1. Joint International Research Lab. of Agriculture and Agri‐Product Safety of the Ministry of Education of China Yangzhou University Yangzhou 225009 China
2. Dep. of Agronomy, College of Agricultural and Environment Science Univ. of Gadarif
3. Dep. of Agronomy, College of Agricultural Studies Sudan Univ. of Science and Technology Khartoum 13311 Sudan
4. Faculty of Agriculture Univ. of Khartoum 11115 Khartoum Sudan