Survival and proliferation of alginate encapsulated Trichoderma spp. in Egyptian soil in comparison with allyl alcohol soil fumigation

Conidia of Trichoderma harzianum and T. pseudokoningii (Rifai) were formula ted to make alginate pellets with or without 10% cellulose as a food-base m aterial. The formulations were compared for their ability for survival and proliferation of Trichoderma spp. in clay-loamy soil (50% moisture content) with allyl alcohol fumigation (0.05, 0.1 and 0.2 ml/1000 ml space). Tricho derma medium E (TME) containing 100 mug/ml pentachloronitrobenzene (PCNB) w as valuable for isolation and counting of Trichoderma spp. from the tested soil than the Glucose-Czapek's agar medium containing 1:15000 Rose-bengal. The promotive effect of Trichoderma by different doses of allyl alcohol fum igation still enhanced after two-month incubation period. Conidia entrapped in alginate with or without cellulose and introduced into the soil survive d better than conidia added directly to the same soil after three months in cubation period. Sterile soil provided a more favorable environment for the proliferation and survival of immobilized conidia than the non-sterile soi l, and the addition of 10% cellulose increased the survival of the entrappe d conidia more than those prepared without cellulose. Soil fumigation inhib ited the occurrence of other fungal species; however, inoculation of the so il with alginate immobilized conidia or conidial suspension had such inhibi tory effect but in a less extent.