Marcos Morcillo and Mónica Sánchez
MICOLOGIA FORESTAL & APLICADA
TRUFFLE AS A FUNGI
Truffles are the fruit of a mycorrhizal fungi. That means that lives associated to the roots
of some host trees or shrubs, as oaks, holm oaks and hazels, Cistus or some pines. Truffles
fruits into the ground and some species become aromatic with the aim that some animals
dig them up the ground and while eating them spread their spores. The aroma is also
appreciated by humans and recognized by dogs that can be trained to harvest them.
Truffles belong to the genus Tuber, into de Ascomicotina. There are several species, around
40, but a few of them have a real market value, like the black truffle or Perigord truffle
Tuber melanosporum, the winter truffle Tuber brumale, the summer trufle Tuber aestivum
and its ecotype the bourgundy truffle Tuber uncinatum, and the white truffle from
Piamonte Tuber magnatum, with great value, but its cultivation still has random results.
Black truffle (Tuber melanosporum Vitt.) Winter truffle (Tuber brumale)
Summer truffle (Tuber aestivum) Burgundi truffle (Tuber uncinatum)
ECOLOGY OF TRUFFIERES
Geographic, geologic and topographic characteristics
Black truffles fruits on limy soils under holm oaks, oak on the Mediterranean region in
Spain. Most of them can be found in the east part of the Iberic Peninsula, and over rocks
from the Primary, Secondary-mesozoic (Triasic, Jurasic and Cretacic), mostly on the Jurasic
Black Truffle naturally fruits at elevations between 100-1500m.o.s.l. and facing south. Are
recommended light slopes, avoiding floods and also avoiding the erosion from high slopes.
Natural Black truffle fruiting area in Spain.
Black truffle soil characteristics
Most of parameters before analyzed for truffle culture are not bearing in mind nowadays.
Texture, carbonates, iron, magnesium, potassium...have great variability. Actually the soil
structure trough the study of the horizons and the biological activity are more studied.
So to know if we can grow truffles on a soil we should study the horizons, confirm the
presence of carbonates and analyze the pH (that should be between 7.5-8.5)
Soil should not be water Proof, allowing water and air to drain trough.
To check if the soil has carbonates we can just drop diluted clorhidric acid and see that the
soil boils (effervescence).
Should not have discontinuities between layers, with some difficult to mark limits between
Crumble structure and spherical particles. Avoid prismatic structures, sign of lixiviation.
Laminar structures shows compactation and flood. Bad soil structures get grooved and
heavy on dry weather.
Some grey and green colours on the soil profile mean bad drainage.
GOOD SOIL PROFILE FOR BLACK TRUFFLE
♦ Light colour
A ♦ linked OM > free OM
♦ delayed clohidric reaction
♦ layer more than 20cm deep
♦ crumble structure
♦ more than 30cm deep
B ♦ Continuity between layers
ESTRUCTURAL ♦ Abundant rocks
♦ White zones are precipitates of calcium
carbonates. Unless they become a general
layer that avoid drainage.
♦ Red zones from carbonates loosing
♦ Biological activity (ants, worms...)
C ♦ Mother rock with grooves and porous
MOTHER ROCK ♦ Calcareous precipitations underneath the
♦ Positive reaction to clorhidric
BAD SOIL PROFILE FOR BLACK TRUFFLE
♦ Dark-brown colour
A ♦ High organic material content.
♦ Clorhidric reaction quick and high or no
UPPER reaction at all.
♦ Massive, prismatic and laminar
♦ Clay or calcareous layer that does not
B allow roots to cross down.
STRUCTURAL ♦ Blue colours from bad air flow
♦ Red colours from iron oxides mean
♦ Grey or green colours means frequent
♦ Deep and continuous clay layer
♦ Shallow and compact Mother rock
Black and summer truffle are adapted to dry and hot
conditions, with well marked seasons, humid temperate or
cold sub humid Mediterranean climate. Hot and humid
springs, dry summers with some storms, no frost at the
beginning of autumn, and winters with no long cold periods
Rain between 425-900 mm. (600-1500 mm in Italy and
France). 48-64 mm of rain monthly from June to the end of
august, from a few summer storms.
Previous crops will condition the organic matter contents
and fungi contaminations on the area we’re planning to
plant the mycorhized seedlings.
Best previous crops are cereals, pulses, lucerne, most of
fruit trees, as they are endomycorhizal.
