It’s getting dry again in South Carolina.  This is bad for corn, and certainly bad for cotton--if you are still hoping for seed to germinate.  On the positive side of the ledger, this is great weather for harvesting wheat.  Also the roots of seedling cotton plants will search a little deeper for moisture, thereby developing a better root system than would be the case where moisture was abundant.

     According to Randal Lynch, Manager of the SC Boll Weevil Foundation, farmers signed up 345,000 intended acres of cotton at FSA offices.  If the ratio of intended to actual acres planted works as in past years, there could be over 300,000 acres of cotton planted this year. 

Scouting Schools
     This is the last reminder about Scouting Schools at Orangeburg-Calhoun Tech. in room 118 Bldg. C on June 8 and at the Pee Dee REC near Florence on June 9.  Registration will begin about 8:15 and there will be a $10 fee.  It’s a good idea to bring paper and pen to take notes.

     Pesticide applicator certification credits will be awarded for participation in a Scouting School.  Those who need CCA credits will be able to get 4.5 credits for Pest Management and 0.5 for Crop Production.

Fertilizer and Agrichemicals Meeting
     The SC Fertilizer and Agrichemicals Association will hold their Summer Meeting and Convention, July 21-23, 1999 at the Charleston Harbor Hilton Resort at Patriots Point. The meeting theme is “Agriculture 2000".  Motel reservations must be made by June 21 to receive special rates of $99 for single or double.   Registration fees are $75 for family and $60 for single if registration form is received by July 5.  Late fees are $85 for family and $70 for single.

Section 18 for Pirate?
     I hear from Don Adams that EPA is considering a Section 18 label for Pirate on beet armyworm this year.  The catch is this: Each field would have to be checked by an official (myself, County Agent, maybe others) to confirm that the infestation is 5 BAW’s/100 terminals before a farmer could use the product.  In other words a problem field could not be treated before a confirmation document was received in the Pesticide Regulations office at Clemson.

Insect Situation
     What’s with the thrips this year?  Seems like there are a lot more foliar sprays going out than we are used to seeing.  Temik and other soil insecticides may not be performing quite up to snuff in some cases.  Most of the problems can be blamed on extremes--too wet, or too dry.  The big rain about the first of May probably washed much of the insecticide out of the upper soil profile.  Then the problems on the smaller cotton may have resulted from not having sufficient moisture to properly activate the insecticide.

     Foliar sprays could probably have gone out a lot earlier in some cases.  These are fairly inexpensive treatments, especially when you spray the insecticide in conjunction with another operation and band over the row. 

     There have been a few reports of heavy thrips pressure in North Carolina, primarily caused by western flower thrips.  They are not alone in having western flower thrips infesting cotton.  These insects have been a problem for us on seedling cotton for a number of years.  They can also be found in blooms later in the season. 

     I have heard some complaints from both North and South Carolina about control of western flower thrips  with the recommended  materials (Orthene, Bidrin, and dimethoate) applied as foliar sprays.  If you experience a failure, your alternative products would include Monitor (no information as of yet), which is on the recommended list and the pyrethoids which are labeled for thrips control. 

     Generally, I do not recommend treating cotton plants for thrips when they have more than four true leaves.  The only exception would be where the plant terminals are so damaged that growth is being inhibited, and new leaves aren’t unfolding in a normal fashion. 

     In four years (1985-88) of field testing at the PDREC to determine the proper timing of foliar sprays,  there was no yield advantage to initiating foliar sprays on 3- or 4-leaf stage cotton when compared to the untreated plots.  In a couple of those years there was no yield advantage to spraying thrips at any stage.  We always planted during the first week of May, so plants were exposed to the bulk of the thrips population that came from small grains.  The most “bang for the buck” in thrips control was always achieved when foliar treatments were initiated at the first-leaf stage of development.  Controls were less effective when initiated at the 2-leaf, 3-leaf, and 4-leaf stages, respectively.  In all cases a second treatment was applied within a week. 

     These results taught me  that protection of the terminal buds is the most important function of a foliar treatment for thrips.  When thrips jump on cotton as it comes up, foliar sprays applied at the 3- and 4-leaf stages, or later, are usually applied after the terminal-bud damage has been done.  That’s why it is so important to get back to cotton fields soon after plants emerge to check for thrips.  If after checking 25 or more plants in a field, you are finding one adult thrips per plant on plants with one or two true leaves, then a foliar spray should be applied.  In 3- and 4-leaf cotton, the presence of two or more adults and immatures on most plants would suggest the need for treatment. 

     Even when soil insecticides have had a good chance to work, with warm temperatures and adequate moisture, thrips could overwhelm the defense.  When thousands of acres of wheat plants are drying down and releasing billions of thrips, it’s possible on any given day for several thrips per plant to descend upon a cotton field.  In this scenario the insecticide might do the job, but damage would still occur.  It takes a few probes and sucks for the thrips to each get a killing dose.

     Thrips should not be a problem for too much longer.  Most thrips have found a home and there shouldn’t be many left to move out of  grain fields.  Plants will be responding to warm weather and doing what they do best, growing.  Rain will fall, and a good heavy downpour can be as effective as an insecticide. 

     One last word about thrips.  Don’t continue to spray damaged cotton after the new leaves come out clean.  There is no way to undamage cotton (I know that’s not a word, but it works for me) and you can cause problems with other insects by killing beneficials.

     Cutworms have shown up in a few minimum tillage situations.  Problems can usually be avoided if winter annuals, and other vegetation  are destroyed 3-4 weeks prior to planting. 

Mitchell Roof
Extension Entomologist