Document Type : Research Paper

Authors

• Gholamhosein Eslamnia ¹
• Mohammad Reza Moradi Telavat ²
• SeyedAtaollah Siadat ³
• Khalil Alami-Saeid ⁴
• Ali akbar Saneinejad ⁵

¹ Agricultural Sciences and Natural Resources University of Khuzestan

² Associate Professor, Department of Plant production and Genetics, Faculty of Agriculture, Agriculture and Natural Resources University of Khouzestan, Iran

³ Professors of Agronomy and Plant Breeding Department, Ramin Agriculture and Natural Resourses University,

⁴ Department Plant Production and Genetics, Agriculture Faculty, Agriculture and Natural Resources University of Khuzestan

⁵ Safiabad Agricultural Research and Education and Natural Resources Center

Abstract

Fodder corn varieties are divided into three classes including: I. early varieties with a life period of less than 85 days, II. medium varieties with a life period between 85-135 days and late varieties with a life period of more than 135 days. Optimum planting density is one of the important factors to achieve the highest yield according to the climatic conditions of each region and especially the cultivated cultivars..Commercial varieties of corn for cultivation in different regions of the world for the production of seeds and fodder include hybrid varieties that are supplied annually by seed production companies for planting in farmers' fields. Therefore, investigating the growth, performance and physiological adaptation characteristics of corn lines in different management and agricultural conditions can lead to the identification of optimal management of the desired lines for the production of corn hybrids. Therefore, in order to investigate the ecophysiological responses of different corn lines to the planting density in the north of Khuzestan, an experiment was conducted in the summer of 2018 and 2019 at the Agriculture and Natural Resources Research and Training Center in Safiabad, Dezful, Khuzestan province. This research was conducted as a two-factor factorial experiment in the basic design of randomized complete blocks with three replications. In this experiment, plant density (60, 78 and 110 thousand plants per hectare) as the first factor in the main plots and genotypes (lines SD-95-11, C3-95-5, C3-95-15, C4-95-2, C4-95-3 and control line MO17) were investigated as the second factor in the sub-plots. The examined traits included leaf area index, leaf specific area, leaf chlorophyll, plant height, yield and yield components, harvest index, and biological yield. The results showed a significant difference between corn lines in response to plant density per unit area of the field. According to the comparison results, the highest seed yield was observed at a density of 110 thousand plants per hectare and line 103 (2115 kg per hectare) and the lowest seed yield was observed at a density of 60 thousand plants per hectare and line 119 (1030 kg per hectare). The results of the statistical analysis obtained from this research showed that the density of 110 thousand plants per hectare in most of the measured traits had the highest value of that trait and was the best planting density for the tested lines. Among the morphological traits affecting plant growth, specific leaf area showed a positive and significant correlation with biological performance and grain yield. Also, line number 103 was selected as the best line that can be used in the corn improvement program in hot and dry regions of the country. Achieving the appropriate density in corn lines can be very important for individuals or companies that are active in the field of seed production, because in this field pure maternal and paternal lines are used. On the other hand, among the 6 lines used, line number 103 was selected as the best line that can be used in the corn improvement program in hot and dry regions of the country.

Keywords

• Biological yield
• Ecophysiology
• Grain yield
• Specific leaf area
• Warm and dry regions

Main Subjects

• A: Agronomy