Rutgers Cooperative Extension
By Jim Murphy
Several weeks ago the cool wet weather brought on some red thread disease activity that has increased over the past 4 to 5 days. Turfs under low maintenance, particularly low nitrogen fertility, have been the areas with the greatest amount of red thread. This disease has been active on on slender and strong creeping red fescues, Chewings fescue, velvet bentgrass, perennial ryegrass, and tall fescue this spring. [Read more…]
By Jim Murphy
Very small first and second leaves of emerging crabgrass can be seen now in open turf areas.
During the last couple weeks, we have seen crabgrass emerging from open turf areas that were previously infested with crabgrass. Crabgrass emergence will probably occur later than this on better maintained turfs with a dense canopy.
Red thread has been festering in turfgrass for some weeks now, but really blew up over the last few days. As long as there is plenty of moisture – light rain, heavy fogs, dew – and optimal temperatures (60ºF to- 75ºF) – the fungus that causes red thread, Laetisaria fuciformis, will tear up susceptible grasses.
Pseudosclerotia (red threads) of Isaria fuciformis are clearly evident on red thread infected fine fescue. Photo: Sabrina Tirpak, Rutgers PDL
Several samples of brown ring patch found their way into the Plant Diagnostic Laboratory this week. Sometimes confused with take-all, fairy ring, or yellow patch, this relatively newly described malady of Poa annua putting greens is caused by the fungus Waitea circinata.
Brown ring patch on Poa annua. Photo: Richard Buckley, Rutgers PDL
By Jim Murphy
There are numerous elite varieties of Kentucky bluegrass (Compact Types) that have excellent tolerance of leaf spot, summer patch, and stripe smut diseases. Many varieties produce a very attractive, dense, compact (low growing) turf with dark green color during the summer.
Some elite varieties of Kentucky bluegrass exhibit slow spring green-up (plot in center foreground).
However, many of these Kentucky bluegrass varieties that are grown and sold as sod have the growth characteristic of long winter dormancy and slow spring green-up. The cool dry weather of this spring has certainly exacerbated this growth response. Full green-up of these varieties typically occurs by mid- to late-May.
Practices that hasten spring green-up of turf include fertilization with moderate amounts (0.4 to 0.7 pounds per 1,000 square feet) of water soluble nitrogen (WSN) and covering the turf with a growth blanket early in the spring (March and April).
Perennial ryegrass and tall fescue will often green-up several weeks earlier than these Compact Type Kentucky bluegrasses. Perennial ryegrass typically will have the earliest green-up.
Of the fine fescues used for turf, creeping red fescue will green-up earlier than Chewings fescue and hard fescue will have the slowest spring green-up. Green-up of creeping red fescue is relatively early and not too different from perennial ryegrass.
By Jim Murphy
Slow growth of grasses has been a common complaint this spring. There are many factors that can cause this but cool dry weather has been a major factor this year.
Slow growth of turf can be due to many factors but cool dry weather has been important this spring.
But this is changing as I type. The abundant rains of this week will stimulate a lot of shoot growth. Be on the watch for large surges of growth from turfs that have been fertilized with relatively large amounts of nitrogen fertilizer. Water, warmer weather, and nitrogen can stimulate plenty of shoot growth.
Moreover, rains could interrupt mowing schedules. Sharp blades and bedknives will be very helpful in cutting fast growing, dense turfs. Overgrown turf will present the greatest challenge to mulching mowers. Raise the cutting height if rains significantly delays mowing and turf becomes severely overgrown. Double cutting may be another useful practice to reduce clipping debris.
Avoid mowing turf areas that are squishy wet. Operating equipment under these conditions can cause significant traffic damage to the turf and soil.