Host plant election
Black truffle grows in symbiosis with a wide variety of
plants (see next chart). But just some of them are used for
its cultivation. Actually in Spain about 90% of plantation are
with holm oak (Quercus ilex ssp. ballota), and secondary
oaks (Quercus pubescens, Quercus faginea)and hazel
Secondary speciies tthatt ttrufffflle has been
Secondary spec es ha ru e has been
Hostt pllantts used iin ttrufffflle cullttiivattiion
Hos p an s used n ru e cu va on ffound associiatted natturally..
ound assoc a ed na ura y
• pine (Pinus nigra)
• Pine (Pinus sylvestris)
• Holm oak • Turkish hazel (Corylus colurna)
(Quercus ilex ssp. ilex, Q. ilex ssp. Ballota, Q. • Birch (Betula pendula)
coccifera) • Carpinus
• Oaks • Lime tree (Tilia)
(Quercus pubescens Q. cerriodes, Q. petrae, • Cork oak (Quercus suber)
Q. robur , Q. faginea) • Popplar (Populus)
• willow (Salix)
• Hazel • Beech (Fagus)
• Chestnut tree (Castanea)
• (Cistus albidus, C. incanus, C. laurifolius, C.
salvifolius) and other Cistacea as Fumana
• Cedar (Cedrus)
DENSITY AND PLATATION DISTANCES
We recommend densities between 200-400 trees/Ha for
the black truffle. Less density as deeper, rich soils and
with water stocks, as trees will grow faster. More trees
per hectare allow more trees to fruit and less time to
wait for the production to start, but we have to prune
more to avoid the plantation to get closed.
Usually plants are located at 6x6 or 7x7 but we can also
join plants in the row and separate the rows at more
distance (6x8, 5x7 or 4x10). In this case rows are
planted north to south, allowing sun to light the centre of the whole row.
DISTANCE (m) PLANTS/Ha
Plant density depending of plant distances.
Previous works to get the soil ready to plant are done in summer and autumn. Any
ploughing will be done with no heavy tractors and on dry soil avoiding soil compactation.
If soil is OK, but there’s no drainage we can plough deeper trying to break the plough layer
that appear after several years working at the same deep. Note not to tumble and mix soil
layers, that can lead to a delay starting to fruit.
Between November and may dig the plant holes and mark them not to harm the small
seedlings once planted, hard to see trough the weeds.
Plantation’s evolution and different works on every phase
PHASES RECOMMENDED WORKS
• Aim: plants should just survive, not to
develop in excess. Maintain mycorrhizae.
• Just on aerated, limy, draining soil, with
NSTALL • Do not mix soil layers in the previous works.
Break ploughing layer if necessary.
2--3 years • Natural mulching
2 3 years
• No pruning.
• Water just if necessary (10-20 l/plant).
• Avoid weeds competence.
• Aim: avoid excessive grow of the tree.
• Chose between mow or plough 1-2 times a
PREFRU T N G
PREFRU T NG years (end of march)
6-1 2 years
6 12 years • Hand plough just around plants.
• Water just if necessary.
• Start pruning regularly.
• Mowing to avoid weed competence
• On best trees centrifugal hand ploughs.
FRU T N G
FRU T NG • From the end of June, in case of drought (20-
25 days without rain (depending on soil).
10-3 5 years
10 35 years • Use straw, branches, rock mulching to sep
humidity and improve biological activity.
• Regular pruning to keep sunlight on the brûle.
• Aim: Do not allow trees to get a full
RENOVAT Ó N
RENOVAT ÓN canopy
35-4 5 years
35 45 years • Thin not producing trees to generate new
clears and zones that allow existing brûles to
General Works during the fruiting phase
• 1-2 times a year. Shallow (15-20cm deep) outside he brûle, and 5-
10cm into the active brûle.
• End of march and April for melanosporum
• January and February for the aestivum variety
• We can allow weeds to develop in the middle of the rows
• Hand Works seems to be in harmony with the centrifugal growth of
the roots and mycorrhizae.
• Branches from pruning or just rocks
• Located where the brûle grows, at 1,5m one from each other, never
MULCH NG covering the whole brûle.
• Put them n June and we can move hem once or twice during he
• Just in case of drought, 48-64 mm. monthly from June to the end of
WATER NG august, by sprinkles and leaving some dry days.
• Usually like a turned upside down cone form.
• Adapt to every place. Light pruning in case of shallow soils and
PRUNN NG warm places
MATURE TREES INOCULATION
Other fungi coexist with truffles into the brûle. Mushrooms that fruit at young stands are
not the same that appear when the forest gets older. A temporal succession exists and we
can take part on it when the conditions are suitable.
Truffles live associated to mature trees and their inoculation could reduce the time we wait
for start fruiting.
These techniques have a great value for the regeneration and creation of new truffieres, as
well as for those artificial plantations that lose truffle mycorrhizae.
But with the last results, conclusion is that is hard to mycorrhizate mature trees with
truffle when they already have other fungi on their roots. In our studies, some trees, like
hazel, are easier to mycorrhizate in late stages than oaks.
Download here our results on this field .PDF
Truffles should be harvested just with trained dogs. Other animals as pigs could harm the
truffiere. Always use the truffle machete. Do not use any other tools for digging as you
would harm the truffiere. Just dig where the dog marks. Never plough for harvest truffles
as you would do for potatoes.
Truffle season in Spain starts from 15th November to
15th march for the black and winter truffle. And from
1st May to the end of august for the summer truffle.
No season by law is applied for burgundy truffle. It’s
forbidden to sell fresh truffles in the markets a week
later after the dateline.
