BLACK TRUFFLE ANDITS CULTIVATION Marcos Morcillo and Mónica Sánchez MICOLOGIA FORESTAL & APLICADA
TRUFFLE AS A FUNGITruffles are the fruit of a mycorrhizal fungi. That means that lives associated to the rootsof some host trees or shrubs, as oaks, holm oaks and hazels, Cistus or some pines. Trufflesfruits into the ground and some species become aromatic with the aim that some animalsdig them up the ground and while eating them spread their spores. The aroma is alsoappreciated 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, around40, but a few of them have a real market value, like the black truffle or Perigord truffleTuber melanosporum, the winter truffle Tuber brumale, the summer trufle Tuber aestivumand its ecotype the bourgundy truffle Tuber uncinatum, and the white truffle fromPiamonte 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 characteristicsBlack truffles fruits on limy soils under holm oaks, oak on the Mediterranean region inSpain. Most of them can be found in the east part of the Iberic Peninsula, and over rocksfrom the Primary, Secondary-mesozoic (Triasic, Jurasic and Cretacic), mostly on the Jurasicsuperior.Black Truffle naturally fruits at elevations between 100-1500m.o.s.l. and facing south. Arerecommended light slopes, avoiding floods and also avoiding the erosion from high slopes. Natural Black truffle fruiting area in Spain. Black truffle soil characteristicsMost of parameters before analyzed for truffle culture are not bearing in mind nowadays.Texture, carbonates, iron, magnesium, potassium...have great variability. Actually the soilstructure 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 thepresence 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 thesoil boils (effervescence).
Soil profileShould not have discontinuities between layers, with some difficult to mark limits betweenthem.Crumble structure and spherical particles. Avoid prismatic structures, sign of lixiviation.Laminar structures shows compactation and flood. Bad soil structures get grooved andheavy on dry weather.Some grey and green colours on the soil profile mean bad drainage.
GOOD SOIL PROFILE FOR BLACK TRUFFLE LAYER CHARACTERÍSTICS ♦ Light colourAA ♦ linked OM > free OM ♦ delayed clohidric reactionUPPERUPPERUPPER ♦ ♦ layer more than 20cm deep ♦ crumble structure ♦ more than 30cm deepBB ♦ Continuity between layersESTRUCTURAL ♦ 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...)CC ♦ Mother rock with grooves and porousMOTHER ROCK ♦ Calcareous precipitations underneath the rocks ♦ Positive reaction to clorhidric
BAD SOIL PROFILE FOR BLACK TRUFFLE LAYER CHARACTERÍSTICS ♦ Dark-brown colourAA ♦ High organic material content. ♦ Clorhidric reaction quick and high or noUPPER reaction at all. ♦ Massive, prismatic and laminar structure ♦ Clay or calcareous layer that does notBB allow roots to cross down.STRUCTURAL ♦ Blue colours from bad air flow ♦ Red colours from iron oxides mean flood. ♦ Grey or green colours means frequent flooding.CCMOTHER ROCK ♦ Deep and continuous clay layer ♦ Shallow and compact Mother rock
ClimateBlack and summer truffle are adapted to dry and hotconditions, with well marked seasons, humid temperate orcold sub humid Mediterranean climate. Hot and humidsprings, dry summers with some storms, no frost at thebeginning of autumn, and winters with no long cold periodsbelow 10ºC.Rain between 425-900 mm. (600-1500 mm in Italy andFrance). 48-64 mm of rain monthly from June to the end ofaugust, from a few summer storms. Previous cropsPrevious crops will condition the organic matter contentsand fungi contaminations on the area we’re planning toplant the mycorhized seedlings.Best previous crops are cereals, pulses, lucerne, most offruit trees, as they are endomycorhizal. Host plant electionBlack truffle grows in symbiosis with a wide variety ofplants (see next chart). But just some of them are used forits cultivation. Actually in Spain about 90% of plantation arewith holm oak (Quercus ilex ssp. ballota), and secondaryoaks (Quercus pubescens, Quercus faginea)and hazel(Corylus avellana).
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) (Corylus avellana) • 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 areplanted north to south, allowing sun to light the centre of the whole row. DISTANCE (m) PLANTS/Ha 5x5 400 5x6 333 6x6 277 6x7 238 6x8 238 Plant density depending of plant distances.
OUTPLANTINGPrevious works to get the soil ready to plant are done in summer and autumn. Anyploughing 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 layerthat appear after several years working at the same deep. Note not to tumble and mix soillayers, that can lead to a delay starting to fruit.Between November and may dig the plant holes and mark them not to harm the smallseedlings once planted, hard to see trough the weeds.
CULTIVATION PHASES Plantation’s evolution and different works on every phase PHASES PHASES PHASES RECOMMENDED WORKS RECOMMENDED WORKS RECOMMENDED WORKS • Aim: plants should just survive, not to develop in excess. Maintain mycorrhizae. • Just on aerated, limy, draining soil, with biological activity. IIINSTALL N STALL NSTALL • Do not mix soil layers in the previous works. Break ploughing layer if necessary. 2-3 years 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 aPREFRUIIITIIINGPREFRU T N GPREFRU T NG years (end of march) 6--12 years 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. FRUIIITIIING 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--35 years10-3 5 years10 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 fullRENOVATIIIÓNRENOVAT Ó NRENOVAT ÓN canopy35--45 years 35-4 5 years 35 45 years • Thin not producing trees to generate new clears and zones that allow existing brûles to spread.
