Universal Journal of Agricultural Research 2(2): 83-88, 2013 http://www.hrpub.org DOI: 10.13189/ujar.2014.020208 Effects of Fungal Strains on Seeds Germination of Millet and Striga Hermonthica Mohammed M. Hassan 1,* , Hussien M. Daffalla 2 , Hanan Ibrahim Modwi 1 , Magdoleen G. Osman 2 , Inas Ishag Ahmed 1 , Migdam E. Abdel Gani 1 , Abdel El Gabar E. Babiker 3 1 Environment and Natural Resources Research Institute, Khartoum, Sudan 2 Commission for Biotechnology and Genetic Engineering, Khartoum, Sudan 3 Sudan University of Science and Technology, College of Agricultural Studies, Khartoum, Sudan *Corresponding Author: mohkadis@yahoo.com Copyright © 2014 Horizon Research Publishing All rights reserved. Abstract The effects of aqueous extracts of three fungi were evaluated on three millet varieties and Striga hermonthica seed germination. Striga seeds were inoculated with Trichoderma viride, T. harzianum and Pencillium spp. in presence of GR24. T. viride at concentration 25% improved significantly Striga germination (90.3%) compared to control (85.4%) in presence of 0.1 ppm GR24. However the same fungi T. viride at 75% + 0.01 ppm GR24 was significantly inhibited Striga seed germination (0%). Seeds of three millet verities were treated with 0-75% concentrations of T. viride or Pencillium spp. The results showed that variety MCSRC recorded 100% final germination (FG) in all treatments. However, Mallit and El-Fasher varieties showed 100% FG when treated with the concentrations 0% (control), 25% or 50% only and decreased with application of 75% inoculums. The maximum viguor index (805) occurred on El-Fasher with 50% T. viride compared to its control (787). The minimum viguor index (335) was recorded by Mallit in 75% Pencillium compared to its control (752). When comparing the three varieties in germination rate, MCSRC showed increase in germination rate with increasing inoculums concentration, while Mallit and El-Fasher showed decrease with increasing inoculums concentration. Mallit recorded the highest shoot length (8.18 cm) with 75% T. viride. On the other hand, El-Fasher recorded the highest root length (15.23 cm), shoot dry weight (8.35g) and root dry weight (4.7g) compared with control. Generally, MCSRC appear to be more tolerant to fungal application in the highest concentration followed by El-Fasher and Mallit although no significant differences were observed among millet varieties. Keywords Germination, Millet, Striga, Trichoderma, Pencillium. 1. Introduction Biological control is considered an attractive approach for suppressing parasitic weeds. Some species of fungi can secrete substances or metabolites that have very specialized activity, being lethal to a particular group of life forms. Since 1963, fungi have received great attention as biocontrol organisms against pests (1). Extensive work has been carried out in order to identify fungi with toxic metabolites potential capabilities as natural herbicides. Thus many screenings for activities of fungi can be found in the literature and some promising agents have been found ( 2; 3). These antagonistic effects could be an alternative strategy to look for natural products that will inhibit the germination of Striga seeds. Bioherbicides can be integrated into intensively managed agriculture production systems because of their potential to yield quick and reliable levels of weed control. The use of phytopathogenic fungi and/or their toxic metabolites to control weeds is interesting since their biocontrol agents are highly specific (4) and their toxic metabolites are possibly natural herbicides (2). Although bioherbicides can be used as the sole option for the management of certain weeds in particular situations, typically they have been used as a minor supplement to conventional chemical herbicides ( 5). A large number of phytopathogenic fungi have been, or are being, evaluated for their effectiveness against parasitic weeds. Despite the large number of micro-organisms surveyed, only some are considered effective candidates to control Striga hermonthica, but so far none of them has been used in large-scale application in the field. Clearly, finding a weed pathogen is only a preliminary step in a long process leading to the development of an effective and safe bioherbicide (6). Trichoderma species are free-living fungi that are growing vigorously in soil and plant root ecosystems (3). They have been widely studied for their capacity to stimulate plant growth or enhance defense mechanisms (7). Regarding plant growth, many Trichoderma spp were confirmed to increase germination rate and percentage of emergence, plant height, leaf area and dry weight (8). Most Trichoderma strains produce toxic metabolites that act as antibiotics or antifungal and compete with wide a range of