A Guide to Tree Forage Crops

Compiled by G Halliwell
Advisory Services Division
Ministry of Agriculture and Fisheries
Gisborne, 1979.

Foreword

Over the past years I have received a number of queries concerning Tree Crops for Forage.  These questions cover a diverse field.  They range from providing a balanced diet for stock at certain times of the year, including the place of leaves in the diet of animals, through to the development of a more self-sustaining Agriculture – the latter against a background of rising costs, often hidden, in Sheep and Cattle Farming, coupled with the loss in value of the Pound sterling and dollar, and increasing fertiliser charges.  The queries particularly emphasise using Tree Forage Crops, as a counter to the periodic droughts which wrack this East Coast Region.

However I must add here that I believe, the destruction of natural forests in days gone by in Southern Europe, North Africa, Arabia and the Canaries, has caused and is still causing, desert and semi-desert conditions at a rapid rate.  Our own country lies in similar climatic latitudes to these dry lands, and unless we conserve our native forests now by every possible means, we shall have the same desert conditions here in a few decades.  Already, one of New Zealand’s foremost authorities in this sphere has stated that he thinks the writing is on the wall in this respect and increasingly so.

Lately questions have come from deer farmers with respect to forage crops appropriate to their circumstances – a difficult subject at best, for deer particularly will eat almost anything, either from necessity, for the sake of diversity in diet, or maybe out of sheer wantonness!

Deer will eat to destruction Kamahi, Rata, Fuchsia, some Coprosmas, Pseudo-panax, Neo-panax and many others.  They will also chew such tough things as Olearias, Senecios-alpine and sub-alpine, together with Hebes, and chew them to bits.  They eat out small ferns and grasses, together with the smaller shrubs, chewing them right down to the roots.  Associated with the opossum of course, the damage done in our native forests is fatal.  Deer are not so fond of the Pepper trees and Stinkwood, not of the Totara, but where food is short they will eat even these.  Deer ring-bark trees, sometimes when palatable food is scarce, but sometimes also by choice.  The barking can be fatal.  Deer have killed large trees in the USA so I do not believe that deer farming and Tree Cropping are generally compatible in this country, unlike Britain with its oaks.

Deer are destructive to our tender lush evergreens so effective and essential to our protective rain forests.  It has been said that mankind has taken upon itself the balancing of the relationship between cultivated plants and animals and their environments.  Further, that a massive technical armoury is employed for this purpose, oft-times blindly, so much so that we are now faced with serious problems from an imbalanced agriculture.  The serious loss of topsoil, which took many, many years to build, in the Wairarapa and around Gisborne particularly, illustrates the point.  Where else but Gisborne could we get a flooded river (the Waipaoa) carrying over 12 million cubic metres of sediment to the sea in one day?

To achieve balance within a sustained economic framework of farming, demands sweeping measures, the basic fundamentals of which are first, the retention of our strategic rain forests, and second, I believe, the use of Tree Crops to maintain environmental equilibrium and to make poorer land yield profitable harvests.  This means utilising associations of species and moving away from Monoculture, whether it be Radiata Pine or ryegrass and White Clover – or anything else!

I have set out for reference purposes, a List of Tree Crops for forage in alphabetical order with some comment of each, and where relative, pointers from the Gisborne experience.  This list is based on a paper by J Sholto Douglas, “Tree Crops for Food, Forage and Cash” in “World Crops” (January to April 1972)

This list is only the beginning, for in each genus there are many species, some useful, some not.

There are a wide range of Tree and Shrub species being used for sheep and cattle grazing in other parts of the world which are suitable for investigation in the NZ environment.  In Bulgaria for instance, species of Populus, Quercus and Fagus are all browsed.  The Field is a large one!

Classification of Plants

Plants are classified in this Bulletin according to the 1958 International Code of Nomenclature.  That is, the genus or ‘race’ is given, then the species (within that genus), and if applicable the cultivar within the species.

In effect, an individual plant has two Latin names, the first being the genus to which it belongs, or the generic name, and the second, its species or specific name.  After that, a cultivar name may also be listed.

Acacias

These include a large number of trees (and shrubs).  They are all legumes.  Various types are common in Asia and Australia as elsewhere and several provide useful fodder.

