Raspberry

Raspberry

Raspberry belongs to the Rubus genera, with about 500 species, but the cultivated species are 3 due to their fruit quality: raspberry, blackberry and blackberry hybrids.

There are two type of raspberry: day neutral variety and non day neutral variety. The first is characterized by producing flowers twice per year, the first flowering at beginning of summer and the second at autumn, lasting until the first rains and winter cold conditions allow this flowering process. Spring flowers are developed in lateral branches from the two year stems, while autumn flowers are developed in the shoots terminal branches.

The non neutral day varieties produce only flowers in the two year stems. Two years old stems die on both varieties and must be eliminated and replaced by shoots.

Production levels, depending on the climate, soil and variety, can reach until 30 ton/ha.

Soil: Soil characteristics are determinant for a good raspberries´ development. Soil physical features define the root development and the water retention for the crop. Chemical characteristics determine the essential nutrients´ availability for growing and production and, in certain occasions, toxicity problems by the presence of some elements noxious to the crop.

The pH is a soil characteristic that determines the nutrients´ availability for the crop. The greater nutrients´ availability happens at pH near neutrality (6.5 to 7.5), and the larger retention of these occurs as the pH moves away from 7.0. In alkaline pH, soils deficiencies of iron, copper and zinc are produced by the reaction with OH groups, then, iron, copper and zinc hydroxides are produced which are absorbed by the crops. In soils pH near 5.0 important deficiencies of phosphorus are produced, generating compounds of low solubility and difficult absorption by the roots. Similarly, under acid soil conditions the soluble aluminum presence is increased, generating alterations in the plant and reducing production.

Raspberries are adapted to various type of soils, to pH levels from 6-7.8. Only, high clay soils are limited and those with bad drainage, especially under wet and cold conditions and with water table at 50 cm depth. High sandy soils, due to their low water retention, require a larger organic matter supply and frequently irrigation.

Excess and lack of water produce a negative effect in the plants´ growth and development. The greatest water absorption by raspberries, under good water availability conditions, is produced near the trunk or stem in the first 20 to 30 cm of the soil profile. Water requirements vary according to the agro-climatic areas.

Specific considerations of the crop in relation to irrigation:
A good moisture level control in Raspberry plant allows a greater yield, due to more number of stems, with greater diameter and size, a better floral induction and also improved fruits´ size. Raspberries are generally very sensible crops to a high Electric Conductivity (Table). This produces damage to the crop due to an excessive concentrated salts´ solution, which causes interference in the root absorption. Normally salts´ concentration is greater within the cell than in the soil water. If this occurs, there is no water absorption and the plant wilts.

Irrigation
Excess and lack of water produce a negative effect in the plants´ growth and development. The greatest water absorption by raspberries, under good water availability conditions, is produced near the trunk or stem in the first 20 to 30 cm of the soil profile. Water requirements vary according to the agro-climatic areas.

Specific considerations of the crop in relation to irrigation:

A good moisture level control in Raspberry plant allows a greater yield, due to more number of stems, with greater diameter and size, a better floral induction and also improved fruits´ size.
Salinity
Raspberries are generally very sensible crops to a high Electric Conductivity (Table). This produces damage to the crop due to an excessive concentrated salts´ solution, which causes interference in the root absorption. Normally salts´ concentration is greater within the cell than in the soil water. If this occurs, there is no water absorption and the plant wilts.

 

E.C. (mmhos/cm) to which yield is reduced in

10%

25%

50%

Raspberries

1,5

2

2,5

Salinity tolerance limits, Source: Hirzel y Rodriguez 2003
Phenology in Berries
To achieve an adequate nutrition through irrigation, firstly, it must be considered the berries´ phenology. Then, it is necessary to order each one of their stages according to the time period in every zone. This is for determining in which periods will correspond to apply the quantity and type of nutrients together with water.

Dormancy: The plant is found in a metabolic recess which ends after being submitted to a number of hours of cold temperature. There is neither consumption nor internal transport of water and nutrients. Nutrients are forming part of the reserve chemical compounds.

