Cenchrus purpureus

Last updated

Cenchrus purpureus
Starr 061211-2254 Pennisetum purpureum.jpg
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Monocots
Clade: Commelinids
Order: Poales
Family: Poaceae
Subfamily: Panicoideae
Genus: Cenchrus
Species:
C. purpureus
Binomial name
Cenchrus purpureus
(Schumach.) Morrone

Cenchrus purpureus, synonym Pennisetum purpureum, [1] also known as Napier grass, elephant grass or Uganda grass, is a species of perennial tropical grass native to the African grasslands. [2] It has low water and nutrient requirements, and therefore can make use of otherwise uncultivated lands. [3]

Contents

Historically, this wild species has been used primarily for grazing, [4] recently, however, it has been used as part of a push–pull agricultural pest management strategy. Napier grasses improve soil fertility, and protect arid land from soil erosion. It is also utilized for firebreaks, windbreaks, in paper pulp production and most recently to produce bio-oil, biogas and charcoal. [3]

Description

Common Napier (Non-hybrid) Pennisetum purpureum Schumach.png
Common Napier (Non-hybrid)

Cenchrus purpureus (or napier grass) is a monocot C4 perennial grass in the family Poaceae. [4] It is tall and forms in robust bamboo-like clumps. [2] It is a heterozygous plant, but seeds rarely fully form; more often it reproduces vegetatively through stolons which are horizontal shoots above the soil that extend from the parent plant to offspring. [2] It requires low water and nutrient inputs. [3] The Elephant grass was crossed with Pearl millet species to form Bajra Nappier. Subsequent work was done to decrease the internode length of Elephant grass. Napier grass plantations produce about 40 tonnes of dry biomass per hectare per year [3] with an average energy content 18 GJ (5 MWh) per tonne, [5] and the grass can be harvested many times per year. [2]

Generally, the grass is harvested in relatively short intervals (every 1 to 3 months) when it is to be used as fodder for animals (its main use), and relatively long intervals (4–12 months) when used for bioenergy. Longer intervals increases the stem/leaf ratio, making the forage harder to chew and digest, but in many cases the annual dry yield increases. The grass can reach a height of 7-8 meters after 4 months of growth. [6] It produces best growth between 25 and 40 °C, and little growth below about 15 °C, with growth ceasing at 10 °C. Tops are killed by frost, but plants re-grow with the onset of warm, moist conditions. Napier grass grows from sea level to over 2,000 m elevation. [7]

It can be propagated through seeds, however as seed production is inconsistent, collection is difficult. [2] Alternatively, it can be planted through stem cuttings of the stolons. The cuttings can be planted by inserting them along furrows 75 cm apart, both along and between rows. [8]

Yield

Yield depends on management techniques (e.g. fertilizer), soil quality, rain, sunshine and temperature. Recognizing its potential as a bioenergy crop, some yield trials have been carried out around the world. In Malaysia, Halim et al. tested 9 different napier variants and found that regular napier grass yielded the most (65 dry tonnes per hectare per year), with the King Grass variant second (62 tonnes). [9] In Colombia, Cardona et al. estimates a yield range of 40–60 dry tonnes for the napier variant King Grass, under optimal conditions. [10] In drier areas however, yields decline; Gwayumba et al. estimate 15–40 dry tonnes as the general yield range for Kenya. [11]

At the top end of the range, napier grasses have been shown to yield up to 80 dry tonnes per hectare per year, [12] [13] [14] and commercial napier grass developers advertise yields of roughly 100 dry tonnes per hectare per year, provided there is an adequate amount of rain or irrigation available (100 mm per month). [15] [16] These yields are high compared to other types of energy crops. For large-scale plantations with pines, acacias, poplars and willows in temperate regions, Smil estimates yields of 5–15 dry tonnes per hectare per year, and for similarly large plantations, with eucalyptus, acacia, leucaena, pinus and dalbergia in tropical and subtropical regions, his estimate is 20–25 dry tonnes. In Brazil, the average yield for eucalyptus is 21 t/ha, but in Africa, India and Southeast Asia, typical eucalyptus yields are below 10 t/ha. [17]

