ENHANCING PRE AND POST VEGETATIVE HEAT RESILIENCE AND YIELD POTENTIAL IN THE NEWLY RELEASED MAIZE VARIETY "SAHIWAL GOLD" THROUGH MODIFIED SELECTION

Abstract

Maize is well-anchored crop across the globe due to its nutritional profile, multipurpose usage, and underlying financial benefits. Growing of open-pollinated maize varieties (OPVs) is a traditional trend and is still followed by a huge community of small farmers in most of the developing world. Improvement in yield potential is always inevitable and requires a purposeful and definite strategy. The current climate scenario loaded with heat escalation and extreme fluctuations is creating uncertainty and unsustainability through acute yield losses in domesticated crops. The breeding strategy of Sahiwal Gold (2008-2018) was comprised of four developmental phases i.e. enrichment phase, half-sib selection, pedigree selection, uniformity phase, and field evaluation at various agro-ecological zones of Pakistan. Each consecutive autumn and spring season was utilized to improve yield potential by exploiting pre and post-vegetative heat resilience. Half sib and pedigree selection improved plant features like height (12%), cob length (4.1%), seeds per cob (7.5%), grain (10%), and stalk yield (11.2%) from enrichment to uniformity phase. Sahiwal Gold maintained a high adaption profile across the tested locations and out-yielded the check variety (MMRI Yellow) by 18% and 26% on average in 6 stations and 16 national yield trials, respectively. National yield testing approved its suitability across provinces like Punjab, Khyber-Pakhtunkhwa (KPK), and Islamabad territory under a diverse range of temperatures. Analysis of variance revealed that highly significant interaction between season and genotypes work for plant height, grain, and stalk yield potential. Higher grain yield up to 95 mounds/acre was observed for spring season crop and batter stalk yield results (650 mounds/acre) were assessed during autumn plantation. Twelve (12) feet tall plants with 4 feet long leaves having 75-90% stay green ability provide a good opportunity fodder and grain yield potential at farmer’s field. This work will provide a better understanding to researchers for designing breeding programs for the development of heat resilience germplasm in crops.