1. Origin
2. Taxonomy and morphology
3. Economic importance and geographical distribution
4. Edaphoclimatic requirements
5. Vegetal Material
6. Growing techniques
6.1. Settings for planting
6.2. Pruning
6.3. Ridging up
6.4. Trellising
6.5. Shoot thinning
6.6. Leaf thinning
6.7. Blunting of inflorescences and fruit thinning
6.8. Fertigation
7. Soilless crop
8. Pests and illnesses
8.1. Pests
8.2. Illnesses
9. Alterations of fruits
10. Harvest
11. Post harvest
12. Nutritional value
13. Marketing

7. SOILLESS CROP GROWING

In soilless crop, the root system is confined in a container. This can take various forms, but in any case the volume of the rhizosphere is reduced. These constraints force the use of substrates that ensure the availability of water and oxygen to the roots.

This system favours crop development because:
- Provides optimum air-water-nutrients in the root system.
- Nutrition is much more controlled.
- Humidity is more uniform and the drainage system is excellent.
- Inert substrates are free of pests and diseases (alternative to the use of soil disinfectants).

The objectives of soilless crop focus on:
- Eliminate the discharge of leachate.
- Avoid soil or water contamination.
- Have a substrate free of pests and diseases.
- Have a substrate under optimal conditions for the cultivar to be installed.

In the market you can find different substrates, which are classified as:

- Organic:

. Natural origin: Peats.
. By-products of agricultural activity: Coconut fibre, wood chips, cereal straws, industrial waste cork, etc.
Coconut fibre is a plant material derived from the waste of the coconut industry. Short fibres and dust from the medullary tissue in varying proportions are also used. It is a lightweight material with a very high total porosity and right amount of water available. Aeration is good.
. Synthesis products: non-biodegradable polymers, polyurethane foam and expanded polystyrene.

- Inorganic:

. Natural origin: Sand, gravel and soils of volcanic origin.
. Require a manufacturing process: Rock wool, fibreglass, perlite, vermiculite, expanded clay, Arlit, broken brick, etc.

Stone wool is obtained from the smelting of diabase 60%​​, 20% limestone and 20% coking coal. Subsequently, the melt is converted into fibres, which stabilizers and moisturizing materials are added. Finally, the fibres are compressed and cut into boards or blocks. It is a totally inert and highly porous material in which water is easily available without hardly reserved water.

Perlite is an aluminosilicate of volcanic origin. It is industrially processed by heat treatment and placed in ovens at elevated temperatures to produce a very light material with a high porosity.

Choosing a substrate is subject to its availability, for the purpose of production and crop species, handling experience, installation possibilities and climatic conditions.

The tomato crop is facing scarcity of good quality water. The use of better quality water means higher production costs, which sometimes, due to market fluctuations, it directly affect the profitability of farms. The use of moderately saline water in soilless tomato crop is carried out according to the same stages of plant development and with the aim of saving good quality water while maintaining acceptable levels of production.

The recirculation in soilless crop consists of restoring the circuit of fertigation with the aim of avoiding the creation of leachate as a result of excess irrigation endowments by establishing a closed circuit system of fertigation. Hence, soilless crops that are equipped with recirculation system are called closed soilless crops. Thus, the aim of eliminating or significantly reducing free drainage through a process of reutilization is achieved.

The rate of drainage recirculation depends on the concentration of salts in the water supply. The rate value is higher when the salt content is lower.

The proper management of the crop and of the composition of water supply depends on the rapid increase of electrical conductivity, and that the total recirculation rate is higher or lower.

Tests of tomato varieties in the south-eastern Spanish

Test	Substrate	Greenhouse	Total Prod. (kg/m2)	Cycle (days)	Water E.C. (dS/m)
Tomato Daniela	Perlite	Plain	12	167	1.05
Tomato Rambo	Rockwool	Plain	16	249	2.60
Tomato Rambo recirculation system.	Perlite	Multitunnel with heater. Support	19.3	231	0.50
Tomato Durina recirculation system.	Sand	Climate-controlled multitunnel	23	210	1.30
Tomato Durina recirculation system.	Rockwool	Climate-controlled multitunnel	21	210	1.30
Tomato cv. Brillante recirculation system.	Perlite	Multitunnel with heater.	13.2	119	0.90-1.5
Tomato cv. Brillante recirculation system.	Rockwool	Climate-controlled multitunnel	13.4	119	0.90-1.5
Tomato cv. 322 recirculation system.	Sand	Climate-controlled multitunnel	18.4	253	1.2-1.6

The pH of irrigation solutions should be 5.5-6.5. This pH range favours the assimilation of most of the nutrients by the plant.