Push-pull pest management

The push-pull pest management technique involves the desired crop being planted alongside a 'push' plant, which repels pests, in combination with a 'pull' crop around the perimeter of the plot, which draw insects out of the plot. [4] Napier grass has shown potential at attracting stemborer moths (a main cause of yield loss in Africa) away from maize [4] and hence is the "pull" crop. This strategy is much more sustainable, serves more purposes and is more affordable for farmers than insecticide use. Stemborers ( Busseola fusca and Chilo partellus ) are the cause of 10% of total yield loss in Southern and Eastern Africa and on average 14-15% in sub-Saharan Africa. [2] The larvae cause immense damage to maize and sorghum by burrowing into their stems and eating from within. This not only makes them difficult to detect and remove but also damages the vascular tissue necessary for plant growth. [4]

Insecticide effectiveness is low against stemborers, as larvae are protected by protective cell wall layers around the stem. [8] Insecticides are also expensive for poor farmers and can build chemical resistance by the pests. [18] In addition, chemicals are carried into final food products. [18] Instead of trying to prevent the occurrence of pests, the push-pull strategy (also known as stimuli-deterrent) aims to guide their inevitable biological evolution to prevent damage to valued crops. [18] The method proposes that sorghum or corn be intercropped with Desmodium (the "push" plant), which repels the moths as they look to lay their eggs. Desmodium also provides a ground cover and is nitrogen fixing, which improves soil fertility while decreasing labour involved with weeding. [4] This deterrent is used in combination with Napier grass planted around the perimeter of the plot. [4] A study of Kenyan farmers using the push-pull strategy reported an 89% reduction in Striga (a parasitic weed), an 83% increase in soil fertility, and 52% effectiveness in stemborer control. [19] Considering that striga, stemborers, and low soil fertility together cause yield losses of an estimated 7 billion US dollars or enough to feed 27 million people, [19] the implementation of this technique could significantly reduce food insecurity.

Although promising as a sustainable and affordable option, the success of push-pull pest management highly depends on proper implementation in combination with other good ecological practices. Firstly, not all varieties of Napier grass function as a trap. In a study of eight varieties, only two bana and Ugandan hairless Napier varieties significantly attracted female moths for egg placement over maize. [4] Of these two, only bana significantly decreased survival rates. [4] In a farmer's field, it is recommended that three rows of bana Napier grass be planted as a border crop around the entire field. [8] Potential exists to improve the push-pull strategy through further trials with different intercrops, by manipulating allelochemicals in each intercrop, as well as by investigating insect sensitivity to natural chemicals. [18] Once prominent in a field, it is difficult to rid the area of the stemborer pests as larvae can remain dormant, and therefore push-pull management will not have the intended effect. [4] It is recommended that if an infestation is particularly severe, neither corn, nor sorghum should be planted in the same field the following year but instead rotated with other crops. [4] It is also important to burn infested stalks or, if they have an intended use, to leave them out in the sun for three days. [4] The use of push-pull pest management must be used in combination with good ecological practices to yield the desired results.

Finally, the establishment of a push-pull system requires increased labour in the primary stages and a large enough land plot to allow space for a non-food crop to be planted; these factors often deter its adoption. [19] A program could increase adoption rates through promoting its use in combination with livestock, giving economic value to the planting of Napier grass.

Other uses

Use as fodder crop in Kenya Harvesting Napier.jpg
Use as fodder crop in Kenya

Napier grass is the most important fodder crop for the dairy farmers in East Africa. [2] Its high productivity makes it particularly suited to feed cattle and buffaloes. [20] Hairless varieties, such as Ugandan hairless, have much higher value as fodder. [2] As it is able to grow with little water and nutrients, grazing has made productive use of arid lands for food production. Furthermore, livestock can be incorporated into the pull-push management system providing another economically viable purpose for the ‘trap’ plant. Napier grass is valuable to African landscapes as it prevents soil erosion. It can also serve as a fire break, a wind break, and to improve soil fertility. [2]

