GUIDELINES FOR THE HAZELNUT GROWERS FARM ASSESSMENT, ORCHARD ESTABLISHMENT AND MANAGEMENT UNTIL THE PRODUCTION PERIOD
OUTGROWING PROJECT
HAZELNUT CULTIVATION
This document is intended to be a user friendly operational guide addressed to the hazelnut growers. Ferrero Group waives any responsibility in respect to the completeness and accuracy of the content of this operational guide which in no case is to be considered as a binding document for the hazelnut growers.
This publication was made possible through support provided by the U.S. Agency for International Development, under the terms of Contract No. 72011219C00001. The opinions expressed herein are those of the author and do not necessarily reflect the views of the U.S. Agency for International Development.
Copyright Reserved - Disclosure of this document is not permitted unless expressly authorized by the Ferrero Group
INDEX Farm assessment Soil survey
5 6
Climate survey 14
Orchard establishment 17 Land Preparation 18 Mechanical operations 18 Pre-planting fertilization 22 Planing of planting and planting 31 Planting layout and varieties 31 Receiving of the seedlings 36 Squaring and planting 38 Additional land investments
41
Maintaining of the orchard until production period 45 Pruning 46 Soil management 49 Irrigation 54
4
FARM ASSESMENT 5
SOIL SURVEY Preliminary survey Besides the economic aspects and considerations, when a farmer decides to plant a hazelnut orchard he must necessarily take into account the pedoclimatic characteristics of the area where the cultivation will be carried on. The knowledge of the soils characters of the area is of crucial importance The success or failure of the investment depends on such knowledge. Soil characteristics depend also on morphology that affects parameters like quantity of soil available for the root system, area of accumulation of materials/minerals, depth of the underground water, etc. For this reason, we have to make a preliminary survey of our farm to understand the best sites where to take the soil samples. We should proceed as follow: X Preliminary investigation of the area based on: z the own knowledge of the farm; z the satellite images. By using internet applications (i.e.: Google earth) it is possible to see differences on the site. Choose 7-8 points where to take the soil samplings. The quantity of surveys to perform may, for example, be 7 auger-holes and 1 profile each 10 hectares. If, after 3-4 samples, it is clear that the soil is homogeneous along the profile, less samples can be carried out on our farm. The methodology of sampling is explained at the paragraph “Sampling on the field”. In case of surfaces smaller than 10 hectares we have to get at least 3-4 samples. X In order to make a good survey of our farm, should be considered the following instructions: z Do not choose only sites at the border of the plot z Do not focus the samplings in a limited area z Do not focus the samplings in a homogenous area z Take in consideration the variability in term of altitude: when you have not flat area, usually there are many differences between the upper and the lower part
Soil surface Mother rock Possible soil morphology trend
6
SOIL SAMPLINGS Examples of points to be sampled on 10 hectares according to the “X method” NOT FLAT AREA
FLAT AREA
Slope direction
In case of flat area we can proceed taking samples marking a “X” on our orchard. The soil profile could be dug on the middle or in a point where we think could persist some issues.
In case of not flat area we can proceed dividing the orchard in two parts (lower and upper) digging The soil profile in the middle and making the auger-halls on the top and on the bottom part of the orchard
Soil profile Auger holes
7
SOIL SAMPLINGS Examples of points to be sampled on 10 hectares according to the “W and Z methods” FLAT AREA
NOT FLAT AREA W METHOD
W METHOD
Z METHOD
Z METHOD
Soil profile Auger holes
8
SOIL SAMPLINGS Samplings on the field Soil samplings are made by augers or vertical sections called soil profiles. In both case, it’s fundamental to collect soil at different depths according to the different horizons that are visually recognisable. Commonly soil is sampled at 0-30 cm, 30 – 60 cm, 60 – 90 cm, because hazelnut root system does not usually go deeper than 70 cm. For each sample, the different horizons must be taken separated into plastic bags: it’s enough to take 0,5 / 1,0 Kg of soil for each horizon.
AUGER HOLES They can be done using manual “Dutch” samplers (Edelmann).
It is indicated to: z lay a meter on a white sheet on the ground to recreate the profile and to measure easily the depth of the layers; z sign by a marker/label each bag with the number of the sample and the depth range; z take a picture of the profile with the related numbered plate; z take the coordinates of the point by a GPS system.
1 0-30
1 30-60
1 60-90
SAMPLE 1
30
0-
9
60
30
90
60
20
9
1 0-
SOIL PROFILE The profile consists on an excavation in the soil to directly check characteristics that cannot be detected using the auger. Profiles are excavated to a depth of 150 cm, or until a layer impenetrable to roots is reached, and a width of 1 m. The vertical section of the soil highlights the variability of the soil composition, horizons, at different depths. The horizons may be indicated by a change in colour, by a different clod shape, by the presence or the lack of skeleton, or by other indicators such as different crop performances (dead trees or failed to germinate, different plant heights, presence of chlorides, different fruit ripening times, etc.).
The quantity of surveys to perform may, for example, be 7-8 auger-holes and 1 profile each 10 hectares.
0 - 30 cm 30 - 60 cm 60 - 90 cm 90 - 120 cm 120 - 160 cm In this profile it is possible to observe 5 different horizons. As already mentioned about the auger holes, it is enough to take samples up to 90 cm (horizons 1, 2 and 3). If in the deeper horizons are present some critical issues (i.e.: high presence of carbonates), it would be advisable to take also a sample of the layer below.
10
Chemical and physical soil analysis After our survey in the field, the samples have to be delivered to a laboratory for soil analysis. The most important parameters to be taken in consideration, with range for suitability classes, are showed in the table below. Each class (S1 to N2) has to be considerate as indicative and each parameter (Reaction to Rockiness) must to be evaluate in depth and in correlation to all the other pedo-climatic parameters and farm characteristics. CHEMICAL - PHYSICAL ANALYSIS S1
S2
S3
N1
N2
CONSIDERATIONS
Reaction (pH in water)
6.5-7.5
5.0 - 6.5 7.5 - 8.0
4.5 - 5.0 8.0 - 8.5
/
<4.5 > 8.5
Too low: Mg deficiencies, reduces P availability, Al toxicity, low microbiological activity, low development of the root system, low nutrients availability Too high: Carbonates, Al and Fe toxicity; high level of exchangeable Na that reduce the soil fertility
CEC (meq/100gr)
>18
10 - 18
10 - 12
5 - 10
<5
Important for macro and micro nutrients availability in the soil
Total limestone %
<8
8 - 15
15 - 25
25-35
>35
Important for macro and micro nutrients availability in the soil
Active limestone %
<2.5
2.5 - 5
5-8
8 - 12
>12
Foliar chlorosis caused by the immobilization of nutrients like Fe and P
Depth(m)
1,00 - 0,80
0,80 - 0,70
0,70 - 0,50
/
< 0,50
In the first 50 - 70 cm we can find the 90 % of the root system
Slope (%)
<5
5 - 10
10 - 15
/
>25
Mainly mechanization issues
Stoniness (%)
<1
1-3
3 - 15
15 - 35
>35
Mainly harvesting issues
Rockiness (%)
<2
2-5
5 - 10
>10
Mainly harvesting issues
SUITABILITY
S Suitable
CLASS S1 – Suitable – Absence of critical issues S2 – Moderately suitable – It needs of more inputs or mechanical operations S3 – Marginally suitable – It needs of more inputs or mechanical operations
N Not Suitable
N1 – Temporarily not suitable – Presence of strong critical issues that can be not overcome at the moment (i.e.: low pH) N2 – Not suitable – Critical issues that can be not overcome at all
11
SOIL TEXTURE Hazelnut prefers well-drained soils. Heavy clay percentage could cause roots’ asphyxiation issues while very sandy soils request high water volumes. Suitable range of the soil texture can be found on the table below. Out of these ranges we have to carefully take our decision and manage the tillage operations.