Recommendations before installing a soilless crop:

- If the greenhouse has been used and disease has been detected, it is necessary to disinfect both the soil and the structures.
- Cover the ground with plastic.
- It is advisable to have a footbath with disinfectant solution at the entrance of the greenhouse.
- Cover the irrigation pond so that it stays closed.
- Keep the greenhouse and its surroundings free of weeds.
- Do not leave plant residues or wastes in places near the greenhouse.
- Disinfect tools with bleach.
- Adequately train operators to prevent contaminations.

8. PESTS AND ILLNESSES

8.1. Pests

- Red spider (Tetranychus urticae, T. turkestani and T. ludeni)

The first specie mentioned (T. urticae) is the most common in protected horticultural crops, but the biology, ecology and damage that they cause are similar, that is why the three species can be addressed together.

The first symptoms develop on the undersides of the leaves causing discolorations and pitting or yellowish spots that can be seen also at the upper face thereof. When the population of the pest is high, desiccation or defoliation occurs. The most serious attacks occur during early growth stages.

High temperatures and low relative humidity favour the development of the pest.

Preventive control and cultivation techniques

- Disinfection of structures and grounds before planting in plots with prior incident of red spider.
- Elimination of weeds and crop residues.
- Avoid excessive nitrogen.
- Monitoring of crops during the early stages of development.

Biological control through natural enemies

The natural enemies of red spider are:

- Phytoseiulus persimilis: The size of the adult mite is similar to red spider, orange in colour and very active especially at high temperatures. Under normal conditions, the time for its development is shorter than the red spider.

The female predatory mite feeds on all stages of red spider. When the temperature increases, so does the consumption of red spiders. The temperature at which the predator can control better the red spider is between 15-25ºC.

As soon as the first red spider is detected, the introduction of the predator should begin.

- Amblyseius californicus: The size of the adult mite is similar to red spider. They are very active and transparent (white-orange to yellow) at the beginning. They change colour as they feed. Both temperature and humidity influence the time needed to complete their development.

The female predatory mite feeds on all stages of red spider.

As soon as the first red spider is detected, the introduction of the predator should begin.

Chemical control

Active substances	Mode of Action	Doses	T.S.	I.P.
Acrinathrin	Ing, Con	40-80cc/hl	3	NAu
Sulfur		20-30kg/ha	NA	A
Wettable sulfur		0.2-0.5%	NA	A
Clofentezin	Con	20-40cc/hl	3	A
Fenbutaestan	Ing, Con	0.05-0.1%	7	A
Fenbutaestan DP	Ing, Con	20-30kg/ha	7	A
Fenpiroximato	Ing, Con	100-200cc/hl	3	A
Flufenoxuron	Ing, Trans	0.05-0.1%	7	A
Pyridaben		100g/hl	3	A
Propargite	Ing, Con, Inh	150-200cc/hl	2	NAu
Spiromesifen	Con	0.04-0.06%	3	A
Tebufenpyrad	Ing, Con, Trans	100g/hl	7	A

(T.S., Term Security; I.P., Integrated Production; N.A., Not Applicable; A, Authorized; N.Au., Not Authorized)

- Tomato russet mite (Aculops lycopersici)

The first symptoms are browning on the stem and later on leaves and even on fruits. Brown spots evolve and ascend from the basal to the upper part of the plant.

The plague appears in groups and dispersed mechanically favoured by high temperature and low humidity.

Preventive control and cultivation techniques

- Disinfected the work clothes, footwear, etc.
- Remove infected plants.

Chemical control

Active substances: abamectin, paraffin oil, amitraz, coloidal sulfur, micronized sulfur, wettable sulfur, ground sulfuro, sublimed sulfur, micronized sulfur + dicofol, bromopropylate, diazinon, dicofol, endosulfan + sulfur, potassium permanganate + micronized sulfur, tetradifon.

