Integrated control of Allium white rot with Trichoderma viride, tebuconazole and composted onion waste

Abstract

Two isolates of Trichoderma viride (L4 and S17A) were assessed for biological control of Allium white rot (AWR) with different onion accessions and cultivars, alone and in combination with a tebuconazole-based seed treatment or composted onion waste. In glasshouse tests, 23 new bulb-onion accessions from previous work to detect resistance to Sclerotium cepivorum showed no differences in susceptibility to AWR but, when combined with S17A, disease was reduced by up to two-thirds over all accessions. Trichoderma viride L4 and S17A also reduced the proportion of infected plants for five commercial bulb-onion cultivars and one advanced breeding line by at least one-third. Further glasshouse tests using a salad-onion cultivar showed that L4, S17A, tebuconazole or composted onion waste controlled AWR and at least halved the proportion of diseased plants. Combination treatments of T. viride with either tebuconazole or compost enhanced control and, in some treatments, disease was almost eliminated. In field trials, control of AWR by S17A was significant for 17 out of 18 individual or mixed bulb-onion accessions, with disease reduced overall by more than half. In another field experiment, S17A failed significantly to reduce AWR for two out of three commercial bulb-onion cultivars, while tebuconazole reduced the final proportion of AWR-infected plants over all cultivars from 0·47 to 0·09. Combining S17A and tebuconazole resulted in a similar level of AWR to using tebuconazole alone. The use of T. viride in an integrated strategy with other treatments to enhance control of S. cepivorum is discussed.

Endomycorrhizal Fungi and <i>Opuntia ficus-indica</i> Seed Germination on a Lunar Regolith Simulant

“…This fungus is known for its protective function in different plants and is now exploited in agriculture as a natural biocontrol agent. T. viride and other Trichoderma species were successfully tested against pathogens of the onion [25]. In Turkey Trichoderma species have been introduced as a biocontrol agent against soil-borne diseases of several crops [26].…”

Integrated Management of Garli c White Rot (Sclerotium cepivorum Berk)Using Some Fungicides and Antifungal Trichoderma Species

“…Box 37, Ambo, Ethiopia, Tel: +251-(0)911-044929, Fax: +251-(0)112362325; E-mail: tarikuh2012@gmail.com, tarikuh2002@yahoo.com of all possible combinations with the objective to achieve integrated management of garlic white rot using four Trichoderma spp of PPRC isolates and two recommended fungicides [Apron Star 42 WS and Tebuconazole (Folicur 250 EC] under greenhouse condition. The Sclerotium cepivorum sclerotia propagules were maintained and undertaken in pot experiment (Seedling bioassay), as described earlier by [23,29]. Inoculated local garlic clove with S. cepivorum and un-inoculated alone were used as positive and absolute control, respectively.…”

Biological Control of Onion White Rot Disease Caused by Sclerotium cepivorum

“…have a lot of mechanisms to reduce disease severity and increase vegetative growth for plant such as, as production of growth hormones, solubilization of insoluble minor nutrients in soil and increased uptake and translocation of less-available minerals (Kleifeld and Chet, 1992;Near et al, 1994). Trichoderma strains grow rapidly when inoculated in the soil, because they are naturally resistant to many toxic compounds, including herbicides, fungicides and pesticides such as DDT and phenolic compounds (Chet et al, 1997 bromide, benomyl, captan or other chemicals (Vyas and Vyas, 1995).Some researchers also reported that combinations of tebuconazole and a biocontrol agent enhanced the control of onion white rot (Clarkson et al, 2006).…”