  1. A. longifolia.  Sydney Golden Wattle, growing as a volunteer on the consolidated sands of upper Northland (Pukenui) is popular as a food source (ie seeds) amongst the Australian aborigines but it does not appear to have much merit as far as stock are concerned.
  2. A. decurrens.  Black Wattle.  (Ref: J W Harris) Is effective along with the Weeping Willow as a bloat control medicine and provides ample feed in winter.  Grass grows well under Black Wattles and Weeping Willows if reasonably pruned for fodder.  Can alternate Weeping Willows and Black Wattle along fencelines in some circumstances, with one-wire protections until they are established.

Grazing animals will kill any young suckers which spread through a fence onto pastures.  Species such as Acacia pendula (Weeping Myall) may provide a useful standby stock fodder in times of drought.

Acer saccharum – Maple

Native to North America.  The Maples are hardy, deciduous trees favouring well-drained soils.  Acer saccharum and others bear edible foliage which provides good forage for livestock.  There are over 150 species in the genus.

Brachychiton populneum (syn b. diversifolia) – Kurrajong

Kurrajong is regarded in Australia as one of that country’s most valuable fodder trees.  It grows in most soils preferring those with lime.

The tree attains large size with emphasis on spread rather than height.  It is deep rooting and drought resisting.  Its dense glossy green foliage remains succulent throughout the hottest and driest summer.

The foliage is highly nutritious and many Australian pastoralists claim that lambs will fatten on Kurrajong foliage alone.  In fact on some large central and mid-western stations, Kurrajong is grown as a standby drought fodder.  (Ref. N Barr)

Provided the lopping of branches is carried out with reasonable care, many branches will grow where only one grew before.

Kurrajongs are readily grown from spring sown seed.  The seed itself has a tough outer casing and needs soaking in near-boiling water for about one hour before sowing.  Seedlings, which move slowly at first can be planted our while quite small provided they are given adequate protection.

The bark does not appear to be damaged by stock.

Kurrajongs can be grown for 5 years – wrenching or cutting through the fleshy roots every year, and at the same time freeing the bole of side branches.  When the trees are 4 to 5 metres high they are finally wrenched and planted at 8 to 10 metres apart.

Trees are growing well in Gisborne and I notice one in Frimley Park, Hastings

Carya species – Pecan and Hickories

Natives of North American, the Carya species thrives best on deep friable, and moderately fertile soils.  Yields of nuts from individual Pecan trees of over 270 kg per season are not unusual.

First class grafted and budded varieties should be uses.  Bearing can begin in about the third year after setting out.  Pecan nuts after milling make excellent meals for livestock.

Hickories and Pecans are relatively little known in New Zealand but they make first class isolated specimen trees.

The main Carya species are:

Carya illinoensis Pecan

Cary olivaeformis Also classed as Pecan

Carya ovata Shagbark Hickory

Carya laciniosa Bill Shellbark Hickory

There is a Shagbark Hickory bearing nuts at South Makaretu, back of Norsewood.

Castanea species – The Sweet Chestnut

There are four species of Chestnut producing edible nuts.

Castanea sativa Spanish Chestnut

Castanea dentata American Chestnut

Castanea mollisima Chinese Chestnut

Castanea crenata Japanese Chestnut

Chestnuts are long lived prolific seeders.  The milled nuts are very valuable in animal and human diets.  Species (and cultivars) suit mountain land.  In choosing varieties of all types of chestnuts select for blight-resistant strains.  Endothis parasitica of proven high yield and quick growing cultivars.  Grafting is normally employed.  Good trees can produce harvests of about 270 kg of nuts annually.

The meal produced from chestnuts is liked by farm livestock.  It is a Carbohydrate food containing about 5 to 7% protein as well as appreciable far, Calcium and Iron.

Chestnuts of well in the Dannevirke and Napier districts on drier hill slops and lighter stony soils as in Corsica, Spain etc.  They thrive of course around Hamilton.

Ceratonia siliqua – Carob

A medium sized tree and fine ornamental tree originally native to the eastern Mediterranean.  It bears heavy crops of sweet, sugary pods or ‘beans’ from 15-25cm in length, over 2.5cm broad, dark brown in colour and very palatable.  The pods are a valuable food for farm livestock but are also relished by human beings.  They contain over 50% sugar and may be eaten whole or ground into meal and flour.

