Nitrogen levels and growth regulators effect on wheat (Triticum aestivum) lodging, productivity and profitability under restricted irrigation in a Vertisols of Central India

The field experiment was carried out during rabi seasons of 2019–20 and 2020–21 at Research Farm of ICARIndian Agricultural Research Institute, Regional Station, Indore (M.P). A total nine treatments consisted of absolute control, 50%, 75%, 100%, 125%, 150% doses of recommended N, 100%, 125% and 150% N along with Growth regulators (Grs) spray were laid out in randomized block design with three replications under restricted irrigation condition. Pooled analysis revealed that spray of Grs along with 100 to 150% of recommended N significantly decreased the plant height and ultimately reduced lodging. However, maximum grain yield (4.40 t/ha) recorded with 100% N was statistically at par with 100 and 150% of N applied along with Grs but significantly higher over rest of the treatments. Wheat crop was lodged only in the plots, where nitrogen was applied @ 125 and 150% of the recommended N and lodging score was 5.23 and 12.53, respectively. Application of Grs recorded significantly higher wheat yields only when crop lodged or lower N levels. Highest values of net returns (` 85,114/ha), B:C ratio (2.73), energy productivity (256.9 g grain/MJ), energy responsiveness (7.84 MJ/Re), agronomic N-use efficiency (20.5 kg grain/kg-N applied), physiological N-use efficiency (38.5 kg grain/kg N uptake) and apparent recovery efficiency (66.5% N uptake/kg N applied) were recorded at 100% N, however, maximum values of energy ratio (9.46) was obtained with 100% N + Grs, partial factor productivity (68.0 kg grain/kg N applied) in 50% N, nitrogen harvest index (75.0%) under 75% N applied and total N uptakes (125.7 kg) as well as crude protein yield with 150% N + Grs. Overall, concluded that application of growth retardants, viz. 0.2% Chlormequat chloride + 0.1% Tebuconazole was found effective in shortening of wheat plant and reduced lodging but did not improve productivity and profitability under restricted irrigation condition in Vertisols of Central India.