ASSESSMENT OF VARIOUS HUMIC ACID AND SULFUR LEVELS FOR HIGHER YIELDS IN WHEAT (Triticum aestivum L.)

To assess the effect of various humic acid (HA) and sulfur (S) levels for higher yields in wheat, an experiment was conducted at New Developmental Farm, The University of Agriculture, Peshawar during rabi 2011-12. The experiment was conducted in simple randomized complete block design having three replications. Plot size of 15 m2(5 m x 3 m), seed rate of 120 kg ha^-1 and row to row distance of 30 cm was used. Various combinations of humic acid (0, 1, 2, 3, 4, 5, and 6 kg ha^-1) and sulfur (0, 15, 30 and 45 kg ha^-1) were used. Ammonium sulfate (NH4)2SO4 was used as a source of sulfur. Recommended rates of NP (135:60 kg ha^-1) for were applied. Nitrogen was applied in two split doses i.e. half at sowing and half at first irrigation about 21 days after sowing. Variety ATTA-HABIB- 2010 was studied during the experiment. Number of spike m^-2, grains spike^-1, thousand grains weight, biological yield and grain yield were significantly affected by humic acid and sulfur levels. The interactions of HA x S was significant only for grain yield. Higher spikes m-2 (502), grains spike-1 (55) and biological yield (11380 kg ha^-1) with humic acid @ 1, 6 and 3 kg ha^-1 as compared with 416, 51 and 9614 kg ha^-1 respectively with 0 kg HA ha^-1. Similarly, higher 1000 grains weight (44.72 g) and grain yield (4325 kg ha^-1) were produced with HA @ 2 kg ha^-1 as compared with 42.01 g and 3208 kg ha^-1 at 0 kg ha^-1, respectively. Sulfur @ 15 kg ha^-1 produced higher spikes m^-2 (513), grains spike^-1 (54), grain (4208 kg ha^-1) and biological (11242 kg ha^-1) yields as compared 458, 51, 3858 kg ha^-1 and 10312 kg ha^-1 with 0 kg S ha^-1. Similarly, S @ 30 kg ha^-1 produced higher 1000 grains weight (44.85 g) as compared with 42.37 g and 43.47 g produced with 0 and 15 kg S ha^-1 respectively. Highest grain yield (4447 kg ha^-1) of wheat was produced in the interaction of 1 kg HA and 30 kg S ha^-1. Based on the results, it is recommended that humic acid @ 1 kg ha^-1 in combination with sulfur @ 30 kg ha^-1 may be applied to get higher grain yield in wheat in the agro-climatic conditions of Peshawar.