Both the pod and the seed of the Carob are edible and high in energy.  The tree is ‘dioecious’ (having male and female flowers on separate plants), generally, and in cultivation it is essential to graft selected varieties on to strong seedling stocks.

Alternatively male trees may have branches inset from a good female tree reserving two or three males branches so as to ensure good pollination.  In seedlings the tap roots are delicate and must not be exposed or handles.  Unimproved Carobs can be slow growers but the new cultivars begin to bear at 3 to 4 years after planting out and yields may be as much as 450kg of pods per tree.  C. siliqua is a legume and likes rocky and strong land in arid and semi-arid regions.

The productive life of trees is possibly 100 years.  Harvests of up to 50 tonnes/hectare annually are known in Carob plantations overseas.

Winter temperatures of -6°C (20°F) or below will cause injury and in general even slight prolonged frosts can retard fruiting.  Carobs then are not recommended for cropping in areas where the climatic conditions are too cold.  Nor do they like excessive dampness.  They have drought resistant qualities and have the ability to utilise underground water supplies.

The Californian State Experiment Station reports that for livestock feeding Carob beans are slightly superior to barley.  All kinds of stock readily eat the pods with 2.5kg or thereabouts a day of the pods with a little grass are reported sufficient for a working horse!

Ceratonia siliqua is grown widely and bears well in Hawkes Bay.  There are a few trees around Gisborne and some at Opoutama, Mahia which have been growing for many years.  The tree is more resistant to cold than citrus.

Apparently one can take cuttings about 30cm long and insert them 12cm in the ground.  Seed should be fresh and possibly hot water treated.  One male is needed to every 20 (or more) female trees.

Carob trees grown to produce food are permitted to branch low and require little training.  A small seedling (15cm) given me by C Van Kraayenood about 1963 is now a tree over 7 metres high at Mill Bay, Mangonui, Northland

Chamaecytisus proliferus
Tagasaste (syn prior to 1960 Cytisus proliferus) –
False Tree Lucerne

A small evergreen tree producing a heavy yield of valuable livestock fodder – the leafy branches can be cut and fed directly.

Chamaecytisus proliferus (Tagasaste) is indigenous to the hills of the Canary Islands where it is valued for cattle farming.  The plants all require fairly light friable soils

Two harvests are taken annually.  C. proliferus is used as a fast growing temporary hedge in parts of New Zealand.  It can be relied on for 10 to 12 years for this purpose.

Allied species are C stenopetalus (Canary Islands) with yellow flowers and C. pallida bearing white flowers.

Tagasaste C. proliferus was successfully used by Mr Williams Puketiti Station, Te Puia Springs (Gisborne – East Coast) as a nurse tree to establish very large native and mixed forest blocks out of bracken fern and burnt over Manuka about 1915.  Odd Tree Lucerne plants are still present in the forest area.

Tagasaste planted a year or more in advance is excellent for establishing many Eucalypts and for frost-tender species such as Karakas.

There are several varieties of the species, some palatable, but some not so.  The foliage has a high protein content and a feeding value almost equal to that of Lucerne.  Bees (and Kereru, Native Wood Pigeon) are strongly attracted to the white pea-like flowers.  The black seeds that form in the flat pods make a good high protein food for poultry.

Tagasaste Fact Sheet…

Corylus species – Hazel

There are eleven economic species!

Filberts or Hazelnuts contain on the average about 13% protein and over 60% fat.  The trees are suited to temperate climates and will form dense thickets as a secondary ground layer beneath the open canopies of larger trees.

Most soils are satisfactory, including poorer ones.

‘Cobnuts’, ‘Filberts’ and ‘Barcelona’ are simply highly developed forms of the ordinary Hazel, Corylus avellana. Only superior strains should be planted.  The Hazelnut is somewhat slow growing. Reasonably good ‘Barcelona’ trees in Spain yield about 23kg of nuts in a season.

The nuts are relished by livestock and when ground up form a good feeding meal.

Corynocarpus laevigata – Karaka Nut

The NZ Karaka reaches a height of 12m or more.  The tree has orange coloured fruits about 4cm long with an edible pulp.  The kernels – about the size of a small acorn were eaten by the Maori but only after preliminary soaking and washing in salt water.  The seeds are poisonous unless steamed or seeped in salt water.

