This study is primarily related to use humic acid as a soil conditioner and calcium carbide as plant growth regulator. Humic acid improves soil organic matter, water holding capacity, and nutrient use efficiency, whereas calcium carbide is potential source of two gases, acetylene and ethylene. Acetylene acts as nitrification inhibitor while slowly releasing ethylene works as phytohormone. The study shows that plant height, number of flowers, number of green pods per plant, green pod dry weight, shoot and root dry weight, nutrient uptake in fruit of okra plants were positively affected by calcium carbide and humic acid.

Calcium carbide releases acetylene gas upon its reaction with water that is further converted to ethylene in soil due to microbial reduction. Acetylene inhibits the activity of ammonia-oxidizing enzymes involved in the nitrification process, thus resulting in the inhibition of nitrification and denitrification processes and increase in the nitrogen fertilizer use efficiency. A series of studies were conducted with collaboration of Higher Education Commission (HEC), Pakistan during 2008-2011. The outcomes of these studies demonstrated the improvement in growth and yield of vegetable crops through bi-facet action of calcium carbide i.e. as a source of plant hormone, Ethylene as well as nitrification inhibitor, Acetylene. Any formulation of Calcium carbide which leads to slow and gradual release of ethylene and acetylene gases in soil could be useful in improving the nutrient use efficiency as well as growth and yields of vegetables.

This study is primarily related to growth regulators focusing on a major group ethylene produced from a solid i.e. calcium carbide (C2H4). Calcium carbide is best source of two gases, acetylene and ethylene. Acetylene acts as nitrification inhibitor while ethylene acts as phytohormone. Calcium carbide based formulations are effective to augment yield of vegetables especially cucumber. A pot experiment was conducted in the wire house of Institute of Soil and Environment & Sciences; University of Agriculture Faisalabad to evaluate the effect of different rates of formulated (paint coated) calcium carbide (CaC2) on growth and yield of cucumber (Cucumis sativus L.).

Salinity is one of the major constraints, whichhamper agricultural production. The higherconcentration of salts in root zone may stimulateendogenous ethylene biosynthesis in roots, whichconsequently inhibits its growth. One of the majormechanism utilized by plant growth promotingrhizobacteria (PGPR) to facilitate plant growth anddevelopment is the lowering of ethylene levels in theplant roots by deamination of1-aminocyclopropane-1-carboxylic acid (ACC), theimmediate precursor of ethylene in plants. In thegiven study, three pre-isolated bacterial strainshaving ACC deaminase activity were used forinoculation of wheat seeds. Inoculated seeds weresown in salt affected field, fertilized with NPK@120-100-60 kg ha-1, respectively. Data regardingvarious growth parameters and yield parameters wasrecorded at the time of harvesting and statisticallyanalyzed. From data it was concluded that plantgrowth promoting rhizobacteria containingACC-deaminase activity can enhance the growth andyield of wheat under salinity stress field conditionsand the strain ACC10 performs the best.