HEAVY CLAY SOIL
SANDY SOIL
y Make a deep ripping (about 80 – 100 cm);
y Deep ripping could not be necessary because the soil is already well drained. But the characteristic of the soil profile should every time taken in consideration. Example: in presence of sandy soil but with a carbonate layer 60 cm deep, could be useful to break this layer up.
y If the organic matter content is good only in the superficial horizons (30 cm), consider to raise the percentage also in the lower levels. Suggested to plow mature manure up to 50 cm. y Consider the realization of proper drainage systems;
y Deeper evaluation on the water needs; y Usually these kind of soils are poor on organic matter also in the first cm
y Sand could be added and mixed but it is a really expensive operation
MEDIUM VALUES (g/kg) SAND
250-550
SILT
250-500
CLAY
100-300
Soil highly suitable Soil suitable
12
Biochemical soil analysis PARAMETERS TO BE INVESTIGATED ADDITIONAL PARAMETERS
BASIC PARAMETERS Parameters
Medium Value
Bulk density (g/dm3)
-
Texture
Texture (g/kg) Sand
250-550
Silt
250-500
Clay
Parameters
Optimal Values
Aqueous Extract (mg/Kg)
100-300
Aqueous Extract
Chlorides
max 50
Sulfates
10-250
Nitrates
20-30
Macroelements
Reaction (pH in water, 20°C)
6.5-7.3
N (%)
0.10-0.18
Electrical conductivity (mS/cm)
<2.3
P2O5 (mg/kg)
100
K2O (mg/kg)
200
CaO (mg/kg)
3500-4500
MgO (mg/kg)
180-320
CEC (meq/100gr) CEC Total
10-20
Potassium
2-4
Sodium
max 15
Calcium
65-85
Magnesium
Microelements (mg/Kg)
8-12
Carbonates (%) Total limestone Active limestone
5-30
B
0.4-1
Mn
2-10
Cu
2-4
Zn
2-3
Elements Ratio 2.5 - 10.0 ≤8
Macroelements (%) Organic matter
Fe
3-3.5
C/N
8-12
Ca/Mg
5-10
Ca/K
25-40
Mg/K
2-5
Sodium Adsorption Ratio (SAR)
<0.8
For the soil suitability assessment of a farm area it is enough to focus on some crucial parameters for hazelnut cultivation. After having evaluated them, it is important also to take in consideration additional parameters in order to make a proper preplanting fertilization plan.
13
CLIMATE SURVEY Main climatic parameters Hazelnut is a really rustic tree. Despite this, we have to take in consideration some parameters that are important for its cultivation. The evaluation of these parameters can be based both on personal experience and by collecting data from regional and/or local meteorological stations.
The hazelnut tree does not suffer low T° and can resist up to minus 35 °C. However, T° below - 2 °C, during the fecundation period (late March - April), could affect the future production. It should be avoided area where late frost phenomena often occur
The damage depends on the duration of the frost and on the vegetative phase of the plant. For example: if the plant is still not in the fecundation period in March or April because the cold delayed the vegetative phase, an eventual frost will not affect the production
Excessively high temperatures in July and August, along with persistent droughts, could result in fall of leaves, lower yield and death of young plants
The damage depends on the duration of the drought period and of the high T°. The use of an irrigation system will drastically reduce the effects of these issues
There should be 700 - 800 mm of rainfall in the area, well distributed during the year without droughts periods in the hot season (June, July, August). It’s important to collect data from meteorological stations
The modern orchards are always provided with an irrigation system that usually is on function from May to August, before the harvesting period
Setting up of windbreaks will help in reducing of strong and persistent winds that can be dangerous during the summer (increasing the draughts effect) and also during the winter damaging the young trees or hindering the pollination.
Wind is important for pollination but strong and constant winds represent a problem if related to warm temperatures
14
15
16
ORCHARD ESTABLISHMENT 1
LAND PREPARATION MECHANICAL OPERATIONS Assumptions z
The soil should be prepared in summer: the best period is between July and September
z
Deep tillage, up to 1 meter deep, could be fundamental in case of heavy soils in order to promote absorption of rain water and to take any excess to deeper levels. Deep tillage will encourage an easier development of the root system. It could be also taken in consideration the possibility of realizing the ridging, in presence of heavy clay, flat and superficial soils with drainage problems. Ridging allows a good drainage and a deeper soil availability for the root system. It needs to be considered the higher cost of the investment.
z
Soils with different structure, are cultivated with different mechanical operations and right moisture content facilitating the root growth and tree performance. The use of heavy machinery on bare wet ground should be avoided, particularly on soils with high clay content
z
Land cultivation should be done accordingly to the morphology of the soil, without movement of big amount of land during flatting operations
z
Evaluate and cultivate the land with necessary declination so there will not be waterlogging or problems due to standing water: sometimes could be useful to make a quoted plan in order to make a good drainage system. Water flow should be managed to minimize soil erosion and nutrients run off
z
Planning before the first land cultivation inner road, drainage or irrigation system
z
After deep tillage, the surface is worked with arrows, disks or other tools in order to break the clods formed on the ground
Disking operation
Ripping operation 18
Shredding and mulching z
In case of needs to clean the soil surface from grass, bushes and small trees.
z
It could be needed powerful tractors.
z
If necessary use herbicides for weeding
z
Also disk arrows can be used
Ripping and rigging z
Used to loosen and break up soil at depths below the level of a traditional disk harrow or rototiller. To cross the ripping is a good practice to tillage the soil improving growth of the trees where soil compaction and waterlogging is a problem. If needed, one of the two ripping should be done at a 45 degree angle by favoring the water flow to the drainage channels
z
Heavy soil: the ripper is usually used at depth of 80 - 100 cm in order to guarantee a good development of the root system ensuring a good aeration of the soil profile
z
Loose soils: if the soil profile does not present dangerous layer in depth, not ripping more than 60-70 cm because the soil is already well drained.
