The Effect of Spraying Ascorbic and Humic acid on Growth Parameters and Yield of Okra Plant ( Abelmoschus esculentus L . Moench.)

Field experiment was conducted in a farm of Najaf governorate during 2013-2014 season , to study the effect of different concentrations of ascorbic acid and humic acid on the growth and productivity of okra plant cv. Betra . The experiment included 9 treatments i.e. the interaction of three concentrations of ascorbic acid ( 0 , 50 and 100 mg.L-1 ) and three concentrations of humic acid ( 0 , 1.5 and 3 ml.L-1 ) spraying were applied twice during growth season at fifteen days interval. Factorials experiment within Randomized complete Block Design ( R.C.B.D ) was used with three replications , Means were compared according to least significant difference L.S.D test at probability of 0.05 . Results can be summarized as follow: The use of concentration 100 mg. L-1 of ascorbic acid had a significant effect on all vegetative growth parameters ( plant length , leaves number , branches number, stem diameter , shoot fresh and dry weights) compared with control treatment ( sprays with distilled water ) which gave the least means values . Humic acid spraying with 3 ml. L-1 had a significant effect on all vegetative growth parameters compared with control treatment . Interaction between the two factors gave a significant effect on all vegetative growth .100 mg.L-1 of ascorbic acid had a significant effect on all root growth parameters ( root length , main roots number , root fresh and dry weights) compared with control treatment which gave the least means .Humic acid spraying with conc. 3 ml.L-1 had a significant effect on all root growth parameters compared with control treatment . The use of 100 mg.L-1 ascorbic acid had a significant effect on some chemical charcterstictis and yield (total chlorophyll content in leaves, total soluble carbohydrate content in leaves and yield of plant) compared with control treatment which gave the least means. Humic acid spraying with conc. 3 ml. L-1 had a significant effect on some chemical characteristics and yield of plant compared with control treatment which gave the least values. Interaction between both factors showed significant effect on some chemical characteristics and yield of plant.