Activation: Dormancy ends. An internal transformation of the starches to sugars is generated. The nutrients´ mobilization is initiated from the roots and wood to the sprouting points. The plant supplies from its own reserves. The swollen bud stage is initiated.

Sprouting: The first leaves appear. The plant starts to absorb water and nutrients.

Development: A large cellular activity is produced oriented to the formation of new organs and the roots´ development is initiated. In this stage, Calcium is very important, which becomes to form part of the plant’s structures. Besides, in this stage this element has a greater mobility in relation to other stages in which it has reduced mobility.

Growing: A size expansion of organs, and an increasing daily demand of water and nutrients especially Nitrogen. In the stage there is a high dependency of external supply of nutrients.

Flowering: Nutrients, sugars and water are mobilized toward the reproductive organs and in this stage there is maximum roots´ absorption. In this stage, potassium is fundamental due its transport role of carbohydrates, which form 90% of the fruit dry weight.

Fruit set: This occurs during the flower pollination and determine the initial of the fruit filling stage.

Fruit filling: This is the process of greatest internal translocation activity of nutrients, sugars and external water and nutrients´ absorption. In this stage the maximum nutrients´ demand is reached, especially potassium.

Veraison: In this stage the fruit has reached to its maximum size and the color change is initiated. The fruit becomes to be the principal organ of photosynthates´ demand.

Harvest: Fruit removing according to the commercial parameters.

Post-harvest: The plant presents once again root activity and a flow of nutrients toward the roots and wood is generated. This is the key moment for applying nutrients and for increasing reserves for the growing initiation of the next season.

Approximate periods in days of phenological stages of Blueberries, day neutral Raspberries and non day neutral Raspberries under two pruning systems in temperate climate.
Main Nutrients
The application of balanced nutrition aims to ensure adequate aerial and root growth to store as much carbohydrate in specialized organs. Adequate nutrition of the crop is a key factor in obtaining good harvests.

To achieve an appropriate nutrition plan in raspberry is necessary to know the nutrient demand in quantity and type of nutrient. It is also important to know the role of each nutrient for crop growth, yield and quality of production.

Nutritional demands of different berries´ species significantly differ among them. This is due to their specific growing patterns and production levels; in addition to the optimum foliar levels for each one of these species.

The demand or nutrient extraction for the crops has been determined by numerous authors, who have generated these values especially for macro nutrients (Table). A summary of the described information in the existing literature about the subject is presented in the following tables.

Nutrient

Estracción (kg/ton of Fruit)

Critical Foliar Level (%)

Blueberry

Raspberry

Strawberry

Blueberry

Raspberry

Strawberry

N

4.7

16.9

2.5

1.8

2.75

2.8

P

0.5

1.6

0.5

0.12

0.3

0.25

K

4

8

3.8

0.35

1.5

1.5

Ca

1.4

5.7

1.1

0.4

0.6

0.7

Mg

0.8

2.3

0.5

0.12

0.4

0.25

Comparison of nutrients´ extraction levels per ton of fruit and foliar levels for Blueberry - Raspberry and Strawberry Vidal and others 1999 and Vidal and Burgos 2003.

The exported levels for raspberry and strawberry are rather higher than of blueberry. This is explained by the difference in the nutrient absorption rate; consequently the fertilizer levels must be different according to the specie, production level, and plant age. Even though, in each type of crop the essential nutrients for obtaining good yields are Nitrogen, Potassium and Calcium.

The annual growth can vary according the climatic conditions, soil and technological level or management of the orchard. The annual growth in each of the conditions determines a different requirement level for satisfying the photosynthates´ formation, cellular structures and metabolic reactions. The considered demand components of annual growth are: fruits, leaves, sprouts, roots and the increment of permanent structures.

For the nutrition dose calculation, the nutrients´ content in the tissues exported from the orchard must be considered, being these the pruning remains none incorporated and fruits, since leaves and roots are left in the soil and are recycled.

As the plant increases the production also its potassium requirements increase due to the high extraction by the fruit, becoming this nutrient essential for a good production level and desired quality.

