Smallhold Farming

A smallhold farmer in Kenya. Photo: Salim Shaban.

Smallhold farming. Primarily aimed at smallhold farmers in developing countries, particularly in the tropics and subtropics, but also for hobby vegetable growers in Western countries in cooler climates. Started 01/01/2020.

Please see also the pages and articles on this site on “Zai Holes”, “Mixed Improved Fallows”, “Fire Shields Living Fences”,  “Oil Palms and Deforestation”, and Faidherbia albida.

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“There is always a way to do it better… find it”. Thomas Edison.

“Improvise, adapt and overcome”. US Marines slogan.

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If you believe you have something to contribute which may help smallhold farmers, please feel free to add comments at the bottom of this page, or contact me by email: daveclode@hotmail.com.

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Push-pull agriculture technology

For more information about this amazingly successful strategy:

rstb.2012.0284.pdfPushPull

planting_for_prosperity.pdfPushPull

See videos on YouTube, with the search terms “push pull agricultural technology” especially ICIPE. See the ICIPE web site.

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Fall Armyworm (FAW)

01/01/2020. This moth is spreading alarmingly quickly, and in just a few years has spread throughout Africa South of the Sahara, and now into India, China, and moving into South-east Asia. The caterpillars can cause disastrous failures in staple crops such as maize, potentially causing catastrophic famine for millions of people around the world, and reducing the incomes of smallhold farmers who trade excess harvest for additional and vital income.

Maize crop in Kenya. Photo: Salim Shaban.

My intention is to add useful links to this page on this issue to help smallhold farmers. There are many excellent scientists working on FAW, including entomologists, agricultural scientists, and so on. My hope is that as someone qualified and experienced in horticultural science, with extensive plant knowledge, that I may be able to make an additional contribution in suggesting some more strategies which may be helpful in managing this pest.

For more information/links:

Try the search terms “fall armyworm tagetes” for an article in Standard Media about a couple of farmers in Kenya using sprays made from strong-smelling plants to repel Fall Armyworm from maize (the link didn’t work). There is a search space at the top right hand corner of the page.

Fall-Armyworm-IPM-Guide-for-Africa-Jan_30-2018

FAO booklet:

i8665en

insects-10-00195

Integrated pest management in oil palm plantations. The experience gained in integrated pest management in oil palm plantations, such as growing plants which provide nectar and shelter for parasitic wasps which control caterpillar pests could be applied and may well be helpful to control Fall Armyworm:

Search for “benefits of turnera subulata asianagri”

and: “Integrated pest management angloeastern”

5- BMP for Oil Palm Cultivation on Peat Soils – Integrated Pest (Mukesh)

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Some suggestions and possible additional solutions or strategies for managing Fall Armyworm

Desperate situations sometimes require desperate measures, and because of the urgency and seriousness of the spread of Fall Armyworm across Africa and Asia, I have presented suggestions below, including some which may seem outlandish, but sometimes brainstorming can result in good ideas. It is nevertheless necessary to be cautious, since with new ideas there is always the chance of unintended and unexpected negative consequences (as well as unintended and unexpected positive consequences). It is also true, however, that doing nothing has consequences.

There are many potential areas for more research which could prove fruitful.

Pull plants or decoy plants

These plants are grown deliberately to attract the pests so that it feeds or lays its eggs on  the pull plant (decoy plant, sacrificial plant, trap plant) rather than the crop plants. Examples presently include Napier grass/Elephant grass Cenchrus purpureus, formerly Pennisetum purpureum, and Brachiara grass species.

Napier grass, Cenchrus purpureus or Pennisetum purpureum, growing five metres tall in sandy soil, without irrigation or fertilization. Cairns, North Queensland, Australia. Photo: David Clode.

Zai holes are likely to be a good technique to grow pull plants.

See also: Napier grass production – Tumbukiza technology

Some additional possibilities:

Dracaena fragrans – very fragrant creamy white flowers at night may attract moths. Flowers could be sprayed at night, possibly with the bacteria Bacillus thuringiensis or a formulation or isolate of Metarhizium anisopliae (or some other entomopathogen specific to armyworm caterpillars or moths which may become available), so that the moths get covered in nectar and bacteria or fungus (the bacteria may even multiply in the nectar), and transfer the bacteria/fungus to crop plants when laying their eggs, and deposit the pathogen right next to the eggs, and so infect eggs and/or first instar caterpillars (called auto-dissemination strategy). ICIPE has a product called “Achieve” (ICIPE 78) which looks like it may be suitable for this. On the ICIPE website, click on “impacts”, then “products”.

