For further information contact: Luis Horacio Franco

More information on these Research Themes in our Annual Report:
Superior and diverse grasses and legumes (376 Kb)

• Evaluating Legumes as Cover Crops in Plantations in the Colombian Eastern Plains
• Genetic Diversity and Core Collection Approaches in the Multipurpose Shrub Legume Cratylia argentea
• Genetic Diversity and Core Collection Approaches in the Multipurpose Shrub Legume Flemingia macrophylla
• Evaluating a Core Collection of Lablab purpureus for Multipurpose Use
• Agronomic Characterization of a Collection of Rhynchosia schomburgkii
• Evaluating an IITA Collection of Vigna unguiculata Accessions for Multipurpose Use
• Genotypic Variation in Paspalum for Adaptation to Poorly Drained Soils
• Genotypic Variation in a Core Collection of Calliandra calothyrsus for Dry-season Tolerance
• On-farm Evaluation, with Farmer Participation, of Forages for Multipurpose Use in Central America

Evaluating Legumes as Cover Crops in Plantations in the Colombian Eastern Plains

The plantation industry of the Colombian Eastern Plains needs to find sustainable ways to reduce weed infestation, maintain and improve soil fertility, control erosion, and increase microfaunal biomass. Currently, the trend is to promote plantation systems in the Eastern Plains. For example, for rubber, promotion is targeted at small to medium-scale farmers who want to diversify their farming operations. For oil palm, plots of up to 5 ha are rented out to landless farmers who manage the palms for the industry. Both activities attempt to benefit resource-poor farmers.

In 1999, a range of legumes accessions of Arachis pintoi, Desmodium heterocarpon ssp. ovalifolium, and Pueraria phaseoloides were sown under shade and no-shades conditions in the Department of Meta, Colombia. Based on year 2000 results, this work was amplified by studying different establishment procedures for the most promising accession, D. heterocarpon ssp. ovalifolium CIAT 13651, and compared with the standard management of the standard cover crop, P. phaseoloides.

About 80 m² plots of legumes were established under commercial young and old rubber and oil-palm plantations in the Altillanura and Piedemonte areas of the Eastern Plains. A randomized complete block design with three replicates was used. Agronomic parameters and insect pest incidence were measured. The following treatments were sown: A. pintoi: CIAT 17434, 18744, 18748, 22159, and 22160 (seed rate at 10 kg/ha); D. heterocarpon ssp. ovalifolium CIAT 350, 13105, 13110, 13651, and 23762 (0.5 kg/ha); P. phaseoloides CIAT 8042 and 9900 (3 kg/ha); and a mixture of A. pintoi CIAT 18744 and D. ovalifolium CIAT 13651.

During the first 4 months of establishment, the legume covers grew slowly, except for P. phaseoloides. However, 6 months after planting, all the legumes were well established, with the best covers being achieved under young oil-palm plantations and with legume Desmodium. Because of shading, legume cover was less in rubber plantations, particularly when planted under old trees or directly beneath trees. Cover did not establish well under existing oil palms.

Although it establishes extremely slowly, we suggest that the advantages of Desmodium as a cover crop increases over time, because, once established, it is persistent and productive. Desmodium could therefore be an excellent cover until plantations are fully established and weeds suppressed by shade. We are awaiting results on how the legume covers being evaluated develop under older rubber trees and how established legumes persist under heavier shading conditions.

Genetic Diversity and Core Collection Approaches in the Multipurpose Shrub Legume Cratylia Argentea

Cratylia argentea has been identified, and developed and propagated by CIAT, as a key forage species for dry-season feeding. Some accessions are currently being adopted by Central American and Colombian farmers.

CIAT has received a range of new germplasm of Cratylia argentea from the Centro Nacional de Pesquisa de Recursos Genéticos e Biotecnologia (CENARGEN of the Empresa Brasileira de Pesquisa Agropecuária, Embrapa) in Brazil. These accessions were combined with those available in the CIAT collection. In all, 41 accessions of Cratylia argentea were planted in a randomized complete block design, with three replicates, on acid soil at Santander de Quilichao. Each replicate consisted of seven plants per accession.

Characterization of these materials will concentrate on productivity, nutritive value, and seed production, and will be complemented by studies using molecular markers and geographic information system (GIS) tools (e.g., FLORAMAP).

Genetic Diversity and Core Collection Approaches in the Multipurpose Shrub Legume Flemingia macrophylla

The genetic diversity of tropical forage legumes was previously assessed through morphological, physiological, and agronomic germplasm characterization. Today, such characterization is increasingly complemented or substituted by laboratory studies such as isozyme electrophoresis and DNA-marker analysis.