Besides of determining the nutrients´ concentration of tissues, it is important to know the development of these tissues during the crop’s growing cycle, with the objective of defining the stages and adequate nutrients quantities to applied.

Specie

Yield Level (ton/ha)

N Requeriments (kg/ha)

P2O5 Requeriments (kg/ha)

K2O Requeriments (kg/ha)

Blueberry

6

15-18

5-6

15-18

10

25-30

8-9

25-30

15

38-45

12-14

38-45

Raspberry

10

55-60

20-22

60-68

12

66-72

25-28

73-80

15

82-90

30-35

90-100

Annual requirements of nitrogen, phosphorus and potassium of some fruit crops in the productive stage for three yield levels - Hirzel and Rodríguez 1993.
Characteristics of soluble fertilizers to be considered in the Berries´ nutrition: Solubility: The solubility of crystallized solid fertilizers is the capacity to dissolve the salt or fertilizer molecule in water. This capacity is related to the chemical and physical composition of the molecule, which influence the dissolution rate.

Electric conductivity of soluble fertilizers: The electric conductivity (E.C.) is a salt concentration measurement in a liquid or solid media. As greater saline concentration, the greater is the electric conductivity, measured with a conductivity meter. All soluble fertilizers have different E.C. In soluble fertilizers this variable is utilized for determining the salinity generated by the fertilizer in comparison to other fertilizer salts. This information is used for selecting the most adequate products according the specific situation.

pH of soluble fertilizers: As it is known, the pH is a measurement of the H+ ions´ concentration in solid or liquid media. All fertilizers have different pH in the solution and this parameter is also the key in the selection of a soluble fertilizer. The reason of this is that in some cases acid reaction soluble fertilizers are required, in other situations, neutral reaction and in others, alkaline reaction, according to the soil type and specific crop.
Role of Nutrients
Nutrients extracted in larger quantity by berries are potassium, nitrogen and calcium which determine their importance in this type of crops.

Boron and chloride are also important nutrients. The first one is particularly important in Raspberries and Blackberries since these have composite fruits and their deficiency cause fruit deformity. In the case of chloride, in addition to its role of essential nutrient, it can increase the salinity level.

Quality parameters for the fresh and frozen market for Berries are based mainly on appearance (color, size, shape, lack of defects), firmness, flavor (soluble solids, titratable acidity and aromatic volatile compounds) and nutritive value (Vitamins A & C).

It is convenient to know how that as larger is the fruit size, the greater will be the price.

Within the most common physiopathies of Berries, one of the most important is of Wrinkling/loss of water: berries are very sensible to loss of water, which conduces wrinkling of the fruit and its loss of brightness.

Blueberry presents a greater post-harvest durability (thirty days) than other Berries (raspberry, boysenberry and strawberry). This is due to its fruit consistence and for its waxy cuticle (epicarp).

Nitrogen

Absorption forms

NO3- y NH4+

Plant functions

Component of proteins, chlorophyll and enzymes
Estimula Crecimiento vegetativo.

Deficiencies

Generalized yellowish for detecting the chlorophyll production.

Excess

Vegetative excessive growth
Soft and succulent tissues
Soft fruit.

Required nitrogen levels for these types of crops are not high. It is important in the vegetative development and post-harvest stages. An excess of this nutrient causes serious fruit quality problems, producing soft fruit and vey sensible to mechanic and disease problems.


Potasio

Absorption form

K+

Plant functions

Osmotic regulation and sugars´ transport to the fruit
Activates more than 60 enzymatic processes.

Deficiencias

Light green color leaves, with marginal necrosis and wilting
Size loss and fruit consistency
Low level of soluble solids (°Brix).

This nutrient is the one of greater importance regarding yield and fruit quality in berries. Potassium is in charge of carbohydrates´ mobilization from the leaves to the fruits. Consequently, potassium plays an important role in the fruit frozen commercialization for determining the sugar quantity which will transport to the fruit. Due to this function the main potassium benefic is in the fruit quality, such a sugars and color contents.


Calcium

Absorption form

Ca++

Plant functions

Firmness and cellular structures, cementation of cellular walls
Structure and permeability of cellular membranes.

