It’s not just humans and animals that suffer when the mercury rises. Plants feel the heat, too. Heat stress is a major issue in agriculture, as it can significantly reduce crop yield and quality. Even small increases in temperature or short episodes of high temperatures can affect plant growth and development. Heat stress can reduce leaf photosynthesis and accelerate leaf senescence rates, contributing to late season crop decline.
It has been known since 1939 (Laude, et al) that plants’ response to heat stress differs significantly between day and night. If you apply heat stress to a plant in the middle of the day, it is much more likely to survive than if you applied the same heat stress at night. Plants’ daily cycle of heat resistance is a strategy that protects plants from the hottest parts of the day, while saving energy at night.
Plants sense temperature and then use this information to activate chemical pathways to protect themselves by, among other things, manufacturing protective heat shock proteins (HSP). We’ve learned is that these HSPs are activated by light and that is why high nighttime temperatures can have such a devasting impact on crops. Plants lose this heat resistance capability in darkness and will only regain the protection when exposed to light again.
In general, at temperatures above 86°F the rate of photosynthesis is reduced, and at higher temperatures heat stress at key crop stages can reduce yield and quality. It’s a good idea to have a plan in place, including the right products, to mitigate the negative impact. Andaman Ag has some unique and excellent products proven to combat heat stress. For best results, these foliar products should be applied 48 hours prior to heat stress.
- Aquasap 0-0-35 is a seaweed extract that has been shown to assist plants through times of heat stress. Betaines in the kelp increase chlorophyll and thus photosynthesis. Cytokinins that induce heat tolerance also increase potassium uptake and antioxidants that help plants in temperature extremes. The additional potassium (K) in Aquasap is very important for combatting heat stress. It is an essential nutrient that affects most of the biochemical and physiological processes that influence plant growth and metabolism. It also contributes to the survival of plants exposed to various biotic and abiotic stresses.
- Vitazyme is a great biostimulant to combat heat stress, with 20-plus years of research confirming this ability. Vitazyme has triacontanol that increases chlorophyll content and CO2 assimilation and brassinosteroids that protect cells from the oxidative damage induced by high temperatures.
- CropBioLife is a flavonoid and, as a secondary metabolite, possesses the qualities to reduce heat stress and improve the plant’s ability to transpire and photosynthesize. It also helps the plant recover more quickly.
All the above mentioned products possess excellent attributes in addition to battling heat stress, and they can and should be used in conjunction with each other.
I would also recommend applying drip/fertigation applications of our MetaGrow ST compost tea coupled with our humic-based microbial package, FertiBOOST WP. MetaGrow ST increases the size and diversity of that microbial population that boost plants’ ability to access nutrients and the soil’s abililty to hold water, helping the plant function more efficiently in high heat. FertiBOOST WP will mitigate the crop decline, or crashing, during high stress periods and enhances the positive impact of the compost tea.