Tomato

Tomato

The tomato (Lycopersicon esculentum Mill.) belongs to the solanaceas family.

This is a warm season crop, being the temperature a key factor in certain critical periods of the crop, such as flowering.

The range of optimum growing temperatures is from 18º to the 27ºC. Outside this range the production can be seriously affected, since temperatures below 10ºC affect flowering and similarly temperatures too high, combined with low humidity, can produce flower abortion, affecting the pollen viability due to lower environmental humidity.

The sunshine conditions also are important for the crop development, requiring al least a direct light quantity of 6 hours for flowering. With additional light, the plant will be better prepared to sustain and develop the fruits, which improves crop yields.

For an optimum crop growing and development, it is important to maintain an adequate quantity of moisture through irrigation and to regulate the soil pH (ideal: 6.0 – 6.5) for assuring the availability of all nutrients.

Despite tomato is relative tolerant to salinity, this is an important factor to consider, due to high levels make difficult the crop nutrition through the roots.

There are varieties of determinate and indeterminate types. The first once are those in which the principal and lateral stems stop growing, ending in an inflorescence. Besides, in the indeterminate varieties, the principal and lateral stems continue their vegetative (leaves, sprouts) and reproductive growing (flowers and fruits).

The indeterminate varieties are directed to the fresh market, being harvested manually. On the other hand, the determinate varieties are for industrial purpose, which are generally harvested in a mechanized form, being important their crop and fruit uniformity (size and maturity). The crop length period is commonly longer in the indeterminate varieties (greenhouse), covering between 150 – 300 DAT (days after transplant) differing from tomatoes for industrial purpose (open field), which the period takes between 90 – 150 DAT).

Among different tomato types, the most distinguished are 4: cherry tomato (small, with two lobules), pear tomato (medium size y with two lobules), common tomato (4 to 6 lobules) and beefsteak tomato (6 lobules).

The market requirements differ according the type of tomato, fresh consumption or industrial use. In the first case, the important attributes are flavor, color, shape, texture (firm fruits) and the fruit form and size uniformity; while for industrial tomato the main requirements are strong red color, uniform and free of defects such as cracks and blows.

Nutritional Requeriments
In order to recognize the nutritional requirement of the tomato plant, firstly the crop’s phenological stages must be recognized:

• Stage 1: Plant establishment. The plant focuses in the strong root development and utilizes its reserves for the photosynthesis and the initial formation of the plant’s aerial parts.

• Stage 2: Vegetative growth. This happens in the first 40-45 days. This period is followed by another 4 weeks of rapid growing, mean time the plant is flowering and developing its fruits. After 70 days, the vegetative growth and the dry matter accumulation in the leaves and stems cease. In this stage, the plant requires a greater nutrient´s quantity to sustain leave growing and the branche´s expansion.

• Stage 3: Flowering and fruit set. According to the variety, environmental conditions and crop management, begins around 20 to 40 days after the transplant. The pollination is performed by bees, wind and hormones (auxins) application to promote fruit set.

• Stage 4: Fruit development. The fruits´ dry matter accumulation is produced in a relative stable pace.

• Stage 5: Physiological maturity and harvest. The fruit maturity is produced around 80 DAT.

Figure 1 shows N, P, K, Ca and Mg macronutrients which are required from the post-transplant initiation.

Absorption of the main nutrients by the tomato plants after transplanting
Figure 1. Absorption of the main nutrients by the tomato plants after transplanting.

In the case of N, the maximum increment of its absorption is produced just previous flowering. Besides, all nutrients, with the exception of phosphorus, increment their absorption reaching flowering, and continue at fruit set and fruit filling. Phosphorus, on the other hand, plays a key role in the initial stage, and after this, drastically diminished its absorption. Despite of this, it is important to have an adequate P level at flowering and fruit set, since it has a role in the reduction of green fruits at harvest.
Nutritional Recomendation
A table with the nutritional requirements according each phenological stage of the tomato plant is presented as follows.

