The dominant question last week was concerning spider mite control. Several calls were received from consultants or agri fieldmen in the southern part of the state. Their question was not so much what to spray with (chemical choice) but instead when to spray. Most were scheduling stink bug sprays within a few days and wanted to know whether to add a miticide or not. Without seeing the fields, that is a difficult decision to make over the phone. My thoughts were that it could depend somewhat on how widespread the mites were in the field, the level of mite infestation and maybe most importantly – what is the weather outlook for the next 7-10 days.
Mite populations seem to hold steady in good rainfall patterns
but explode during hot-dry weather. Even though we have had scattered
thunderstorms for the past several weeks, there are many places where no
rainfall has occurred. Last week was hot, mid 90’s or higher all week, so mites
likely increased in number.
My suggestion would be to go ahead and treat mites if the
weather outlook is for hot dry weather for the next 5-7 days. Most of our mites
controls this season have been with abamectin (Agri Mek) at 8 oz/ac and results
have been good.
Stink bug populations are still hanging around, in low
numbers in many fields. However, from personal experience in a plant bug trial
area in central Alabama that is located adjacent to corn, stink bug numbers
have exploded in the past two weeks. Both brown and southern green species are
well above the threshold level on the corn-cotton borders. Where cotton yields
are promising and quarter diameter 10 day old bolls are still developing, stink
bugs should be watched closely and controlled when above threshold. Cotton is
at various stages now so our “dynamic threshold” would depend on where we are in
the blooming-boll development cycle. Remember that 10% is our suggested
threshold from weeks 3 through about 6 of bloom.
One other call was received last week concerning one or more
fields in Baldwin County (Gulf Coast) infested with damaging levels of the
garden fleahopper. We had several fields in recent seasons with this pest in
the Mobile county area. The GFH seems to be primarily a foliage feeder but can
damage every leaf in a field.
As of this date the bollworm/budworm complex is almost
non-detectable, even in cotton with no caterpillar technology.