19
Plowing z
Used for turn over the upper layer of the soil, homogenizing the layer interested from the roots, interring weed seeds and previous crop residuals.
z
It has to be avoided in presence of unsuitable horizons in the deeper levels (i.e.: high level of carbonates)
z
After basal dressing, the plowing operation should not go deeper than 50 cm, depending on soil characteristics
Fine tillage z
Disc harrows are primarily used to chop up soil that has been recently plowed to eliminate clumps and loosen the soil if it has been packed
z
Two/tree times are enough for creating a good soil structure that is suitable for planting use
20
Drainage The drainage can be done by special pipes with micro-holes or by ditcher that can produce open channel It is suggested to make a drainage system mainly on flat area and soils with high percentage of clay. Also on hilly area it can be set up, in particular when soil morphology does not allow the correct running off of the water. The drainage system has to be designed before planting operations according to the orchard layout and soil morphology
Pipes with micro-holes
Open channel
Opening of a drainage channel
21
PREPLANTING FERTILIZATION Principles z
In order to enable proper growth and development of hazelnuts, it is necessary to import all necessary nutrients in the form of mineral and organic fertilizers
z
For the time being, hazel should be fertilized according to the results obtained by the analysis of soil that can be chemical and physical
z
Different types of soil require a different approach to the interpretation of soil analysis
z
Interpretation of the analysis and recommendation of the fertilization rate should be done by an expert
z
Fertilization before planting allows for the introduction of larger quantities of fertilizers into the soil, which will significantly change the chemical, mechanical and biological soil structure
z
During fertilization prior to planting, we can influence the amount of organic matter in the soil, the amount of phosphorus and potassium that are poorly moving in the soil, the pH of soil changes, etc.
z
In this chapter, one of the basic principles of fertilization before planting will be presented in more details
22
Soil pH Soil pH highly affects the microbiological activity, the mineral elements availability and the growth of the plants. In particular: z
the majority of bacterials, influencing the Nitrogen process, prefers sub-acid o slightly alkalin pH (pH 6,1÷7,8);
z
fungus prefer acid pH ensuring the organic compounds decomposition;
z
the soil pH affects the solubility of various mineral elements, resulting in their accumulation in more or less available forms for plants or their leaching towards deeper layers
Soil classification based on pH Extremely acid
below 4.5
Very strong acid
4.5-5.0
Strongly acid
5.1-5.5
Medium acid
5.6-6.0
Slightly acid
6.1-6.5
Neutral
6.6-7.3
Mildly alkaline
7.4-7.8
Moderately alkaline
7.9-8.4
Strongly alkaline
8.5-9.0
Very strongly alkaline
9.1and higher
The Influence of Soil pH on Nutrient Availability
4.04
.0
4.04
.0
6.0
6.5
7.0
7.5
RANGE OF ACIDITY
8.0
8.5
9.0
RANGE OF ALKALINITY NITROGEN PHOSPHORUS POTASSIUM SULFUR CALCIUM MAGNESIUM IRON MANGANESE BORON COPPER & ZINC MOLYBDENUM
23
9.5
10.0
Soil pH – ACID SOIL TO BE CORRECTED z
The most common method of repairing acid soils, ie, the increase of pH value, is the CALCIFICATION, which involves the addition of various lime materials to the soil: dolomite, hydrated lime, saturated sludge, marl, lime limestone, etc.
z
The application of this measure also implies the application of organic fertilizer (most often manure), in order to increase the solubility of the applied lime
z
Increasing the soil pH is not a permanent measure, and it is necessary to work continuously on increasing and maintaining soil pH.
z
Before planting, it is possible to significantly increase the pH value, but with the required soil analysis and following the recommendations of the experts in order not to disturb the chemical and microbiological relationships in the soil. After establishment of the plantation, it is necessary to apply smaller quantities of a lime for the above mentioned reason.
z
COMMON FERTILIZERS WITH ALCALINE REACTION Anhydrous Ammonia Calcium Nitrate Magnesium Nitrate Sodium Nitrate Thomas Slag Calcium cyanamide
In these soils, fertilizers of neutral or base reactions should be used Overall quantities of lime need to be added for pH correction pH
Needs in agricultural lime in
From
To
Sandy
Sandy loam
Loam
Silt loam
Clay loam
4
6,5
4,5
6,7
8
9
11,25
4,5
6,5
3,3
3,5
6,75
7,5
9
5
6,5
2,25
3,75
5,25
6
7,5
5,5
6,5
1,5
3
3,75
4,5
6
6
6,5
0,75
1,5
1,8
2,25
5,25
4
6
3,3
2,25
6,75
7,5
9
4,5
6
2,25
3,75
5,25
6
7,5
5
6
1,5
3
3,75
4,5
6
5,5
6
0,75
1,5
1,8
2,25
5,25
4
5,5
2,25
3,75
5,25
6
7,5
4,5
5,5
1,5
3
3,75
4,5
6
5
5,5
0,75
1,5
1,8
2,25
5,25
24
Soil pH – BASIC SOIL TO BE CORRECTED X We can differentiate alkalinity in: z
Alkalinity due to the high content of carbonates: it is illusory to try to correct the reaction with acidic substances: the amount of acid that can only solubilize small amounts of limestone (not usually affecting the level of soil alkalinity) is generally enormous and therefore economically prohibitive.
z
Alkalinity due to the high content of salt: in that case we have to consider the Exchangeable Sodium Percentage (ESP), percentage between sodium exchangeable and Cationic Exchange Capacity (CEC), together with pH and Electric Conductivity (EC).
If we have salty soils (EC>4 mS/cm, ESP<15% e pH<8,5) it will be enough to irrigate; If we have alkaline-salty soils (EC>4 mS/cm, ESP>15% e pH<8,5) it will be needed to irrigate adding substances that can favor the displacement of the sodium ion adsorbed on the colloids; the most used are sulphur based products like plaster (calcium sulphate), iron sulphate and sulfur. The corrective action of these substances is due to the formation of sodium sulphate which is diluted due to its high solubility. The choice of correction must be dictated not only by economic reasons but above all by chemical-biological considerations related to the soil and to the nature of the fertilizer For the purpose of assessing the necessity to take corrective action of sodium alkalinity, it is possible to divide the soils according to the ESP in three groups:
ESP <5: do not take corrective actions;
ESP 5-7: To take under control, particularly if the irrigation water is rich in sodium and poor in calcium and magnesium;
ESP >7: the pH needs to be corrected.