- Whitefly (Trialeurodes vaporariorum and Bemisia tabaci)

The young parts of the plants are colonized by adults by laying their eggs on the underside of leaves. The first larvae that emerge are mobile. After being fixed on the plant, they pass through three larval stages and one pupal stage.

- Direct damage (yellowing and weakening of the plants) are caused during larvae and adults feeding by absorbing the sap of the leaves.
- Indirect damage is due to the proliferation of black moulds produced during feeding. This damage stains and lowers the value of the fruits and hinders the normal development of the plants.

Both types of damage become important when the pest population level is high. Another indirect damage that takes place is the transmission of viruses.

Preventive control and cultivation techniques

- Placement of mesh on the bands of the greenhouse.
- Cleaning of weeds and crop residues.
- Do not combine different crops in the same greenhouse.
- Do not leave the buds at the end of the cycle, as young shoots attract adult whiteflies.
- Placement of yellow chromatic traps.

Biological control through natural enemies

Major parasites of whitefly larvae:

- Trialeurodes vaporariorum. Native beneficial insects: Encarsia formosa, Encarsia transvena, Encarsia lutea, Encarsia tricolor, Cyrtopeltis tenuis. Beneficial insects used in release: Encarsia formosa, Eretmocerus californicus.

E. formosa feeds on the honeydew and whitefly larvae.

For proper balance between whitefly and E. formosa, start the release of the parasite weekly since the first detection of the pest until parasitism is sufficient. It is important to note that:
- At temperatures below 18°C, Encarsia formosa almost cannot fly and its behaviour is very limited. On the contrary, at temperatures above 30°C adult life is reduced.
- Certain pesticides can have a lasting effect on Encarsia Formosa.
- When Encarsia formosa is released too late, molasses on leaf hinders its mobility and consequently, the parasitism.
- Newly parasitized pupae can be removed by removing very young leaves.
- Bemisia tabaci. Native beneficial insect: Eretmocerus mundus, Encarsia transvena, Encarsia lutea, Cyrtopeltis tenuis. Beneficial insects used in released: Eretmocerus californicus.

Special mention should be made in the case of Nesidiocorus tenuis. Studies have shown that the presence of whitefly in plants is lower with the release of N. tenuis. This beneficial insect causes some kind of rejection of B. tabaci. This rejection is not due to the mere presence of predator but the reactions it provokes in ground floor.

Chemical control

Active substances	Mode of Action	Doses	T.S.	I.P.
Paraffin oil	Con	75-150cc/hl	NA	A
Acetamiprid		250-400g/ha	3	NAu
Azadirachtin	Ing, Con	75-100cc/hl	3	A
Beauveria bassiana		100-150cc/hl	NA	A
Cyfluthrin (isomers)	Ing, Con	50-80cc/hl	3	NAu
Alpha-cypermethrin	Ing, Con	30-40cc/hl	2	NAu
Zeta-cypermethrin	Ing, Con	0.2-0.4l/ha	2	NAu
Imidacloprid	Ing, Con, Sis	50-75cc/hl	3	NAu
Lambda cyhalothrin	Ing, Con, Rep	10-20cc/hl	3	NAu
Pymethrozine	Ing, Con, Sis	0.04-0.05%	3	A
Pyridaben		100g/hl	3	A
Pyriproxyfen	Ing, Con	50-75cc/hl	3	A
Spiromesifen	Con	0.04-0.06cc/hl	3	A
Tau Fluvalinate	Con	10-20cc/hl	7	NAu
Teflubenzuron	Ing	40-60cc/hl	3	A
Thiacloprid	Ing, Con, Sis	20-30cc/hl	3	A
Thiamethoxam	Ing, Con, Sis	20-40g/hl	3	A
Verticilum lecanii	Con	3kg/ha	NA	A

(T.S., Term Security; I.P., Integrated Production; N.A., Not Applicable; A, Authorized; N.Au., Not Authorized)

- Aphid (Aphis gossypii and Myzus persicae)

They are the most common and abundant aphid species in greenhouses. They exhibit polymorphism, with winged and wingless females of viviparous reproduction. The wingless types of Aphis gossypii have black siphons on their green or yellowish body while Myzus are completely green (sometimes brown or pink). They form colonies and are distributed in clusters that are scattered mainly in spring and autumn by the winged females.

