CONTROL OF BOTRYTIS SPP. IN TULIP WITH REDUCED INPUT OF CHEMICAL CROP PROTECTANTS

A.Th.J. Koster, L.J.v.d. Meer
Foliage and flowers of many flowerbulb species can be infected by Botrytis spp. causing the so-called 'fire' disease. At present, these diseases are controlled mainly by weekly sprays of the crops with dithiocarbamate compounds, supplemented with a dicarboximide or benzimidazole compound in three sprays around flowering time.

To reduce the input of chemical crop protectants and to avoid the use of ethylene-thioureum (ETU)-forming dithiocarbamate compounds (e.g., zineb, maneb, mancozeb), which are expected to be banned in the future, field experiments were carried out, in a.o., tulips, with a number of potentially effective, alternative chemicals. We tested chlorothalonil, chlorothalonil plus prochloraz, fluazinam, and CGA 173506 sprayed in low dosages once every fortnight. These compounds were applied alone or in combination with compounds especially active against Botrytis spp., e.g., a dicarboximide and a benzimidazole.

The experiments have shown that fortnightly, low-dosage applications of chlorothalonil, chlorothalonil plus prochloraz, or fluazinam in combination with a low dosage of a compound especially active against Botrytis spp., resulted in a 70–82% reduction of inputs and in Botrytis control at least equal to that of the presently applied spraying scheme.

The full article on 'Control of Botrytis spp. in tulip with reduced input of chemical crop protectants' will be published in: Malathrakis, N.E. (ed.) 1992. Proceedings of the Xth Botrytis symposium, Gouves, Greece (in press).

Requests for reprints should be sent to the first author.

Koster, A.Th.J. and Meer, L.J.v.d. (1992). CONTROL OF BOTRYTIS SPP. IN TULIP WITH REDUCED INPUT OF CHEMICAL CROP PROTECTANTS. Acta Hortic. 325, 809-810
DOI: 10.17660/ActaHortic.1992.325.118
https://doi.org/10.17660/ActaHortic.1992.325.118

Acta Horticulturae