Bacillus thuringiensis does not, however, survive long in sunlight and may not last long enough for auto-dissemination. Neem could also be tried on flowers but also degrades fairly quickly. Other more durable entomopathogenic fungi, bacteria, viruses, or similar, or new more durable formulations of Bt, may become available in the future. It would be important to use strains that impact only caterpillars in the armyworm genus, to avoid indiscriminate effects on other insect species.

 

Dracaena fragrans. Photo: David Clode.

Dracaena fragrans plants also look a little like maize and could attract moths at night to lay eggs on them. The plant also grows much taller than maize and so may be an obvious target for moths to lay their eggs. The plant is easily propagated from stem cuttings pushed directly into moist cultivated soil.

Tall Dracaena fragrans. Photo: David Clode.

Cordyline fruticosa is similar to Dracaena fragrans and may also be useful. The flowers may attract moths at night, and in the day in tropical Australia, they attract native bees of various species, and so they may be attractive to parasitoid wasps. Both seem to be palatable to grasshoppers and locusts, and so may be attractive to caterpillars as well, or work as a pull plant for locusts. This plant grows easily from stem cuttings pushed into moist cultivated soil in the wet season or with irrigation.

Cordyline fruticosa cultivar. Photo: David Clode.

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Locust devouring leaves of Cordyline fruticosa. Cairns, Australia. Photo: David Clode.

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Cordyline fruticosa cultivars. Photo: David Clode.

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Varieties of Cordyline fruticosa in a nursery. Photo: David Clode.

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Dracaena trifasciata – a smaller, low-growing succulent plant, which flowers at night and has scented cream-coloured flowers which may attract moths.  Previously Sansevieria trifasciata. This plant should not be intercropped as it may be difficult to get rid of it once planted. Likely to be a weed in some places. Easy to propagate from leaf cuttings placed directly into the soil, and very tough.

Dracaena trifasciata (Syn. Sansevieria trifasciata). Photo: David Clode.

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Dracaena trifasciata, previously Sansevieria trifasciata. Commonly called Mother-in-law’s-tongue. Cairns, Australia. Photo: David Clode.

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Jasminum species. Some species of Jasmine could be better than the plants above, as they also have scented white flowers at night, but may flower for longer and flower repeatedly, especially if numerous plants are grown and they are pruned on a rotation.

Jasmine. Photo: David Clode.

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Jasmine. Photo: Bibi Pace on Unsplash.com.

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Some maize varieties which are particularly attractive to FAW and could be grown as pull plants, but not if seed is collected from the crop for future crops, and cross pollination may have occurred. A spray could be made from susceptible maize varieties, which could be applied to pull plants to possibly make them even more attractive to moths to lay their eggs.

Pull plants which are over fertilized, especially with nitrogen, and over watered, should produce lush sappy growth which may make them more attractive to pests such as FAW. News paper Zai holes fertilized with human manure and human urine would be a cheap and effective way to produce such growth. Please see the Zai holes pages for more information on this topic.

Human urine trial with maize in Zimbabwe. Maize on the right fertilized with human urine. Photo: Peter Morgan, Epworth 2005.

Possibly other grasses such as Gamba grass Andropogon gayanus and Guinea grass Megathyrsus maximus, previously Panicum maximum, could be worth testing as pull plants.

In Central America and some Pacific Islands, Erythrina species are often combined with Napier grass to form a living fence, with each species alternating. Erythrina species could be good pull plants, and have flowers which attract birds which may eat caterpillars. The genus is nitrogen-fixing, and the leaves can be used as fodder, as mulch, and for making compost. Erythrina species can be established from large branch cuttings, placed directly in the soil.

Coral tree, Erythrina indica.

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Yellow-bellied Sunbird (Olive-backed Sunbird), Erythrina indica flower. Photo: David Clode.

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Erythrina x bidwillii. Coral trees (and lower bushy spp.) make excellent living fences, providing fodder, and habitat and nectar for wild life. They are also nitrogen fixing, improving soil fertility.