X The correction of an alkaline soil is more complex than that of acidic as there are several possible reasons causing the anomalous reaction: Plants absorb sulfur in the sulfate form: z
Sulfates - combined with ammonium, potassium, magnesium, etc. (not calcium because it forms a insoluble salt in water) are promptly available for the plant after have been applied
z
Thiosulfates, - normally combined to ammonium or potassium but also to calcium and magnesium, form high soluble salts.
25
Kind of soil Reducing pH
Sandy
Silty / Loamy
Clay
Kg / ha of sulfur 8,5 - 6,5
220
275
330
8,0 - 6,5
135
165
220
7,5 - 6,5
55
90
110
Kind of fertilizer
%S
%SO3
Availability of sulfate
Calcium sulfate
18%
45%
Depending on the presence of colloids in the soil
Thiosulfates (potassium, ammonium)
17-26%
42-65%
Immediate (50%) to 3-4 weeks the rest (50%)
Grounded sulfur (1-10 μm)
>80%
>200%
to 2-3 weeks
Sulphur powder (40 - 50 μm)
99,5%
>248,75%
to 3-5 weeks
Sulphur Bentonite or clay (0 - 400 μm)
>85%
>212,50%
to 15 weeks
Industrial sulphur (some mm)
>99,9%
>249,75%
Not less than some years
Depending on the physical and chemical formula in which sulfur is present in the fertilizer, different results can be obtained in terms of soil availability, which allows different strategies by applying the form considered suitable according to the crop cycle, sulphate release or the application mode. Industrial sulfur is coarse and is insoluble and unsuitable for normal cultivation cycles. It is used as improver of calcium and sodium alkaline soils.
26
Organic matter Nutritional functions z
mineralization of the organic substance causes release of the elements contained in it as nitrogen, phosphorus, potassium, magnesium, calcium, etc .; these can be absorbed and used by the plant;
z
certain classes of microorganisms, important for fertility of soil, requires organic substances to get survival;
z
organic compounds carry some microelements such as iron, boron, manganese, zinc, copper and phosphorus, making them available for the root system;
z
some organic substances are absorbed by plants where they perform hormonal functions, promoting development of some plant tissues;
z
It constitutes much of the exchange soil surfaces that can retain nutrients preventing them from sinking.
Structural functions z
the organic matter forms, together with the clay, stable aggregates called “humo-clayey complexes” that are able to give more structure to the soil;
z
in sandy soils, it increases the water retention capacity, preventing nutrient dilution;
z
in limy soils, it avoids the formation of surface crusts or working soles and other waterproof layers;
z
in clay soils, it contrasts the compaction, erosion and crack-soils phenomena.
27
ORGANIC MATTER – Example on Input calculation
a) Depth of the soil: 0,30 m
Example: calculation Effective surface Length of the row: 200 m Width of the row: 2 m Layout: 5 * 3 Buffer from the fence: 4 m
b) Bulk density: 1,2 t/m3 c) Orchard surface: 1 ha Effective surface to be fertilized in 1 ha: 200 m (length of the row) * 2 m (width of the row)* 9 (n° of rows) in 1 hectare = 0.36 ha d) % OM from the analysis: 1.15 %
200m
e) % OM we want to reach: 2 % f)
Δ OM: e-d = 0.85 %
g) Weight of the soil: a * (b*1,000) * (c*10,000) = 3,600.000 Kg h) OM in the soil: g* (d/100) = 41,400 Kg i)
Optimum of OM: g* (e/100) = 72,000 Kg
j)
Δ OM: i-h =30,600 Kg
k)
OM to be furnished on the effective surface:
c * j = 0.36 * 30,600 = 11,016 Kg/ha = 11,016 ton/ha
Level
Organic Matter (%)
Very Low Example: using cow manure: Dry matter: 25%
11.016 ton / 0.25 % = 44 ton /ha
Manure (kg/ton)
% Dry matter
N
P2O5
K 2O
Average Pigs
25
5,8
3,8
Average Cows
25
4,9
Average Poultry
70
38,5
<0,8
Low
0,8 - 1,2
Medium
1,2 - 2,0
Good
2,0 - 4,0
Very Good
4,0 - 8,0
Sauvage (kg/ton)
% Dry matter
N
P2O5
K 2O
6,3
3
2,7
1,6
2,3
4,4
6,5
10
3,8
2,8
3,6
19
15,5
10
10,5
10,4
5,4
28
Technique and Machines Pre-planting fertilization can be localized or spread on all the orchard. X Localized fertilization: at the planting time, putting mature manure or granular fertilizer (slow release) directly into the hole, paying attention on the fact that the root system could be damaged if directly in contact with fertilizer. This kind of fertilization is possible only if the soil is already rich in nutrients
X Fertilization on the all orchard: spreading the fertilizer on all the orchard surface and interring subsequently by a plower (or similar) to a depth of 30 cm.
29
30
PLANTING OPERATIONS PLANTING LAYOUT AND VARIETIES The choice of the position of the plot and the direction of spreading the rows is essential both for the normal growth and development of the plant itself and for facilitated agro-technical measures. The basic parameters in this decision-making should be the shape and dimensions of the plot, the sides of the world, the slope of the terrain and the most common directions of wind blowing during flowering and during vegetation. Right way of alocation of different varietes in orchard is to plant only one variety per row. Reason for this way of planting is to easier follow development of different varietets, better pollination and easier harvesting according to different rippening period. z
In case of small plots one row of pollinizers can be planted each 4-5 rows of main cultivar
z
In case of big plots trees are planted in blocks composed of the same variety
The term “main cultivar” is referred to the variety that we plant in larger quantity in our orchard SMALL PLOT
Variety 1
Variety 3
Variety 2
Variety 4
BIG PLOT
Winds
31
Variety 1
Variety 3
Variety 2
Variety 4
Winds
SELECTION OF THE CULTIVARS Selecting the most appropriate hazelnut varieties for planting is an important decision. There are many varieties of the hazelnut , mainly unknown origins or wild, that have been selected and adapted to different area. But still now are the number of controlled genetic breeding are missing, because the interest and scientific research related to this crop have been started only in the past few years.
