Cover Crop - Perennial Peanut (Arachis pintoi)

Sustainable Agriculture in Hawai'i info block

Perennial Peanut

Arachis pintoi

Direct seeded perennial peanut used a ground cover in a landscape nursery on the Hamakua Coast of the Big Island. This site (elevation = 320 ft.) averages about 90 inches of rainfall a year. The peanut cover is maintained with regular mowing and selective postemergence herbicides to manage grassy weeds.

Photo: DeFrank

Photo: DeFrank

Also known as: Pintoi Peanut, Amarillo Peanut

Summary

Tropical low growing (about 8 inches high), non-twining, nitrogen-fixing legume
Used as a cover crop (‘Amarillo’) in coffee, banana, oil palm, macadamia, cocoa, cassava, citrus, pineapples, plantains, dryland taro, and hearts of palm
Used as ground cover (‘Golden Glory’ var.) in Hawai`i
Used for intensively managed grass/legume pastures in South America (CIAT, Colombia)
Used for pasture legume in tree plantations
Takes about 6 months to become well established and requires weed control during that time. Once established it provides excellent weed control.
CAUTION: Researchers in Hawai`i report it very difficult to eradicate once established
Shade tolerant
Tolerant of high Aluminum saturation. Some indications of tolerance to Manganese.

Common Name
Its common name is perennial peanut or pinto peanut (Hensley). According to Cook, the common name is pinto peanut or thua lisong tao (Thailand).

Scientific Name
The scientific name is Arachis pintoi Krap. & Greg., nom. nud. (Cook).

Cultivar
Two popular cultivars are ‘Golden Glory’ which is becoming a popular landscape ground cover in Hawai`i and ‘Amarillo’ which was developed in Australia for forage and cover crop uses (Hensley). CIAT accessions are used primarily as pasture legumes.

Seed Description
Seeds are light brown, 8-11 mm x 4-6 mm (Cook).

Seedling Description
No information is available in this database on this topic.

Mature Plant Description
Perennial or pinto peanut species and cultivars are low growing, about 8 inches (20 cm) high, non-twining, nitrogen-fixing legumes. The plants have four oval leaflets on each petiole and yellow, pea-like flowers. The seed is an underground nut, one per pod, which is not edible. Plants flower year round (Hensley). Stems grow along the ground and root at the nodes (Glover).

Temperature
Perennial peanut is adapted to the tropics (Cook).

Origin and Geographic Range
Perennial peanut originates from central Brazil (collected from the mouth of the Jequitinhonha River). It has since been distributed to Argentina, Australia, Colombia, the United States, and more recently to South East Asia, Central America and the Pacific (Cook).

Ecology
Central Brazil’s climate is humid tropical, with rainfalls ranging from 1800-2000 mm (70-80 in) from October to May and 200 mm (8 inches) from June to September. Perennial peanut grows naturally in red sandy-loam alluviums under low forest with a fairly dense canopy (Cook).

Water
Perennial peanut grows best in areas receiving an annual rainfall of 40 inches (1000 mm) or more. It can withstand 3-4 months of drought, but will shed many of its leaves (Glover). It is adapted to low areas (with sandy loam soils) that are wet to flooded in the wet season. It will not persist on waterlogged, poorly structure clays (Cook).

Nutrients
Perennial peanut originates from central Brazil and is adapted to that region. It tolerates soils with low fertility (it is a legume and fixes its own nitrogen). It tolerates soils with 70% or greater Al saturation. It performs best with >3% organic matter in the soil (Glover). In pot experiments it has shown a tolerance of Mn (Cook).

Soil pH
Although naturally adapted to areas of lower pH, under cultivation it can adapt to pH ranges from low to neutral (Cook).

Soil Type
Perennial peanut’s native habitat is in red, sandy loam alluviums, seasonally wet to flooded. Under cultivation it has proven adaptable to soils ranging from sand to clay texture. It will not persist on seasonally waterlogged, poorly structured clays (Cook).

Shade Tolerance
Perennial peanut prefers shaded conditions and even grows well under heavy (70-80%) shade (Glover).

Salinity Tolerance
Perennial peanut has a low tolerance for salinity (Cook).

Herbicide Sensitivity
The herbicides Dualä , Balanä Granular, Treflanä Granules, Snapshotä Granular, Fusilade IIä , and Vantageä are reported not harmful to pinto peanut at recommended label rates. Ronstarä can yellow the leaves and kill the plant (Hensley).

