Effect Of Plant Spacing And Humic Acid Spraying On Growth And Yield Of Barley

Abstract

A field experiment was conducted during the winter season of 2018_2019 at the Al-Hamdeah research station affiliate to the field Crops Dept.- college of Agriculture - Anbar University to study: effect of plant spacing and humic acid spraying on growth and yield of barley. The layout of the experiment was RCBD design using split plot pattern with three replicates. The main plots included four concentrations of the humic acid (0, 250, 500 and 750 mg.L-1). While the sub-plots included the planting spaces (manually broadcasting (control), 15, 20 and 25 cm between the rows). The results of the statistical analysis showed a significant difference among the planting spaces treatments. The treatment of 15 cm between the rows was significantly superior in most growth and yield parameters, such as number of tillers per square meter, flag leaf area, leaf content of chlorophyll, crop growth rate (CGR) after 80 days of planting, number of days from planting to 50% flowering, spike length, number of spikes per square meter, number of grains per spike, grains yield, harvest index and protein yield, which gave the highest values reached 328.58 tiller.m2, 35 (cm2) , 43.5 (spad), 4.07, 14.9 (gm.m-2.day-1) , 103.5 days, 5.3 (cm), 323.5 (spike.m-2), 45.50 (grain.spike-1), 3.592 (ton.ha-1), 37.88(%) and 329 (kg.ha-1), respectively, compared to the control treatment. The results also showed significant differences among the concentrations of humic acid. The concentration of (500 mg .L -1) was significantly superior compared to the control treatment, with the highest values in most of the growth parameters which mentioned above with values reached: number of tillers per square meter (330.5 tiller.m2), flag leaf area (34.5 cm2), leaf content of chlorophyll (44.7 spad), crop growth rate (CGR) after 80 days of planting (4.26 16 gm.m-2.day-1), number of days from planting to 50% flowering 103.5 days, spike length (5.3cm), number of spikes per square meter (325.5 spike.m-2), number of grains per spike (45.41 grain.spike-1), grains yield ( 4.979 ton.ha-1), biological yield (10.333 ton.ha-1), harvest index (38.66%) protein percentage (10.04 %) and protein yield (397.7 kg.ha-1), respectively. The results of the statistical analysis showed significant differences between the interaction treatments of most studied parameters, ii the treatment (15 cm × 500 mg L-1) gave the highest mean of tillers per square meter (341.67 tiller m-2), leaf content of chlorophyll (50.00 Spad), growth rate (CGR) after 80 days (20.67 gm.m-2.day-1), number of spikes per square meter (337.00 spike.m-2) and biological yield (11.300 ton.ha-1).