Research could be done with this tree as a potential fodder crop including the food value of the fruit and processed kernel.

A Broadwood farmer (Hokianga county) advises that every summer they eat lots of the fruit, that is, both the ripe fruit and the processed kernel.

To process the Karaka nuts the whole fruit is boiled for at least 8 hours (not necessarily all at one time) and then they are placed in a sugar bag and soaked in running water for 2 or 3 days.  This is the technique used by Maori people in the district.  The processed nuts are very palatable.

The trees are fast growing and the fruits have a good potential for most farm stock.  Pigs thrive on the fallen fruits with excellent weight gains.

Crataegus Species – Hawthorn

One type of particular economic value, the Mexican Hawthorn, Crataegus orientalis has been under investigation overseas.  The fruits after drying can be ground into a good meal for farm animals.

Hawthorn leaves are edible and palatable as cattle fodder.  There are individual trees which are thornless and these could be utilised for further improvement.

Mr Sykes, Botany Division, once told me he had tried some Crataegus fruits raw but they were pretty insipid and tasteless.

Both Crataegus oxycantha and C. monogyna, the Common Hawthorn were declared noxious in many counties under the Old Noxious Weeds Act.

Casuarina

A genus containing about 35 species of evergreen trees and shrubs, chiefly Australian.  Some species are used in time of drought.

Most of the larger species popularly known as ‘She Oaks’ or ‘Sheokes’ yield valuable timber.

Propagation is by cuttings of half-ripened wood.

Diospyros Species – Persimmons

There are over 200 species of Persimmons distributed throughout the world, and within these literally several thousand strains or varieties.  There is a Persimmon for every area.  The trees are tolerant of soil conditions and will thrive on a wide range of soil types including quite poor ground.  The fruits are very nutritious, farm animals relish them, and it is not difficult to dry them for storage or make them into meal.  Some attain a size of 12cm in diameter with a weight of more than 0.5kg.  The pulp is rich in Vitamin A.  Persimmons have long bearing seasons and yield substantial crops.  The trees are deep rooting.

The leaves are not palatable and animals seldom eat them or damage newly planted specimens.  Most Persimmon trees favour moderate rainfall zones.

Persimmons are usually dioecious so that it is necessary to have a few male tree in plantations for fertilisation purposes.  Some kinds have slightly astringent fruits but drying mostly removes any astringency.  Modern ones are not astringent.

Diospyros virginiata is the American Persimmon and D. Kaki the Chinese or Japanese Persimmon.

There is a Persimmon from the southern USA in Danniverke about 12m tall and loaded each year with yellow fruit.  It is shapely and good shade tree – and stands cold.

Dovyalis caffra – Kei Apple

This is a small thorny tree, very resistant to drought.  The foliage makes useful fodder, often in some parts of the world constituting a helpful supplementary ration for livestock in bad seasons.  The species is valuable for a hedge – more so if you don’t like your neighbours!

Fagus Species – Beeches

There are both European And American beeches with yield nuts.  Like that of so many tree crops, yields alternate from season to season.

In the Middles Ages, beech nuts or ‘Mast’ formed an important item in the livestock rations.

Beech trees vary markedly in yield so only good quality strains should be utilised.  Propagation should be by grafting onto vigorous rootstock in spring.  The nuts, after milling, form an excellent meal for farm animals.

Ficus Species – Figs

Ficus carica is the cultivated Fig tree commonly grown in NZ (Height 6m).  It develops its fruit without pollination.  The seeds of the common fig are not fertile.  Many of the Ficus species provide useful fodder.  The fruits are often sought after by animals and birds too!

Pollination can be a problem with some of the fig species.  The Ficus genus contains over 700 species.  Yields in the USA seem to vary from about 5 to 13 tonnes per/ha in large Fig orchards.

Ginkgo biloba – Maidenhair Tree

This species, native to china and Japan, is now naturalised in other temperate countries including NZ.  It is a deciduous tree (height 25m) which prefers deeper soil and shelter from strong winds.

It produces edible seeds which when roasted are relished in East Asia.  In fact, in their country of origin, the nuts are often eaten at banquets and are ‘supposed to help digestion and nullify the effects of alcoholic vapours’.

