Changes in fungal and bacterial populations in soil treated with two triorganotin(IV) compounds

Abstract

AbstractThe effects of two triorganotin(IV) compounds, diphenylbutyltin bromide (Ph2BuSnBr) and triphenyltin chloride·triphenylphosphine oxide (Ph3SnCl·Ph3PO), on soil bacterial and fungal populations were compared with that of Thiram and the commercial triorganotin fungicide ‘Brestan’ (triphenyltin acetate, Ph3SnOAc). Soil fungal populations were reduced most by Thiram, then by Ph3SnCl·Ph3PO, Ph2BuSnBr and Ph3SnOAc, in that order. Following the application of the compounds, there was a marked increase in the bacterial population in soil, the increase being greatest with Thiram and least with Ph3SnCl·Ph3PO. The triorganotin(IV) compounds were less harmful to soil fungi than Thiram. In Thiram‐treated soil, recolonization was slower than in soil treated with the triorganotin(IV) compounds. More species of fungi were tolerant to and persisted after application of the triorganotin(IV) compounds compared with Thiram. Among the fungi that were tolerant to the triorganotin(IV) compounds were cellulolytic species such as Trichoderma.