Wheat is the second most important food grain of India next only to rice and it is a staple diet of people. It contributes 35% of the total food grain production of the country. In India, wheat is cultivated over an area of 28.17 million hectares with a production and productivity of 73.70 million tones and 26.17 qha^-1, respectively (Anonymous, 2007). India alone produces 13% of world’s wheat. Green revolution has enabled India to make about four fold increase in food production during the last 50 years, whereas before green revolution annual wheat imported touched 10 million tones and India was a beggar bowl. Uttar Pradesh, an important wheat growing state of India, has an area of 9 million hectares under wheat cultivation with a production of 22.51 million tones and productivity of 25.02 q ha^-1 (Anonymous, 2005). The lower productivity could be attributed to the fact that under intense cereal-cereal cropping system and immense use of inorganic fertilizers, especially nitrogen, there has been great depletion of soil fertility. The role of macro and micro nutrients is crucial in crop nutrition for achieving higher yields (Raun and Johnson, 1999). The soils of India are deficient in nitrogen and are supplemented with chemical fertilizer for enhancing the crop productivity. Nitrogenous fertilizers play a vital role in modern farm technology, however only 20-50% of the soil applied nitrogen is recovered by the annual crops (Bajwa, 1992). The left over nitrogen is lost from the soil system through denitrification, volatilization and leaching. The partial and in-efficient use of nitrogen results in lower crop harvests.  Moreover, fertilizers are energy intensive to produce and are very expensive. The present price hike of fertilizers is one of the main constraints to increase the economic yield of crops. Thus efforts are needed to minimize its losses and to enhance its economic use. Foliar fertilization, that is nutrient supplementation through leaves, is an efficient technique of fertilization which enhances the availability of nutrients. A favourable balance of macro and micronutrients is required for optimum crop production. However, the nutrient imbalances can occur due to non-judicious and liberal use of major nutrient and presence of low levels of micronutrients. Zinc is known to be involved in the synthesis of Indole-3-acetic acid thereby indirectly involved in elongation of stems, whereas manganese plays an active role in the photolysis of water in the light reaction of photosynthesis.  Boron functions in cell wall formation, transport of sugars, flower retention and pollen formation thereby improving grain production. Maleic hydrazide, a known growth inhibitor, has been found to be involved in the improvement of growth at very low concentrations. Similarly salicylic acid improves the transport and uptake of ions, induces changes in chloroplast structure and is involved in growth and development, photosynthesis and respiration. Since the deficiency of micronutrients viz. zinc, boron and manganese is widely noticed in wheat so their foliar spray in a mixture can improve the yield.

The experiment was conduct at Crop Research Farm, Department of Agronomy, Sam Higginbottom Institute of Agriculture, Sciences and Technology AllahabadIndia during rabi2007-2008 and 2008-2009. The soil of the experimental field was sandy loam in texture, low in available nitrogen (221 kg ha^-1), medium in available phosphorous (14.4 kg ha^-1) and potassium (253.0 kg ha^-1) with pH 7.9 (Alkaline) and 0.27% organic carbon. Variety PBW-443 was chosen for the study. The experiment comprised of two factors (four nitrogen levels viz. N₁:30 kg ha^-1, N₂:60 kg ha^-1, N₃:90 kg ha^-1, N₄:120 kg ha^-1 and four foliar spray of nutrient mixture vizF₁: 2% DAP + 1% KCl, F₂: 2% DAP + 1% KCl + nutrient mixture, F₃: 2% DAP + 1% KCl + 100 ppm salicylic acid and F₄: 2% DAP + 1% KCl + 100 ppm maleic hydrazide) laid out in randomized block design replicated thrice (NB: Nutrient mixture = 0.5% MgSO₄, 0.2% ZnSO4, 0.2% MnSO4 and 0.1% Borax, DAP = Di-ammonium phosphate  and  MOP= Murate of potash). A uniform dose of phosphorous and potassium at the rate of 60 and 40 kg P₂O₅ and K₂0/ha, respectively and half dose of nitrogen as per treatments was applied as basal at the time of sowing while as remaining half dose of nitrogen was applied in two equal splits, one each at 30 DAS and tillering stage as per treatment. Nitrogen, phosphorous and potassium was applied through urea, DAP and MOP. Foliar application of different nutrient mixtures was applied at full vegetative growth to each plot as per treatment. Nutrient analysis in grain and straw was carried out by taking five plants from each treatment at harvest and then oven dried at 60-65°C to a constant weight. The dried samples were finely ground and passed through 2mm sieve. Nitrogen content in grain and straw samples was determined by Macro Kjeldahl method, phosphorous content was determined by Colorimetric method (Jackson, 1973) and potassium content was determined by Flame photometer method (Toth and Prince, 1949). Soil sample from each plot was drawn to a depth of 15 cm after the harvest of crop and subjected to chemical analysis for available nitrogen (alkaline potassium permanganate method by Subbiah and Asija, 1956), available phosphorous (Olsen et al., 1954) and available potassium (Flame photometric method by Toth and Prince, 1949). Economics of different treatments was worked out on the basis of grain and straw yield per hectare. The cost of input and output was estimated as per prevailing market rates. The data obtained in respect of various observations was statistically analysed by method described by Cochran and Cox (1963). The significance of “F” and “t” was tested at 5% level of significance.

Based on the results of the experiments carried out during two consecutive years, it may be concluded that nitrogen@ 120 Kg ha^-1 and (2% DAP + 1% KCl + Nutrient mixture) was found best to increase the yield and nutrient content and uptake of nitrogen, phosphorus and potassium.

The author(s) did not declare any conflict of interest.