For the varieties’ choice, it should be kept in mind the following parameters in order to get a successful profitable planting
PRODUCTIVITY (ton/ha) SHELLING RATE MARKET SUITABILITY CROSS COMPATIBILITY CERTIFICATED SEEDLINGS 32
Main cultivars In the next chart we give a short description of the main varieties cultivated/propagated in Europe and growth by Ferrero in its own Agrifarms. All the varieties descripted have a suitable match with the parameters above
TONDA GENTILE DELLE LANGHE y y y y y y y
FERTILE DE COUTARD
Origin from Piedmont Vigorous Semi-erect growth habit Early male flowering Low productivity Easy peelable High kernel ratio: 44-48 %
TONDA GENTILE ROMANA y y y y y y y
y y y y y y y
Spread in western Europe High Vigour Middle season flowering High productivity Fairly peelable Easily rancid Medium kernel ratio: 39-42 %
y y y y y y y
Origin from South Italy Medium-high vigour Open branching Quite early flowering Easily peelable High productivity Low kernel ratio: 38-40 %
NOCCHIONE Origin from Lazio Medium Low vigour Semi-erect growth habit Middle season flowering Medium-high productivity Hardly peelable High kernel ratio: 44-48 %
TONDA di GIFFONI y y y y y y y
33
Origin from South Italy Vigorous Semi-erect growth habit Early male flowering High productivity Easy peelable High kernel ratio: 44-47 %
Pollination Hazelnuts are wind pollinated and self-incompatible: that means, a tree cannot pollinize itself or any other tree of the same variety. In addition, the pollen of a variety could not compatible to pollinate the female flower of another variety (cross-incompatibility). An other point to take in consideration is the different time of flowering among varieties. For these reasons, in order to reach a good cross pollination, it is generally considered that, at least, three different varieties should be planted in our orchard. X Successful pollination mainly requiresi: z
Suitable amount of pollen: pollen can float on the air up to 30 km far from the tree. Each catkin (male flower) releases millions of pollen grains;
z
Pollen of compatible type that is available at the same time as the female flowers are in bloom: stigmas are receptive from the time they first appear as a tiny red dot at the tip of the bus until they extend to their maximum length;
z
Favorable weather conditions: For a good pollination it is needed presence of wind and absence of persistent rainfall during the male flowering. Do not forget that hazelnut flower require a certain amount of chill hours before blooming (different between male and female).
Male and female flowers lay on the same plant
Male flower during pollen release
Female flowers during blooming
X Here below we can propose an example of 4 cross compatible varieties that can be used for our plantation: z
Tonda di Giffoni
z
Tonda Gentile Romana
z
Tonda Gentile delle Langhe
z
Nocchione
As we can see in the next chart, the combination guarantees a successful pollination. Other combinations are allowed that will enable quality pollination and fertilization. 34
GENETIC COMPATIBILITY
The percentage of the different varieties is flexible and depends on the presence of hazelnut orchard in the surrounding area. For instance, in many Italian areas where hazelnut is strongly present, farmers sometimes plant only one variety.
Giffoni
Variety
Romana Langhe
The same must not to be done in area where hazelnuts are low or not present at all
Fertil Nocchione Key:
As we can see from the table above, the proposed varieties have a really good mutual genetic compatibility.
Incompatible
Compatible
BLOOMING COMPATIBILITY VARIETY Tonda di Giffoni
DECEMBER 15 20 25
31
JANUARY 5
FEBRUARY
10 15 20 31
5
JANUARY
FEBRUARY
10 15
Male flowering Female flowering SORTA Tonda Gentile Romana
DECEMBER 31
15 20 25
5
10 15 20 31
5
10 15
Male flowering Female flowering SORTA Tonda Gentile Langhe
DECEMBER 15 20 25
31
JANUARY 5
10 15 20 31
FEBRUARY 5
10 15
Male flowering Female flowering SORTA Nocchione
DECEMBER 15 20 25
31
JANUARY 5
10 15 20 31
FEBRUARY 5
10 15
Male flowering Female flowering
35
Blooming is different among the cultivars but it particularly depends on the Temperature. It can be given a general indication of blooming timing: y Male blooming: pollen shedding form the middle of December to February y Female blooming: middle of January to March As we can see, from the scheme above, thanks to this varieties’ combination, it can be ensured an excellent pollination.
CROSS POLLINATION
Nocchione
Fertil
Langhe
Giffoni
Romana
Pollenizer
RECEIVING OF THE SEEDLINGS Plants characteristics To achieve uniform planting with good rooting assurances, it should be checked that seedlings received have: z
all the organs free from any kind of diseases like fungus, parasites, etc.;
z
good root system;
z
good diameter of the stem (1-2 cm);
z
guarantee in terms of variety and phytosanitary status: it is advisable to buy plants from nurseries “accredited” and able to supply certificates;
z
if the plants received are in pots check that the root system has not spiral shape
Label of certificated plant (cv. Fertile de Coutard)
BARE ROOTS
POTS z z z z
Certificated plant
Wider period for planting: early in fall or late in spring Higher transportation costs Higher price Difficult to handle
z z z z
36
Shorter window for planting Lower transportation costs Lower price Easy to handle
RECEIVING OF THE SEEDLINGS Plants management That’s a crucial phase. It should be paid much attention to the seedling during this period in order to reduce the percentage of failures on the 1st year of plantation. X If the climatic and soil conditions do not allow the planting: y it is necessary to dig a trench (30 cm deep) or use a substrate of sawdust where to put as soon as possible the plants; y the bunches of seedlings can be put into the trench directly; y the plants have to be irrigated because, in particular at this stage, the root system suffers the lack of water and to better stick the soil to the roots y planting out within March. X If the climatic and soil conditions allow the planting: y cut the roots if longer than 25 cm; y cut the plants according to the final shape to be reached (see paragraph “tree shaping”)
When we plan of planting in the current season it is not necessary to untie the bunches but it’s enough to well cover the root system protecting it from the frost and from the lack of water. Make sure that also the seedlings in the middle of the bunch will be well managed. If at the end of the planting season it is not possible to realize the plantation, it is advisable to opt for the system below Untie the bunches requires more time for the pre-planting and planting activities. It is needed also more space for the preplanting phase. It is advisable either if there are few seedlings to be planted or if there is no time for planting in the current season
37
PLANTING LAYOUT and VARIETIES Layout The choice of the planting layout involves many factors: soil fertility, training system, vigor of the cv, productivity during the first years. During the recent years the higher density plantings have been adopted (i.e. 5x3) instead of lower density (i.e. 6x6).
HIGH DENSITY (6x3 – 5x3) This kind of layout is considered more efficient as yields have the potential to double that of the lower density within the first 10 years and it may be crucial to the economic survival of a new orchard. Trees can be thinned in the long term (removing every second tree down the row at 11 to 15 years) if the excessive shading and crowding occur. A close space orchard could be maintained with appropriate pruning, but this will incur more higher costs for maintenance. 3m Suckers emission after cutting
LOW DENSITY (6x4 – 6x5 – 5x5)
Planting with a wider spacing along the rows is suitable for trees when they mature. Choosing a lower density from the beginning allows to reduce the cost of investment, of removing trees and of pruning.
6m
Particularly suggested in case of poor soils (lack of nutrients) or loose soils (water availability for the plants).