Preventive control and cultivation techniques

- Placement of mesh on the bands of the greenhouse.
- Elimination of weeds and wastes from the previous crop.
- Placement of yellow chromatic traps.

Biological control through natural enemies

- Native predatory species: Aphidoletes aphidimyza.
- Native parasitoid species: Aphidius matricariae, Aphidius colemani, Lysiphlebus testaicepes.
- Native parasitoid used in release: Aphidius colemani.

Chemical control

Active Substances	Mode of Action	Doses	T.S.	I.P.
Paraffin oil	Con	75-150cc/hl	NA	A
Acetamiprid		250-400g/ha	3	NAu
Cypermethrin (isomers)	Ing, Con, Rep	50-100cc/hl	3	NAu
Alpha-cypermethrin	Ing, Con	30-40cc/hl	2	NAu
Zeta-cypermethrin	Ing, Con	0.2-0.4l/ha	2	NAu
Deltamethrin	Ing, Con, Rep	0.05-0.083%	3	NAu
Esfenvalerate	Ing, Con	0.2-0.3l/ha	3	NAu
Etofenprox	Ing, Con	40-100cc/hl	3	A
Flonicamid		0.01%	1	A
Lambda cyhalothrin	Ing, Con, Rep	10-20cc/hl	3	NAu
Oxamyl	Sis	10l/ha	21	A
Pyrethrin	Con, Rep	0.1-0.2%	3	A
B. Piperonyl + Pyrethrin	Con, Rep	0.1-0.2%	3	A
Pirimicarb	Con, Trans	100g/hl	3	A
Potassium salts Fatty acids	Con	1-2l/hl	3	A
Tau Fluvalinate	Con	10-20cc/hl	7	NAu
Thiaclopride	Ing, Con, Sis	20-30cc/hl	3	A
Thiamethoxam	Ing, Con, Sis	20-40g/hl	3	A

- Thrips (Frankliniella occidentalis)

Adults thrips colonize crops by laying their eggs inside the vegetal tissues of leaves, fruits and especially of flowers (they are floriculture), where the highest levels of population of adults and hatched larvae are found in sunsets.

- Direct damage is caused by larvae and adults feeding, especially on the undersides of the leaves, leaving a silvery appearance in the affected parts which become necrotic later on. These symptoms can be seen in affected fruits and in extreme cases on the leaves. The laying of eggs occurs in the fruits.
- Indirect damage has the utmost importance due to the transmission of tomato spotted wilt virus (TSWV).

Preventive control and cultivation techniques

- Placement of mesh on the bands of the greenhouse.
- Cleaning of weeds and crop residues.
- Placement of blue chromatic traps.

Biological control through natural enemies

Native beneficial insects: The most common are the following Amblyseius spp. (A. swirskii, A. cucumeris), Aeolothrips sp., Orius spp., Verticillium lecanii, etc.

Chemical control

Active Substances	Mode of Action	Doses	T.S.	I.P.
Paraffin oil	Con	75-150cc/hl	NA	A
Acrinathrin	Ing, Con	40-80cc/hl	3	NAu
Azadirachtin	Ing, Con	75-100cc/hl	3	A
Deltamethrin	Ing, Con, Rep	0.05-0.083%	3	NAu
Formetanate	Ing, Con	100g/hl+sugar 1%	14	NAu
Lufenuron	Ing,	200cc/hl	7	A
Methiocarb	Ing, Con	150-200g/hl	NA	NAu
Chlorpyrifos-methyl	Ing, Con, Fum	300-400c/hl	5	NAu
Spinosad	Ing, Con, Trans	20-25cc/hl	3	A
Tau Fluvalinate	Con	10-20cc/hl	7	NAu
Verticilium lecanii	Con	3kg/ha	NA	A

- Leafminers (Liriomyza trifolii, Liriomyza bryoniae, Liriomyza strigata, Liriomyza huidobrensis)

Adult females lay their eggs within the tissue of young leaves, where a larva that feeds on the parenchyma begins to develop, causing the typical galleries. The shapes of the galleries are different from one another, but not always distinguishable between species and crops. Once the larval development is completed, larvae leave the leaves to pupate in the soil or on other leaves, to subsequently transform them into adults.