Large germplasm collections of any given species are currently facing continuously and increasingly limited research resources for managing collections, whether to assess genetic diversity, documentation, conduct seed multiplication and periodic rejuvenation, or establish ex situ conservation in cold rooms. To cope with this situation, the core collection concept was suggested, by which a large collection is reduced to a size that is easier and more cost-efficient to manage. The diversity of this smaller collection, however, is, by definition, representative of the total collection.

The most appropriate and resource-efficient ways of identifying a core collection for tropical wild legumes need to be found, comparing agronomic evaluation, the use of molecular markers and geographic information system (GIS) tools.

We intend to use Flemingia macrophylla (Willd.) Kuntze ex Merr. (syns. F. congesta and Moghania macrophylla) as a test species to evaluate the concept of core collection. For F. macrophylla, documentation of genetic diversity is, so far, particularly challenging because (1) many accessions, independent of their original collection sites, look similar; (2) the value of (naturalized) African and South American materials awaits clarification; and (3) variability in tannin content needs to be explored.

Beyond this basic research, we need to know F. macrophylla's agronomic performance, that is, (1) as a multipurpose shrub species—for feed, firewood, and mulch, and as a cover crop, shade plant, erosion barrier, or nematicide; (2) its adaptation to extremely acid, low-fertility soils in the subhumid and humid tropics; and (3) drought tolerance. Particular attention must be given to quality parameters in terms of feed and natural resource conservation.

Flemingia macrophylla germplasm was obtained from CSIRO (Australia) and ILRI (Ethiopia) and, with accessions from the gene bank at CIAT, 74 accessions—about 90 percent of available germplasm worldwide—were used. We planted a randomized complete block design, with three replicates and nine plants for each accession per replicate. Phenotypic and agronomic parameters were collected. Genetic characterization is being prepared and will eventually be combined with a GIS-based assessment (FloraMap) of origin information.

Evaluating a Core Collection of Lablab purpureus for Multipurpose Use

Lablab purpureus (lablab) germplasm that is sown by farmers is a free seeding, fast-growing annual or short-term perennial that originated mainly in eastern and southern Africa and Asia. The legume is best adapted to lower altitudes and a rainfall regime of 750–2000 mm/year, and is drought tolerant. Lablab grows in a variety of soils, the pH of which can range between 4.0 and 7.5. It is used mostly as a forage and fodder legume throughout the tropics. In Africa, it is also commonly used as human food. Cultivars have been released in Australia.

ILRI (Ethiopia) and CSIRO (Australia) have studied lablab collections. To characterize lablab materials in Latin America, CIAT obtained germplasm from the collections available at ILRI and CSIRO. Emphasis is given to tolerance of various pH levels. We therefore plant lablab at two sites of contrasting pH levels: acid (4.0) and neutral to alkaline (around 7.0). Assessment will aim at defining niches for lablab as green manure and fodder plant (especially for hay and silage or deferred feed), with emphasis on Central America, which has soils that, typically, are highly variable in pH. Because of its potential as a green manure crop, contributions in N-equivalents to a following maize crop will also be evaluated.

So far, 44 accessions of L. purpureus have been sown on an acid soil (pH 4.0) in Santander de Quilichao, Colombia, for seed multiplication, and the best materials were then planted at a later date in Quilichao (acid soil) and Palmira (neutral to alkaline soil) for evaluation as green manure.

Agronomic Characterization of a Collection of Rhynchosia schomburgkii

From an evaluation of a range of shrub legumes that tolerate cool temperatures, Rhynchosia schomburgkii emerged as significantly promising for higher altitude hillsides.

Thirteen accessions of R. schomburgkii, mostly originating from Colombia, were planted at Santander de Quilichao. Plants were transplanted into single-row plots, with four replicates. Dry matter yield, plant persistence, drought tolerance, and forage quality are the main parameters to be evaluated.

Phenotypic variation among R. schomburgkii accessions seems to be low, with a growth habit that is intermediate between herbaceous and shrub, with a twining ability. Although forage attributes still need to be studied, the main potential is as a cover plant.

Evaluating an IITA Collection of Vigna unguiculata Accessions for Multipurpose Use

Cowpea (Vigna unguiculata) is used in the subhumid and semiarid tropics of West Africa and India as food and feed. Work at CIAT, even though with a limited number of accessions, indicated the cowpea's high potential for improving degraded hillside soils. However, distribution and evaluation of cowpea in Latin America so far has been limited.

