An invasive species in Kenya, Opuntia (Prickly Pear)

Photo credit: SciDevNet

Copyright: CABI

Sap-sucking insects may combat Kenyan cactus plague

“So when times are good it will continue to displace local plants and make more valuable pasture inaccessible.” – Arne Witt, CABI-Africa

Speed read

  • Prickly pear cactus is an invasive plant that threatens grazing areas in Kenya
  • A trial now shows that a species of bug can be used to control the cactus
  • But further safety testing and approvals are needed before rolling it out

An insect that sucks the sap out of cactus plants has been trialled in East Africa to contain the spread of an invasive cactus species that threatens local grazing areas.

The cochineal bug, known as dudu in Swahili, for biological control has been released on farmland in Kenya’s Laikipia region, which is used by Maasai for livestock herding. The trial showed that the bug feeds exclusively on the Opuntia stricta cactus, better known as prickly pear, which has invaded grasslands and drives out local plants used to feed cattle.

The Maasai community in Laikipia partnered with the Centre for Agriculture Biosciences International (CABI) to conduct the trial and halt the spread of the cactus. According to CABI, an non-profit science organisation from the United Kingdom, the trial, which concluded last month, has shown that the dudu bug will not be harmful to native and non-harmful imported plants in the region.

“The cochineal has not been found on other cactus species such as Austrocylindropuntia subulata and Cereus jamacaru that are growing in association with Opuntia stricta,” says Arne Witt, the coordinator of the invasive species programme at CABI-Africa. “In a nutshell, there is no risk.”

The prickly pear cactus was introduced in Kenya during colonial times as an ornamental plant capable of living in arid regions. Since then, the plant has colonised thousands of acres of fragile rangelands in northern Kenya, putting at risk the livelihood of animal herders.

According to CABI the cactus is also suspected to have caused the death of baby elephants after they consumed its fruit, meaning it poses a threat to local wildlife and related income from tourism.

Read the full article: SciDevNet

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COMMENT OF Willem Van Cotthem

The prickly pear (Opuntia ficus-indica) is an invasive species.  Due to its hard spines it has almost no predators and known methods to destroy it are expensive.

On the contrary, the spineless variety (Opuntia ficus-indica var.inermis) is a widely cultivated plant in Central and South America, edible for men and animals.

Therefore, describing the prickly pear (Opuntia ficus-indica) as a noxious invasive species is a generalisation that is far too negative for its edible and ornamental spineless variety.  Moreover, the prickly pear can also be used to produce an interesting biofuel.

Enabling women to combine farming with bringing up children and running household

Photo credit: ICARDA

Cactus thrives on very little water and does not require frequent labor inputs. 

Female farmers show the way

In parts of Egypt’s arid New Lands, female farmers are choosing to grow prickly pear, a type of cactus, rather than more conventional crops such as wheat. Prickly pear is better suited to desert conditions than most of the crops promoted by the Egyptian government. It also generates an income which helps women to pay for their children’s education. Against a backdrop of climate change and associated water shortages, ICARDA researchers have identified ways that the government can support female farmers in the New Lands and promote the cultivation of prickly pear and other drought-tolerant crops throughout desert settlements.

OPUNTIA BIOGAS ELQUIGLOBALENERGY P9270040_2 copy.JPG
OPUNTIA BIOGAS ELQUIGLOBALENERGY P9270040_2 copy.JPG

Due to climate change and population growth in the Nile Basin, Egypt is set to face severe shortages of irrigation and drinking water in coming years – it is predicted that by 2050, Egypt will need to use around 50 per cent of the Nile’s water for drinking alone. At the same time, up to 15 per cent of agricultural land in the fertile Nile delta could be inundated as sea levels rise.

Since the 1980s, the Egyptian government has been resettling farmers in desert regions, the so-called ‘New Lands’, in response to land and water shortages and as a strategy for boosting food production. Each settler is provided with a plot of land, a shared irrigation pump, and a house. ICARDA researchers have been investigating how female settlers have adapted to farming in these arid conditions.

PRICKLY PEAR: AN ADAPTATION TO A THORNY PROBLEM

Female farmers in some New Lands settlements grow spineless prickly pear, Opuntia ficus-indica f. inermis, to supply the tourist sector in Cairo and Alexandria. This is partly a response to their marginalization from support programs, such as agricultural extension activities, which promote more conventional cash crops such as wheat.

