Influence of foliar-applied growth retardants on Russet Burbank potato tuber production.

摘要

The potato cv Russet Burbank grows poorly in the semi-arid climate of the High Plains, primarily due to its tendency to produce misshaped tubers. Since gibberellic acid (GA₃) is associated with stem elongation and may be involved in tuber shape, the objective of this study was to determine whether GA₃ biosynthesis inhibitors could improve tuber shape. Prohexadione-Ca and chlormequat-Cl are two well-known such inhibitors. They were applied to 'Russet Burbank' at 0, 70, 280, 1,120, 4,480 g/ha when the largest tubers were 20, 60 and 100 g/tuber from 2001 to 2003. Neither compound affected tuber shape. Yields increased 17-20% by prohexadione-Ca at 280 g/ha and 9-33% by chlormequat-Cl at 4,480 g/ha. In 2004, prohexadione-Ca at 280 g/ha was applied when the largest tubers were 3, 25, 100, 180, and 370 g to determine a tuber stage response. Yield increased 14% when applied at 25 and 100 g/tuber growth stages, but the number of misshaped tubers increased from 48% to 75%. These two inhibitors did not overcome tuber misshaping and should not be used for that purpose.