Phenological stages

Nutritional requirements

Stage 1: Establishment

Nitrogen: promotes early growing and high vigor in the initial stage-
Phosphorus: maximizes the root development. Requirements of this element are around 50 kg/ha during the complete crop cycle.
Potassium: promotes photosynthesis (CO2 and more sugars) and proteins production.
Calcium: is important for root growing since it is a key component in the cellular wall structure. Also promotes Potassium in the regularion of the stomata opening and closing regulation, allowing the water movement within the cell.
Boron, Zinc, Manganese and Molybdenum: assure good aerial growing and development.

Stage 2: Vegetative growing

Nitrogen: assures a continuos growing. It is required in a quantity near 250 kg/ha during the crop season period.
Potassium: improves the Nitrogen fertilizer efficiency. It improves also the water use efficiency. It regulates the stomata opening and closing. The requirement of this element are around 300 kg/ha during the crop cycle.
Calcium: detains the leaves vigor and the canopy growing. The requirement of this element is around 170kg/ha for an open field tomato that yields 100 t/ha.
Sulphur: It is important for a good yield and forincreasing the total soluble solids (TSS).
Boro, Zinc, Manganese and Molybdenum: assure growing without limitation.

It is imortant to maintain an adequate Potassium balance with Magnesium and Calcium, since much of Potassium restrings the absorption of other two cations. A high Potassium level can avoid roots problems caused by Nitrogen excess, also, to maintain the plant growing under saline conditions.

It is advisable to conduct foliar analyses for evaluating the micronutrients requirements.

Stage 3: Flowering and fruit

Nitrogen and Potassium: maintain the plant growth and minimize the flower number.
Phosphorus: is involved in fruit development.
Calcium: maximizes the crops reproductive development.
Magnesium: assures a good flower supply and fruit filling. The requirement of this element is about 60 kg/ha during the crop cycle. It is necessary a regular supply during the complete cycle, avoiding an excess of Potassium, NH4 and Calcium, since this could limit the Magnesium absorption.
Boron: has an important role in the pollen germination, pollen tube growing and fruit development (it facilitates the Calcium movement within the plant).
Zinc: maximizes the fruit set, development and fructification.

Stage 4: Fruit development.

Potassium: is the principal nutrient in relation to the tomato quality, improving the fruit uniformity, shape y firmnesses. It helps the transport and storage of assimilates from the leaf to the fruit. It helps the transport and storage of assimilates from the leaf to the fruit. It reduces the problem of fruit hallow proportion.
Calcium: has a key influence over the fruit firmness and quality; its deficiency can produce Blossom End Rot (BER) disorder.
Magnesium: is particularly important for assuring well formed fruits toward maturity.
Boron: is important in the cell wall formation and as structural component of this wall.

Stage 5: Physiological maturity and harvest

Potassium: is responsible for the licopene synthesis (red color). It reduces the maturity disorders incidience at maturity. It imporves the fruit flavor through the increase of acidity.
Calcium: contributes to the storage quality and less diseases susceptibilities.

Nutrient Absorption
Nutrient Absorption

Figure 1 shows the nitrogen absorption by different structures in an open field tomato crop (industrial use).

The Figure 2 left describes that the initial period of N absorption by the leaves and stems is greater until around 70 days. In this period the absorption of these plant’s structures is stabilize, originating a large demand by the fruits. This pattern of N absorption by the fruits vs. leaves and stems is also similar for the potassium and phosphorus absorption.

Nitrogen absorption curve in tomato
Figure 1
N, P and K absorption curves in tomato
Figure 2

On the other hand, if the total absorption of N, P and K by the plants is compared, as shown in Figure 2, the absorption magnitudes are very different: A high K2O absorption is produced from 40 DAT, reaching 500 kg/ha at 110 DAT. This is followed by a total N absorption of 250 kg/ha and 100 kg/ha of P2O5.

In relation to greenhouse tomato (indeterminate growing), there is a sharp increase in potassium absorption during flowering in the first 10 bunches, with a maximum between the 7th and the 10th bunch (Figure 3).
Greenhouse Tomato Nutrition
Figure 3. K, Ca and Mg absorption by the tomato plant in relation to the bunches´ development and time.

