**3.2 Humates**

**2. Cultivation systems for cucumber growing in greenhouses**

cultivated mostly in the first and second system.

*Cucumber Economic Values and Its Cultivation and Breeding*

system is rarely used for cucumber cultivation.

vegetables [4] it can be used also for cucumber cultivation.

**3. Biostimulators to enhance cucumber growth**

**2.1 Substrate culture**

**2.2 Water culture**

stabilize the root system.

**2.3 Aeroponics**

**2.4 Aquaponics**

**3.1 Lactate**

**68**

In the last 45 years different hydroponic systems are developed in the world, the

Hydroponic systems in a small amount of substrate (3 to 15 l per plant) filled in containers, bags, slabs or channels. Slabs of rockwool, peat or coconut fiber are used. This system is combined with different types of trickle irrigation. There are 'open systems' in which the drainwater flows out of the substrate slabs or cultivation container in the ground. Preferable used are the 'closed systems' in which the growing medium is lying in channels and the nutrient solution is recirculating.

The plants are cultivated without any substrate, except the substrate for propagation of the young plants. The plants are staying or hanging also in channels in recirculating nutrient solution. Quite known systems are the 'Nutrient-Film-Techniques' (NFT) and the 'Deep-Flow-Techniques' (DFT). Also gravel culture can be grouped belong to the water culture, because the gravel has only the function to

The plants are cultivated without any substrate and staying or hanging on plastic-foam-sheets and the root system is hanging in a closed space. The nutrient solution is given by very fine nozzles as a kind of fog-system. Important is a high frequency of spraying with nutrient solution, advisably to spray every 2 to

4 minutes for 20 to 30 seconds according to the developmental stage of plants. This

Is a combination of aquaculture with typical fish keeping in ponds and the water culture system 'nutrient-film-technique' (NFT) as a closed aquaponics, where the plants were fertilized only with the fish water. This technique becomes more and more important for the food production and has an increasing popularity, even though the system is not methodologically sound and completely scientifically investigated. Nowadays, this system is mainly used to cultivate tomatoes and leafy

According to previous investigations, lactates (salts of lactic acid) seem to produce bioregulatory effects. The application of lactates was tested as an approach to improve the nutrient balance and plant vitality. Investigations have shown that lactates have more stable bonds with several metal ions than other chelates.

different systems can be subdivide in four groups [3]. Whereas, cucumbers are

Humates are the salts of Humic acids which are complex polymers including amino acids, amino sugars, peptides, aliphatic compounds involved in linkages between the aromatic groups [7]. There are different types of humates related to the organic material used and the method of extraction of the Humic Acid; in the experiments were used different types:

	- Na Humate
	- K Humate
	- NH4 Humate
	- Fulvic Acid
	- K Humate
	- K Humate
	- K Humate


#### **Table 2.** *Composition of LACTOFOL O®.*

Na Humate is not very useful as Bioregulator, because the negative effects of high Na in the nutrient solution or substrates, therefore K Humates or NH4 were used in the experiments.

In relation to crop growth or soil condition can be divided in Direct and Indirect effect of humates:

Following the investigations in the research and practical experiences in agriculture and horticulture, it was found out that *Bacillus subtilis* could have different

*Growth Promoting and Stabilizing of Cucumber Plants Cultivated in Soilless Cultivation…*

◦ Formation of growth hormones and enzymes for nutrient mobilization, based on better this nutrient availability and the nutrient uptake can be

◦ Improvement of plant growth, biomass production and marketable yield.

◦ Improving of the earliness of generative development and vegetative

◦ Reducing the effects of diseases in terms of intensity and frequency.

**4. Mineral, organic and synthetic substrates used in the substrate**

because the ecological aspects are becoming more and more important when choosing substrates, as well the economic efficiency is important. Substrate were filled in containers or available as mats, between 8 and 9 liters of substrate were available per plant. The aim was to use substrates with different physical and

◦ Achieve resistance of the plants in particular against soil born diseases.

As mentioned in the introduction different substrates can be used for cucumber cultivation in substrate culture systems. In principle, most substrates are suitable for successful cucumber growing, if adequately supplied with water and plant

In one experiment were compared substrates from the three groups (**Table 1**),

• Organic substrate, consisted of pine bark (40% v /v), low-bog peat (40% v/v)

Comparing the four substrates used, the significantly highest total yields of cucumbers were obtained in the variants 'organic substrate'. The differences in crop

effects:

• Growth promoting of plants.

*DOI: http://dx.doi.org/10.5772/intechopen.96536*

◦ Improvement of seed and tuber germination.

◦ Improvement of root formation of plants.

enhanced.

growth.

nutrients.

**71**

• Promoting of plant health.

◦ Improving plant resilience.

**cultivation system of cucumbers**

chemical parameters (**Table 3**).

• Urea-methanal foam,

and manure straw mix (20% v/v).

