2015 was the warmest year on record, and 2016 is on track to be even warmer. We asked representatives from fungicide manufacturing companies: What impact is the increased heat and humidity having on turf disease on cool- and warm-season turfgrass?
Senior Technical Specialist – Northern Region
BASF Professional and Specialty Solutions
This was a warm year and for some parts of the Northeast quite dry. With the hot weather, we saw Pythium diseases were much more widespread because areas that usually are not as hot were this year. The prolonged hot weather also meant cool-season turf was more stressed than usual, meaning greater disease pressure which resulted in thinned stands. This all added up to more stress for the superintendent. It was not an easy year to grow grass!
We are definitely seeing the trend of a longer summer season and thus a longer time frame necessitating a need for fungicide applications. In parts of the Southeast and Midwest, the past two years have seen high temperatures coupled with drought conditions, followed by high temperatures and heavy rains. The drought conditions put the turf in a compromised state. When the rain increases the humidity, it sets up the turf for heavy disease pressure. This scenario has been true on both warm- and cool-season turf.
Director of Technical Services T&O
Warmer temperatures impact a turfgrass disease management program in a number of ways. In many locations, not only have we observed an extended growing season, especially in the late summer and fall, but also extreme heat stress during the season. When combined, it becomes even more important that diseases are managed from the very beginning until the very end of the season — especially when turf is low on reserves from a stressful summer. Scouting and preventive applications to ensure your turf goes into dormancy as healthy and protected as possible will start you in the right direction the following year.
Senior Technical Representative
Warmer temperatures are bad news for cool-season grasses. Hotter summers put these grasses under an enormous amount of physiological stress, which renders them more susceptible to anthracnose, summer patch, Pythium root rot, nematodes and other stressrelated diseases. So, we’ll all just switch to warm-season grasses! Not so fast. It seems counterintuitive, but warmer temperatures can be harmful to the warm-season grasses as well, especially if they come during the fall, winter, and spring when light is the factor most limiting to the health and growth of these grasses. During these months, warm and wet conditions are favorable to diseases like leaf spot, Pythium blight and take-all root rot. These can cause severe damage to weak, slowly growing warm-season grasses and lead to a difficult spring transition.
Turf and Ornamental Manager
Engage Agro USA
Weather is a primary factor in the health and vigor of turfgrass. Hot and humid conditions seen in 2015 and 2016 can increase disease incidence that continually challenges turf managers. Among others, brown patch, Pythium, dollar spot and summer patch are common diseases during hot, humid conditions. The following methods can help control disease:
- Chemical — Utilizing different modes of action, preventive and curative, inhibits the spread of disease during its active growing season.
- Varietal — Identify the strongest turf varieties for your geography. The National Turf grass Evaluation Program is a great resource.
- Cultural — A proper nutrient management program as well as aeration/overseeding in the fall.
In the end, due diligence goes a long way in fighting the good fight against turf disease.
Green Solutions Specialist
Providing quality golf course playing conditions has been more challenging than ever this year due to the humidity and high temperatures, especially during nighttime. These extreme environmental factors have contributed to significant disease pressure in cool- and warm-season turf as well as the occurrence of diseases not commonly seen within local geographic regions. The superintendents who experienced great success this year implemented preventive programs with fungicides containing other beneficial components beyond disease control.
Account Manager – Midwest
The increased heat and humidity of the past two years has been a strain on both warm- and cool-season turf. With continued high demands on course conditioning, the cultural and mechanical stress applied to turf is creating great strains on even the soundest programs. SipcamRotam and other companies continue to develop innovative products that not only provide disease control but also minimize turfgrass stress. These products feature sunscreen-like technology specifically developed to counter the negative effects of intense weather and have benefits on all varieties of turf.