More recently, Napier has been used to alleviate pressure on food production by bioenergyZ as there are 2 billion ha of non-arable land suitable for energy crop production. [3] Thermal pyrolytic conversion could be used to produce charcoal, biogas and bio-oil. [3] Although this technology is not currently in use, it could be implemented as a means of providing energy to African communities, while enriching the soils of the local landscape. [3] It is also used as source of fuel. The young leaves and shoots are edible and are cooked to make soups and stews. [21]

A Dutch company has turned the grass into a plastic that can be used for packaging. [22]

Related Research Articles

<i>Vigna subterranea</i> Species of plant

Vigna subterranea is a member of the family Fabaceae. Its name is derived from the Bambara tribe. The plant originated in West Africa. As a food and source of income, the Bambara groundnut is considered to be the third most important leguminous crop in those African countries where it is grown, after peanut and cowpea. The crop is mainly cultivated, sold and processed by women, and is, thus, particularly valuable for female subsistence farmers.

<i>Panicum virgatum</i> Species of plant

Panicum virgatum, commonly known as switchgrass, is a perennial warm season bunchgrass native to North America, where it occurs naturally from 55°N latitude in Canada southwards into the United States and Mexico. Switchgrass is one of the dominant species of the central North American tallgrass prairie and can be found in remnant prairies, in native grass pastures, and naturalized along roadsides. It is used primarily for soil conservation, forage production, game cover, as an ornamental grass, in phytoremediation projects, fiber, electricity, heat production, for biosequestration of atmospheric carbon dioxide, and more recently as a biomass crop for ethanol and butanol.

<i>Pennisetum</i> Genus of grasses

Pennisetum is a widespread genus of plants in the grass family, native to tropical and warm temperate regions of the world. They are known commonly as fountaingrasses. Pennisetum is considered a synonym of Cenchrus in Kew's Plants of the World Online.

<span class="mw-page-title-main">Foxtail millet</span> Species of grass

Foxtail millet, scientific name Setaria italica, is an annual grass grown for human food. It is the second-most widely planted species of millet, and the most grown millet species in Asia. The oldest evidence of foxtail millet cultivation was found along the ancient course of the Yellow River in Cishan, China, carbon dated to be from around 8,000 years before present. Foxtail millet has also been grown in India since antiquity.

<i>Miscanthus</i> Genus of grasses

Miscanthus, or silvergrass, is a genus of African, Eurasian, and Pacific Island plants in the grass family, Poaceae.

Energy forestry is a form of forestry in which a fast-growing species of tree or woody shrub is grown specifically to provide biomass or biofuel for heating or power generation.

<span class="mw-page-title-main">Push–pull agricultural pest management</span> Intercropping strategy for controlling agricultural pests

Push–pull technology is an intercropping strategy for controlling agricultural pests by using repellent "push" plants and trap "pull" plants. For example, cereal crops like maize or sorghum are often infested by stem borers. Grasses planted around the perimeter of the crop attract and trap the pests, whereas other plants, like Desmodium, planted between the rows of maize, repel the pests and control the parasitic plant Striga. Push–pull technology was developed at the International Centre of Insect Physiology and Ecology (ICIPE) in Kenya in collaboration with Rothamsted Research, UK. and national partners. This technology has been taught to smallholder farmers through collaborations with universities, NGOs and national research organizations.

<span class="mw-page-title-main">Energy crop</span> Crops grown solely for energy production by combustion

Energy crops are low-cost and low-maintenance crops grown solely for renewable bioenergy production. The crops are processed into solid, liquid or gaseous fuels, such as pellets, bioethanol or biogas. The fuels are burned to generate electrical power or heat.

<i>Miscanthus × giganteus</i> Species of grass

Miscanthus × giganteus, also known as the giant miscanthus, is a sterile hybrid of Miscanthus sinensis and Miscanthus sacchariflorus. It is a perennial grass with bamboo-like stems that can grow to heights of 3–4 metres (13 ft) in one season. Just like Pennisetum purpureum, Arundo donax and Saccharum ravennae, it is also called elephant grass.