Life Cycle
Seedlings develop quickly with good growing conditions when planted at a rate of several plants per square meter. Complete ground cover can be reached by about 6 months via a network of stolons. Flowering begins 3-4 weeks after emergence and continues through the growing season. Flowering intensifies after rain or irrigation. Seeds remain viable in the ground for more than one season (Cook).

Seeding Rate
17-22 lbs./acre (15-20 kg/ha) (Glover).
Seed pods or husks can be planted.
Perennial peanut can also be established by cutting (see Establishment below).

Seeding Depth
1-2 inch deep (Hensley) to 1 inch (2-3 cm) deep (Glover).

Seeding Method
Drill if possible. Seed can be broadcast and covered or rolled. Consider seeding with a nurse crop of buckwheat or alfalfa to control weeds during establishment (Glover).

Seeding Dates
Year round in Hawai`i.

Inoculation
Inoculate all propagation material (seedpods, seed, stolons) with cowpea type rhizobia (Hensley, Glover).

Seed Cost
No information available in this database.

Seed Availability
Readily available.

Days to Flowering
Flowering commences 3-4 weeks after emergence and continues through the growing season (Cook).

Days to Maturity
No information is available in this database on this topic.

Seed Production
No information is available in this database on this topic.

Seed Storage
Seed should be dried and stored under cool conditions with low humidity (Cook).

Growth Habit
Low growing and non-twining. Once established, crowds out weeds effectively. It will compete with other groundcovers (Hensley).

Maximum Height
Perennial peanut grows to a maximum height of about 8 inches (20 cm). (Cook).

Root System
It is stoloniferous and will develop a strong taproot on the older crowns as well as large numbers of nodules on both the taproot and subsidiary roots (Cook).

Establishment
Perennial peanut can be established by seed, by cuttings or by stolons. Data from CIAT indicate superior rates of production of dry matter and leaf area of plants from seed compared with those of vegetative material (Kerridge & Hardy).
Cuttings: Cuttings should be 4-8 inches long and partially buried 3-5 inches deep in soil in pots or a prepared seedbed. For quick soil cover, plant cuttings 10-15 inches apart. Do not allow cuttings to dry out before, during or after planting (Hensley).
Stolons (runners, sprigs): Remove stolon section from the mother plant and place 1/2 - 1 inch deep in the soil at 10-12 inch spacing. Do not allow cuttings to dry out before, during or after planting (Hensley).

Maintenance
Irrigate as needed or plant at the beginning of the rainy season (Glover).

Mowing
Mow at 2-3 inches the first year to reduce weeds and stimulate lateral growth. Subsequent mowings should be at 6-8 inch height (Glover).

Incorporation
Not applicable. Not generally used as a green manure.

Harvesting
Not generally harvested, although taller growing accessions can be used for hay making or cut-and-carry forage systems (Cook).

Equipment
No information is available in this database on this topic.

Uses

‘Amarillo’ is used as a cover crop (‘Amarillo’) in coffee, banana, oil palm, macadamia, and hearts of palm in Hawai`i
‘Golden Glory’ is used as ground cover in Hawai`i.
CIAT (Centro Internacional de Agricultura Tropical) releases are used for intensively managed grass/legume pastures in South America.

Photo: DeFrank

Mixtures
No information is available in this database on this topic.

Biomass
No information is available in this database on this topic.

N Contribution
No information is available in this database on this topic.

Non-N Nutrient Contribution
No information is available in this database on this topic.

Effects on Water
No information is available in this database on this topic.

Effects on Soil
No information is available in this database on this topic.

Effects on Livestock
Perennial peanut is used as a pasture legume in tree plantations and as an intensively managed grass/legume pasture. In vitro digestibility varies from 60-76%, N concentrations from 2.5-3.0% and P concentrations from 0.18-0.37%. It is well accepted by cattle at all growth stages (Cook).

Pest Effects, Insects
Slugs and snails can be a problem during establishment and may require control via pesticide baits. Chinese rose beetles may become a problem later on (Hensley).

Pest Effects, Nematodes
‘Amarillo’ has moderate to high resistance to various root-knot nematodes (Meloidogyne spp.) but is susceptible to the root-lesion nematode (Pratylenchus brachyurus) (Cook).

Pest Effects, Diseases
‘Amarillo’ is reported to be resistant to major groundnut diseases, rust (Puccinia arachidis) and leaf-spot (Mycosphaerella spp.). Other fungi have been isolated from leaf-spots, but no long-term or serious damage has been reported (Cook).