Also, in this stage, a decrease in root growing occurs. The absorption concentration of Ca and Mg is diminished and the N, P and K absorption is maintained in a more or less stable relation in time.

The fertilizer pattern and nutritive adjustment are made from the anthesis stage. These processes are related to the selected bunches quantity for each phenological stage.
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):

Special Plan Nutrition

The following table shows specialty plan nutrition available for supplying the nutritive needs of the tomato crop.

Nutrients

Common name

Chemical formula

Caracteristics

Preferd source

Nitrogen

Urea: Urea
Urea phosphate

CO(NH2)2
CO(NH2>2 H3PO4

This product cannot be directly utilized by the plants; previously it is transformed to ammonium. It is the least efficient source of Nitrogen.

Ammonium: Ammonium Sulphate
Monoamonic (MAP)
Diamonic Phosphate (DAP)

NH4)2SO4
NH4H2PO4
(NH4)2HPO4

This is inmovil in the soil, restricting its availability to the root zone. Its assimilation by the plant is slow. Since it is a cation, competes with other cations for the roots absorption.

Nitrate:
Potassium Nitrate
Solid Calcium Nitrate
Liquid Calcium Nitrate
Magnesium Nitrate
Amonium Nitrate
Nitric Acid

KNO3
(5(Ca(NO3)2) NH4NO3 10H2O
Ca(NO3)2 en solución
Mg(NO3)2 6H2O
NH4NOz3
HNO3

This is easily and rapidly assimilated by the plants. Since it is a cation, promotes the absorption of other nutrients (cations: K+, Ca2+, Mg2+ and Nh4+). The ammonium as well the nitrate can be absorbed by the plants, therefore the ammonium / nitrate relation must be considered, wich will vary in function to the specie, temperature and the pH in the root zone.

Phosphorus

Monoamonic Phosphate (MAP)

NH4H2PO4

For soils with pH > 7.5

Diamonic Phosphate (DAP)

(NH4)2HPO4

For soils with pH 6 - 7.5

Monopotasic Phosphate (MKP)

KH2PO4

 

Triple Superphosphate (TSP)

Mainly Ca(H2PO4)2

For soils with pH < 6

Urea Phosphate

CO(NH2)2 H3PO4

Strong acidifying solid.

Phosphoric Acid

H3PO4

Strong acidifying liquid.

Potassium

Potassium Nitrate

KNO3

This is ideal Potassium fertilized in all growing stages, due to its high solubility.

Sodium Potassium Nitrate

KN3 NaNO3

Contains 19% of Sodium. It improves °Brix and matter content in the fruits.

Potassium Sulphate

K2SO4

It is recommended for the final growing stage.

Potassium Bicarbonate

KHCO3

It is recommended for correcting pH (increasing).

Potassium Chloride

KCl

It is used for increasing the tomato flavor.

Calcium

Calcium Nitrate (solid)

(5Ca(NO3)2) NH4NO3 10H2O

It is the most used water soluble Calcium source contains some ammonium for pH.

Calcium Nitrate (Liquid)

Ca(NO3)2 in solution

It does not contain Ammunium

Calcium Chloride

CaCl2

It is used for increasing the tomato flavor.

Chlorine

CaCl2
MgCl2
KCl
NaCl

 

It is used for increasing the tomato flavor. It is necessary to avoid excess application, since it can produce salinity in the root zone, competing for the absorption with other ions, producing "golspeck" and a shorter postharvest life.

Magnesium

Magnesium Sulphate

MgSO4 7h2O

It is the most used Magnesium source. It cannot be mixed with Calcium in the mother tank.

Magnesium Nitrate

Mg(NO3)2 6H2O

It has rapid dissolution and high solubility.

Sulphur

Magnesium Sulphate

MgSO4 7H2O

To complete the Sulphate and Magnesium demand.