4m
Low density layout: 6 x 5
38
SQUARING AND PLANTING Squaring (after soil preparation and before planting) After preparing the soil, the plantation is marked out in relation to the chosen plan: layout, presence of internal roads, buffer from the boarder (usually not less than 5 meters), etc. In the last years, this operation has been performed using GPS devices that ensure greater accuracy and better use of time and labour. It is usually placed a stake at the point where the plant has to be planted. In the following paragraph it will be explained the use of GPS system directly by the planting machine.
Manual Planting (Timing: November -leaves fall- to March -vegetative growth-)
2
1
Dig an hole (deep and width) of about 40 cm. If we are in presence of loose soils, holes can also be dug by a drill.
3
Put fertilizer on the bottom. It is suggested mature manure or slow release granular fertilizer. If we have already made the preplanting fertilization, this step has to be skipped.
4
If directly in contact with the roots, fertilizers could damage the root system. For this reason we have to put loose soil into the hole before planting.
5
Fill the hole up to the base of the stem and slightly .compact with topsoil
Planting out paying attention to the right depth of the setting.
39
SQUARING AND PLANTING Mechanical Planting Mechanical planting allows to reduce the man power and the time needed for this operation. The machine is equipped with a GPS system that is preset by the operator with the chosen orchard layout. A ditch is dug by a ripper and an acoustic signal will give the operator the right time to leave the plant down. After planting, the ditch is immediately covered by the machine.
MECHANICAL PLANTING
MANUAL PLANTING
X Area planted per day: 5 ha (8 hours)
X Area planted per day: 5 ha / day
X Manpower: 10
X Manpower : 50
z 1 tractor driver
z 15 Markers
z 4 for planting
z 15 holing
z 5 transport/unload
z 15 planting z 5 transport/unload
The max. capacity of the mechanical planting is around 5 ha/day. To reach the same area by manual, there is much more need of manpower.
40
ADDITIONAL LAND INVESTMENTS Fence
z
To be installed if plots are located in areas with considerable presence of wild animals.
z
Height: enough 1.80 m
z
Underground the mesh 20 to 30 cm
Windbreaks X Hazelnut plants are very susceptible to the drying effects of hot persistent winds
SINGLE ROW
X Wind breaks should be installed on the prevalent wind direction, in single or double rows with fastgrowing high drum plants (poplar, cypress, etc.). X Single row: density of 1 tree every 1 meter in line. X Double row: increase the windbreak efficiency. Density of 1 plant each 1.5 meter in line X Windbreaks have to be irrigated for a good and fast growth of the plants X Hazelnuts are wind pollinated and blooming takes place in winter, so any windbreak should be deciduous, allowing some air movement for pollen to be carried
1.5m
1.5m Prevailing wind direction
1.5m
DOUBLE ROW Lenght of the area protected by the windbreak is 15-20X larger than the height of the tallest trees
41
MAIN OPERATIONS ON THE 1ST YEAR Orchard establishment and management Here below a quick summary about the main operations to be carried out during the first year of plantation. All these operations should be carried out according to a deep pedo-climatic analysis: this is a crucial step for our orchard success in term of quantity and quality of the production in the future. OPERATIONS TO BE PERFORMED Soil and climate analysis ORCHARD ESTABLISHMENT 1ST YEAR
Land preparation (mechanical operations) Preplanting fertilization Planting out activities: squaring, holing and planting Training pruning 1-2 manual weeding around the plants
ORCHARD MANAGEMENT
2-3 mechanical weeding on/between the rows 1-2 treatments with copper products. If necessary, also mineral oil but only on February/March Manual desuckering and training pruning
Suitable Period to perform the main operations June
July
August
September October November December January February
Land preparation Pre-planting fertilization Planting
Training pruning Manual weeding around the plants Mechanical weeding on/between rows Manual de-suckering Treatments (copper + mineral oil)
42
Marcg
April
May
June
July
August
September October November
43
44
MAINTAINANCE OF THE ORCHARD UNTIL PRODUCTION PERIOD 1
PRUNING TREE SHAPING The main objective of training trees is to develop a strong system of major scaffold limbs to form the tree’s framework. Hazelnut can growth by 3 different training methods: bush, bush vase and tree/sapling. According to the shape we want to get, different pruning operations will be realized.
BUSH YEAR 0
30 cm
In case we receive from nursery a single stem seedling, at the planting cut the seedling at 30 cm in order to let the plant developing a good root system and to encourage suckers emission from the bottom
YEAR 1-2
50 cm
During the next 2 years let the branches grow freely eliminating only suckers in excess. It is suggested to grow up only 6-7 branches in total eliminating the shoots to much far from the centre
In case we receive from nursery a bush seedling, at the planting cut the seedling at around 50 cm. As we have already other suckers, it is not needed to do a shorter cut.
YEAR 3
ADVANTAGES Easy management of the adversities Growth training pruning is easier DISADVANTAGES
Next fall, choose 4-5 best oriented and vigorous shoots that will constitute the final tree. Eliminate all the suckers in excess.
Harvesting is more difficult In the next years, cut only new suckers/shoots 46
Suckers management
TREE SHAPING BUSH VASE
If the tree is still not well developed it can be decided to postpone this operation at next fall (Year 3)
YEAR 0
30 cm
In case we receive from nursery a single stem seedling, at the planting cut the seedling at 30 cm from the ground level letting develop
YEAR 1
30 cm
During the summer, let grow 5-6 branches on the top of the tree.
In case we receive from nursery a bush seedling, at the planting eliminate all the branches leaving only the main stem cutting it at 30 cm from the ground level
Cutting out all the other suckers or shoots.
YEAR 2
ADVANTAGES Harvesting and other management operations are much easier (de-suckering, weeds control, etc.) Easy management of the avversities
Next fall, select 4-5 branches best oriented and vigorous that will constitute the final tree. Cutting out all the other suckers or shoots.
DISADVANTAGES Training pruning is more difficult In the next years, cut only new suckers/ shoots 47
TREE SHAPING CLASSIC TREE SHAPE YEAR 0
YEAR 1
80 cm
In this case it is of crucial importance to receive from nursery a single stem seedling. At the planting cut the seedling at 80 cm.
During the summer, let grow the shoots on the top and eliminate all the other shoots or suckers below.
YEAR 2
ADVANTAGES Harvesting and other management operations are easier (de-suckering, weeding, etc. DISADVANTAGES Only with vigorous varieties Training pruning is more difficult
Next fall, select 4-5 branches that will constitute the final plant. Eliminate all the other shoots or suckers. If the branches on the top are still not well developed they can be selected on the next fall (Year 3)
Difficult management of the adversities: a deasease could damage the whole tree In the next years, cut only new suckers/shoots 48
Less productive in the first years
SOIL MANAGEMENT Soil management until the 4th year One of the most common fault observed in establishing the newly planted tree is the lack of weed control. Weeds need to be controlled on all the surface during the first 4 years because they deprive the developing tree of moisture, nutrients and sunlight. In case of use of chemical products, must be utilized only those authorized for the hazelnut cultivation.
