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Forages & Grains
Volume 59 Number 13 Date 07/31/2014 POTATO LEAFHOPPER - This alfalfa pest has been less of a problem than anticipated throughout July. Surveys continue to yield low counts of 0.2-1.0 per sweep in 12 to 30-inch fields. The leaf yellowing occurring at sites on sandy soils may be due to boron deficiency, a disorder common on the second and third cuttings during dry periods that is often misdiagnosed as leafhopper damage. Boron deficiency causes discoloration of the entire leaflet, whereas leafhopper feeding usually results in yellowing of only part of the leaflet, in a typical V-shaped pattern. Low leafhopper counts in fields with extensive leaf yellowing suggest insufficient boron levels as the cause of the symptoms. GRASSHOPPER - Moderate to high populations have developed in a few sandy fields in the west-central area. Average counts in Jackson, Monroe and Vernon counties varied from 0.3-2.5 nymphs per sweep, though exceptional fields contained as many as 5-6 per sweep. PLANT BUG - Near-economic counts of 3.6-4.5 plant bugs per sweep were found in scattered fields this week. The high ratio of plant bug nymphs to adults indicates significant reproduction is occurring and signals the potential for damaging populations in alfalfa and other crops next month. -- Krista Hamilton, DATCP Entomologist 
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