Effect of addition of humic acid and water stress in some growth traits of wheat plant Triticum aestivium L.

A field experiment was conducted for the cultivation of wheat crop Triticum aestivum L.in one of the fields belonging to the extension farm experiments in Al-Mahnawiya belongingto the Extension Center in Babylon province during the winter season (2017-2018) to studythe effect of adding humic acid in wheat bearing to water stress during branching stage andgrains filling stage, In the experiment, three levels of humic acid were used (0: The controltreatment, 20 kg.ha-1: Added to soil, 10 ml.L-1: Sprayed on the plant) which are symbolized by(H0, H1, H2), respectively. Three water stresses were also used: S0 is the control treatment,(S1) stopping irrigation in the branching stage, (S2) stopping irrigation in the grain fillingstage. The experiment was applied within the classification of the Randomized CompleteBlocks Design (R.C.B.D), in the order of split plots, with three replicates. Wheat seeds (Aba99 cultivar) were cultivated which obtained from Agricultural Research Station in Babylon.Concentrations of nutrient elements have estimated of nitrogen, phosphorus and potassium inpost-harvest soil. Plant height, number of branches, weight of 1000 grains, Biologic yield,grain yield and harvest index, concentrations of nutrient elements (N, P, K) in grain, Proteinand Leaves content of K were also estimated. The depth of irrigation water and its date weredetermined depending on the moisture of the soil and according to the depth of the plant rootsystem and the results were as follows:1. The spraying treatment with humic acid H2 was excelled compared to the controltreatment was significantly increased in most of the growth traits of wheat yield(100.05 cm plant height, 9.33 branches, 48.93 cm2flag leaf area, 49.96 spad unit,chlorophyll index).2. The interaction treatment (H2S0) gave the highest values and for most of the studyindicators of (104.39 cm plant height, 12 branches, 56.80 cm2flag leaf area, 55.20spad unit chlorophyll index)