Potassium Sulphate (SOP)

K2SO4

Can be used to supply the remainder of the Sulphur demand and part of the Potassium demand in tomato nutrient.

Ammonium Sulphate

(NH4)2SO4

Excess doses should be avoided in order to prevent slainty and nutritive unbalances.

Sulphuric Acid

H2SO4

Strong acid. Avoid excessive application.



Beside these mentioned fertilizers of direct application, there are in the market NPK granular and soluble mixture which are available for each phenological stage (Ultrasol® Initial, Ultrasol® Development, Ultrasol® Growing, Ultrasol® Production, Ultrasol® Multipurpose, Ultrasol® Color, Ultrasol® Quality, Ultrasol® Post-Harvest, Ultrasol® Fruit and Ultrasol® Special) and also by crop (Ultrasol® Tomato, in this case). There is a special segmentation in Qrop™, the line of plant nutrition of specialty for direct soil application.

Following the table shows products in base on microelements that are available for supplying the nutritive needs of the tomato crop.

Nutrient

Chemical formula

Characteristics

Iron

EDTA

For fertirrigation when the pH < 6 and as foliar.

DTPA

For fertirrigation when the pH < 7.

EDDHA / EDDHMA

For fertirrigation when pH > 7.

Zinc

EDTA

Is more easily dissolved than the sulphate.

Sulphate

 

Manganese

EDTA

Is more easily dissolved than the sulphate.

Sulphate

 

Copper

EDTA

Is more easily dissolved than the sulphate.

Sulphate

 

Boron

Boric acid

Is the most efficient Boron source; the plants dissolve Boron only in this form.

Sodium borate

Has an alkaline reaction.

Ulexite

Calcium Sodium Borate. Deliver Boron in a progressive form, reducing toxicity risks of Boron.

Molybdenum

Sodium Molybdenum

Is a less expensive source than ammonium Molybdenum.

Ammonium Molybdenum

 

Response Application
Response to the application of Specialty Plan Nutrition products

Effects: Levels of K, Ca and Mg.

Organ

N Source

Dry matter nutrients content (meq/100g)

K

Ca

Mg

Leaf

NO3

58

161

30

NH4

29

62

25

Petiole

NO3

176

126

38

NH4

90

61

17

Stem

NO3

162

86

35

NH4

54

50

18

Root

NO3

93

44

40

NH4

43

38

11

Source: Xu et al, 2001

Details / Comments of the trial: When using nitrate and ammonium as nitrogen fertilizer sources in pepper plants, higher levels of K, Ca and Mg were found in the plants that were fertilized with nitrate.

Effects: Incidence of fruit with BER and Ca content in the leaves.

Effect

% N supplied as Ammonium N

0

20

40

Effected fruit by BER in the first 4 harvests (% by number)

0,0

24,0

46,0

Calcium content in the leaves (% Calcium)

1,8

1,5

0,9

Source: Massey y Winsor, 1980

Details / Comments of the trial: It was observed the effect of ammonium N on the fruit damage percent by Blossom End Rot (BER) and the Ca content in the leaves. At a higher content, the BER incidence increased and the Ca content decreased in the leaves.

Effects: Incidence of BER and chlorosis.

Treatment %

Relative Yield

Relative Fruit Weight

BER %

Chlorosis Index

NO3

NH4

Urea

100

 

 

100

100

0,2

5,2

75

25

 

101

100

3,0

3,5

50

50

 

96

90

2,8

2,7

75

 

25

94

94

2,2

4,4

50

 

50

104

97

4,2

1,0

75

25)*

 

96

94

2,7

3,6

50

50)*

 

101

93

2,1

2,0

Source: Sonneveld y Voogt, 1983 y 1985

Details / Comments of the trial: Tomato response to fertilizer application in a hydroponic medium. It was observed that a high dose of N-NO3- reduced the BER percent. Contrarily, high level of N-NO4+ induces chlorosis. Therefore, the most adequate is to apply a proportion of 93% of NO3- and 7% of N-NO4+.