<span class="mw-page-title-main">Short rotation coppice</span> Coppice grown as an energy crop

Short rotation coppice (SRC) is coppice grown as an energy crop. This woody solid biomass can be used in applications such as district heating, electric power generating stations, alone or in combination with other fuels. Currently, the leading countries in area planted for energy generation are Sweden and the UK.

<span class="mw-page-title-main">Commercial sorghum</span>

Commercial sorghum is the cultivation and commercial exploitation of species of grasses within the genus Sorghum. These plants are used for grain, fibre and fodder. The plants are cultivated in warmer climates worldwide. Commercial Sorghum species are native to tropical and subtropical regions of Africa and Asia.

<span class="mw-page-title-main">Sugarcane</span> Several species of grass cultivated for sugar production

Sugarcane or sugar cane is a species of tall, perennial grass that is used for sugar production. The plants are 2–6 m (6–20 ft) tall with stout, jointed, fibrous stalks that are rich in sucrose, which accumulates in the stalk internodes. Sugarcanes belong to the grass family, Poaceae, an economically important flowering plant family that includes maize, wheat, rice, and sorghum, and many forage crops. It is native to the warm temperate and tropical regions of India, Southeast Asia, and New Guinea. Grown in tropical and subtropical regions, sugarcane is the world's largest crop by production quantity, totaling 1.9 billion tonnes in 2020, with Brazil accounting for 40% of the world total. Sugarcane accounts for 79% of sugar produced globally. About 70% of the sugar produced comes from Saccharum officinarum and its hybrids. All sugarcane species can interbreed, and the major commercial cultivars are complex hybrids.

<i>Paspalum scrobiculatum</i> Species of grass

Paspalum scrobiculatum, commonly called Kodo millet or Koda millet, is an annual grain that is grown primarily in Nepal and also in India, Philippines, Indonesia, Vietnam, Thailand, and in West Africa from where it originated. It is grown as a minor crop in most of these areas, with the exception of the Deccan plateau in India where it is grown as a major food source. It is a very hardy crop that is drought tolerant and can survive on marginal soils where other crops may not survive, and can supply 450–900 kg of grain per hectare. Kodo millet has large potential to provide nourishing food to subsistence farmers in Africa and elsewhere.

<i>Striga hermonthica</i> Species of flowering plant

Striga hermonthica, commonly known as purple witchweed or giant witchweed, is a hemiparasitic plant that belongs to the family Orobanchaceae. It is devastating to major crops such as sorghum and rice. In sub-Saharan Africa, apart from sorghum and rice, it also infests maize, pearl millet, and sugar cane.

<i>Busseola fusca</i> Species of moth

Busseola fusca is a species of moth that is also known as the maize stalk borer. It is known from Ethiopia.

<span class="mw-page-title-main">Yam production in Nigeria</span>

Nigeria is by far the world’s largest producer of yams, accounting for over 70–76 percent of the world production. According to the Food and Agriculture Organization report, in 1985, Nigeria produced 18.3 million tonnes of yam from 1.5 million hectares, representing 73.8 percent of total yam production in Africa. According to 2008 figures, yam production in Nigeria has nearly doubled since 1985, with Nigeria producing 35.017 million metric tonnes with value equivalent of US$5.654 billion. In perspective, the world's second and third largest producers of yams, Côte d'Ivoire and Ghana, only produced 6.9 and 4.8 million tonnes of yams in 2008 respectively. According to the International Institute of Tropical Agriculture, Nigeria accounted for about 70 percent of the world production amounting to 17 million tonnes from land area 2,837,000 hectares under yam cultivation.

<i>Centrosema pubescens</i> Species of legume

Centrosema pubescens, common name centro or butterfly pea, is a legume in the family Fabaceae, subfamily Faboideae, and tribe Phaseolae. It is native to Central and South America and cultivated in other tropical areas as a forage for livestock.

Chilo partellus, the spotted stalk borer or spotted stem borer, is a moth in the family Crambidae. It was described by Charles Swinhoe in 1885. It is found in India, Pakistan, Iran, Ethiopia, Lesotho, Madagascar, Malawi, South Africa, Sudan, Tanzania, Uganda and on Mayotte.