3rd – 4th YEAR
1st – 2nd YEAR
z No-tillage system of soil management can eliminate most of the ground preparation for harvest. It is used after the 3rd year of plantation
z 2 – 3 manual weeding around the trees z 2 – 3 weed controls on the remaining surface by rotary tiller or disc arrows
z Usually 4-5 mulching per season can satisfactorily control weeds. They are done starting from March till July (before nuts fall down)
z During the first 2 years it is also recommended to avoid the use of herbicides because they could seriously damage the young trees if they get in contact with the plants
z Mulching machine is pulled by a tractor of medium size, 70-100 hp.
z It is also important not go deeper than 20 cm close to the plants, preserving the root system by potential damages
z From the 3rd year can also be applied herbicides down on the row paying attention to not spray the plants. Between the rows it can be used the mulcher.
49
PRUNING Mechanical pruning Over the last few years there have been many trials involving mechanical pruning in hazelnut groves, using very different system and techniques, in order to assess the real benefits that this new pruning might bring out. In essence, traditional manual pruning is replaced by mechanical performed by special disks mounted on adjustable bars It is a rapid, economical way to prune but the cuts are made indiscriminately in a straight plane not respecting the habitus of the plant. The intensity, depth and direction of the cut may change from time to time in order to adapt to different operating situations. The mechanical pruning can be carried out only from the 4th year when the plant has reached a good size: starting from that period the growth of the plant can be easily managed since the beginning.
Before pruning
After pruning
3 years later
5 years later
Evolution of enlightenment in a hazelnut orchard after pruning 50
Mechanical pruning There are 2 kinds of cut: X Hedging: lateral cut X Topping: cut on the top of trees The mechanical pruning makes a big cut on the tree and for this reason it has to be carried out just on one side of the tree in order to minimize the lost of production, leaving the other side for the following year. In any case, it will be necessary to control suckers and more accurate manual pruning operations. After pruning it needs to protect the cut by a specific paste or by copper based treatments. Many other aspects have to be still considered but the difficulty in finding manpower and the high costs of traditional pruning are compelling factors in this direction.
51
Control of the suckers Hazelnut is a tree producing a lot of suckers that have to be kept under control whichever training system has been chosen.
They are undesirable for several reasons: z
They are undesirable for several reasons:
z
Suckers divert growth from the main tree structure. Energy is wasted on a shoot, so they need to be removed
z
Suckers reduce lighting and air circulation
z
They obstacle the harvesting
z
Excessive sucker growth interferes with the shaping of the tree
z
Young fleshy suckers can be attractive to insect attack.
SUCKERS TO BE CONTROLLED
2 YEARS LATER
52
Control of suckers Suckers can be controlled chemically and mechanically.
MANUAL
Usually the 1st year we leave the suckers grow freely, according to the final shape we want to reach (compare with the “pruning chapter”) and to the quantity of suckers emitted (too much suckers obstacle the plant growth). In the first 2 years, it is advisable to control the suckers manually, in order to not damage the young trees using chemical treatments.
1st – 2nd year y y
Slow operation > manpower
y Compared to the chemical, it requests more manpower and time (hours/hectare) to be carried out but it’s enough one time per year between July and November. y It is particularly important to establish the final shape of the tree.
When: July/August or November (just 1 time)
CHEMICAL
y If you promptly and carefully remove suckers during the first 2 years after planting, the tree will produce fewer suckers in late years, thus greatly reducing the labor needed for sucker removal. From the third years it is also possible to use chemical product paying attention to not damage the trees. Chemical control involves spraying the suckers with a knockdown registered herbicide. y Correct timing is important: apply herbicide when suckers are 5 to 10 cm tall: application when the sucker is fleshy gives optimum control. Larger suckers that have become woody will need to be cut out.
3rd - 4th year y y
> risks if not properly performed Different applications during the year
y Particular care is necessary to not over spray on the stems of young plants. y Weather conditions are also important: best results are achieved in overcast weather. Not spray if windy y Spray when needed, April to October, but no more than 3 times.
When: from April to November (3 times)
53
IRRIGATION Assumptions Hazelnut is sensitive to scarcity of water and thus it is one of the key task that growers need to be able to manage, in particular, in young tree. A lack of water can lead to: z
Plants’ death
z
Reduced production, kernel ratio, yield and plant growth
z
Increasing of biennal bearing
z
Catckins drop
z
Early nut/leaves fall
For these reasons farmers have to establish an irrigation system since the planting. X In order to set a good irrigation system growers have to consider: z
Soil characteristics: texture, AWC, etc.
z
Climate characteristics: distribution and quantity of rainfall (mm/year), T° during the summer, presence of prevalent winds
z
Farm characteristics: source and availability of water
z
Cultivar needs
z
Water quality
z
The possibility to carry out the fertigation reducing doses, costs for fertilizers, compactation of the soil and allowing to fertilize also with wet soil
WATER IN SOIL Soil texture has to be considered: i.e. in a clay soil water remains more time in the area explored by the root system CLAY
LOAMY
SANDY
IMPERMEABLE
WATER QUALITY PARAMETER Electrical Conductivity (EC) pH
COMMENTS If salinity is less than 0.8 dS/m then the water is generally suitable for irrigationon well drained soils Water with pH to 8.5 is generally suitable for irrigation
Chloride
Levels below 140 mg/l (140 ppm) are generally acceptable
Alkalinity
Highly alkaline water can affect the uptake of calcium and magnesium. Levels up to 150 mg/l are acceptable
Calcium Carbonate Saturation Index
Index determinated taking into account pH, salinity, alkalinity and hardness. Figures between - 0.5 / + 0.5 are usually acceptable
Organic
Algae and other organic elements can cause blockage of filters and dripper
54
Surface Drip Irrigation DRIPLINES ON THE GROUND ADVANTAGES
DISADVANTAGES
Low Costs
Chemical weeds control on the row during first years
Short time for Installation
Obstructs harvesting and other mechanical operations
2 drippers per plant Distance of the dripper from the stem: about 30 - 40 cm Dripper flow: 2 l/hour
RAISED DRIPLINES ADVANTAGES
2 drippers per plant Distance of the dripper form the stem: about 30 - 40 cm 1 stake each 10 m 1 iron cable to support the dripline Use dripper wires when are driplines raised more than 1 m
DISADVANTAGES Higher Costs
No harvesting and other mechanical issues
More time for installation Evaporation losses
H=1m H=0,5m
55
H=2.2m
Sub-Surface Drip Irrigation Driplines are buried mechanically by a machine that at the same time digs the ditch and buries the drip tape. Depth of the tube placement, emitter spacing, flow and soil properties should be carefully considered. The use of specific equipment for this kind of irrigation system is also mandatory. Both the options proposed below are considered as permanent (up to the irrigation system shelf-life). FROM THE PLANTING YEAR OPTION 1
y y y y
Depth of setting: 25-30 cm Distance from the plant: 30 cm Dripper each 80 cm; The optimum could be to set up 2 driplines
FROM THE 4TH YEAR OPTION 2 POSITION OF DRIPPERS
ADVANTAGES No harvesting and other mechanical issues
30cm
1,10m
1,10m
DRIPPER
y Depth of setting: 30 cm y Dripper each 80 cm y Distance of the pipelines from the stem: 1.10 m (yellow lines) or in the middle of the row (red line) y Make attention to not damage the root system during the setting up
56
More water efficiency and efficacy DISADVANTAGES
Problems with breakages and occlusions
Basic of irrigation scheduling Generally, hazelnut has to be irrigated from the end of April to August (before the harvesting) according to climate (rainfall – temperature), soil characteristics and plant stage of growth. There are many methods developed for measuring crop water use/needs. These methods can be grouped into three categories: z
Plant-based methods: information from the plant itself, including direct observations. Usually light green and crimped leaves are symptoms of water deficiency
z
Weather-based methods: data from climatic factors, including sunlight, temperature, wind and humidity
z
Soil-based methods: that monitor the quantity of water taken up by the plant from the soil using sensors
X The key issues remain how much and when to irrigate. Knowing how much to irrigate requires first establishing how much water is held in the root zone because not all water applied or already in the soil is available to the tree. Some water is held tightly in the soil; this is known as soil moisture tension. There are different levels of soil moisture tension that differently allow the plant to extract water. Thanks to irrigation we have to maintain the moisture between the “Field Capacity” and the “Refill point”. Nowadays the quantity and timing of watering are (in most of the cases) arbitrarily decided by the farmer. In the next slides is given a simple example that could help to carry out a more rational use of the irrigation also according to the plant’s needs.
