HUMIC ACID APPLICATION IMPROVES THE GROWTH, FLORET AND BULB INDICES OF GLADIOLUS (Gladiolus grandiflorus L.)

Abstract

Humic acid is an organic acid having positive effect on plant growth. The present
study was carried out to see the effect of humic acid in combination with NPK on soil for growth,
flower production and vase life of gladiolus flowers. Five treatments i.e. nitrogen, phosphorous, potash
(NPK) (17:17:17) (10 g), 8% humic acid (1.0 mL) + NPK (17:17:17) (10 g), 8% humic acid (2.0 mL)+ NPK (17:17:17) (10 g), 8% humic acid (3.0 mL) + NPK (17:17:17) (10g) were studied, whereastreatment without exogenous feeding of NPK and humic acid served as control. All the treatments were applied at plating and 3rd leaf stage through soil. All the treatments were arranged in randomized complete block design (RCBD) in triplicate. Results depicted that humic acid (3.0 mL) in combination
with NPK (17:17:17) produced higher sprouting, plant height, number of leaves per plant, leaf area,
spike length, spike diameter, stem length, flower characteristics, vase life, number of cormels plant-1
diameter of cormels and weight of cormels per plant than all other treatments. However, plants grown
without application of humic acid (only NPK) showed relatively less and least growth characteristics
and poor floral and bulb indices as compared to other treatments. It could be concluded that humic acid
application can increase the vase life by increasing growth indices such as leaf area, fresh and dry
weight of floret.