<i>Neustanthus</i> Species of legume

Neustanthus is a monotypic genus of flowering plants belonging to the pea family Fabaceae and its tribe Phaseoleae. The only species is Neustanthus phaseoloides, called tropical kudzu. This species is a forage crop and cover crop used in the tropics. It is known as puero in Australia and tropical kudzu in most tropical regions.

<span class="mw-page-title-main">Chintala Venkat Reddy</span>

Chintala Venkat Reddy is an organic farmer known for his soil and nutrient management techniques in farming. He is the first independent farmer in India to receive an international patent for his technique in soil swapping and soil fertility.

References

  1. Paudel, Dev; Kannan, Baskaran; Yang, Xiping; Harris-Shultz, Karen; Thudi, Mahendar; Varshney, Rajeev K.; Altpeter, Fredy; Wang, Jianping (2018-09-26). "Surveying the genome and constructing a high-density genetic map of napiergrass ( Cenchrus purpureus Schumach)". Scientific Reports. 8 (1): 14419. Bibcode:2018NatSR...814419P. doi:10.1038/s41598-018-32674-x. ISSN   2045-2322. PMC   6158254 . PMID   30258215.
  2. 1 2 3 4 5 6 7 8 9 [Farrell, G., Simons, S. A., & Hillocks, R. J. (2002). Pests, diseases, and weeds of Napier grass, Pennisetum purpureum: a review. International Journal of Pest Management, 48(1), 39-48.]
  3. 1 2 3 4 5 6 7 [Strezov, V., Evans, T. J., & Hayman, C. (2008). Thermal conversion of elephant grass Pennisetum purpureum Schum) to biogas, bio-oil and charcoal. Bioresources Technology, 99, 8394-8399.]
  4. 1 2 3 4 5 6 7 8 9 10 11 12 [Khan, Z. R., Midega, C. A. O., Wadhams, L. J., Pickett, J. A., & Mumuni, A. (2007). Evaluation of Napier grass (Pennisetum purpureun) varieties for use as trap plants for the management of African stemborer (Busseola fusca) in a push-pull strategy Entomologia Experimentalis et Applicata, 124, 201-211.]
  5. See page 831: Flores, Rilner A.; Urquiaga, Segundo; Alves, Bruno J. R.; Collier, Leonardo S.; Boddey, Robert M. (1990-01-06). "Yield and quality of elephant grass biomass produced in the cerrados region for bioenergy". Engenharia Agrícola. 32 (5): 831–839. doi: 10.1590/S0100-69162012000500003 . ISSN   0100-6916.
  6. Ansah, T.; Osafo, E.; Hansen, Hanne (2010). "Herbage yield and chemical composition of four varieties of Napier (Pennisetum purpureum) grass harvested at three different days after planting". Agriculture and Biology Journal of North America. Science Hub. 1 (5): 928, table 4. doi: 10.5251/abjna.2010.1.5.923.929 . ISSN   2151-7525.
  7. "Cenchrus purpureus & hybrids". Tropical Forages. Retrieved 2020-10-04.
  8. 1 2 3 [Aminah, A. Wong, C. C. & Eng P. K. (1997). Techniques for rapid vegetative multiplication for pasture species and commercial production. Regional Forage Development, FAO, Rome, pp167-178.]
  9. The soil was fertilised, rainfall was 2700 mm. For yield results, see table 2, page 40: "Yield and nutritive quality of nine Napier grass varieties in Malaysia". S2CID   59143548.{{cite journal}}: Cite journal requires |journal= (help)
  10. See page 206: Cardona, Eliana; Rios, Jorge; Peña, Juan; Peñuela, Mariana; Rios, Luis (2016). "King Grass: A very promising material for the production of second generation ethanol in tropical countries". Biomass and Bioenergy. Elsevier BV. 95: 206–213. doi:10.1016/j.biombioe.2016.10.008. ISSN   0961-9534.