A core collection of 15 cowpea accessions was obtained from B.B. Singh, cowpea breeder at the International Institute of Tropical Agriculture (IITA, Nigeria). These accessions were planted at CIAT's Santander de Quilichao and Palmira stations to evaluate grain and forage yields and nutritive value as a green manure to a following maize crop.

The accessions established quickly, showing a cover of more than 70 percent 2 months after sowing; at the time of incorporation into the soil as green manure all accessions were fully established.

Quality of cowpea varied between accessions as expressed in protein and lignin concentrations and digestibility (P=0.01) and P and Ca concentrations (P=0.05). With protein concentrations of 14-21 percent and a dry matter digestibility of more than 80 percent, cowpea is an excellent fodder for livestock.

For cowpea to realize its value to small farmers as green manure, source of fodder for livestock, and grain for human consumption, it must be accepted by people in target areas (Central America).

Genotypic Variation in Paspalum for Adaptation to Poorly Drained Soils

Some species of Paspalum are well known for their adaptation to poorly drained conditions. The germplasm collection at CIAT, Palmira, has been deficient in Paspalum accessions until recent introductions of Brazilian materials, which are currently being evaluated at Santander de Quilichao, Colombia.

Eight accessions of Paspalum spp. were established in 1996 in a poorly drained site in Quilichao. They had been planted in a randomized complete block design with replicates. Measurements include plant survival, DM yield, forage quality, and observations on flowering and seed production.

For more information, see the following reference:

Peters, M.; Hincapié B.; Avila, P.; Lascano, C.E. 2001. Evaluation of Paspalum spp. with adaptation to poorly drained soils in the tropical Americas. Proceedings of the XIX International Grassland Congress. FEALQ. p. 13-08; 530-532.

Genotypic Variation in a Core Collection of Calliandra calothyrsus for Dry-season Tolerance

Calliandra calothyrsus is a shrub legume with potential as a dry-season cut-and-carry supplement for livestock. A total of 13 accessions from the Oxford Forestry Institute (OFI), UK, were planted in Santander de Quilichao, Colombia, in single rows of nine plants each. The design was randomized complete block with three replicates. Variables measured include quality, dry matter production, ratio of edible to total dry matter, nutritive value of edible dry matter, and regrowth after cutting.

For more information, see the following reference:

Peters, M.; Hincapié, B.; Avila, P.; Franco, L.H. 2000. Evaluación de una colección de Calliandra calothyrsus en suelos ácidos. Paper presented at the International Workshop of Calliandra CIAT-OFI, held at Atenas, Costa Rica 17-19 May 2000.

On-farm Evaluation, with Farmer Participation, of Forages for Multipurpose Use in Central America

Evaluating Forage Germplasm with Farmers

Forage germplasm, which often has multiple purposes—feed, suppressing weeds, maintaining and improving soil fertility, and controlling erosion—could play an important role in improving the well being of small and medium-scale farmers in Central American hillsides. However, adoption, particularly of forage legumes, has been limited, possibly because of a lack of direct interaction with farmers. Forage germplasm technologies must therefore be developed with farmers, using a participatory approach.

To address this issue, CIAT, in collaboration with NARS, NGOs, and farmer groups, identifies germplasm preferred by farmers. Geographic information system (GIS) tools are being developed to strategically target forage germplasm, first to environmental, then to socioeconomic, niches in Central American hillsides. The work is expected to also contribute to the development of an overall strategy to guide future research and to aid the diffusion and final adoption of forage-based technology by small farmers. Interaction with strong national partners—as well as with farmers—will be of paramount importance to the approach's success.

A combination of agronomic evaluation techniques, participatory technologies, soil indicators, socioeconomic studies, and GIS tools is employed. The work links closely with the TROPILECHE project, using some of the same germplasm. Likewise, forage germplasm selected from this work will be useful to TROPILECHE and other projects working to develop new forage alternatives for crop/livestock systems in hillsides.

To begin the participatory selection of improved forage options, several training and planning activities with involved partners were executed. These include:

• A course on Methods and Techniques of Participatory Research was carried in collaboration with CIAT's Participatory Research Group (Project SN-3) in February-March 2000. Twelve participants from several institutions in Honduras, Nicaragua, Costa Rica, and Colombia were trained and are now using participatory methods in collaborative activities with CIAT.
• In May 2000, with collaboration from CIAT's SN-3 project, research and development personnel from various national and international research institutions and NGOs in Honduras (participants from CIAT, DICTA, and SERTEDESO), Nicaragua (CIAT, INTA, and PRODESSA), and Costa Rica (MAG and Fundación Ecotropica) were trained in methods for stakeholder analysis. These methods are now applied as part of the diagnosis in the study sites.
• A major activity in 2000 was a planning workshop for the project held in Comayagua, Honduras. Participants included 15 representatives from institutions in Honduras (DICTA, SERTEDESO, and CIAT), Nicaragua (INTA, PRODESSA, and CIAT), Costa Rica (MAG, IICA-GTZ, CIAT, and Fundación Ecotropica), Colombia (CIAT), and Germany (University of Hohenheim). Staff from IICA-GTZ, Costa Rica, facilitated the course.