Macaranga tanarius (Asia) and possibly Musanga cecropiodes (Africa). Macaranga is eaten by a range of caterpillars and locusts and grows quickly and easily.

Macaranga tanarius leaf. Photo: David Clode.

 

Lamiaceae plants.

Solenostemon (Coleus). In my experience of growing this plant, it seems to be very attractive to caterpillars, but may or may not attract FAW. The flowers may possibly provide nectar for parasitoid wasps. Not very tough, needing extra moisture and may need some shade for part of the day, or partial overhead shade, to grow well, but will probably flourish in news paper Zai holes with extra water and nutrients.

Varieties of Solenostemon scutellariodes in a nursery. Photo: David Clode.

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Push plants or repellent plants

These plants repel the pest away from the crop, such as Desmodium intortum, D. uncinatum, Tagetes spp.

See Desmodium in push-pull technology.

Asteraceae plants:

Tagetes species have been tried with some success. They could be an intercrop, perhaps every fourth plant between cereal plants, and also used in mixed improved fallows. Some species may exert some control of nematodes. They may provide nectar for beneficial insects. Some species tend to be weeds.

Possibly Artemisia species, and different species may push or pull. Plants in this genus generally need full sun and well-drained soils (and often infertile soils) to grow well. Research is needed. Artemisia annua is grown as a crop in Kenya to produce anti-malarial pharmaceuticals.

Artemisia species are likely to be allelopathic (produce chemicals which inhibit the growth of plants growing near them or after them) and so may not be a good choice as a relay crop, nor as an intercrop, but rather grown as a border on the edge of the crop.  tropical.theferns.info

Plant-based repellent sprays

These sprays often have a strong smell and will hopefully deter the moths from landing on the crops in the first place (and therefore they don’t lay eggs which turn into caterpillars). Garlic, Tagetes species (marigolds) and a few other plants have already been tried and shown promise.

Some possibilities:

Allium tuberosum garlic chives. Unlike many culinary herbs, garlic chives also grow well in the tropics. The leaves have a strong garlic smell and may be repellent to moths. In addition, the flowers should attract beneficial wasps/bees and flies. The leaves and flowers can be used in cooking as well.

the flowers of garlic chives being visited by a species of native bee. Photographed in a friend’s garden in Cairns Australia (wet tropical climate)..

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The flowers of garlic chives being visited by a Hymenoptera species of insect. Photographed in Cairns Australia.

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Cymbopogon citratus Lemon grass.

Lemon grass, Cymbopogon citratus.

Lantana camara is an invasive weed outside Latin America but has strong smelling leaves which may possibly repel moths from laying eggs on crops. It may be available as an existing weed.

Lantana camara is a very common weed throughout the tropics.

Artemisia species including possibly Artemisia afra and Artemisia annua, and in cooler climates and possibly higher altitudes, A. absinthium and A. abrotanum. Researchgate.net, plantzafrica, ECHO.

Ibosa riparia has strong smelling leaves and may be repellent. (Tetradenai riparia) tropical.theferns.info.

Lamiaceae. The mint/sage family:

Plants in this family, such as mints and sages, commonly have scented or pungent leaves. The flowers of some attract Hymenoptera insects, and some attract nectar/insect eating birds. Many plants in this family can be grown from cuttings struck in the ground, if the soil is friable and moist.

Plectranthus species, including Plectranthus neochilus. Strong smelling leaves. Has shown some effectiveness in repelling mosquitoes.

Plectranthus amboinicus (syn. Solenostemon amboinicus, Coleus amboinicus). This plant has strong smelling leaves and is also used as a spice. There are many other species of Plectranthus and related genera with pungent leaves which could be repellent to moths. The flowers are possibly attractive to parasitoid wasps. Some Plectranthus species grow in cooler climates.

Anti-feedant sprays

These cause the caterpillars to eat less and therefore cause less damage. Some of the plants mentioned in the section before could work.

Some possibilities:

Olea africana and O. europaea.

Artemisia species – many species contain bitter compounds in their leaves which may reduce the feeding and therefore damage caused by caterpillars.

Aloe species – nearly all, including Aloe vera, have very bitter viscous sap which may stick on the crop plants and last for a while, perhaps reducing the feeding of caterpillars. Their flowers also attract birds which may eat caterpillars. Plantzafrica.