The seeds can be milled to form a useful livestock feed.

Gleditsia triacanthos – Honey Locust

A leguminous tree 10 to 20 metres in height which bears pods or beans in late autumn.  About 30 to 45cm long containing a sweet ‘succulent pulp’ with a sugar content of about 27%, but very variable in this, and relished by livestock.  It is sometimes eaten by humans.  The deciduous trees which are very attractive have desirable wood.  They can be propagated by seed planted during spring or early summer.

By employing superior cultivars high yields of up to 450kg of beans per tree a year have been secured in the USA on reasonably good soil.  The Te Puke yields are understand about 160kg per tree.  The pods curl slightly when dry and make excellent meal or flour.  The pods themselves have the food value of oats and are readily eaten by cattle.  Gleditsia triacanthos is frost resistant and will thrive without difficulty on some lighter soils with its deep penetrating roots.

Grass will grow satisfactorily under honey locusts.  There are both male and female trees.

Other species of Gleditsia have on a number of occasions been planted in this country in mistake for G. triacanthos – with disastrous results!

In the first years it is necessary to provide stockproof fencing around each Honey Locust tree as the bark is very soft and sheep will kill the young trees by ring-barking.

According to the NZ Forest Service under NZ conditions and 7.3m spacings 180kg of pods per tree could be produced, or approximately 33 tonnes per hectare.  At 7.3m spacings the area will give maximum grazing with a maximum amount of pods and at this spacing you would need 187 trees per hectare.

A line of trees on the Gisborne flats has been in over 20 years and they have fairly short thorns.

Juglans Species – Walnuts

There are 17 economic species of walnuts commonly in cultivation.  Within these one must get the right cultivar to suit local environments, have good pollinisers and utilise disease free, high yielding plant material.

Walnuts contain about 16% protein as well as appreciable fat and useful Calcium and Iron.  When ground into meal they make a satisfactory food for livestock.  However, I have known Corriedale ewes in Mid-Canterbury to seek out walnuts on the ground – from memory a somewhat thin shelled variety of walnut – and a tough strain of ewes.

Most recommended cultivars bear some nuts at quite and early age and will often carry crops of up to 5kg at 12 years of age in good years.

A grafted specimen will usually bear crops at from 5 to 10 years.

Morus Species – Mulberries

There are a number of different economic species in cultivation originating from Asia and North America

Morus nigra is the common or ‘black-fruited’ Mulberry and has large cordate leaves.  A tree about 8m in height but sometimes more M. nigra bears great crops of blackberry -like clusters of fruit.  Crops have a high nutritional values.  The leaves are used for feeding silkworms but are inferior in this respect to those of Morus alba, the White Mulberry, which is a much taller tree.  The White Mulberries are practically seedless, tasty and when dried contain appreciable amounts of Calcium, Iron and Vitamin B complex.

Flowers are one sex, the sexes being on separate short pendulous catkins.

M. nigra can be propagated by leafless cuttings put in sandy soil after the leaves have fallen.

The fruit was once considered a cure for toothache, a medicine against the bite of spiders, and a laxative.

Mulberries will crop well throughout New Zealand but the fruits are very attractive to birds when nearly mature.  Livestock consume the produce avidly.  The foliage forms a useful fodder as well.  Farmers have found mulberries valuable for pig feeding.

Morus species are shallow rooters, possess the ability to develop rapidly and will begin to yield crops within two years from the striking of cuttings.

We have the occasional Mulberry tree in and around Gisborne.  There are several along the main highways from Gisborne to Wairoa.  There is a White Mulberry 4m in height in the Eastwoodhill Arboretum near Gisborne.

Mulberries may be propagated by seeds and cuttings and grafting.  Good results can be obtained by seed.  Seedlings however take a considerable time to reach fruiting size.  It is usual to plant cuttings about 30cm in length with some two year-old wood at the base, and these are then planted deeply in early spring or autumn.  Large branches will often root if planted deeply and staked.

Pigs and poultry feed on the fruits of Morus rubra in North America.

Pinus Species – Pines

There are in the region of 90 species of Pine.  Some kinds of pines yield excellent crops of food nut and have a pleasing taste.  Food nuts are obtained from about 18 pine species distributed throughout the different regions of the world, from the Arctic Circle to the Equatorial Plains of the tropics and from sea level to heights above sea level of 4,000m.  The nuts vary a great deal in size and taste.

