Drought stress can cause abortion of small bolls on heavily fruited cotton. However, abortion of small bolls was observed in some fields that had just begun blooming and were not under moisture stress. Roundup-induced fruit abortion is a result of poor pollination, although the exact cause of the poor pollination is unknown. Such bolls had low seed counts in many locks. An excessive amount of cavitation was also observed in some growers' fields planted to DPL 5409, DPL 458, DPL 655, DPL 5415RR, DPL 5690RR and DPL 90RR in 1998 and 1999.
Cavitated fruit turn brown and dry up, but they hang on the plant for a few weeks rather than shed.
Cavitated fruit are accompanied by a clearly noticeable V-shaped scar along the fruiting branch running from the peduncle of the affected fruit down toward the main stem. Cavitation did not appear to be as prevalent in 2000. Another potential problem with certain varieties is a genetic predisposition to the disease bronze wilt. This was observed in 1998 in Georgia, Louisiana, Mississippi, and South Carolina. The problem is not confined to Roundup Ready varieties nor is it associated with use of Roundup.