Incidence, Distribution and Characteristics of Major Tomato Leaf ...

Incidence, distribution and characteristics of major tomato leaf curl and mosaic virus diseases
crops present at tomato planting play a big role in harbouring whiteflies, which
eventually infest tomatoes. Similar observations were made in Egypt, Cyprus, Lebanon,
Jordan, Saudi Arabia and Israel (loannou et al., 1991; Mazyad et al., 1986; Makkouk et
al., 1979; Nitzany, 1975). Although some whitefly vector-host studies have been
conducted in relation to Cassava mosaic geminiviruses (CMGs) in Uganda (Legg, 1996),
there is a need to establish the relationship between whitefly vector and transmitted
TYLCV in order to develop sound TYLCV management options.
Management of Tomato Yellow Curl Virus
The most effective way of managing Tomato yellow leaf curl virus (sensu stricto) is by
use of an integrated management package, which combines cultural practices, insecticide
application, UV-absorbing plastic films, insect vector proof nets, and variation of weather
conditions like light intensity, photoperiod and temperature (loannou et al., 1985;
Mazyad et al., 1986; Cohen and Antignus, 1994; Perring et al., 1999; Palumbo et al.,
2001; Hilje et al., 2001; Mutwiwa et al., 2005; Zilahi-Balogh et al., 2006; Kumar et al.,
2006). Mazyad et al. (1986), and Chan and Jeger (1994) controlled TYLCV by
eliminating or reducing sources of initial inoculums through uprooting diseased plants.
Chan and Jeger (1994) reported that uprooting was most effective where plants were
sparsely distributed and with minimal contact. This may also relate to young plants
whose canopies are still small. Ioannou et al. (1987) recommended the use of healthy
transplants, and later in 1991 reported successful control of TYLCV by timely planting.
Thus, the whitefly population is low during the rainy season and high in the dry season.
Careful tomato seedling protection against whiteflies in the dry season, and transplanting
at the beginning of the rainy season helped to avoid TYLCV infection. Sharaf et al.
(1986); Prabhaker et al. (1988); Mason et al. (2000); and Palumbo et al. (2001) managed
vector populations by using chemical pest control options, such as Imidacloprid (a
nicotinoid), buprofezin (a chitin synthesis inhibitor), and pyriproxyfen (a juvenile
hormone analog). However, Palumbo et al. (2001) recommend use of cultural and
biological options for controlling B.tabaci because of pest resistance to insecticides.
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