%0 Journal Article %T Integration between Compost, Trichoderma harzianum and Essential Oils for Controlling Peanut Crown Rot under Field Conditions %A Mokhtar M. Abdel-Kader %A Faried Abdel-Kareem %A Nehal S. El-Mougy %A R. S. El-Mohamady %J Journal of Mycology %D 2013 %I Hindawi Publishing Corporation %R 10.1155/2013/262130 %X The effect of T. harzianum and some essential oils alone or in combination with compost on the peanut crown rot disease under field conditions was evaluated. Under laboratory conditions, results indicated that all concentrations of essential oils significantly reduced the growth of A. niger. Complete reduction was obtained with thyme and lemongrass oils at 0.5%. All T. harzianum isolates significantly reduced the growth of A. niger. The highest reduction was obtained with isolate no. 1 which reduced the growth by 81.1%. Under field conditions, results indicated that all treatments significantly reduced the peanut crown rot disease. The highest reduction was obtained with combined treatments (compost + T. harzianum + thyme and compost + T. harzianum + lemongrass) which reduced the disease incidence at both pre- and post-emergence growth stages, respectively. Similar trend corresponding to the previous treatments significantly increased the peanut yield which calculated as an increase in yield more than 75.0 and 80.0 during two growing seasons, respectively. It could be suggested that combined treatment between biocompost and essential oils might be used commercially for controlling peanut crown rot disease under field conditions. 1. Introduction Peanut (Arachis hypogaea L.) is attacked by certain soil borne fungi causing root diseases. The main pathogen responsible for crown rot incidence of peanut was reported to be Aspergillus niger [1]. Crown rot of peanut was found in the sandy and reclaimed soils in Egypt [2, 3]. Also, it was reported that the fungus Aspergillus niger may cause seed rot and preemergence dampingoff of seedlings; the most obvious symptom is the sudden wilting of young plants [4¨C6]. The economic importance of Aspergillus crown rot is difficult to assess. Generally scattered plants are affected, although stand losses of 50% have been reported in isolated fields [7]. In Egypt, due to the economic importance of peanut, the farmers repeat planting even in the same land, which leads to a high buildup of pathogens, causing serious losses that could reach up to 18% [3]. As the management strategy followed by the farmers was considered to be an unwise, intensive use of fungicides, this strategy was not a satisfactory solution for controlling root rot disease. An investigation of crown rot disease is considered particularly important in light of its wide prevalence in Egypt, particularly in sandy soils. The application of biological controls using antagonistic microorganisms has proved to be successful for controlling various plant diseases in %U http://www.hindawi.com/journals/jmy/2013/262130/