Date: June 29, 2001
Category: Agronomy Subject: Turf Recovery from Armyworm Infestation
Cultural Recommendations for Recovery from Lawn Caterpillar (Armyworm)
Infestations: Turf can usually outgrow light caterpillar infestations
when plant growth conditions (temperature and soil moisture) are favorable.
Extended weather forecasts for next week (early July) indicate unseasonably
cool conditions (high around 80ºF) that are favorable for growth
of cool-season turfgrass. Because lawn caterpillars are foliar feeding
insects, most turf may recover under such conditions. Furthermore, light
applications of fertilizer (0.5 lb N per 1,000ft2) and ensuring soil water
is non-limiting by irrigating insect damaged lawns can enhance recovery.
In the end, maintaining a healthy turf with fertilizer and water will
maximize recovery so long as heat (and humidity) is not oppressive ( >
85).
In the Fall, if insect damage was especially severe and recovery slow,
consider over-seeding with endophytic grasses (insect resistant perennial
ryegrass and fine-leaf fescue) and reduce thatch where surface feeding
insect can hide. Also, soil testing in the Fall will provide critical
information regarding the nutrient status (phosphorous and potassium levels)
to ensure optimum nutrition for maximum recovery from insect damage as
well as summer stress. Corrective applications of fertilizer addressing
phosphorous and potassium deficiencies (identified by soil testing) should
be applied beginning in September during periods of peak shoot growth
and turf recovery.
