Assessment of various humic acid and sulfur 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 per ha and row to row distance of 30 cm was used. Various combinations of humic acid (0, 1, 2, 3, 4, 5, and 6 kg per ha) and sulfur (0, 15, 30 and 45 kg per ha) were used. Ammonium sulfate (NH4)2SO4 was used as a source of sulfur. Recommended rates of NP (135:60 kg per ha) 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 ATA-HABIB- 2010 was studied during the experiment. Number of spike m-2, grains per spike, 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 per spike (5) and biological yield (1380 kg per ha) with humic acid @ 1, 6 and 3 kg per ha as compared with 416, 51 and 9614 kg per ha respectively with 0 kg HA per ha. Similarly, higher 100 grains weight (4.72 g) and grain yield (4325 kg per ha) were produced with HA @ 2 kg per ha as compared with 42.01 g and 3208 kg per ha at 0 kg per ha, respectively. Sulfur @ 15 kg per ha produced higher spikes m-2 (513), grains per spike (54), grain (4208 kg per ha) and biological (1242 kg per ha) yields as compared 458, 51, 3858 kg per ha and 10312 kg per ha with 0 kg S per ha. Similarly, S @ 30 kg per ha produced higher 100 grains weight (4.85 g) as compared with 42.37 g and 43.47 g produced with 0 and 15 kg S per ha respectively. Highest grain yield (447 kg per ha) of wheat was produced in the interaction of 1 kg HA and 30 kg S per ha. Based on the results, it is recommended that humic acid @ 1 kg per ha in combination with sulfur @ 30 kg per ha may be applied to get higher grain yield in wheat in the agro-climatic conditions of Peshawar.