Studies were carried out to find out the effect of mechanical stress(MS) treatment on the growth and flowering responses in various floricultural crops. The effect of MS treatment was also compared with that of the succinic acid 2, 2-dimethyl hydrazide (SADH).
The growth of MS treated plant was significantly retarded as compared to the control plant. The degree of growth retardation was dependent to the species; around 50 per cent reduction in salvia (Salvia splendens), lily (Lilium longiflorum), and mimosa(Mimosa pudica), around 30 per cent in marigold (Tagetes erecta), celosia (Celosia cristata), and sunflower(Helianthus annus) and below 20 per cent in zinnia (Zinnia elegans) and aster(Callistephus chinesis).
Lily and mimosa plant responded very sensitively to the single MS treatment where repeated MS treatment did not show any further height reduction. However, in four o´clock, salvia, and aster, growth was further retarded by the MS treatment for five times. With sunflower, zinnia, celosia and marigold, only repeated MS treatment showed growth retarding effects.
For the lateral shoot elongation, MS treatment inhibited in aster and mimosa. However, no significant inhibition was observed in salvia and zinnia. There were no changes in the number of lateral shoot by MS treatment.
The diameter of stem only in four o´clock and celosia and the number of leaves only in celosia was increased by the MS treatment. While the flowering date was not delayed, the size of flower in four o´clock, salvia, aster, and lily was reduced by the MS treatment.
The effect of MS treatment was compared with that of SADH. These two treatments showed almost the same growth and flowering responses in aster, celosia and sunflower. However, MS treatment retarded the stem elongation more efficiently in four o´clock, salvia, lily, mimosa, zinnia and marigold as compared to the SADH treatment.
Therefore, it is suggested that MS treatment can effectively employed for the height reduction in various floricultural crop production as a potted crops.
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