Abstract

An emerging problem for the wider adoption of anise plantations in Egypt is the damage caused by the rust fungus. The detailed description and taxonomic studies (using light and scanning electron microscopy) show that such an obligate parasite fungus (Puccinia pimpinellae) is autoecious microcyclic (uredinial-telial stage only). Among tested Apiaceae plants, the host range test proved the specificity of the rust fungus to anise. To the authors' knowledge, this is the first investigated record of a rust fungus on P. anisum plants in Egypt. The effectiveness of some plant resistance elicitors and two active chitinase producers, i.e. Bacillus subtilis Bio4 and Trichoderma harizianum Ch4 (both of them recorded the highest clear zone/colony size ratio on chitin agar plates), in controlling anise rust disease and on growth and yield of anise was evaluated in two successive growing seasons. Spraying chitosan  at 1000 ppm was the most potent in reducing disease severity (DS) and incidence (DI), as well as improving plant height, chlorophyll content, inflorescence no. plant^-1 (74.2 and 76), 1000-fruit weight (2.94 and 2.83 g) and anise yield (646.8 and 670.0 kg fed.^-1), during both seasons. B. subtilis Bio4 and T. harizianum Ch4 showed a moderate effect on the tested parameters.

Key words: Pimpinella anisum, rust, Puccinia pimpinellae, biological control, elicitors, chitinase.