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 varietyPLOUGHIINGPLOUGH NG • 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, neverMULCHIINGMULCH NG covering the whole brûle. • Put them n June and we can move hem once or twice during he summer. • Just in case of drought, 48-64 mm. monthly from June to the end ofWATERIINGWATER 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 andPRUNNIINGPRUNN NG warm places
MATURE TREES INOCULATIONOther fungi coexist with truffles into the brûle. Mushrooms that fruit at young stands arenot the same that appear when the forest gets older. A temporal succession exists and wecan take part on it when the conditions are suitable.Truffles live associated to mature trees and their inoculation could reduce the time we waitfor start fruiting.These techniques have a great value for the regeneration and creation of new truffieres, aswell as for those artificial plantations that lose truffle mycorrhizae.But with the last results, conclusion is that is hard to mycorrhizate mature trees withtruffle when they already have other fungi on their roots. In our studies, some trees, likehazel, are easier to mycorrhizate in late stages than oaks.Download here our results on this field .PDF HARVESTTruffles should be harvested just with trained dogs. Other animals as pigs could harm thetruffiere. Always use the truffle machete. Do not use any other tools for digging as youwould 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 season.
ECONOMICAL FEATURES ABOUT TRUFFLEUsually truffle fruits on poor agronomical soils, on places where crops need grants tosustain. Truffle cultivation gives independence from those grants, with incomes that cantreble traditional crops, and even raise the value of the land in those potential trufflegrowing areas. 19% 38% 43% 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 worldblack truffle production. About 10.000 familieshave truffle harvesters.Truffle price depends on the quality of the truffleseason. Demand adjusts to the typical modelswhere high productions lead to lower prices. BlackTruffle prices at harvester are around 200-850€/kg.A little bit less than half this quantity for thewinter truffle. Summer truffle is paid to theharvester 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 truffletradition, 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 tothe general citizens. In fact you can be on a pub at the market time and not realize onthat. Harvesters and buyers meet there, talk, negotiate prices, then go outside and takethe 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 howmuch 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 toFrance, Italy, Belgium, Germany and The USA. The inner consumption of black truffle inSpain is really low. There’s a lot of work to do in their promotion and attach importance toour truffles. Truffle Cannery SPAIIIN SPA N SPA N FRANCE FRANCE FRANCE IIITALY T AL Y T AL Y TOTAL U...E... TOTAL U E TOTAL U E Tuberrmelllanosporrum Tuber me a nosporu m Tube me anospo um 5--80 5-8 0 5 80 15--80 15-8 0 15 80 10--80 10-8 0 10 80 30--240 30-2 40 30 240 Tuberraestttiivum Tuber aes iv um Tube aes vum 20--30 20-3 0 20 30 15--30 15-3 0 15 30 15--30 15-3 0 15 30 55--120 55-1 20 55 120 Tuberruniiinatttum Tuber un n a u m Tube un na um 5--10 5-1 0 5 10 2--5 2-5 25 2--5 2-5 25 9--20 9-2 0 9 20 Tuberrmagnatttum Tuber magna u m Tube magna um 5--50 5-5 0 5 50 5--50 5-5 0 5 50 Tuberrmesenttterriicum Tuber mesen e ric um Tube mesen e cum 2--4 2-4 24 4--9 4-9 49 4--9 4-9 49 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 15% 10% 75% Trufa invierno Trufa verano Trufa negraMedia production in the whole European Community is about 100Tn, usually there no a googyear in the three countries at the same season. At the beginning of the XX century, the1000Tn harvested in France where absorbed by the marked. On 1966 the estimation froFrance demand on truffles where 340Tn, If we take into account that the standard of livingand the raise in population, that demand should be higher. In conclusion there is a truffledemand for a decreasing production. TURN OVER ON TRUFFLE CULTUREIt’s hard to get average of productions on artificial plantations. Some references exist: asingle brûle can produce 10kg of truffles and some plantations can get 200kg a year perhectare, but at the same time there are plantations that never become productive. Quallliity plllanttattiion 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 Hiiigh producttiiviiity H g h productiv tty H gh produc v y 30 30 30 60 60 60 90 90 90 ((kg//Ha//year)) (k g/H a/y ear) kg Ha year Mediiium producttiiviiity u m productiv tty Med um produc v y Med 15 15 15 30 30 30 45 45 45 ((kg//Ha//year)) (k g/H a/y ear) kg Ha year Low producttiiviiity Low productiv tty Low produc v y 3 3 3 6 6 6 9 9 9 ((kg//Ha//year)) (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 IItems Year tems Acumulated €/ha €/ha €/ha €/ha Kg/ha Kg/ha €/ha €/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 Vallado -1500 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 35100Other studies say that actual net value in plantations from Spain, France and Italy arebetween 19.424€/ha and 66.972 €/Ha. Medium profitability get with the inner profit tax isalways higher that 9%, and the time to get back the invest equal or higher to 10 years.