Abstract
The main emphasis of this research was to evaluate ability of Trichoderma species in field conditions to improve sunflower growth and reduce the disease severity cause by Macrophomina phaseolina (Tassi) Goid. Conidia of four different Trichoderma species namely, T. pseudokoningii, T. longibrachiatum, T. harzianum and T. viridi were coated on the seeds of sunflower before sowing in soil; soil was naturally infested with M. phaseolina (6-9 sclerotia per g of soil). The data of plant growth and M. phaseolina infection was recorded at 30 and 60 days of sowing. It was recorded that T. viridi treatment on sunflower elicited better growth of plant in terms of germination, plant length, plant weight, vigor index, petiole of the smallest and the largest leaf, area of small and the large leaf and stem diameter after 60 days of treatment. It was followed by T. longibrachiatum. The colonization of Macrophomina phaseolina was greatly reduced after 30 days of seed treatment with T. harzianum.
