Examples of abiotic stress include drought, flooding, heat, cold, salt, foot traffic, lack of nutrient availability, etc.

The opposite of abiotic stress is biotic stress (insect, fungus, virus, etc.) Many times people blame biotic stress (insect or fungus) on a problem that is abiotic (too much or not enough water). This misdiagnosis often causes the unnecessary use of pesticides or fungicides. Proper diagnosis should take place before treatment.

The best way to reduce abiotic stress

The best way to reduce abiotic stress is to follow good “cultural practices” (right plant, right place, right amount of water, the right amount of fertilizer, right amount of sunlight, etc).

Also, a healthy root zone and proper soil health can go a long way to reduce abiotic stress. Biostimulants like Yeti Trax Liquid or Biotrax increase root development and increase soil health which reduces the effects of abiotic stress on plants.

It is easily recognizable by its foul odor. Most applicators use it to treat for fire ants. It can also be used for bagworms and many other pests.

on the pH scale. If a soil is said to be “alkaline” that means the pH is on the upper end of the pH scale. Neutral pH is 7. So anything over 7 is considered Alkaline.

It is very common and is applied as a granular or melted in the tank and sprayed.

Of all the sources of Nitrogen, AS has the highest salt index or “burn potential” and so must be applied cautiously. However, most lawns will green up rapidly after AS is applied. The application will need to be repeated about every 3 weeks.

It is more common in the Spring with high temps and high moisture.

Commonly found on turf that is under stress from drought or compaction.

Symptoms include brown to reddish-brown spots that have a narrow “halo” around the spot. The halo is usually yellow in color. Sometimes the whole leaf blade is affected and will cause dead patches throughout the turf. You can see the fungus up close with a hand lens by looking closely at the base of the blade. The fungus appears black with tiny spines. For control, reduce stress on the turf.

Use a balanced fertilizer (15-0-15) or make sure to apply Potassium (K) and not too much Nitrogen (N). For chemical control include azoxystrobin (Heritage), chlorothalonil (Daconil), myclobutanil propiconazole, and T Methyl (Transom)

including Fall Armyworm, Southern Armyworm, and the Yellow Striped Armyworm. Their eggs are deposited by a moth in clusters of up to several hundred. You can find these clusters of eggs on leaf blades or almost anywhere. The eggs are brown to pinkish in color. Armyworms have a distinct pattern of damage done to turf as they form “armies” and march in uniform defoliating turf in straight lines.

Do not spray on turf if temps are above 90 F. It may cause some turf damage. Simazine is another option that is less damaging to the turf.

Atrazine Products

Can be used as a perimeter spray or on lawns.

Sea kelp

A popular biostimulant is sea kelp. As kelp is applied to the soil, microbes break down all the parts of the kelp plant and the plant then scavenges the nutrients from the kelp. These nutrients are then taken up and used by the plant.

Types of biotic stress

Examples of biotic stress are bacteria, virus, fungus, or insect.


Palms can get a boron deficiency and take a hard right turn. Also shows up as “hook leaf” in palms; other symptoms of B deficiency are stunted, deformed growth, folded or crumpled fronds, and spears that do not open

…caused by Rhizoctonia Solani and affects warm season turf like St Augustine and Zoysia.

Mostly seen in November through May, it is triggered by too much water/irrigation and higher humidity.

The affected areas look like a “large patch” of dead/declining turf. The turf blades will appear yellow and necrotic. The roots are brown and dead-looking and you can smell rotting plant material.

Treatment involves reducing heavy doses of fertilizer, reducing irrigation, and allowing the turf to grow taller. If fungicides are used, make sure there is a follow-up application. You can treat Large Patch with T Methyl, Azoxystrobin, and/or Propiconazole.

a good supplement for turf or plants because these nutrients are needed in larger quantities

Sandy soils usually have low CEC levels and so do not hold many nutrients while clay soils tend to have higher CEC levels.

Chelators are designed to keep the element in suspension near the rootzone so the plant can use the nutrient when it needs it.

Common chelators are EDTA, EDDTA, and DTPA.

It is important to control this pest early in the Spring before they reach adulthood.

If a lawn has known chinch bug issues, then early prevention with imidacloprid is important. Adding products like growth regulators can also reduce adult populations. However, proper diagnosis is a must when treating with chemicals. The best way to deal with chinch bugs is to keep the lawn healthy with proper irrigation, proper mowing, and slow-release fertilizers. Healthy turfgrass can handle most chinch bug pressure.

Most Nitrogen is lost right away when applied. Some forms of nitrogen like UFLEXX and Defend inhibit denitrification to last longer.

Pre/Post selective herbicide. Dithiopyr. Good for crabgrass control when applied regularly starting in Feb/Mar.

A calcium carbonate that is used to raise pH in soils and can provide a small amount of Magnesium and Calcium. Be careful not to over apply.


Has small, light tan to straw colored spots on the blade. Usually appears as softball size patches in turf. Proper irrigation and fertilization is a must to control Dollar Spot. If using chemicals such as T Methyl, Propiconazole, Azoxystrobin, or Myclobutanil then follow label exactly.