Aloe, possibly Aloe camperi. Photo: David Clode.

Plant-based insecticides

Resistance has been already recorded to many insecticides, and the caterpillars are sometimes buried in the plant and not susceptible to contact insecticides. Pyrethrum is commonly used. There are also more toxic systemic sprays, but these are best avoided if possible. Something which may not have been explored much is granular insecticides incorporated into the soil. Recently planted crop plants could be watered with a water and Neem or Melia leaves mixture, and the mixture be absorbed by the roots and possibly the leaves of the plant and result in a systemic effect. Perhaps the leaves of Neem or Melia placed on the soil at the base of plants when the caterpillars drop to the soil to burrow and pupate may have an impact.

Host plants for beneficial insects

These would include plants which host parasitic and predatory wasps. The photos below show species in the order Hymenoptera, with the assumption that these plants may be attractive to most Hymenoptera, including parasitic and predatory wasps and perhaps beneficial fly species. If parasitoid wasps are bred and released to protect crops, then the presence of host plants may enable the wasps to form permanent colonies and so provide ongoing protection.

Video below of a few species of bees visiting the flowers of a Coral Vine Antigonon leptopus.

Allium tuberosum garlic chives.

Crotalaria species. Many species in Africa and Asia. In addition to floral nectar,  Crotalaria pallida also has extra-floral nectaries which may make it particularly effective providing nectar for parasitic and predatory wasps. There are probably other Crotalaria species which have extra-floral nectaries. As a bonus, this genus fixes nitrogen and some can be used as fodder and can be used as green manure/fallow plants.

Crotalaria species, probably Crotalaria goreensis. Photo: David Clode.

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A Crotalaria flower visited by a Fire-tailed Resin Bee Megachile mystaceana. Photo: David Clode.

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A Carpenter Bee visiting a Crotalaria flower. Photo: David Clode.

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Guinea grass and crotalaria growing together. Photo: David Clode.

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Turnera subulata has been proven to be effective in oil palm plantations in SE Asia, providing nectar and shelter for parasitic and predatory wasps. It only flowers in the morning, so it could be combined with Antigonon leptopus (see below) which attracts insects all day. See more photos and information further down this page.

Antigonon leptopus – as above. This is a vigorous easy-to-grow climber and can be grown on a fence or other support and so not take up much space in a smallholding. This plant has proven to be an invasive weed in some places, so in my opinion it should not be grown in places where it has not already been introduced. It may be best to grow this plant in containers, to confine the spread of tubers, and to cut back near the end of flowering, to reduce seed set.

Antigonon leptopus. Photo: David Clode.

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An Australian Native Bee visiting Antigonon leptopus.

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A wasp getting nectar from an Antigonon leptopus flower. Photo: David Clode.

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A black bee visiting Antigonon leptopus for nectar. Photo: David Clode.

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Cuckoo bee. Photo: David Clode.

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Asteraceae:

Plants in the daisy family commonly have flowers with easily accessible nectar and pollen, and can support beneficial insects.

Sunflowers.

A honeybee visits a sunflower. Cairns, Australia. Photo: David Clode.

Tithonia diversifolia (may be an invasive weed).

Tithonia diversifolia. The flowers attract pollinating and other beneficial insects. Photo: David Clode.

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Tetradenia riparia Flowers may provide nectar and leaves are strongly scented.

Faidherbia albida flowers contain nectar and may host beneficial insects, along with multiple other benefits.

Maize grown under Faidherbia trees. Photo: learningenglish.voanews.com.

Euphorbia species. Perhaps some smaller herbaceous species.

Terminalia tree species may provide nectar and pollen for beneficial wasps and flies.

In cooler climates, Allysum Lobularia maritima, Ajuga reptans, Dill, Tansy, and other plants in the Asteraceae, Rosaceae and Apiaceae/Umbelliferae may help to attract beneficial insects.

Healthy plants

Plants grown with optimal weeding, fertilizing, watering, etc. may be healthier and better able to produce volatile compounds which repel pests, and/or recover from damage. Zai holes could have a role in this.

Fast-maturing crops

As the caterpillars grow larger, they eat more and so most of the damage is caused towards the end of the life of the crop. Fast maturing crop varieties may produce a harvest before the caterpillars cause major damage.