  11. See page 516: Gwayumba, W.; Christensen, D. A.; McKinnon, J. J.; Yu, P. (2002-04-01). "Dry Matter Intake, Digestibility and Milk Yield by Friesian Cows Fed Two Napier Grass Varieties" (PDF). Asian-Australasian Journal of Animal Sciences. Asian Australasian Association of Animal Production Societies. 15 (4): 516–521. doi:10.5713/ajas.2002.516. ISSN   1011-2367.
  12. Zhang et al. measured a bana grass yield of 74 dry tonnes per hectare per year with light fertilisation and 1000 mm rainfall. See pages 96, 98: Zhang, Xia; Gu, Hongru; Ding, Chenglong; Zhong, Jianli; Xu, Nengxiang (2010). "Path coefficient and cluster analyses of yield and morphological traits in Pennisetum purpureum" (PDF). Tropical Grasslands. Institute of Animal Science, Jiangsu Academy of Agricultural Sciences, Nanjing, China. 44: 95–102. S2CID   55554503.
  13. Hoshino et al. measured a yield of 75.6 dry tonnes per hectare per year the second year of growth under heavy fertilisation and with rainfall level 1000 mm annually. See pages 310, 311, 315: Hoshino, Masao; Ono, Shigeru; Sirikiratayanond, Nittaya (1979). "Dry Matter Production of Tropical Grasses and Legumes and its Seasonal Change in Thailand" (PDF). Japanese Journal of Grassland Science. 24: 310–317. doi:10.14941/grass.24.310.
  14. Vicente-Chandler et al. found that heavily fertilized napiergrass produced 75,661 pounds of dry matter per acre per year when cut at 90-day intervals, equivalent to 84.8 tonnes per hectare per year. See page 202: Vicente-Chandler, Jose; Silva, Servando; Figarella, Jacinto (1959). "The Effect of Nitrogen Fertilization and Frequency of Cutting on the Yield and Composition of Three Tropical Grasses". Agronomy Journal. Wiley. 51 (4): 202–206. doi:10.2134/agronj1959.00021962005100040006x. ISSN   0002-1962.
  15. "The total water requirements are approximately 100 mm (4 inches) per month rainfall equivalent. [...] The yield of Giant King Grass depends on the time between harvests. For example, a six-month harvest of tall Giant King Grass, one can expect to obtain 80 or more US tons per acre (180 metric tons per hectare) of fresh grass at approximately 70-75% moisture. For two harvests per year, double these figures." Viaspace (2020). "Giant King® Grass: Grow and Harvest" . Retrieved 11 July 2020.
  16. Mackay quotes yields of 360 wet tonnes per hectare per year, but does not quantify moisture content. Mackay (2020). "Mackay Bana Grass" . Retrieved 11 July 2020.
  17. See pages 85-86: Smil, Vaclav (2015). Power density: a key to understanding energy sources and uses . Cambridge, Massachusetts: The MIT Press. ISBN   978-0-262-02914-8. OCLC   897401827.
  18. 1 2 3 4 [Miller, J. R., & Cowles, R. S. (1990). Stimulo-deterrent diversion: A concept and its possible application to onion maggot control. Journal of Chemical Ecology, 16(11), 3197-3212.]
  19. 1 2 3 [Khan, Z. R., Amudavi, D. M., Midega, C. A. O., Wanyama, J. M., & Pickett, J. A.(2008). Farmers' perceptions of a 'push-pull' technology for control of cereal stemborers and striga weed in western Kenya. Crop Protection, 27, 976-987.]
  20. "Scientists back use of Napier grass as sustainable way to feed herds". Africanews. 2020-01-31. Retrieved 2020-02-07.
  21. Heuzé V., Tran G., Giger-Reverdin S., Lebas F., 2016. Elephant grass (Pennisetum purpureum). Feedipedia, a programme by INRA, CIRAD, AFZ and FAO. https://www.feedipedia.org/node/395 Last updated on June 23, 2016, 17:09
  22. "Bioplastic – Vibers" . Retrieved 2020-02-13.

Wikispecies-logo.svg Data related to Cenchrus purpureus at Wikispecies