In fact, prickly pear suits desert conditions better than other produce grown in Egypt, such as fruit trees. The cactus thrives on very little water and does not require frequent labor inputs. Because of these characteristics, it has sometimes been dismissed as a ‘lazy farmers’ crop. These same features, however, enable women in the New Lands to combine farming with bringing up their children and running their households, which are often located some distance from their farms. The cash they earn from selling prickly pear fruits has helped them to fund their children’s schooling and provide for their daughters’ marriages.

BARRIERS TO EXPANDING THE PRODUCTION OF DROUGHT-TOLERANT CROPS

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For more information:

Najjar, D. (2015). Women’s contributions to climate change adaptation in Egypt’s Mubarak Resettlement Scheme through cactus cultivation and adjusted irrigation. In Buechler, S and Hanson A.S. (Eds). A Political Ecology of Women, Water and Global Environmental Change. Chapter 8.

Read the full article: ICARDA

A plant with universal value : the prickly pear (Opuntia)

Photo credit: FAO

Cactus pear

Opuntia ficus-indica (Indian fig, mission cactus, prickly pear, Barbary fig, tunas, palma forrageira, among others)

Traditional Crop of the Month

EXCERPT

Where it is found

The centre of origin and domestication is Mexico but the plant is now found in the wild in several countries including the USA, across the Mediterranean, Angola, Australia, Kenya, and South Africa.

Spineless variety of the prickly pear cactus - http://pixabay.com/static/uploads/photo/2014/12/03/15/01/prickly-pear-555530_640.jpg
Spineless variety of the prickly pear cactus – http://pixabay.com/static/uploads/photo/2014/12/03/15/01/prickly-pear-555530_640.jpg

How to eat it

Nopalitos with Tomatoes and Onions

1 lb nopalitos (cactus pear branches that have been stripped of spines, cleaned, and chopped); 1 tablespoon olive oil; 2 large cloves garlic, minced; half a red onion, roughly chopped; 1 jalapeño pepper, stem and seeds removed, chopped; 1 medium tomato, roughly chopped; quarter of a teaspoon ground cumin, or to taste; salt and pepper to taste.

Heat a tablespoon of olive oil (enough to coat the bottom of the pan) in a large sauté pan on medium high heat. Add red onion, garlic and jalapeño. Cook for a minute, stirring occasionally, then add the nopalitos and continue cooking for 15 minutes. Then add the chopped tomato and cumin and simmer until the vegetables are cooked. Season with salt and pepper and serve immediately with corn tortillas. Serves 4.

Read the full article: FAO

Read at : Google Alerts – drought-tolerant plants

http://www.mercurynews.com/home-garden/ci_24819176/ruths-tips-hardy-aloes-tasty-prickly-pears

Ruth’s Tips: Hardy aloes, tasty prickly pears

Walnut Creek’s Ruth Bancroft is a national authority on drought-resistant gardening. Twice a month, she and her staff share their knowledge with readers.

Q My wife’s birthday is in December, and she likes aloes. So I planted one for her in our garden in Walnut Creek, chosen because it comes into flower in December. It started to put out a flower stalk in November, but the flowers froze during a cold spell in early December, before they even had a chance to open. The plant itself is OK, but can you recommend another choice with more cold-tolerant flowers?

A We can relate to your problem with cold-damaged aloe flowers, since the same cold snap ruined many blooms at the Ruth Bancroft Garden. An exception was Aloe mutabilis, native to the high plateau in northeastern South Africa, near Johannesburg. In full flower in December, it came through unscathed while others around it did not.

Q I just read the Ruth’s Tips column relating to prickly pear cacti (Dec. 7) and would like to know the following: Can this cactus be planted in a large pot? What species and type of soil are best suited to ensure growth and fruit production? Where can this plant be purchased?

A Prickly pears are quite easy to grow, and do well in containers, as long as the soil has good drainage and the pot is placed in the sun. However, the pot should not be located where it might be brushed against by passers-by, since the many tiny spines (glochids) could wind up embedded in the clothes or skin of people who come into contact with them. One protective measure is to place other pots around the prickly pear, to provide a barrier. Occasional applications of small amounts of fertilizer will ensure good growth and flowering, as well as fruit production.

(continued)

Email questions on drought-resistant plants to info@ruthbancroftgarden.org.

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