Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Protection of sugar beet seed plants against Phoma betae (Frank). Part I. Effect on seed health and quality.

Abstract

In an attempt to reduce infection of sugarbeet seeds by P. betae [Pleospora betae], field trials were conducted on IHAR (Plant Breeding and Acclimatization Institute) breeding materials in ZDHiAR Kończewice, Poland during 1988-90. Out of the tested fungicides (triadimefon, triadimenol, imazalil, fenpropimorph, flutriafol, bupirimate, propamocarb, iprodione, fenarimol, captafol, prochloraz, propiconazole, thiram and carboxin), only Zaprawa Oxafun T (a.i. thiram 37.5% and carboxin 37.5%) and Sportak 45 EC (a.i. prochloraz 450 g/l) showed fungitoxic activity against the mycelium and pycnidia of P. betae. These fungicides were non-phytotoxic to sugarbeet seeds: their application did not negatively affect germination. Zaprawa Oxafun T at 2 kg/ha and Sportak 45 EC at 2 l/ha and 3 l/ha (1989-90) were used for spraying seed plants. The average level of seed infection in control samples in the succeeding years was 84.4% (1988), 24.2% (1989) and 55.5% (1990). Zaprawa Oxafun T reduced seed infection only in the dry season of 1989. Leaf spraying with Sportak 45 EC at a dose of 2 l/ha decreased the level of P. betae infection by 58.8% (1988), 63.0% (1989) and 43.5% (1990), as compared with the infection level of control samples (taken as 100%). Deep-seated infection of seeds from control plants, 49.3%, was reduced to 19.8% by spraying with Sportak 45 EC at a dose of 2 l/ha. Germinability of seeds from protected plots was increased by 3-4% compared with seeds from unprotected plots. Growing P. betae mycelium for 1 year on the medium containing 5 ppm of a.i. of the tested fungicides did not alter the susceptibility of this pathogen to these fungicides.