Effect of humic acid and seaweed extract rates on yield and yield components of barley (Hordeum vulgare L.)

Abstract

The present study was carried out at the Agricultural Experiment Farm, Faculty of Agriculture (Saba-Basha), Alexandria University, in 2022/2023 winter season to investigate the effect of humic acid levels (0, 6 and 12 k/fed) as soil application before the first irrigation as main-plot and seaweed extract (0, 3 and 6 l/fed) as foliar application before the second irrigation as sub-plot, on growth, yield, yield attributes and grain protein content of six-rowed barley ( Hordeum vulgare L.), Giza 2000 variety. The experimental design was R.C.B.D. in split plot arrangement using three replicates. Obtained results indicated that increasing both humic acid and seaweed extract levels up to 12 kg/fed and 6 l/fed, respectively, significantly and gradually increased all the studied traits. The tallest plants (80.87 and 78.48 cm), highest number of pikes/m 2 (280.33 and 282.42), highest number of spikelets/spike (47.39 and 46.09), heaviest 1000-grain weight (37.65 and 35.82 g), highest grain yield (4.08 and 3.87 t/fed.), biological yield (9.62 and 9.06 t/fed.), harvest index (42.41 and 42.72 %) and grain protein content (8.70 and 8.88 %) resulted from application both humic acid and seaweed extracts at (12 kg and 6 l/fed.), respectively. Interaction between humic acid and seaweed levels had significant effect on all the studied traits of Giza 2000 barley variety. Combination between 12 kg/fed. humic acid, applied before the first irrigation and 6 l/fed. seaweed extract, sprayed before the second irrigation produced the highest values of the studied characters, except number of spikelets/spike, harvest index and grain protein content.