In landscaping, Epsom Salts can be used to add Magnesium to the soil that can treat a deficiency or for maintenance.

Gray Leaf Spot is more common in St Augustine.


GLF is usually easy to treat with common fungicides like: T Methyl, Propiconazole, Myclobutanil, and Azoxystrobin or any combination. However, prevention is better than trying to treat a fungus. Make sure irrigation system has a rainfall shutoff sensor installed and working. Keep irrigation to minimum during rain season and keep turf healthy by proper mowing height and proper fertilization rates. If a fungicide application is necessary, make sure to follow up with 2nd or 3rd application and to rotate chemicals throughout the year.

Most common in FL from May to August.

Grubs can do extensive damage to the roots of turfgrass. However, healthy turfgrass can handle some pressure from grubs. Ibis help control the population of grubs in turf.

The best solution for grubs is to maintain healthy turf through proper irrigation, mowing height, and fertilization. If chemicals are needed to stop an outbreak and you have a positive ID, then Dylox is usually effective. For natural control, products using Spinosad (conserve) or B Thuringensis (thuricide) are useful.

Calcium Sulfate that is used to increase water flocculation in clay soils. Gypsum is sometimes used to help mitigate salt stress in turf when sodium levels are high in soil (sodic). Calcium can disperse and replace sodium (Na) at soil exchange sites and allow for quicker leaching of sodium out of the soil. Gypsum may be helpful when drought conditions increase sodium in soils.

Humic acid may slightly lower soil pH to increase nutrient uptake.

The pesticide is taken up by the plant and kills pests that feed on the plant.


Iron applications should be based on a soil or tissue test.


The center of the Chlorophyll molecule; Mg is mobile in the plant.

Interveinal chlorosis symptom of Mg deficiency.


Manganese often shows up as deficient in FL soils; immobile in plants.


This form of micronutrients is very effective for soils with a pH range of 6-8.

Spread rate

Spread Rate is 1lb per acre


They are called micro or minor elements because they are required in very small amounts by plants. Some common micronutrients are Iron, Manganese, Boron, Copper, Zinc, Molybdenum, and Cobalt. Adding too much of one nutrient can cause a deficiency in some micronutrients.

A popular form of potassium with an analysis of 0-0-60/62. Highest in chlorine content


It is required in large amounts for turfgrass management. It is the primary driver for new growth.

Osmocote is the name of the polymer coating that contains the nutrient. Most osmocote blends are homogenous meaning that all the nutrients are inside the polymer coating and thus released slowly over time.


“Potenital of Hydrogen” or the measure used to determine the acidity or alkalinity of soil. Soil pH ranges from 0 to 14. For plants to grow properly, soil pH should be close to neutral (7). Soil that is either too acidic or too alkaline (basic) will prevent nutrients from being taken up by the plant. Adding substances like compost, sulfur, or lime can help move soil pH to a more neutral level.

A very important nutrient, especially for root growth. Plants need larger amounts of phosphorus which is determined by a soil test.

This is the plant’s ability to convert sunlight into energy for basic plant functions.

Plants need larger amounts of Potassium to function properly. There are many forms of Potassium available including K Thiosulfate, Muriate of Potash, Sulfate of Potash, and Potassium Acetate.

Following the label is very important for these herbicides to work properly. Some common pre emergent herbicides are Barricade/Resolute (prodiamine), Ronstar (oxidiazon), Pendulum (pendimethalin), Dimension (dithiopyr), Treflan (trifluralin), Snapshot (isoxaban and trifluralin), Rout (oxyflourafen), etc

Root rot disease is caused by too much water or poorly draining soil. It can affect plants and turf any time of year; extra potassium can help reduce the impact of disease; treat with foliar fungicide and reduce water

Usually not serious and the plant will recover in Spring when temperatures rise; excess shade/water can cause rust disease.

This can come from saltwater, excessive fertilizer, and reclaimed water.

There are two categories: armored scale and soft scale. Both attack weakened plants and can be difficult to treat. Some cycads and other plants are more susceptible to attacks. Systemic pesticides (Zylam or Dominion) and insect growth regulators can be effective treatments.

which allow the plant to “run” by sending out roots at the nodes which are on the stolons

Sometimes used to lower pH. It is considered a secondary nutrient.


a fungal disease in turf that typically has orangeish colored uneven borders around the brown area; Rhizoctonia Soloni

Caused by Gaeumannomyces graminis var. graminis.

Common during Summer and early Fall and can affect all warm season turf.

Avoid heavy applications of Nitrogen and turf stress; best to apply fungicides preventatively if history of disease is known. Roots are damaged so best to apply fertilizer or fungicide with a foliar application if Take All Patch occurs

Thatch Build-up is common when too much Nitrogen is applied. Excess thatch buildup can cause St Augustine grass to feel “Spongy.”

A source of Nitrogen that has urea inhibitors to keep Nitrogen in the soil longer. It can be applied as a granular or liquid


A source of Nitrogen that has urea inhibitors to keep Nitrogen in the soil longer. It can be applied as a granular or liquid


reduces surface tension on the leaf and allows a chemical to spread evenly over the leaf surface for better coverage.

Some wetting agents are applied to the soil to allow water to move through the soil profile.