Abstract
A pot experiment was conducted during 2004-2005 on opium poppy (Papaver somniferum L.) and the influence of 10
−6
M gibberellic acid (GA
3
) and 10
−6
M triacontanol (TRIA) either alone or together, on the growth, yield, quality and morphine content. Among the treatments, foliar spray of GA
3
+TRIA significantly promoted the values of most of the physiological and biochemical parameters including the opium yield. The morphine content was also enhanced. The effects of GA
3
and TRIA were similar when given individually, in general, while only TRIA induced branching in the plants. Another important finding of this experiment was that GA
3
+TRIA favoured the branching as well as the development of capsules at the same levels of height in all the branches. This influence will bring about a practical benefit by facilitating easier manual or mechanical lancing of the capsules, the collection of the latex and the harvesting of the opium poppies. Thus, we conclude that 10
−6
M each of GA
3
and TRIA given together may be used for maximizing the yield of opium and morphine.