Tomato
Soil type:
Tomatoes can be grown on soils with a wide range of textures, from light, sandy soils to heavy, clay soils. Sandy soils are preferable if early harvest is desired. Favorable pH level: 6.0-6.5. At higher or lower pH levels micronutrients become less available for plant uptake
Climate:
Temperature is the primary factor influencing all stages of development of the plant: vegetative growth, flowering, fruit setting and fruit ripening. Growth requires temperatures between 10°C and 30°C.
Irrigation:
Tomato plants are fairly resistant to moderate drought. However, proper management is essential to assure high yield and quality.
The water requirement of outdoor grown tomatoes varies between 4000 - 6000 m³/ha. In greenhouses up to 10,000 m3/ha of water are required. 70% or more of the root system are in the upper 20 cm of the soil. Therefore, a drip system equipped with a fertigation device is advisable.
On light soils or when saline water is used, it is necessary to increase water quantities by 20% - 30%. Water requirements will differ at various growth stages. The requirement increases from germination until beginning of fruit setting, reaching a peak during fruit development and then decreasing during ripening.
Mild water stress during fruit development and ripening has a positive effect on fruit quality: firmness, taste and shelf-life quality, but may result in smaller fruit. Late irrigation, close to harvesting, may impair quality and induce rotting.
Nutrition:
Nitrogen (N)
The form in which N is supplied is of major importance in producing a successful tomato crop. The optimal ratio between ammonium and nitrate depends on growth stage and on the pH of the growing medium.
Plants grown in NH4+ -supplemented medium have a lower fresh weight and more stress signs than plants grown on NO3- only. By increasing the ammonium nitrate rates, the EC increases and consequently the yield decreases. However, when doubling the rate of Multi-K® potassium nitrate, the EC increases without adverse effect on the yield that increases as well
Potassium (K)
Ample amounts of potassium must be supplied to the crop in order to ensure optimal K levels in all major organs, mainly due to the key role K plays in tomatoes:
As a cation, K+ is THE dominant cation, balancing negative charges of organic and mineral anions. Therefore, high K concentration is required for this purpose in the cells.