environmental Science 6: 372011.Available at http://iopscience.iop.org/1755-1315/6/37/372011.

Calleja D. 2010. ICRISAT developsmeasures toward climate change adaptation. Available athttp://balita.ph/2010/05/21/icrisat-develops-measures-toward-climatechange-adaptation/.

Dreyer J, Duncan WG and McCloud DE.1981. Fruit temperature, growth rates, and yield of peanuts. Crop Science21:686–688.

Fortanier EJ. 1957. Control of floweringin Arachis hypogaea L. Mededelingenvan de Landbouwhogeschool, Wageningen 57:1–116.

Frank AH. 2009. Adapting to climatechange: ICRISAT Policy Recommendations for the Developing World. Available athttp://www.americanchronicle.com/articles/ view/118486.

Kakani VG, Prasad PVV, Craufurd PQ andWheeler T R. 2002. Response of in vitro pollen germination and pollen tubegrowth of groundnut (Arachis hypogaea L.) genotypes to temperature. Plant, Cell& Environment 25(12):1651–1661.

Mohamed HA, Clark JA and Ong CK. 1988.Genotypic differences in the temperature responses of tropical crops. I. Germinationcharacteristics of groundnut (Arachishypogaea L.) and pearl-millet. (Pennisetumtyphoides S & L.). Journal of Experimental Botany 39:1121—1128

Murant AF, Rajeswari R, Robinson DJ andRaschke JH. 1988. A satellite RNA of groundnut rosette virus that is largelyresponsible for symptoms of groundnut rosette virus disease: Current status andfuture research needs. Annals of Applied Biology 132:525–548.

Nambiar PTC and Dart PJ. 1983. Factorsinfluencing nitrogenase activity (acetylene reduction) by root nodules ofgroundnut, Arachis hypogaea L. Peanut Science 10:26– 29. 35

Prasad PVV, Craufurd PQ and SummerfieldRJ. 1999. Fruit number in relation to pollen production and viability ingroundnut exposed to short episodes of heat stress. Annals of Botany84:381–386.

Shew BB, Beute MK, Wynne JC. 1988.Effects of temperature and relative humidity on expression of resistance toCercosporidium personatum in peanut. Phytopathology 78:493–498.

William Dar. 2010. Technical, policyoptions for drylands. Available at www.ittefaq.com/issues/2010/05/24/news0786.htm.

Yayock JY, Rossel HW and Harkness C.1976. A review of the 1975 groundnut rosette epidemic in Nigeria. SamaruConference Paper 9. Institute of Agricultural Research, Ahmadu BelloUniversity, Zaria, Nigeria.