The aim is not to harvest too young truffles and allow
some mature truffles to get ripped at the end of the
ECONOMICAL FEATURES ABOUT TRUFFLE
Usually truffle fruits on poor agronomical soils, on places where crops need grants to
sustain. Truffle cultivation gives independence from those grants, with incomes that can
treble traditional crops, and even raise the value of the land in those potential truffle
España Francia Italia
Production of truffles on the three main countries. Average of productions from 1990-2002.
In Spain we harvest about 30-50% on the world
black truffle production. About 10.000 families
have truffle harvesters.
Truffle price depends on the quality of the truffle
season. Demand adjusts to the typical models
where high productions lead to lower prices. Black
Truffle prices at harvester are around 200-850€/kg.
A little bit less than half this quantity for the
winter truffle. Summer truffle is paid to the
harvester between 35-80 €/kg.
Some trade shows just about truffle can join crouds during the truffle season. Tourism related with
the visits to truffle plantations could improve the income of this crop.
Truffle is commercialized trough the truffle markets all along the natural areas with truffle
tradition, intermediaries usually buy on this markets and visit harvesters at their homes.
These markets, despite of being on public places (restaurants, pubs...) they are not open to
the general citizens. In fact you can be on a pub at the market time and not realize on
that. Harvesters and buyers meet there, talk, negotiate prices, then go outside and take
the truffles from one car to another. Sometimes you can not smell, even touch the product.
What a big difference from French markets, where you can get their aroma and say how
much you want to pay for.
Truffle market at Limogne (Francia)
Nowadays in Spain there are 20-25 canneries that export most of our black truffle to
France, Italy, Belgium, Germany and The USA. The inner consumption of black truffle in
Spain is really low. There’s a lot of work to do in their promotion and attach importance to
SPA N FRANCE
T AL Y
T AL Y TOTAL U...E...
TOTAL U E
TOTAL U E
Tuber me a nosporu m
Tube me anospo um 5--80
5 80 15--80
15 80 10--80
10 80 30--240
Tuber aes iv um
Tube aes vum 20--30
20 30 15--30
15 30 15--30
15 30 55--120
Tuber un n a u m
Tube un na um 5--10
5 10 2--5
Tuber magna u m
Tube magna um 5--50
5 50 5--50
Tuber mesen e ric um
Tube mesen e cum 2--4
Production of truffles in the three main countries. Minimum and maximum amounts in Tons.
The value of the truffle market between harvesters and buyers is about 600.000 € and 15M€
every year, with higher values once transformed and exported.
Porcentajes de facturación de las diferentes trufas
Trufa invierno Trufa verano Trufa negra
Media production in the whole European Community is about 100Tn, usually there no a goog
year in the three countries at the same season. At the beginning of the XX century, the
1000Tn harvested in France where absorbed by the marked. On 1966 the estimation fro
France demand on truffles where 340Tn, If we take into account that the standard of living
and the raise in population, that demand should be higher. In conclusion there is a truffle
demand for a decreasing production.
TURN OVER ON TRUFFLE CULTURE
It’s hard to get average of productions on artificial plantations. Some references exist: a
single brûle can produce 10kg of truffles and some plantations can get 200kg a year per
hectare, but at the same time there are plantations that never become productive.
Qua itty p a nta tio n
Qua y p an a on 10--20 yearss
10-2 0 yearss
10 20 yearss 20--30 years
20-3 0 years
20 30 years Unttiillll 50 years
Untill 50 years
Un 50 years
H g h productiv tty
H gh produc v y 30
(k g/H a/y ear)
kg Ha year
u m productiv tty
Med um produc v y
(k g/H a/y ear)
kg Ha year
Low productiv tty
Low produc v y 3
(k g/H a/y ear)
kg Ha year
Some black truffle productions from different quality plantations
A truffle plantation should produce at least 8-10kg/ha/year to redemption the investments.
Some French truffle grower says that from year 50 production decreases.
Next chart shows a financial study for a hectare truffle plantation in Spain
Cost Maiintenance Productiion Truffflle Cash ffllow
Cost Ma ntenance Product on Truf e Cash ow Acumulated
Year tems Acumulated
€/ha €/ha Kg/ha
0 Plantación -1800 -1800 -1800
1 -300 -300 -2100
2 -300 -300 -2400
3 -300 -300 -2700
4 -300 -300 -3000
5 -300 -300 -3300
6 -300 -300 -3600
7 -300 -300 -3900
8 -300 -300 -4200
9 -300 -300 -4500
10 Riego -1500 -300 -1800 -6300
11 -300 8 2400 2100 -4200
12 -300 10 3000 2700 -1500
13 -300 12 3600 3300 1800
14 -300 13 3900 3600 5400
15 -300 15 4500 4200 9600
16 -300 16 4800 4500 14100
17 -300 17 5100 4800 18900
18 -300 18 5400 5100 24000
19 -300 19 5700 5400 29400
20 -300 20 6000 5700 35100
Other studies say that actual net value in plantations from Spain, France and Italy are
between 19.424€/ha and 66.972 €/Ha. Medium profitability get with the inner profit tax is
always higher that 9%, and the time to get back the invest equal or higher to 10 years.