Efficacy of Fungicides For The Control of Myrothecium: Roridum On Dieffenbachia Picta Compacta'
Efficacy of Fungicides For The Control of Myrothecium: Roridum On Dieffenbachia Picta Compacta'
Efficacy of Fungicides For The Control of Myrothecium: Roridum On Dieffenbachia Picta Compacta'
The dieffenbachia aroid is dedicated to Ernst Dieffenbachia, a foliage plant was described in 1981 on Aphelandra squarrosa
a 19th century German physician. The genus Dieffenbachia is a Ness. Since then many other foliage plants, including dieffenba-
monocot of the Araceae family that is indigenous to the Caribbean, chia, have been added to the expanding list of susceptible hosts
Central America, and South America. Dieffenbachia is a very (Chase, 1983; Chase, 1997; Daughtrey et al., 1992).
popular interiorscape plant due to low light tolerance, it is easy Lesions on the leaf surface produce irregularly shaped black
to grow and maintain, and its attractive foliar variegation (Fig. 1). sporodochia, with a white fringe of mycelium, that form in con-
Diseases caused by Myrothecium roridum Tode exx. Fr. have centric rings within necrotic areas (Agrios, 1997). The lesions are
been found on many agricultural plants, including ornamental, not confined to the leaf blade but can be found on leaf margins,
vegetable, and agronomic crops (Alfieri et al., 1991; Pirone et tips, and wound sites. These lesions frequently occur all over the
al., 1960). The first description of a Myrothecium leaf spot on small tissue-cultured plantlets (Chase, 1997).
To reduce Myrothecium leaf spot on dieffenbachia in a pro-
duction greenhouse, avoid temperatures between 21 and 27 °C,
keep mechanical wounding to a minimum, and fertilize at the
recommended rate (Chase et al., 1983). However, it is not always
possible to control all of the above factors and the growers must
resort to chemical control fungicides. This is especially true for
shade house nurseries that start their crop from tissue culture or
cutting liners.
Chlorothalonil, Daconil 2787, has been shown to be effective
in controlling Myrothecium on many foliage plants. Excellent
control has been reported on ‘Perfection’ dieffenbachia. Man-
cozeb compounds have been shown to provide excellent control
of Myrothecium leaf spot. These compounds should always be
applied as a preventive treatment to avoid infections from My-
rothecium (Chase, 1997).
The purpose of this research was to test the efficacy of resent fun-
gicides for Myrothecium, especially systemics on dieffenbachia.