© by PSP Volume 25 – No. 6 / 2016, pages 2113-2120 Fresenius Environmental Bulletin 2113 STABILITY OF MODIFIED DOUBLE CROSS MAIZE HYBRIDS FOR YIELD PARAMETERS ACROSS FOUR ENVIRONMENTS Syed Majid Rasheed 1,2 , Hidayatur Rahman 1 , Ikramullah 2 , Zafar Hayat Khan 3 , Muhammad Ali 4 , Syed Saleem Shah 2 , Wajid Ali Shah 3 , Manzoor Ahmad 3 , Tariq Shah 5 , Amjad Iqbal 6 , Arshad Ali Khan 6 and Farooq Shah 6,c 1 Department of Plant Breeding and Genetics, Khyber Pakhtunkhwa (KP) Agricultural University Peshawar Pakistan. 2 Department of Plant Breeding and Genetics, Bacha Khan University Charsadda, Khyber Pakhtunkhwa, Pakistan. 3 Department of Agronomy, Bacha Khan University Charsadda, Khyber Pakhtunkhwa, Pakistan. 4 Department of Biotechnology, Bacha Khan University Charsadda, Khyber Pakhtunkhwa, Pakistan. 5 College of Economics and Management, Huazhong Agricultural University, Wuhan, Hubei 430070, China. 6 Department of Agriculture, Abdul Wali Khan University Mardan, Khyber Pakhtunkhwa, Pakistan. ABSTRACT A study to investigate the stability in yield and other morphological parameters associated with modified double cross maize hybrids compared with their respective standard parental hybrids across three locations of Khyber Pakhtunkhwa that is, Agricultural University Peshawar (AUP), Agricultural Research Station (ARS), Baffa, (Mansehra) and Cereal Crops Research Institute (CCRI), Pirsabak (Nowshera), was conducted during 2008-2009. Production of modified double cross hybrids of maize having improved yield was carried out during spring crop season of 2008 at Malakandher Research farm of KP Agricultural University Peshawar. Genotype x environment interaction was studied for yield and yield parameters in five modified double cross maize hybrids and their respective parental maize hybrids. Genotype main effect was highly significant for all the parameters except anthesis-silking interval (ASI), while significant genotype x environment effect was observed for all parameters. The genotype x environment (linear) interaction component showed high significance for all the characters studied except ear diameter and 300- kernel weight. This indicated significant differences among the genotypes for linear response to environments. Based on stability parameters and over all mean, the performance of modified hybrid P-3025 excelled other parental hybrids as well as modified hybrids. Selection of modified hybrid P- 3025 for ear length, fresh weight plot -1 and grain yield could enhance the grain yield in the target environments. KEYWORDS: Stability analysis, modified double cross maize hybrids, genotype x environment interaction, yield and related traits INTRODUCTION Maize being the highest yielding cereal crop in the world is of significant importance for countries like Pakistan, where rapidly increasing population has already out stripped the available food supplies. In Pakistan maize is third important cereal after wheat and rice. Maize accounts for 4.8% of the total cropped area and 3.5% of the value of agricultural output. In Pakistan maize is planted on an area of 1.016 million hectare with an average production of 3037 kg ha -1 . In Khyber Pakhtunkhwa (KP) province maize is grown on an area of 0.5161 million hectares and average production of 1780 kg ha -1 [1]. Maize in Pakistan is cultivated as a multipurpose food and forage crop, generally by resource poor farmers using marginal land, limited inputs, with significant portion of harvest distant for home/farm consumption. Increased maize production per unit area is the primary objective in most of the maize-breeding programs which can be achieved by growing improved cultivars and adopting improved package of production technology. In spite of maize great potential for high yield, its yield in Pakistan in general and in KP in particular is very low as compared to other maize producing countries of the world. Some of the reasons for this lag in productivity are availability of superior maize germplasm, lack of production technology, unavailability of suitable maize hybrids and varieties for the target environments as well as high prices of maize hybrids. The production of superior hybrid seed is a lengthy, time consuming and laborious job, and the hybrids available in the market are quite expensive and beyond the reach of an ordinary farmer. As the standard single and double cross hybrids are comparatively expensive, therefore some new avenues need to be explored to produce