Environmental stresses can give rise to various issues when growing chillies. Stressed chillies are susceptible to struggling, producing lower yields and even disease. So it is always a good to ensure you are providing a stress free environment for your plants.

Wind Burn

On hot summer days, extreme hot airflow can result in plant leaves wilting and drying out. The damages of "Wind burn" manifest as brown patches on leaves, mostly at the leaf edges. Much like an air fryer might crisp things. Mature plants are better equipped to cope with Wind burn, but Wind burn on seedlings can be fatal.

Shade netting and hedging along edges of the designated grow area as well as water features can help cool warm air and mitigate the effects of Wind Burn.

Sun Scald

Peak summer temperatures and UV index can be incredibly high in South Africa. Even sun worshiping plants such as chillies have a hard time coping with our extreme summer temperatures. Capsicum can experience "Sun Scald" on fruit and foliage as a result of high temperatures and high UV. Affected pods develop areas of scalded skin, usually on the side of the pod most exposed to the sun. These patches turn into thin brown, parchment like areas.

While "Sun Scald" patches are not caused by pathogens and do not in any way impart on the flavour of the fruit, they do look unappetizing and are visually unappealing.

With time, moisture will seep through these patches and pods. Once moisture gets inside the pods pathogens are usually not far behind, resulting in pods rotting from the inside out. Rotting pods as a result of fungal or bacterial pathogens may well infect other pods, depending on the type of pathogen that is causing the rot and this in turn may affect the whole. If not controlled, this has the potential to infect neighbouring plants. So, it is important to monitor pods affected by "Sun Scald" for rot and remove pods to prevent further issues.

As far as preventing sun scald, we would recommend using a 40% shade netting over crops to reduce the intensity of the sun. Affected pods should be removed to avoid disease and to focus on new growth.

Hail Damage

Summer thunder storms in South Africa can be very severe, bringing with them hail. Severe hail storms will strip unprotected plants of their foliage and even damage branches and stems in severe cases. The destruction can be heart wrenching. At best, small hail stones will leave plants with lesions to their foliage. Late season hail storms can result in plants being set back so far that growers will not materialize a crop.

This having been said, early season hail storms can be advantageous. Damaged early season plants do have a chance to recover in time for a harvest. The damage caused by hail and the nitrates introduced to the soil by hail can result in vigorous regrowth. Damaged plants can come back bushier and with higher yield in our experience.

The best way to avoid the ravages of hail storms is shade netting or tunnels. Shade netting can catch hail stones before they reach the plants. We highly recommend shade netting, not only to mitigate damage from hail, but also protect plants from heat and high UV.

Edema

Edema (Oedema) is a common occurrence with home grown peppers. Edema manifests as crystaline deposits on the underside of pepper leaves. These appear like a white frosting under the leaves. Most growers will presume that this is a fungal infection. Edema is not fungal. Edema is as a result of too much moisture. When a plant has more moisture than it can evaporate through the leaves, these white specs will appear under the leaf.

It is important to control and regulate the watering of plants showing signs of Edema. Once moisture levels are brought back into check, symptoms will vanish and plants will return to normal.

Regulate watering and ensure there is sufficient air flow through your plants. For plants planted in the soil, remove the lower leaves of established plants to encourage airflow through the plant.

Water Stress

As unlikely as this may sound, chillies drowning is a really common occurrence. Most growers that have grown for a few seasons will testify that watering and getting the watering right is a skill all on its own. Chillies hate nothing more than soggy soil. Soggy soils are a real killer for chilli plants. This may also be due to plants growing in clay based soils that hold water. Dense or compacted soils that have poor drainage or pots that have insufficient drainage can and will be the perfect environment for plants to die. What makes drowning plants even more problematic is that the real issue lies under the soil, invisible to the eye. The top of the soil may look perfectly good, but under the soil, roots sit in water logged soil.

Add to this the added complexity that a drowning chilli plant will show the same symptoms as a under watered plant - drooping leaves. Most growers will see drooping leaves and presume the plant needs water. Adding more water to a already water logged situation is usually the final nail in the coffin!

The best advice is to ensure soil condition is optimal for drainage and aeration. Avoid dense, compacted over saturated soils. Regulate and control your watering. If a plant has drooping leaves, check the soil first with the index finger. If the soil is dry, your drooping leaves are most likely due to the plant needing watering. If the soil is moist, hold off on the watering. The drooping leaves are most likely due to the plant being water logged.

Also, if you are growing in pots. Ensure the base of your pot has sufficient drainage holes that are large enough to allow water to run off freely. Raise pots off the ground with spacers.

Dank, wet compacted soils with poor aeration are also great places for pathogens to breed, bringing about disease in plants.

Sodium Stress

Capsicum are relatively tolerant of salts in the soil. Coastal regions and excessive use of soluble nutrients may create high salt levels at the root zone of the plant and this may create issues with the plants ability to absorb nutrients and begin a roller coaster of nutrient related symptoms.

Our advice is to be mindful of using soluble nutrient supplements that are high in sodium – excessively. Use these with restraint. Planting plants in raised rows and using drip irrigation can help flush salts away from the plants root zone.

If you are supplementing your plants with soluble nutrients that are high in sodium and suspect this may be the root of the nutrient issues, suspend and water your plants with plain water. Luckily salt will flush out with regular watering.