Physiology of Heat Stress

We analyze the defense mechanisms of crops, how to interpret the plant's heat stress signals, and the steps for effective physiological recovery.

We need to understand that the ideal temperature range for our crops is between 20 and 30°C. According to the plant health parameters collected by the Ministry of Agriculture, Fisheries and FoodExceeding these thresholds for a prolonged period activates abiotic stress mechanisms that compromise the harvest.

Symptoms that can help identify heat stress:

  • -Curling and cupping of the leaves: Defense to stop water loss by closing stomata and reducing the surface exposed to the sun.
  • -Wilting: Critical water deficit that, if not reversed overnight, can cause irreversible cell damage.
  • -Dry leaf edges: Strategic sacrifice of the outer areas to ensure the survival of the rest of the plant tissue.
  • -Ozone damage: Tissue oxidation due to the entry of harmful gases under conditions of intense heat and poor air quality.
  • -Flower and/or fruit fall: Abortion of reproductive organs so that the plant can prioritize its basic life functions.
  • -Sprouting: Premature flowering due to "panic" in the heat, which ruins the commercial quality in cold climate crops.
  • -Sunburn: Direct radiation burns that cause blisters, spots and dehydration on the fruit's skin.
  • -Flower rot: Diversion of calcium to the leaves due to excessive transpiration, causing necrosis of the base of the fruit due to lack of nutrients.

Practices to Prevent Heat Stress in Plants

There are certain techniques to help our plants recover after a relatively short heat wave.

  • Temporary Shadow: Protect from direct sunlight, especially at midday, to avoid lethal heat spikes.
  • Precision Irrigation: Always water at dawn or dusk; water at midday evaporates before it can hydrate the roots.
  • Pause in the Subscriber: Do not fertilize during a heat wave; forcing growth under stress damages young tissues.
  • Use of Mulch: Cover the ground with straw or organic matter (10-15 cm) to insulate the roots from the heat of the soil.
  • Weed Removal: Weeds compete for water and tend to withstand heat better; eliminate them to leave all the resources to the crop.
  • Cultural Management: Plan the sowing, pruning and planting frames to promote aeration and resilience of the crop.

Heat stress can be a problem that can range from a short recovery time to irreversible damage. Therefore, we must consider it when maintaining our crops in optimal condition to minimize the impact.

How to Help Plants Recover from Heat Stress

Healthy plants are resistant to heat stress and can recover as long as they receive proper care, water, and shade. If your plants are suffering from heat stress, you can take the following steps to reduce damage and speed up recovery:

  • Install a temporary sunshade, such as a light-colored shade cloth.
  • In the morning or evening, use drip irrigation to thoroughly water your crops.
  • Spread a 5-8 cm deep layer of mulch to moderate soil temperature and retain moisture.
  • Do not attempt to replant.
  • Wait until the heat wave has passed before applying fertilizers.
  • Remove dead flowers, but be careful not to prune healthy tissue or leaves that are only partially dead.

Product proposals to help prevent and recover our crops:

-CULTISILK: It improves plant growth, strengthens its resistance to environmental factors and combats heat stress, boosting the plant's defenses.

-MICROVITAL: Increased Carbon/Nitrogen ratio, Cation Exchange Capacity (CEC) and nutrient availability, through increased water and air flow.

MICROVITAL - L