Army worm infestations have been reported

Tuesday, May 1, 2012

The 2012 growing season has allowed wheat to develop earlier than normal. The weather also allowed for early infestations of the aphids that may transmit barley yellow dwarf virus and the foliage disease Septoria Leaf blotch.

We have received recent reports of barley yellow dwarf virus showing up in some local fields. At this point in the season and with the wheat developing rapidly, there are no management recommendations for barley yellow dwarf or other wheat viruses for this year's crop.

Septoria was actively sporulating on what foliage very early in the season, but does not appear to have moved up the plants. Most lesions which are present are on the lowest leaves and the flag leaf and 2-3 leaves below the flag leaf are clean.

Powdery mildew seems to have been controlled by fungicide applications or slowed down by the change in weather conditions from March to April.

Stripe rust hasn't been reported outside of the areas in which it was initially reported. There haven't been any confirmed reports of leaf rust yet this season.

If foliar fungicide applications are being considered, fields need to be scouted for the presence of disease and the growth stage of the plants. In most parts of the state, wheat is reported 25 -28 days ahead of average as far as stage of growth. Most of the fungicides have harvest restrictions of Feekes growth stage 10.5 (head completely emerged) or 30, 35 or 40 days prior to harvest. Due to the warm temperatures, what may be passed the time when it can be sprayed.

The number of black cutworm moths remain low in most areas of the state, although moderate numbers of moths has been captured consistently in southeast Missouri.

At this time the risk for economic infestations in field corn is reduced except for possibly Southeast Missouri counties.

Moth flights may continue for several weeks and cause problems both in corn and soybean fields. Producers are encouraged to monitor crop stands beginning at plant emergence and continuing at least twice weekly for the 6 to 8 weeks just in case they have the ideal conditions to attract moths such as heavy stands of winter annuals.

Infestations of small armyworm in grass pastures and wheat fields have been reported from numerous tall fescue and wheat fields in the southern half of the state. Numbers were relatively low and the larvae were very small in size. However the potential for this pest to cause severe damage in most host crops is elevated by the presence of small larvae this early in the year.