Cut-and-carry stall fed livestock

These systems often depend on Napier grass or Gamba grass Andropogon gayanus. Plants could be sprayed in a rotation with plant-based repellents, and harvested in a rotation to limit damage but also provide fodder which is not recently sprayed and so is still palatable and not tainted. Plants which host predatory and parasitic wasps could be planted around the smallholding, such as Crotalaria species

Napier grass Cenchrus purpureus, syn Pennisetum purpureum Photo: David Clode.

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Beneficial insects and host plants continued

Beneficial insects include honey bees for example, which provide not only honey, but also pollination of crops and fruit and nut trees, parasitic and predatory wasps which control pests, and many others.

Some photos below of the low shrub Turnera subulata which has potential to host beneficial insects such as parasitic wasps, as well as honeybees and other beneficial insects. I have grown this plant myself, and its flowers provide nectar and shelter for beneficial insects, and it flowers repeatedly throughout most of the year.

This plant has been proven to be effective in providing nectar and shelter for beneficial insects, and in turn controlling pests including Bagworm caterpillars in oil palm plantations in SE Asia. It can spread as a weed, but in my estimation is most likely to be a problem only in sandy soils near the coast in the wet tropics. It is probably best if it is only grown where it is native, or in places where it has already been introduced and has not spread as a weed.

The plant grows easily from cuttings and grows best in full sun in well-drained soils, and does not need much fertilizer. If it is cut back once a year, and with occasional fertilizer, perhaps a few weeks before cutting back, it should grow for five years or more. Plants could be pruned on a rotation spread out through the year so that there are almost always flowers present to provide nectar.

In my experience of growing Turnera subulata, the plant attracts a host of arthropods including bees, predatory wasps, spiders, mantids, etc. Photo: David Clode.

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A small native Australian bee busy visiting a Turnera subulata flower, early in the morning, after rain. My Garden in Cairns. Photo: David Clode.

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A Carpenter bee Xylocopa aruana visits flowers of Turnera ulmifolia. This species or colour form does not seem to be quite as effective as  T. subulata. Photo: David Clode, Cairns.

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Blue-banded bee Amegilla species coming in for nectar and pollen (flower – Turnera subulata). Photo: David Clode.

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A Flower Wasp, Campsomeris species, visits a Turnera subulata flower for nectar.

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Honeybees taking turns to visit a Turnera subulata flower. Photo: David Clode.

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Blue-banded bee visiting a Turnera subulata flower. Photo: David Clode.

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Blue-banded bee. Amegilla sp., visiting a Turnera subulata flower. Cairns. Photo: David Clode.

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More photos of beneficial insects and host plants

A carpenter bee visiting Sesbania sesban flowers in Kenya. This plant very fast growing, is nitrogen-fixing, and is useful in mixed improved fallows.

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A Bumblebee visiting a sunflower in Tasmania, Australia.  The closely related Tithonia sp. also attract bees and other beneficial insects.Photo: David Clode.

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Potter wasp building it mud nest. These wasps catch caterpillars to fed to their larvae. Photo: David Clode.

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A honeybee visits Moringa oleifera flowers. Photo: Cairns, Australia, David Clode.

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A Carpenter Bee visiting a Pentas flower. Cairns, Australia. Photo: David Clode.

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A Bumblebee visits Hebe or Veronica flowers in Tasmania, Australia (cool temperate climate).

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Paper wasps Ropalidia species and nests, under a leaf of a Bismarck palm Bismarckia nobilis. Cairns. Photo: David Clode.

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Dung beetles for soil improvement

Dung beetles, Namibia. Dung beetles dig tunnels into the soil and incorporate the dung, improving the soil in numerous ways. Photo: Wikimedia.org.

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Dung beetle tunnel entrances. Photo: John Feehan, http://www.dungbeetleexpert.com.au.

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The potential of livestock concentrated in a small area to improve soil and plant growth. Maize control plot on the left (no livestock), and livestock treated plot on the right. Dung beetles may have helped to incorporate manure into the soil. Photo: Buckminster Fuller Institute.

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An article on growing vegetables in sandy soils in a Mediterranean climate:

vegsand

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Reforestation.me.

David Clode.  B. App. Sc. (Hort.).

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