The seeds contain an average of 14 to 30% protein and often 60% fat. Ground into meal they form excellent stock feed.  Pinus pinea the stone pine is an example of a pine yielding food nuts – the Pignolias of commerce.  Other examples of pines with edible kernels are Pinus cembra and P. torreyana, but I can’t see them being used for stock.  There is a demand overseas for Pine Nuts.

Populus – Poplars

Poplar leaves have long been used on occasions directly for feeding sheep and cattle in this country.  Initially the Lombardy Poplar Populus nigra cv Stricta was used but I have the impression Weeping Willow was more favoured.

The late Mr C Brooks of Te Kuiti advocated the use of Poplar and Plane, Platinus orientalis tree leaves for sheep to help avoid outbreaks of Facial Eczema – and to assist in erosion control.

The leaves of Populus robusta (a fast growing hybrid) have also been used successfully for livestock farming, as also, many of the Italian Hybrids.

Most cattle take to poplar leaves once they get a taste for them, say within two days.  In my experience horses are very partial to the Lombardy Poplar, particularly the bark on young trees.

Mr B Treeby in the NZ Farm Forestry Journal, 1978, records that 3 to 4 large trees pruned or pollarded each day appeared to be sufficient to give 200 beef cows a good ration – the daily operation taking 3 people just over one hour.

Populus yunnanensis now so much in favour on erodible land in the Te Puia Springs District, East Cape region, seems to be quite unpalatable to stock although, I believe, the leaves were used by Mr R Lancaster, Ruakura, about 1965, in vacuum packed ensiling tests on poplar leaves but using several species combined.

The poplar leaves for his trials cam from the Waerenga-o-kuri Soil Conservation Farm, near Gisborne.  It seemed from these trials that Poplar leaves could be conserved satisfactorily after the manner of wilted silage.  However the leaves do not consolidate readily and air penetration can be a problem.  As with wilted silage, air tight silos would be necessary.

I don’t really think there is much merit in silage-making using poplar leaves

Lancaster (1965) did give the comparative percentage feed values:

Water
%
MineralsFatsNitratesSoluble CHOCellulose
Poplar Leaves60.04.11.96.223.25.2
Grass80.02.00.83.59.24.5
Lucerne74.02.0.84.59.29.5

He made the comment that Plane Tree leaves could be used with leaf up to 760kg per tree, and that Poplars may produce something similar.

In a report to the Wairarapa Catchment Board in 1972, Mr M King, the Chief Soil conservator drew the Board’s attention to the value of Silver Poplar leaves Populus alba as stock food as well as the use of trees for soil conservation purposes.  As you knowPopulus alba suckers very freely so that around orchards or gardens it becomes a prime nuisance.

He noted that over a three week period steers had put on condition and registered a 6% weight gain.

The semi-green Lombardy Poplar, Populus nigra CV Sempervirens originated in Chile as a mutation of the common Lombardy Poplar.  It is not a true evergreen as it does not keep its leaves for more than one season as is the case with Eucalypts.  In frost free climates it keeps most of its leaves right through the winter but in spring they are gradually replaced.

For farm shelter planting it has to well fenced off as it is very palatable to all stock – and also to the opossum.

Prosopis Species – Algarobas

There are many species and types here, most of which like warmer climates.  They are legumes.  Some are frost hardy (eg those from South America).  The ground pods of several species are said to more nutritious than maize by those who cultivate them.  Normally they are medium-sized trees often yielding crops of brownish-yellow pods something like wax bean in shape and size.  These are extremely palatable and have a smell like fresh cereal.  The sweet pulp contains about 25% grape sugar (dextrose, glucose) together with up to 17% protein.  The pods or beans are a good livestock feed (and are eaten by some peoples).  The pale yellow flowers, borne on long cylindrical spikes are the source of excellent honey.

The best varieties are thornless, very quick growing, being capable of bearing pods within two years of setting out.  Seed must be chosen with care.  Generally they thrive on light sandy soils.

