mobin, new maize cultivar with tolerant to heat stress

a breeding program was started in safiabad agricultural research center in 1999, to produce an improved maize hybrid with a relative heat stress tolerance. consequently at 2005 a few s6 lines with having moderately tolerance to high temperature were obtained. these combinates were then evaluated for three consecutive years in three sub-tropical regions of the country includes khzestan, ilam and kerman (jiroft) in the semi final, final and on-farm experiments. these experiments resulted to selection of a hybrid with a relatively high temperature tolerance (produced by crossing of sld45/1/2-1 × slh2/29/14/2-4/1 lines). this hybrid was 12 days physiologically early-mature than sc704 hybrid sc704 (control), and heat stress tolerance due to the shorter of tassel to silk initiation period (1.5 days in average). this line had 10500-11500 kg ha-1 average seed yield and non-significant difference with the control in experiments. now because of farmers enthusiasm, seed production level of this hybrid is about 200 ha and consequently over 25000 ha of farms are planting by this line across tropical regions of the country