Fungal diseases in potatoes and tomatoes are among the most common problems during the growing season. Disease pressure increases especially when weather conditions favour infection: high humidity, warm temperatures and leaves remaining wet for a long time after rain or dew.
In such conditions, plant protection is important, but the condition of the plant itself also matters. A well-nourished crop copes better with stress, maintains photosynthesis more efficiently and responds faster to difficult growing conditions.
Why does plant nutrition matter under disease pressure?
Potatoes and tomatoes quickly show when their metabolism is weakened. Slower growth, paler leaves, weaker new growth or poorer recovery after stress may indicate that the plant has limited ability to defend itself.
Under high pressure from fungal diseases, several factors are important:
- efficient photosynthesis,
- strong tissue structure,
- proper water management,
- effective sugar transport,
- active natural defence mechanisms,
- quick recovery after weather stress.
This is why micronutrient fertilisation and potassium support should be treated as part of a broader crop management strategy, especially in seasons with highly variable weather.
Manganese in potato and tomato cultivation
Manganese is involved in many plant metabolic processes. It plays a role in photosynthesis, enzyme activity and overall crop health. When manganese is deficient, the plant may use energy less efficiently, grow more slowly and respond less effectively to stress.
In potato cultivation, manganese is important during canopy development and tuber formation. In tomatoes, it is especially valuable during intensive growth, when the plant needs stable nutrition and efficient metabolism.
Manganese support is worth considering particularly when:
- plants grow unevenly,
- leaves lose their intense green colour,
- the crop is under disease pressure,
- plants recover slowly after stress,
- soil or weather conditions limit nutrient uptake.
Potassium and proline under plant stress
Potassium is responsible for plant water management, stomatal function and sugar transport. In potatoes, it also plays an important role in starch accumulation in tubers. When potassium is deficient, plants may tolerate drought, heat and other stress factors less effectively.
In crops exposed to fungal diseases, potassium supports overall plant condition. It does not replace plant protection treatments, but it helps maintain the physiological efficiency of the crop, which is important during periods of high pathogen pressure.
Proline acts as an osmoprotectant. In practice, this means it supports the protection of cellular structures under stress, helps stabilise metabolism and reduces the effects of drought, high temperature or other unfavourable conditions.
Fungal diseases in potatoes and tomatoes — when does the risk increase?
The risk of infection rises during humid weather, large temperature fluctuations and poor air movement in the crop canopy. In potatoes, late blight and alternaria are especially important. In tomatoes, leaf diseases and infections favoured by high humidity can become serious problems.
It is worth paying attention to the first signals in the crop:
- spots on leaves,
- yellowing or drying leaf edges,
- rapid deterioration of plant condition after rainfall,
- weaker growth,
- uneven crop appearance,
- slower recovery after stress.
The earlier the problem is noticed, the easier it is to combine protection, fertilisation and physiological support into one consistent programme.
How to support potatoes and tomatoes during the season?
Under pressure from fungal diseases, regular crop monitoring and response to weather conditions are essential. A protection programme should go hand in hand with plant nutrition, because intervention against pathogens alone may not be enough if the plant is weakened.
In practice, it is worth focusing on:
- crop inspection after rainfall and periods of high humidity,
- proper micronutrient nutrition,
- potassium support during stress periods,
- maintaining efficient photosynthesis,
- reducing the effects of drought and high temperature,
- matching treatments to the current condition of the crop.
VitaFer Mn Complex and VitaExpert Stress Control in plant support strategy
In a fertilisation programme, it is worth considering products that support plants through micronutrients and water management.
VitaFer Mn Complex contains manganese complexed with heptagluconic acid. It can be used as foliar support for manganese nutrition in potato and tomato cultivation. In potatoes, 2–3 applications may be considered from shoot formation until the tubers reach around 40% of their final mass. In tomatoes, the treatment can be adapted to the period of intensive growth and current plant condition.
VitaExpert Stress Control supplies potassium and proline. It can support plants under water stress, high temperatures and increased disease pressure. Potassium helps regulate water management, while proline supports plant metabolism under difficult conditions.
The combination of manganese, potassium and proline can be a valuable element of a programme supporting the natural resistance of potatoes and tomatoes. It does not replace plant protection, but it helps maintain the crop in better condition when disease pressure and weather stress overlap.
Healthier plants cope better with a difficult season
Fungal diseases in potatoes and tomatoes require quick action, but prevention starts earlier — with plant condition. Efficient metabolism, proper manganese nutrition, balanced water management and potassium support help plants use their potential more effectively during the season.
If disease pressure, weather stress or signs of weakening appear in a potato or tomato crop, it is worth reviewing the foliar fertilisation programme and choosing support suited to the current situation in the field.
Check VitaFer Mn Complex and VitaExpert Stress Control and choose a support programme suited to the needs of your crop.