Preventive control and cultivation techniques

- Placement of mesh in the bands of the greenhouse.
- Elimination of weeds and crop residues.
- In heavy attack, remove and destroy the lower leaves of the plant.
- Placement of yellow chromatic traps.

Biological control

- Native parasitoid species: Diglyphus isaea, Diglyphus minoeus, Diglyphus crassinervis, Chrysonotomyia formosa, Hemiptarsenus zihalisebessi, H. stropersii.
- Parasitoid species used in release: Diglyphus isaea.

Chemical control

Active Substances	Mode of Action	Doses	T.S.	I.P.
Abamectin	Ing, Trans	50-100cc/hl	7	A
Paraffin oil	Con	75-150cc/hl	NA	A
Azadirachtin	Ing, Con	75-100cc/hl	3	A
Cyromazine	Ing, Con, SisR	20-40g/hl	3	A
Oxamyl	Sis	10l/ha	21	A

- Caterpillars (Spodoptera exigua, Spodoptera litoralis, Heliothis armigera, Heliothis peltigera, Chrysodeisis chalcites, Autographa gamma)

The main differences between species in the larval stage are:
- Number of false abdominal legs (5 in Spodoptera and Heliothis and 2 in Autographa Chrysodeixis).
- The way of moving in Chrysodeixis and Autographa by arching their body (camel caterpillars).
- The presence of silks (long "hairs") on the surface of the body of the larva of Heliothis.
- The dark brown coloration especially on the legs and head of the caterpillars Spodoptera litoralis.

The biology of these species is quite similar, passing through egg stage, 5-6 larval stages and to pupa stage. The eggs are layed on leaves, preferably on the underside, by a large number of species of the genus Spodoptera which do the laying of eggs in groups while other species do it in isolation. Damage is caused by larvae feeding.

In Spodoptera and Heliothis, the pupal stage takes place on the ground while Chrysodeixis chalcites and Autographa gamma, takes place on the leaves. The adults are moths with nocturnal and crepuscular habits.

The damage can be classified as follows:
- Damage on the vegetation (Spodoptera, Chrysodeixis)
- Damage on the fruits (Heliothis and Spodoptera)
- Damage on the stems (Heliothis and Ostrinia), which they can get at the point of cutting the plant stem.

Preventive control and cultivation techniques

- Placement of mesh on the bands of the greenhouse.
- Elimination of weeds and crop residues.
- In the case of heavy attacks, remove and destroy the lower leaves of the plant.
- Placement of pheromone traps and light traps.
- To monitor the early stages of crop development, it is during this stage when they can produce irreversible damage.

Biological control through natural enemies

- Indigenous parasites: Apantelles plutellae.
- Indigenous pathogens: VPNSe-SP2
- Biological products: Bacillus thuringiensis.

Chemical control

Active Substances	Mode of Action	Doses	T.S.	I.P.
Azadirachtin	Ing, Con	75-100cc/hl	3	A
B. Thuringiensis Aizawaii	Ing	0.5-1kg/ha	NA	A
B. Thuringiensis Kurstaki	Ing	1-3kg/ha	NA	A
Cyfluthrin (isomers)	Ing, Con	50-80cc/hl	3	NAu
Beta-cyfluthrin	Con	0.05-0.08%	3	NAu
Cypermethrin (isomers)	Ing, Con, Rep	50-100cc/hl	3	NAu
Alpha-cypermethrin	Ing, Con	30-40cc/hl	2	NAu
Zeta-cypermethrin	Ing, Con	0.2-0.4l/ha	2	NAu
Chlorpyrifos	Ing, Con, Inh	150-200cc/hl	7	NAu
Deltamethrin	Ing, Con, Rep	0.05-0.083%	3	NAu
Esfenvalerate	Ing, Con	0.2-0.3l/ha	3	NAu
Etofenprox	Ing, Con	40-100cc/hl	3	NAu
Flufenoxuron	Ing, Trans	0.05-0.1%	7	A
Indoxacarb	Ing	20g/hl	1	A
Lambda cyhalothrin	Ing, Con, Rep	10-20cc/hl	3	NAu
Lufenuron	Ing	40cc/hl	7	A
Chlorpyrifos-methyl	Ing, Con	300-400c/hl	5	NAu
Methoxyfenozide	Ing, Con, IGR	40cc/hl	1	A
Spinosad	Ing, Con, Trans	20-25cc/hl	3	A
Tau Fluvalinate	Con	10-20cc/hl	7	NAu
Tebufenozide	Ing	60-75cc/hl	3	A
Teflubenzuron	Ing	40-60cc/hl	3	A

- Nematodes (Meloidogyne spp.)

