Performance of Plant Growth Regulators

Performance of Plant Growth Regulators

 Plant growth regulators have been labeled for use in cotton for decades.  Despite their age PGR’s continue to have a relatively low acceptance rate among cotton growers when compared to other chemicals such as pesticides.  However, research shows when used appropriately, PGR’s consistently prove their value as a management tool in cotton.  Benefits of PGR use in cotton include:  reduced rank vegetative growth, compact and uniform growth, and uniform maturity, all of which allow for an easier harvest.  This two location study evaluates the performance of STANCE^® and mepiquat chloride over five cotton varieties.  PGR treatments were applied starting at match head square (MHS), additional treatments were applied at MHS plus fourteen days, and MHS plus twenty-eight days.  STANCE^® was applied three times at two rates, 2 oz per acre and 3 oz per acre.  Mepiquat chloride was applied at 4, 8, and 12 oz per acre respectively.  Fibermax 1880, 9180, 1740 and Stoneville 4498, 5458 were planted at three and five seed per foot densities.  Both locations are well watered.  One location is irrigated with sub-surface drip irrigation, while the other utilizes a center pivot system.  Nodes above white flower and nodes above cracked boll measurements were taken throughout the experiment to monitor maturity.  Plant height data was also collected throughout the study.   Yield data will be determined by a mechanical harvester.  The Fiber and Biopolymer Research Institute in Lubbock, Texas will asses the fiber quality by using AFIS. The results obtained show some differences in plant height.  There were no significant differences in the nodes and NAWF when looking at the different PGR treatments across the board.  Data from yield and quality are still pending.