Deficiencies

Death of growing apex in roots and leaves
Weak stems
Firmness problems in the fruit special tissues for calcium deficiencies.

The effect of this nutrient in Berries is of the greatest importance in the fruit quality. This is because the fruit if very perishable and as result of the commercialization form, the post-harvest life becomes very important. Then, a good calcium supply to the plant and fruit plays a fundamental role, especially in transport and fruit life for fresh commercialization.

The calcium absorption by the plant is produced early until the fruit is set and photosynthetically active. From this event onwards the calcium absorption is lower and generally does not reach the fruit, which makes necessary to generate a foliar calcium application strategy for the crop.


Boron

Absorption form

BO3, H2BO3, HBO3

Plant functions

Enzymatic activator
Effect on the Pollinic Tube Fertility.

Deficiencies

Small, deformed, light green color and copper color leaves
This nutrient has low mobility, then, symptoms appear first in younger leaves
Low fruit set and, therefore, less fruits number and/or deformed.

As consequence of its important role in the fruit set, and taking in consideration that in case of raspberries and blackberries, fruits are composed (drupelets), a deficit of this element generates normally deformed fruits. In the case of blueberries the main effect is lower number of fruits. Boron is a nutrient that is required in vey low quantity; consequently its application must be carefully done, since it could pass from deficiency to toxicity.

Nutritional Recommendation
An adequate supply of nutrients to plants should incorporate both macronutrients and micronutrients. SQM in the selection of specialty plant nutrition (SPN) that offers the following alternatives available according to the route of application (fertigation, soil or foliar):

Fertigation Program for Raspberry aprox. Yield 6 y 10 ton/ha

Phenological Stage

Product

Doses (Kg/ha)

Nutritional Aport

N

P2O5

K2O

CaO

MgO

S

B

Fe

Zn

Cu

Sprouting 1st Flowering

Ultrasol® Raspberry

50

8

5

10

 

1

3

0.01

0.01

0.02

0.01

Flowering to Fruit Growing

Ultrasol® Raspberry

200

32

16

40

 

4

12

0.04

0.02

0.08

0.04

Calcium Nitrate

50

8

 

 

13

 

 

 

 

 

 

Harvest

Ultrasol® Raspberry

50

8

4

10

 

1

3

0.01

0.01

0.02

0.01

Harvest to Leaf Drop

Ultrasol® Raspberry

150

24

12

30

 

3

9

0.03

0.02

0.06

0.03

Fertigation program for Raspberry aprox Yield 10 - 15 ton/ha

Phenological Stage

Product

Doses (Kg/ha)

Nutritional Aport

N

P2O5

K2O

CaO

MgO

S

B

Fe

Zn

Cu

Sprouting 1st Flowering

Ultrasol® Raspberry

50

8

4

10

 

1

3

0.01

0.01

0.02

0.01

1st Flower Fruit Harvest End

Ultrasol® Raspberry

150

24

12

30

 

3

9

0.03

0.02

0.06

0.02

Calcium Nitrate

50

8

 

 

13

 

 

 

 

 

 

Harvest End 2nd Flower Start

Ultrasol® Raspberry

50

8

4

10

 

1

3

0.01

0.01

0.02

0.01

2nd Flower to Harvest

Ultrasol® Raspberry

75

12

6

10

 

2

5

0.02

0.01

0.03

0.01

Potassium Nitrate

75

10

 

35

 

 

35

 

 

 

 

Harvest to Leaf Drop

Ultrasol® Raspberry

100

16

8

20

 

2

6

0.02

0.01

0.04

0.01

 

 

500

86

34

120

13

9

26

0.09

0.04

0.04

0.04



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Disclaimer:
All the information is given to the best of SQM's knowledge and is believed to be accurate. Your conditions of use and application of the suggested products and recommendations are beyond our control. There is no warranty regarding the accuracy of any given data or statements. SQM specifically disclaims any responsibility or liability relating to the use of the suggested products and recommendations and shall under no circumstances whatsoever, be liable for any special, incidental or consequential damages which may arise from such use.