Effects: Form and maturity uniformity.
Titratable acidity of fruit juice and Total acidity of fruit juice
Source: Adams et al, 1978

Details / Comments of the trial: It was observed a positive relation between the potassium levels in the leave and the titratable acidity (left) and the total fruit juice (right). Acidity is the characteristic that determine the tomato flavor.

Effects: Fruit quality.

EC in the root Enviroment mS/cm

Lack of Color %

Post-harvest life (days)

Fruit sap

EC S/c

Acidity mmmole/l

Sugar °Brix

0,75

21

6,2

4,5

5,9

6,1

2,50

17

6,6

5,1

6,6

4,1

5,00

2

9,1

5,5

7,6

4,6

Source: Sonneveld y Voogt, 1990

Details / Comments of the trial: Effect of the electric conductivity (EC) on the fruit quality. As a higher EC (higher fertilizer apply), a better color, improved post harvest life, and higher acidity and ºBrix were obtained.

Effects: °Brix and post-harvest life.
Sugar and Post-harvest life
Source: Voogt,2002

Details / Comments of the trial: A higher K/Ca relation (mmole/mmole) in the nutritive solution produces more °Brix and a higher post-harvest life. Besides, a higher Mg content also favors the previous mentioned characteristics.

Effects: Lycopene content.

KNO3 dose kg/ha

Lycopene ppm

100

10,3

200

13,3


Details / Comments of the trial: A tomato paste study demonstrated that a higher K dose produced a higher lycopene quantity in the fruit.

Effects: Yield, °Brix and firmness.

Calcium Nitrate Doses (kg/ha)

Yield ton/ha

°Brix

Firmness kg/cm2

0

64

5,25

2,25

100

63

5,55

2,26

200

71

5,82

2,38

300

87

6,05

2,54

P

*

**

**

Details / Comments of the trial: A study in Turkey showed that a soil with 7.45 pH and 4.4 ppm of Ca, to which calcium nitrate was applied, improved yield, °Brix and firmness of tomato.

Effects: Ca absorption per plant.
Blossom End Rot
Details / Comments of the trial: A higher K/Ca (mmole/mmole) relation and high Mg level in the nutritive solution compite with the Ca absorption by the plant. In addition, a Ca deficiency produces BER.

Effects: Incidence of “Goldspeck” in the plant.
Goldpeck
Details / Comments of the trial:A study showed the effect of different K, Mg and Ca proportion in the nutritive solution on the “goldspeck” incidence. Relative high levels of Ca in the nutritive solution promote goldspeck incidence.
Increase Net Farmer
Increased Net farmer income with Ultrasol® and Speedfol™

“SQMC (Soquimich Comercial) initiated a 3 years trial work with Agrozzi - the biggest tomato processing company in Chili - in order to increase the yield of processing tomato by testing different irrigation systems with respect to the water supply, extraction curves and fertilization programmes” reports Claudio Valdes, Agronomic Engineer, M.Sc. at SQMC.

Applications

During the 2006-2007 season, SQMC’s Specialty Plant Nutrition programme with Ultrasol® and Speedfol™ products (Tables 1 and 2) was compared to the traditional farmer’s programme. The trial was carried out in the area of Sagrada Familia, Curicó. Each trial plot consisted of one hectare with 35.000 plants (1,4 * 0,2 m2/parcel). The plots were harvested and analyzed by Agrozzi. Statistical analysis was done with ANOVA, LSD at P < 0,05.

