29 Jan CHATTAHOOCHEE TURF PRODUCTS NEWS & NOTES Summer 2013 BASIC SCIENCE BEHIND HEAT STRESS
1. PHOTOSYNTHESIS—CO2 + H2O Energy (Sun) Carbs + O2
The heat & drought of summer blocks a key part of the photosynthetic process & promotes the generation of free radicals that damage cellular components. Also, the soil is having difficulty holding moisture (due to evaporation). As the soil dries out & compacts, the gas exchange decreases. So, the photosynthetic process has become stressed because the raw materials (CO2 & water) have decreased. But…sunlight(energy source) is more abundant.
2. RESPIRATION—Carbs + O2 Chem energy new growth + CO2
The speed of respiration (the consuming of carbs) increases with the temperature of the leaves & roots. A high canopy temp leads to ultra-high rates of respiration. High soil temps means higher consumption of carbs. As the supply of carbs from topical growth begins to diminish, the roots will pull carbs from reserves until they are used up. The bottom line is that the energy sources are there but the raw materials are lacking.
3. TRANSLOCATION/TRANSPIRATION—Movement of water& nutrients throughout the plant. Water is needed not only in photosynthesis but also to transport nutrients. Water is also vital in helping the plant stay cool & turgid. However, in high heat & drought conditions, water is less available to perform these functions. There is less water in the soil weaker cell walls are incapable of holding water in the cells. So, there is less evapotranspiration which means higher canopy temps & less water to keep the tissue turgid.
SOLUTIONS FOR HEAT STRESS
1. Supplement the carb supply using Perk Up & Protesyn. The forms of “glycol-“ sugars in the products are readily used by the roots to support respiration.
2. Support the proper & efficient work of stomates with potassium Power 0-0-22.
Potassium controls the water-whether it’s held or expelled. Power technology enhances the uptake of K, controls stomatal opening & closing, and provides antioxidant properties.
3. One of the key nutrients in the stress response mechanisms is calcium. Calcium,
when supplied by Perk Up, is used by the plant to buffer the needed reactions within the nucleus & combines with pectin to strengthen the cell wall and minimize water loss. Many turfgrass managers use growth regulators on tees and fairways during the summer months. Chattahoochee Turf Products encourages the use of Agra-Rouse in conjunction with these PGR’s. Rouse is a highly-concentrated biostimulant containing gibberillic acid (GA3), cytokinin, as Kinetin and Indole-3-Butyric Acid (auxin). We recommend a 3:1 ratio of PGR (Primo) to Rouse (i.e. 12 oz. Primo/Acre to 4 oz. Rouse/Acre) as this ratio will help prevent color loss. Other benefits of using Rouse include: enhanced iron effect, enhanced rooting, stands leaf blades more upright & prevents “grain” that Primo may cause while improving the quality of cut, tightens up leaf blade texture by pulling energy out of the blades & re-directing it to the roots. Most of all, Agra-Rouse mutes the blow up of the plant GA’s once Primo wears off. The auxins in Rouse, which focuses on root growth redirects growth to the roots instead of allowing it to go to the top growth. Rouse causes turf to “squat down” due to pulling the grass closer to the ground by increased pressure on the growth habit of the plant to place emphasis on roots. Remember, the plant’s primary goal is to grow roots first and tops last.
Agra-Rouse at a rate of 4 ounces/acre will cost you only $9.38 per acre.
DON’T FORGET…. FP-747 and Raider Plus titled “Chattahoochee Insurance” make all of your sprays more efficient and valuable.