• Rockwool (Grodan) mats as standard substrate,

• Perlite, grain size between 0.6 mm and 1.0 mm diameter.

	- to increase the vitality and stimulating plant growth,
	- to increase the germination activity and accelerate the germination of seeds.
	- to improves the uptake of some nutrients and enhances the transport and availability of micronutrients in the plant
	- Regulation of soil properties,
	- to improve thermal conditions and soil or substrate structure,
	- to enhance the ion exchange capacity,
	- to stimulate development of micro-organisms.

#### **3.3 Microorganisms**

Intensively cultivated crops such as cucumbers in soilless cultivation systems are stressed because the growth conditions in the rhizosphere are completely different in contrast to the natural conditions. Therefore, studies were done to improve the growth condition in the rhizosphere, to enhance plant growth and to find growth promoters to stabilize the production process. Investigations were carried out to find effective biostimulators and agencies for plant protection from pest and diseases. Different bacteria species and their strains were investigated and practically used for different plants mainly in protected cultivation [8, 9].

Many microorganisms from the rhizosphere can influence plant growth and plant health positively and in case of bacteria they are often referred as "plant growth-promoting rhizobacteria" However, their effects have to be seen as the complex and as a cumulative result of various interactions between plant, pathogen, antagonists, and environmental factors [2].

Following many investigations in the soil are bacteria present in an average amount of 6 108 cells/g of soil, and with a live weight of about 10,000 kg/ha, they are the most common microorganisms in the soil, bacillus species are one of them. The species *Bacillus subtilis* is common in the nature and can be found in every compost pile, but it was important to find active strains promising for developing marketable products. Based on several investigations, some strains of *Bacillus subtilis* are already used in industrially and agricultural fields [10]. An effective strain is in this regard is FZB24® in particular used in agriculture also as growth promoter in the rhizosphere of the cultivated plants [11].

There are various effects induced by *Bacillus subtilis* (syn*. Amyloliquefaciens* ssp. *plantarum*), and different mechanisms of these effects as well as the interactions between them.

*Growth Promoting and Stabilizing of Cucumber Plants Cultivated in Soilless Cultivation… DOI: http://dx.doi.org/10.5772/intechopen.96536*

Following the investigations in the research and practical experiences in agriculture and horticulture, it was found out that *Bacillus subtilis* could have different effects:

• Growth promoting of plants.

Na Humate is not very useful as Bioregulator, because the negative effects of high Na in the nutrient solution or substrates, therefore K Humates or NH4 were

In relation to crop growth or soil condition can be divided in Direct and Indirect

◦ to increase the germination activity and accelerate the germination of seeds.

◦ to improves the uptake of some nutrients and enhances the transport and

Intensively cultivated crops such as cucumbers in soilless cultivation systems are stressed because the growth conditions in the rhizosphere are completely different in contrast to the natural conditions. Therefore, studies were done to improve the growth condition in the rhizosphere, to enhance plant growth and to find growth promoters to stabilize the production process. Investigations were carried out to find effective biostimulators and agencies for plant protection from pest and diseases. Different bacteria species and their strains were

investigated and practically used for different plants mainly in protected cultiva-

Many microorganisms from the rhizosphere can influence plant growth and plant health positively and in case of bacteria they are often referred as "plant growth-promoting rhizobacteria" However, their effects have to be seen as the complex and as a cumulative result of various interactions between plant, pathogen,

Following many investigations in the soil are bacteria present in an average amount of 6 108 cells/g of soil, and with a live weight of about 10,000 kg/ha, they are the most common microorganisms in the soil, bacillus species are one of them. The species *Bacillus subtilis* is common in the nature and can be found in every compost pile, but it was important to find active strains promising for developing marketable products. Based on several investigations, some strains of *Bacillus subtilis* are already used in industrially and agricultural fields [10]. An effective strain is in this regard is FZB24® in particular used in agriculture also as growth

There are various effects induced by *Bacillus subtilis* (syn*. Amyloliquefaciens* ssp. *plantarum*), and different mechanisms of these effects as well as the interactions

◦ to improve thermal conditions and soil or substrate structure,

◦ to increase the vitality and stimulating plant growth,

availability of micronutrients in the plant

*Cucumber Economic Values and Its Cultivation and Breeding*

◦ to enhance the ion - exchange capacity,

◦ to stimulate development of micro-organisms.

used in the experiments.

• Direct effects of humates

• Indirect effects of humates

**3.3 Microorganisms**

tion [8, 9].

between them.

**70**

◦ Regulation of soil properties,

antagonists, and environmental factors [2].

promoter in the rhizosphere of the cultivated plants [11].

effect of humates:

	- Improving plant resilience.
	- Reducing the effects of diseases in terms of intensity and frequency.
	- Achieve resistance of the plants in particular against soil born diseases.
