CATEGORIES OF FORAGE CROPS - Department of Plant Sciences

conditions all varieties will need growth control and situations like poor fruit load or late
planting will require a more aggressive approach. A good rule of thumb is to make applications
based on field history, plant vigor, variety, fruit load and weather forecast. Remember, growth
control should take place before and very near bloom. PGRs can do a lot of things but they can’t
shrink the plant. Take all of these into consideration when making the decision and when in
doubt call an extension agent or specialist for help.
Table 10. Plant growth regulator application strategies.
Single or Dual Application
First Application
Apply when cotton is actively growing and is between 20"
and 30" tall, provided cotton is not more than 7 days beyond
early bloom stage (5-6 blooms per 25 row feet). If cotton is
24" tall and has no blooms apply Mepiquat chloride plant
regulator. Use 2 pint per acre on cotton where excessive
vegetative growth is not likely to be a problem, and 1 pint per
acre in areas tending to have excessive vegetative growth.
Second Application
Field has a history of excessive growth, and/or conditions
after the first application are favorable for excessive growth,
apply a second application 2 to 3 weeks after the first
application.
Multiple Low-rate applications
First Application:
Match head square stage of growth.
Second Application:
14 days later, or when excessive re-growth occurs.
Third Application:
14 days later, or when excessive re-growth occurs.
Fourth Application:
14 days later, or when excessive re-growth occurs.
Rate per acre
Mepiquat Stance
0.5-1.0 pint 2.0-3.0 oz
0.5 pint 2.0 oz
Mepiquat
2.0-4.0 oz
2.0-4.0 oz
2.0-4.0 oz
2.0-4.0 oz
Defoliation and Harvest Timing
Defoliation is an often-overlooked process that if done properly, can pay large dividends.
Defoliation is relatively easy in some situations and extremely difficult in others. Defoliation is
the application of chemicals to encourage or force cotton leaves to drop from the plant in order to
harvest the crop in a timely manner. Proper defoliation requires a balancing act between killing
the leaves too quickly or not affecting the leaf at all. Successful defoliation requires that the leaf
must stay alive long enough to begin the formation of an abscission zone resulting in leaf drop.
Killing the leaf too rapidly results in a leaf that is frozen or "stuck" to the plant, creating
unnecessary trash.
Proper defoliation is a profitable part of a total cotton management system. Benefits include:
1. Elimination of the main source of stain and trash, resulting in better grades.
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