Several types of trials for the agronomic evaluation and simultaneous participatory selection of improved forages as agreed in the planning workshop were established in Honduras, Nicaragua, and Costa Rica. Multipurpose germplasm including grasses, herbaceous legumes, shrub legumes, and cover and green manure legumes were offered to farmers for evaluation.

Sites were selected according to the diagnosis and, in some cases, complemented by approaches from interested farmers.

The different forage options being evaluated in the different sites in Costa Rica, Nicaragua, and Honduras are:

Grasses: Andropogon gayanus CIAT 621; Brachiaria brizantha CIAT 6780, 26110, 26646, 16322, 36061; Brachiaria dictyoneura CIAT 6133; Panicum maximum CIAT 16031; 'King grass' (Pennisetum maximum x P. typhoides).

Herbaceous legumes: Arachis pintoi CIAT 18744, 22160; Centrosema pubescens CIAT 15160; Centrosema plumieri DICTA; Desmodium ovalifolium CIAT 33058; Stylosanthes guianensis CIAT 11844; Clitoria ternatea cv. Tejuana.

Green manure and cover legumes: Pueraria phaseoloides CIAT 7182; Mucuna pruriens IITA-BENIN; Mucuna pruriens DICTA; Mucuna deerengianum DICTA; Canavalia brasiliensis CIAT 17009; Lablab purpureus DICTA.

Shrublegumes: Calliandra calothyrsus CIAT 22310, 22316; Cratylia argentea CIAT 18516/18668; Leucaena leucocephala CIAT 17263; Leucaena macrophylla OFI47/85; Gliricidia sepium; Erythrina verteruana; Erythrina poepigiana.

Each of the 10 trial sites corresponds to a group of 10-15 farmers. A total more than 100 farmers are so far involved in the project.

Participatory Diagnosis in Three Communities in the Department of Yoro, Honduras

A total of 59 persons, of whom 45 percent were women, took part in the participatory diagnosis. Participants were diverse, ranging in age from 18 to about 75 years. The farmers responsible for various activities in the field and at the homestead were involved in livestock, crops, or mixed farming.

Diagnosis included plenum and small-group activities, leading to the identification and prioritization of problems as related to agriculture and natural resource management, with emphasis on forages. The diagnosis was done at three sites in and around CIAT’s reference site, Yorito, that is, El Jícaro (Victoria), Las Cañas (Sulaco), and Luquigue (Yorito).

The sites are characterized by undulating topography with slopes of 30 to 50 percent. Altitudes range from 50 to 650 m.a.s.l. Annual rainfall is 1200 to 1500 mm, with 5 wet, 5 dry, and 2 moderately dry months. Conifers characterize the forests. Soils are moderately acid to neutral clays. Temperatures range between 24 and 30 °C. The main agronomic activities include maize and bean cultivation and small-scale livestock production. Livestock production is extensive, with a tendency toward beef production.

Throughout the diagnosis, women’s participation was significant, except for Luquigue, where only 18 percent of the participants were women. Common problems identified across the three communities include:

• Erosion, lack of water, burning, deforestation, low productivity of the resource base, and low fertility.
• Free roaming of animals in the dry season, lack of wood for poles and firewood, lack of land, and lack of green material in the dry season for conservation and as feed.
• Lack of technology options, lack of technical support, lack of seed and planting materials.
• Interestingly, one farmer group mentioned their own lack of interest in improving their situation.

Most problems were closely related to lack of feed for animals, particularly during dry periods, soil degradation, and lack of firewood. Results of prioritizing these problems were heterogeneous, but tended to emphasize the problem of lack of suitable planting materials and lack of livestock feed, particularly during the dry season. Communities clearly perceived the problems of soil degradation and deforestation, and the inherent negative effects of these on communities.

The farmers

'’ objective in participating in the project was to address the problems mentioned above and, thus, improve family income, and family and community nutrition.

Contributors: M. Peters, P.J. Argel, L.A. Hernández, L.H. Franco, C. Burgos, H. Cruz F., M.I. Posas, W. Sebillón, T. Reyes, M.A. Mena, F.J. Latino, W. Sánchez, R. Guillén M., J. Bustamante, C. Reiche, V. Hoffman, and R. Schultze-Kraft