Pest Effects, Weeds
During establishment, weed control is needed (via mowing, hoeing, hand weeding, herbicides). Consider seeding with a nurse crop of buckwheat or alfalfa to control weeds during establishment (Glover). Once a good stand of perennial peanut is in place, weed suppression is excellent (Hensley).

Pest Effects, Vertebrates
Rats and mice are attracted to the nuts and can be a problem (Cook).

Uses in the Pacific Region

Kerridge & Hardy report very promising legume field trials with Arachis pintoi cv. ‘Amarillo’ in Fiji. Future experiments will investigate fertilizer requirements, seed production, and milk and meat production of cattle grazing A. pintoi-based pastures.
In Vanuatu, Kerridge & Hardy report several forage Arachis accessions are being evaluated as part of the Vanuatu Pasture Improvement Project. It performed well in heavily grazed Brachiaria decumbens pastures. Its value as a cover crop was unclear due to its inability to suppress weeds. Disadvantages reported in Vanuatu include: high cost of seed, rapid decline in germination percentage in humid environments, and a 12 month time span to develop an effective rhizobial symbiosis. Arachis accessions suited to low-fertility, high-pH coralline soils would be helpful to smallholders with cattle under coconuts in the Pacific region.

Uses in Hawai`i

Clement and DeFrank conducted a field trial using ground covers during the establishment of Heart-of-Palm (1998). A. pintoi formed a closed canopy slowly and only controlled weeds after forming a thick canopy, but required less mowing after establishment. All vegetative covers delayed heart-of-palm harvest and reduced yields 1.5 years after planting (possibly due to strong competition for nitrogen). A combination of polypropylene (adjacent to plants) and vegetative covers (in service rows) may provide the best solution.
A farmer in Hakalau (Hawai`i Island) reports using Arachis pintoi as a permanent live mulch under perennial tropical vegetables such as Sauropus androgynus (chekkurmanis) for many years in a permanent system. Their experience is that the perennial peanut requires extensive weed control during the first six months, if a pure stand is to be established. Eliminating most weeds prior to planting (using successive cultivations, herbicide, heat, or plastic mulch) makes establishment much easier and cheaper. After establishment, they have found that even well established plots have to be checked periodically to remove certain difficult weed species, especially vines and trailing grasses that can come in from the perimeter and can out-compete the peanut cover due to the fact that it is non-twining.
An organic farmer in Molokai reports having a problem with southern leaf blight on Arachis pintoi. The plant is also difficult to eradicate under an organic program without access to chemical controls.
Dr. Joe DeFrank, UH Manoa, reports difficulty in eradicating Arachis pintoi from a plantation, due to its ability root at the nodes.
In a preliminary trial on the Hamakua coast (Hawai`i Island), perennial peanut was drilled between rows of taro, survived well under heavy shade (12,000 taro plants/acre), and formed a dense cover within 6-7 months (Glover).

FOR MORE INFORMATION

Introduction and Evaluation of Pejibaye (Bactris gasipaes) for Palm Heart Production in Hawaii
http://www.hort.purdue.edu/newcrop/proceedings1993/V2-465.html

Pejibaye Heart-of-Palm in Hawaii: From Introduction to Market
http://www.hort.purdue.edu/newcrop/proceedings1996/V3-500.html

REFERENCES
Clement, C.R.; DeFrank, J. 1998. The use of ground covers during establishment of heart-of-palm plantations in Hawaii. HortScience. Vol 33, Issue 5. pp 814-815.

Cook, R.G. 1992. Arachis pintoi Krap. & Greg., nom. nud. In:’t Mannetje, L. & Jones, R.M. (Editors): Plant Resources of South-East Asia No 4. Forages. Pudoc-DLO, Wageningen, the Netherlands. pp. 48-50.

Hensley, David, Yogi, Julie, & DeFrank, Joseph. October 1997. Perennial Peanut Groundcover. College of Tropical Agriculture and Human Resources, University of Hawaii at Manoa, Honolulu, USA. 2 pp.

Free publication available at CTAHR Website: http://www2.ctahr.hawaii.edu/oc/freepubs/

Kerridge, Peter C. & Hardy, Bill (Editors), 1994. Biology and Agronomy of Forage Arachis, (CIAT Publication; No. 240), Centro Internacional de Agricultura Tropical, Cali, Colombia. 209 p.

Glover, Nancy. August 1994. Perennial Peanut (Arachis pintoi), ADAP Integrated Farm Development Project, University of Hawai`i, 1994, 4 p.

If you have used this plant as a cover crop in the Pacific Region, please email us with COMMENTS and FEEDBACK about this plant description so we can further refine this educational resource.

Last updated on 7/5/02