Range Value (kPa)
Interpretation
0-8
Soil is saturated (0) to near field capacity (8). Continued low readings indicate water logging
8
Field capacity
8-25
The best conditions of soil moisture and aeration
25-35
Consider irrigation at critical stages of crop cycle: ovary growth and kernel expansion
35-50
Mild stress on well drained soils
50+
Soil is very dry: this will affect yield and kernel quality (PWP)
57
Field water capacity or field capacity (FC) is the upper limit of the available soil water (AW) reservoir, from which water can be released but not necessarily absorbed by plants, until the permanent wilting point (PWP) is reached. Different factors influence these parameters like: soil texture and structure, organic matter, water table, evapotranspiration, etc.
WATER QUANTITY AND TURNS TENSIOMETER’S USE The soil moisture monitoring allows real time determination of the moisture level of the soil and should be the primary monitoring tool. It has to be monitored before and after irrigation and adjusted if soils are too wet or dry. Knowledge of soil moisture content is important for deciding on the first irrigation and the following watering activities.
Tensiometers and gypsum blocks (or other more sophisticated systems) allow continuous monitoring of soil moisture and in particular they measure the soil tension. Way of use of the tensiometer
It is important to have the sensors located in positions that are representative of the soil type, tree health and tree size.
Sensors need to be located: y in different area of the orchard y in the middle of the root zone y near the bottom of the main fibrous root zone y below the root zone
WATERING: it is opportune to water maintaining the soil moisture level between the refill point and the field capacity. This range of soil moisture allows the best crop growth.
58
Bibliography •
Agrion, (2017). Nocciolo in Piemonte. Linee Tecniche per una corilicoltura sostenibile. Ed. Agrion: Fondazione per la ricerca l’innovazione e lo sviluppo tecnologico dell’agricoltura piemontese, Aprile 2017.
•
Ascopiemonte, (2009). Il nocciolo, Guida alla coltivazione. Ascopiemonte s.c. Organizzazione Produttori Frutta a Guscio. Bertone P.P., Gianluca G., organizzazione e coordinament editorial, Dicembre 2009.
•
Bignami C., Cristofori V., Scossa A., Vertazza G., (2002). Effetto dell’irrigazione sulla composizione della nocciola (effect of irrigation on kernel composition in hazelnut), 2° convegno nazionale sul nocciolo, Giffoni V. P. www.nocciolare.it.
•
Confagricoltura, (2013). La coltivazione del nocciolo. Manual pratico. Ed. Confagricoltura Alessandria, Dicembre 2013.
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Corte M., Sonnati C., (2009). La coltivazione del nocciolo in Alta Langa. Linee guida per una corilicoltura sostenibile. A cura di Comunità Montana Alta Langa. Pubblicazione realizzata da Creso, Dicembre 2009.
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Corylus&Co, (2011). Corilicoltura viterbese: dalla realtà locale alla dinamica europea. Pubblicazione realizzata a cura del CeFAS, Azienda speciale della Camera di Commercio di viterbo. Atto II, numero I, Settembre 2011.
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Enzo M., Gianquinto G., Lazzarin R., Pimpini F., Sambo P., (2001). Principi tecnico-agronomici della fertirrigazione e del fuori suolo. Ed. Veneto Agricoltura Settore Divulgazione Tecnica e Formazione Professionale, Ottobre 2001.
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Giandon P., Bortolami P., (2007). L’interpretazione delle analisi del terreno. Strumento per la sostenibilità ambientale. Ed. Veneto Agricoltura Settore Divulgazione Tecnica e Formazione Professionale, Dicembre 2007.
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Mozzone G., Pellegrino S., Bassi R., (1991). La coltivazione del nocciolo. I libri di vita in campagna, Edizioni l’Informatore Agrario snc, Febbraio 2010.
•
Orange Agriculture Institute, (2010). Hazelnut Grower’s Handbook. Lester Snare, coordinating author (Industry & Investment NSW). February, 2010.
•
Regione Piemonte, CReSO, (2014). Necrosi batterica del nocciolo (Xanthomonas arboricola pv. corylina). Ed. CReSO (Consorzio di Consorzio di Ricerca e Sperimentazione per l’Ortofrutticoltura piemontese) e ASSESSORATO AGRICOLTURA, FORESTE, CACCIA E PESCA Direzione Agricoltura Settore Fitosanitario. Aggiornamento 2014.
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Roversi A., (2017). Potatura manuale e meccanica a confront. Potare il nocciolo conviene per migliorare qualità e rese. Ed. L’Informatore Agrario, Febbraio, 2017.
•
Roversi A., Mozzone G., Scocco C., Tosun F.S., (2007). Nocciolo: produzioni più elevate e frutti migliori con la potatura verde. Rivista di Frutticoltura e di Ortofloricoltura, 4: 64-66.
•
Tombesi A., (1991). Il Nocciolo. Manuale Pratico. REDA Edizioni per l’agricoltura, Settembre 1991.
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