A survey of county Extension agents in cotton producing counties in Texas has been conducted since 1973 except for 1978 and 1979. The use of preplant incorporated herbicides has increased from 51.8% of the acreage in 1973 to 76.6% in 1981. The survey also reveals that the number of counties reporting johnsongrass as a problem species has gone from 115 to 73 in the same time period. This may be a cause and effect relationship. The percentage of acreage treated with preemergence herbicides decrease([ from 17.5 to 15.7% from 1973 to 1981. As PPI herbicide use increased the use of preemergence herbicides decreased. Postemergence herbicide use decreased from 18.4% to 10.7% during the 8 year time span. The use of wipe-on devices on 22% and 37% of the acreage in 1980 and 81 respectively probably accounts for the decrease in postemergence herbicide use in recent years.

The broad usage of preplant incorporated herbicides and in recent years wipe-on devices, has led to an increase in the infestation of perennial weeds and annual broadleaf weeds which are resistant to dinitroaniline herbicides. The survey shows an increase in number of counties reporting field bindweed (Convolvulus arvensis, L.), woollyleaf bursage or lakeweed (Franserla tomentosa Cray), devil's claw [Proboscidea lousianica (Mill.)], cocklebur (Xanthium pennsylvanicum Wallr.) and sunflower (Helianthus annus L.).