Note that maximum light interception occurs when light is decreasing. Earlier genetic material should thus be required in order to optimize photosynthesis. Crop Protection Harrowing is generally carried out when plants have between 2 and 5 leaves in order to improve chemical weed control. Irrigation is appropriate if water is available. The optimal period for irrigation is after flowering in order to maintain leaf surface and improve seed production.
Defoliation speeds up maturity and makes the harvest easier.
Diquat or glyphosate can be used. Breeding of earlier cultivars will avoid this application under some conditions. In France yields need to be increased by improved harvesting practices and improvement of earliness. The first hybrids show a reduction of about 10-15 days of the crop cycle duration and no longer require defoliation. A new system for dehusking the seeds during harvesting has been designed.