Prosopis (dulcis ?) are esteemed in South America as cattle fodder pods.  In Argentina there are plantations grown in colder areas under irrigation for the raising of crops of beans as stockfeed.  There are 15 species of Prosopis in Argentina and six in the USA.  Often two crops of beans can be produced in a year, and yields of high quality plantings sometimes exceed 50 tonnes/ha annually.

Owing to the extensive root development it is necessary to keep strict control of plantations.  Prosopis juliflora “Mesquite” of Algaroba Bean for example, considered as a weed can send roots down 30m below the surface of the ground and can resist extreme drought.

Hawaii has many hectares under Algarobo and substantial benefits have resulted through its introduction there.

In Chile, P. tamarugo is grown in the Atacama Desert in salt pans.  Trees are planted at 100 to 120/hectare and sheep graze fallen or fresh leaf and pods.  Carrying capacity increases with age of the stand from one ewe per hectare after five years to an estimated 10 to 12 per hectare at twenty five years.  This species was introduced into New Zealand by Lincoln college in 1973 for evaluation in South Island hill country, but apparently ran into frost damage problems.

Reference: G D Hill – Proceedings of NZ Grasslands Association 1975

Prunus amygdalus – Almonds

There are many almond varieties.  The nuts are high in protein – 19%.  The concentration of Calcium and Iron in the skin is three times that in the kernel.  Almonds like lime but dislike strong winds.  For livestock rations the whole seed should be milled ie from Prunus amygdalus the ‘Sweet’ Almond and not from the ‘Bitter’ Almond Prunus amygdalus cv ‘Amara’.

Quercus Species – Oaks

Oaks which bear sweet acorns have been used as a standard food since earliest times.  Their food value is excellent and generally they are palatable.  There are more than 300 species of oak scattered round the world.

Acorns make an excellent meal after grinding which is liked by farm stocks.  The drawbacks of some strains is that productions can vary in alternate years but this can be readily overcome.  As a long term forage crop oaks have few equals if properly managed.  The major feed component is Carbohydrate.

Quercus ilex – The Holm Oak, an evergreen tree has been known to yield crops of 900kg of nuts in a single season.  The best know acorns of Europe are those yielded by varieties of the Holm Oak.  Quercus ilex cv ballota is a particularly good cultivar.  Ilex oaks bear heavy crops in Hawkes Bay, Manawatu and Taranaki and are of good flavour.

Quercus suber – The Cork Oak – famed for its bark produces edible acorns, eg. pig fattening on these acorns in South-Central Portugal.  In their vast Cork Oak estates, sheep and goats browse upon the bushes, tree foliage and grass ground cover while herds of swine consume the acorns and herbage.

The well known pork from Evora, in the Alto Alemtejo Province is all produced by animals fed of oak crops.  Q. suber can flourish on sandy and stony ground.  One Cork Oak bears many acorns in the High School ground, Dannevirke and these have been sown by Farm Foresters in Southern Hawkes Bay.

Other European Oaks whose Acorns are known to be used by man.

 

Quercus aegilopsValonia Oak(Eastern Mediterranean)
Quercus ballotaThe Barbary Oak(North Africa) – has very sweet acorns
Quercus cocciferaKermes OakMediterranean – an evergreen shrub to small tree.
Quercus persicaManna Oakthis species has a sweet acorn which was used by the Persians for flour

Edible Oaks of North America

In North American about 60 species of Oak occur, over a dozen of which have been used as food by the original inhabitants, eg acorn cakes of the North American Indians

 

Quercus agrifoliaCalifornian OakEvergreen trees thriving in Central Hawkes Bay
Quercus albaWhite Oak
Quercus chrysolepsisMaul OakCalifornia evergreen
Quercus gambeliiShin OakNative of Eastern Slopes of Rocky Mountains in Colorado etc, evergreen
Quercus garryanaOregon OakDeciduous
Quercus kelloggiiCalifornian Black OakNative of California and Oregon. Acorns take 2 seasons to mature
Quercus lobataValley OakNative of West California. Plants doing well in Hawkes Bay
Quercus marilandicaBlack Jack OakEastern USA
Quercus palmeriCalifornian Palmer’s OakTrees doing well in Hawkes Bay
Quercus phellosWillow OakHas willow like leaves, but acorns scarcely bigger than a large red currant.
There are a few in NZ including SI. Evergreen
Quercus prinusRock OakThere are a number in NZ
Quercus stellataPost Oak
Quercus undulataScrub OakSmall deciduous tree up to 9m, but more often a shrub. Acorns are eaten by
Indians and Mexicans and furnish pigs with excellent food
Quercus virginianaVirginian Live OakEvergreen. Not unlike Holm Oak. Very hardy in Southern Hawkes Bay

