Growing Hydroponic Tomatoes : how fast do hydroponic tomatoes grow
How to Grow Hydroponic Tomatoes: Conventional field cultivation of tomatoes, employing fertilizer broadcasting and irrigation, faces economic challenges due to both quantitative and qualitative limitations in plant yield. In contrast, advanced soilless cultivation systems like hydroponics(growing hydroponic tomatoes) involve fertigation, aeroponic systems, where plant root systems grow in air periodically filled with a nutrient solution, nutrient film technique (NFT), where a thin film of the surrounding medium serves as the root growth medium offer greater economic viability.
Soilless cultures utilise minerals which possess low solid phase content and maintain stable air and water properties. Currently, mineral substrates like rockwool which is created by melting a natural rock mixture of diabase (60%) and calcium (20%) with coke (20%) at temperatures ranging from 1500 to 1600°C classified as a mineral substrate, fits these criteria. It has been produced for plant cultivation systems since 1969 by I/S H.J. Henriksen and V. Kähler in Denmark, gaining popularity due to their precise plant nutrition compared to cultures using organic substrates, such as peat and bark or Sawdust. Nowadays growing hydroponic tomatoes is a very eye-catching technique in modern agriculture.
Hydroponic Tomatoes
There are thousands of tomato varieties, and almost all of them can be successfully grown in a hydroponics system. Several tomato varieties have been specifically developed for hydroponic production in controlled environments. Tomato plants are quite large and require ample support, such as a trellis, or can be wrapped around a vertically tied string as they grow. In the absence of a sufficient support structure, these plants should be given enough room to grow. Large crops with a long growing season, like tomatoes and cucumbers, need sufficient room for their roots to grow.
Propagation for Hydroponic Tomatoes
The first step is the selection of the tomato variety (determinate or indeterminate) to be grown hydroponically. The selection of plants depends on factors such as space needed, profitability, potential market, and whether the hydroponic system is to be implemented indoors or outdoors.
Growing media for hydroponic tomato
Growing material is very important to solve the question how to grow hydroponic tomatoes. These are – Rock wool, Coconut coir, Perlite.
Sowing Seeds
Prepare the tomato seedlings (starter plants) 12-16 days before planting. Tomato seeds should be sown 0.6 to 1 cm deep. Sprinkle a thin layer of vermiculite over the seeds or cover the germination cubes or pots with a large piece of clear plastic to conserve moisture at the surface. Avoid the use of plastic if the cubes receive direct light.
Watering Seedlings
Overhead watering or flood and drain (ebb and flow) systems can be used for germinating seedlings. When watering, the water must be sprinkled uniformly over all seedlings to avoid uneven growth. In flood and drain systems, a shallow tray containing the sown cubes or pots is flooded with nutrient solution or water, providing even moisture from the bottom by capillary action.
Transplanting
Once true leaves appear (during post-emergence), seedlings should be transferred into larger growing blocks (pots) and should be evenly spaced to maximize light to each plant. The transplants must be spaced so as not to touch one another and may need to be spread several times during their growth. A good transplant is one that is as wide as it is tall. Tomato plants readily grow adventitious roots from the stems if given the opportunity, producing a stronger plant with more roots. Adventitious roots will grow from the bent stem inside the block.
Transplanting into the final growing media should be done before any flowering. Before transplanting, the growing media should be properly leached, moistened, and at the proper temperature. Plants should be irrigated with a nutrient solution immediately after moving. The spacing of tomatoes in hydroponic systems can be much denser than in soil (approximately 60 square cm per plant). In lower light conditions, wider spacing should be applied.
Light for Hydroponic Tomatoes
Photosynthesis plays an important role in the growth of plants. If photosynthesis is decreased (due to low light conditions, high humidity, or water stress), then the production of sugars will decline, affecting the fruit quality and size. If the tomato plant does not get sufficient light for a long period, its leaves become low in sugars and may become pale and thin. Excess nitrogen at that time can be damaging.
Artificial lighting is generally not economical for vegetable crops, with the exception of seed production. During winter months, especially in Northern latitudes, supplemental light may be required for strong growth of seedlings. The lights should operate 14 to 18 hours per day.
Sometimes it may be necessary to provide shade to tomato plants, especially in areas with high summer temperatures and humidity, because direct sunlight on fruits can cause yellow or green shoulders and cracking. Therefore, shading using a 30 percent shade cloth keeps the temperature within a reasonable range and can improve fruit quality.
Temperature for Hydroponic Tomatoes
The day temperatures for a tomato plant should be around 21-26°C and night temperatures around 16-18.5°C. Some new varieties can do best with little difference between day and night temperatures. For seedlings, the temperatures should be constant at 20-22°C, then slowly acclimated to diurnal temperatures before transplanting.
Humidity for Hydroponic Tomatoes
The ideal humidity for tomatoes during the day is 80-90 percent, and during the night is 65-75 percent. High humidity can lead to nutrient deficiency symptoms such as blossom end rot (calcium deficiency). Low humidity can cause rapid water and nutrient movement, depositing nutrient ions in the leaves rather than in the fruits.
Preparing Nutrient Solution for Hydroponic Tomatoes
The selection of fertilizers and their concentration in the hydroponic nutrient solution depends on the quality of raw water. The concentration of macronutrients progresses with the maturity of the crop, while micronutrient concentration remains constant throughout growth.
Here’s the table representing the nutrient requirements for tomatoes:
| Nutrient | Seedlings to First Fruit Set (ppm or mg/l) | Fruit Set to Harvest (ppm or mg/l) |
| Macronutrients | ||
| Magnesium (Mg) | 50 | 199 |
| Potassium (K) | 50 | 144 |
| Phosphorus (P) | 199 | 62 |
| Nitrogen (N) | 113 | 165 |
| Calcium (Ca) | 122 | 165 |
| Micronutrients | ||
| Iron (Fe) | 2.5 | 2.5 |
| Boron (B) | 0.44 | 0.44 |
| Copper (Cu) | 0.05 | 0.05 |
| Chlorine (Cl) | 0.85 | 0.85 |
| Manganese (Mn) | 0.62 | 0.62 |
| Molybdenum (Mo) | 0.06 | 0.06 |
| Zinc (Zn) | 0.09 | 0.09 |
pH for Hydroponic Tomatoes
The desirable pH range of a hydroponics nutrient solution for tomatoes is 5.5 to 6.5. At pH below 5.0, excessive nutrient absorption can result in toxicity, while at pH above 7.0, some nutrients may become unavailable, leading to deficiencies. The pH can be lowered with nitric or phosphoric acid.
Carbon Dioxide Hydroponic Tomato
Optimal CO₂ levels for tomatoes may be 2 to 5 times the normal atmospheric levels. A CO₂ level of 1100-1500 ppm during the light phase significantly increases tomato yields. CO₂ should be injected during daylight hours, and the greenhouse should remain sealed while CO₂ is introduced.
Diseases of tomatoes
Although proper sanitation and observation can prevent many diseases and pests in hydroponic systems, some common issues still arise:
- Fungal diseases: Gray Mold (Botrytis), various forms of mildews and blight, Verticillium wilt, Fusarium wilt.
- Bacterial diseases: Bacterial canker (Clavibacter michiganensis), bacterial spot (Xanthomonas vesicatoria), bacterial wilt (Burkholderia solanacerum).
- Viral diseases: Tobacco mosaic virus, tomato yellow leaf curl virus (TYLCV), common mosaic, aucuba mosaic, cucumber mosaic virus.