 

kg

N

P2O5

K2O

CaO

MgO

SO3

Base - Base

500

45

95

85

15

25

35

Development - Desarrollo

 

Ultrasol® Growth

120

30

12

12

 

1

 

Ultrasol® Calcium

100

15

 

 

27

 

 

Ultrasol® K

50

7

 

23

 

 

 

Total

270

52

12

35

27

1

0

Flowering - Fruit set
Floración - Amarre de fruta

 

Ultrasol® Calcium

40

6

 

 

11

 

 

Ultrasol® K

150

21

 

69

 

 

 

Ultrasol® Production

100

13

6

40

 

 

 

Total

290

40

6

109

11

0

 

Fruit set - Initial colour
Amarre de fruta - Color inicial

 

Ultrasol® Production

192

25

12

77

 

 

 

Ultrasol® K

297

41

 

137

 

 

 

Total

489

66

12

214

0

0

 

Initial colour - Harvest
Color inicial - Cosecha

 

Ultrasol® Pinta

150

 

8

72

 

 

24

Total

150

0

8

72

0

0

24

Total stages - Etapas totales

1.199

159

38

430

37

1

24

Base + Total Stages
Base + Etapass Totales

1.699

204

133

515

52

26

59


Table 1. SQMC soil applications.

Moment of application
Momento fe aplicación

Product
Producto

Dose per application
Dosis por aplicación

Applications
Aplicaciones

Post - Transplant
Post - Transplante

Speedfol™ AminoStarter SC

21/ha

2

Flowering
Floración

Speedfol™ B SP

1 kg/ha

2

Fruit growth
Crecimiento de frutos

Speedfol™ Amino Calmag SL + Speedfol™ Amino Flower & Fruit SC

3 l/ha + 2 l/ha

2


Ultrasol® and Speedfol™ in processing tomato increased net farmer income with 1.050 US$/ha.

The yield was increased with 32% (25 MT/ha) when Ultrasol® products were used as compared to the farmer programme. The addition of Speedfol™ to the Ultrasol® programme added another 7 MT/ha as compared to the Ultrasol® programme. (Table 3).

The highest average fruit weight was obtained when applying a combination of Ultrasol® and Speedfol™ (Table 4).

The addition of Ultrasol® applications resulted in a higher percentage of mature fruits (Table 5).

The Ultrasol® programme increased the farmer’s net income with 656 US$ per ha. The programme in which both Ultrasol® and Speedfol™ were applied performed even better: the farmer’s net income increased with 1.054 US$/ha (Table 6).

Table 3.
Table 3.

Table 4.
Table 4.

Applications
Aplicaciones

Percentage of mature and green fruits per application
Porcentaje de frutas maduras y verdes por aplicación

 

Ripe Maduro

Green Verde

Farmer - Agricultor

73

27

SQMC 1: Ultrasol®

77

23

SQMC 2: Ultrasol® + Speedfol™

83

17

Table 5.

 

Farmer's Programme
Programa del agricultor

SQMC 1: Ultrasol®

SQMC 2: Ultrasol® + Speedfol™

Farmer's net income
Ingresos netos del agricultor
(US$/ha)

788

1.444

1.842

Difference
Diferencia
(US$/ha)

not applicable
no aplica

+ 656

+ 1.054

Table 6.
Phenological Stages

Tomato has various development stages in its growth cycle: young plant establishment, vegetative growth, flowering, fruit development and ripening.

Each stage being different with respect to its nutritional needs. Hereunder the phenological stages for tomato, grown in open field, are discussed. The information is purely indicative, as timing will depend on variety, environmental conditions and crop management.

Plant establishment: focus on firm root development and the formation of the initial aerial parts of the plant.

Vegetative growth: takes place in the first 40-45 days, after which the fruits start to develop continuously. This period is followed by another 4 weeks of rapid growth, while the plant is flowering and developing fruits. After 70 days, there is almost no further vegetative development, nor accumulation of dry matter in leaves and stems.

Flowering and fruitset: depending on the variety, environmental conditions and crop management, flowering and fruitset both start around 20-40 days after transplanting and continue during the rest of the growing cycle. Pollination is done by bees, wind and hormone application (auxin) in order to promote fruitset.

Fruit development: after flowering and fruitset, the fruit starts to develop and grow, achieving in this period major accumulation of dry matter in the fruit, at a relatively stable rhythm.

Physiological ripeness and harvest: on average, fruit ripeness is achieved at 80 DAT. Harvesting continues permanently, unless being stopped for climatic reasons (frost) or for economical reasons (price of the tomato).


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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.