The Common Oaks

The acorns of the Common Oaks, Quercus robur (British) and Quercus pedunculata (said to be an introduction to Britain from Europe about Tudor times) have long been recognised foodstuff for livestock of various kinds.  They vary a great deal in bitterness but are normally too astringent to be of use as human food except when specially treated.  However they sweeten when stored dry. This applies to the UK Quercus sessiliflora too.

The acorns of the true Quercus pedunculata (borne on a peduncle) are rounder than those of Quercus robur.  However the two species are apparently much crossed and indicated by the intermediate shapes.  They may also be crossed with the Sessile Oak.

Drying may be carried out be spreading thinly on a dry floor and turning fairly frequently.  When the acorns are dry the shells are easily cracked and come away from the kernels.  Some British authorities state that if they are allowed to germinate this also reduces their bitterness.

The ‘chipped’ kernels of well-dried acorns have been fed to poultry as partial substitute for corn with good results.  In the case of laying hens it is recommended not more than 28g per bird per day be included in the ration. Larger amounts may cause discoloured egg yolk.  Other birds may be fed more.  Pheasants, partridge, pigeons, ducks etc eat acorns with no apparent ill effect.  There is no doubt that acorns constitute a useful and nourishing food for many domestic animals provided they are used with discrimination and a certain amount of care.  Their food value lies chiefly in the large quantities of digestible Carbohydrate they contain and their ability to replace cereals, for they have a feeding value comparable with a mixture of oats and maize.

Salix babylonica – Weeping Willow

As you know the Weeping Willow is frost resistant and though it grows well on stream banks it can also withstand drier conditions.  The species originates in Asia Minor.  It is easily propagated by cuttings.  The foliage makes excellent livestock fodder and has been used in the East Coast region during droughts.  Salix subserrata is similar but smaller and flourished on stony sites along gullies and water courses.

The Weeping Willow Salix babylonica provides good anti-bloat medicine and gives better than Lucerne feed whenever wanted from spring through autumn.  There is ample protein in the leaves and starch in the bark which sheep relish once they acquire the taste.

The Weeping Willow Rust Melampsora coleasporioides from Asia and Australia has now appeared in Gisborne as in Northland and we expect in time shrivelling of leaves and premature leaf fall.  Eventually I would expect the rust to be held in check by mites, bees etc provided we get away form the barren environment we have created in this country.  The rust has affected Salix matsudana in China.  The Crack Willow Salix fragilis is apparently susceptible.  The rust on Pussy Willow Salix caprea is a different one.  The latter has been in NZ since 1970.

Both Pussy Willow and the Crack Willow can become serious weeds in swamp land.

The Bitter Willow Salix purpurea is not touched by stock (eg at Tikokino)

The Weeping Willow is really at home in Hawkes Bay, Poverty Bay, Bay of Plenty, Waikato and parts of the Wairarapa district.  Around the Manawatu either the wind or the lack of suitable soil conditions has lead to the early death of most trees of this species in all but a few localities.

Other Tree Forage Crops -There are many other possible or potential tree or shrub crops for forage such as:

Caragana arborescens – the ‘Pea Tree’ which can be a shrub or small tree about 5m in height.  This tree has pods 4 to 5cm with 3 to 5 seeds.  It is a native of Siberia and Manchuria.

 

This article was written in 1979 so some things may have changed but overall the basis is still as relevant today as it was then.  It also seemed to me that it is shame to lose valuable information that knowledgeable and enthusiastic people such as George Halliwell, one of the founding members of NZ Tree Crops Association, and others have written, so it has been copied mainly as he wrote it.

Gail Newcomb, Technical Editor, 1999.
Privacy removals and proprietory format conversion – December 2007

 

This crop guide was produced with the latest information available at the time of publication.  This should not be considered the ultimate in information for New Zealand growing conditions: it is just a basic guide on the subject.  If any member has information to add, or feels that any of the information is misleading, please contact us.

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