M. javanica, M. arenaria and M incógnita are identified. They affect practically all horticultural crops, producing root nodules.

They penetrate underground roots. Fertilized females which are filled with eggs, take a globular aspect within the roots. Together with the hypertrophy produced in the tissues of the same roots, the results will be the formation of a sequence of nodules. These damages cause clogging vessels and prevent the absorption of nutrients by the roots that cause lower plant development, chlorosis, dwarfism and the appearance of green-wilt symptoms in the hottest hours of the day.

They spread in lines or stands and are easily transmitted by irrigation water, by the farmer footwear, by the tools and by any means of land transportation. Furthermore, nematodes interact with other pathogens, either actively (as vectors of virus) or passively by facilitating the entry of bacteria and fungi through the wounds that they cause.

Preventive control and cultivation techniques

- Use of resistant varieties.
- Disinfection of soil in previously infected plots.
- Use healthy seedlings.

Biological control through natural enemies

- Biological products prepared with the fungus Arthrobotrys irregularis

Control by physical methods

- Steam sterilization.
- Soil solarization, which consists in raising the soil temperature by placing a clear plastic sheet on the floor for at least 30 days.

Chemical control

Materia Activa	Modo de Acción	Doses	T.S.	I.P
Ethoprophos	Con, Inh, Pen	60-80kg/ha	60	A
Fenamiphos	Irr, Sis	15-25l/ha	60	A
Fosthiazate	Soil, preplan	30kg/ha	NA	NAu
Metam Sodium		750-1200l/ha	NA	NAu
Oxamyl	Sis	10l/ha	21	A

- Tomato leafminer or South American tomato moth (Tuta absoluta)

Tuta absoluta is a microlepidopter which passes through four stages of development: egg, larva, pupa and adult. It attacks on any phenological stage of the plant and the larvae penetrate the fruit, leaves and stems making holes and galleries. These holes and galleries are often irregular and produce necrosis which affects the plant development.

The control of this pest in its place of origin has been the indiscriminate use of chemical treatments to an integrated management strategy where biological control plays an important role. In Spain, as any exotic pests, T. absoluta was introduced without the presence of natural enemies that could regulate their populations. That is why chemicals are initially used for its control. However, since its inception, there are several natural opportunists enemies who have accepted this exotic herbivore as new host or prey.

Preventive control and cultivation techniques

- Remove damaged leaflets, buds and fruits.
- Pheromone Traps: They attract males by definition, since the lure is similar to the female sex pheromone substances, but cannot be exclusive because it also attracts females.
- Light traps: Light traps are selective with females. This phenomenon may be due to a difference in the activity schedule.
- Leave about 6 weeks since the removal of plant residues (prior to starting treatment) until the new transplant.
- Solarization: Part of the life cycle of T. absoluta, the pupation and adult emergence, happens on the ground. Therefore, solarization just after finishing a crop can be an effective method to prevent the spread of the moths that emerge in the empty greenhouse.

Biological control through natural enemies

The mirid predators Nesidiocoris tenuis and Macrolophus pygmaeus are naturally present in tomato crop. Being opportunistic predators, their prey are eggs and larvae of T. absoluta.

Moreover, other predators like Nabis pseudophorus ibericus and Dicyphus marrocannus had been observed eating both eggs and larvae of T. absoluta. Two phytoseiid predators Amblyseius swirskii and Amblyseius cucumeris, were also observed killing and eating T. absoluta larvae in their initial stage in aubergine crops.

Anyway, the predator that seems to be most useful is N. tenuis which is already being introduced even in seedbed. Thus, the natural enemy installation is simpler and the plant reaches cultivation operation more prepared.

Chemical control

Active Substances	Mode of Action	Doses	T.S.	I.P.
Chlorantraniliprole		10-11.5g/hl	1	A
Emamectin (benzoate)	Ing, Con	100-150g/hl	3	A

Author: Infoagro