Analysis of Agrometeorological Efficiencies, Phenothermal Index and Yield of Brinjal Varieties under Different Growing Environment

A field experiment was conducted to evaluate the effect of dates of transplanting and varietal differences on phenological development, agrometeorological indices use efficiencies and fruit yield of Brinjal (Solanum melongena L.) during the autumn–winter season. The experiment was conducted during the year 2020 at Research Farm of Department of Vegetable Science, CCS Haryana Agricultural University, Hisar. It comprised of four dates of transplanting, viz., 5th July (D₁), 15th July (D₂), 25th July (D₃) and 4th August (D₄), and three brinjal varieties, namely Hisar Shyamal, HLB-12 and BR-112. The study assessed number of days to attain major phenophases, phenothermal index, agrometeorological use efficiencies (HUE, HTUE, PTUE and HYTUE) and fruit yield in Brinjal crop. Results revealed that transplanting dates significantly influenced phenological progression and agrometeorological indices. Early transplanting hastened bud initiation and flowering, while delayed transplanting prolonged phenophases and reduced agrometeorological use efficiencies. Transplanting on 15th July (D₂) recorded the highest fruit yield (271.22 q ha⁻¹), attributed to optimum synchronization of temperature and radiation with critical growth stages, resulting in improved resource-use efficiency. The lowest yield was observed under 4th August transplanting (D₄) due to sub-optimal thermal conditions during reproductive stages. Among varieties, Hisar Shyamal consistently exhibited superior performance with higher agrometeorological use efficiencies, favourable phenothermal indices and maximum fruit yield (276.81 q ha⁻¹), indicating better adaptability to autumn–winter growing conditions. The study concludes that transplanting brinjal around mid-July using the variety Hisar Shyamal is most suitable for maximizing yield during the autumn–winter season under prevalent agroclimatic conditions. Knowledge of phenological stages and weather conditions prevailing helps in preparation of crop weather calendar and agroadvisory services that are helpful to farmers to save their crops from losses.