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TOMATOSPOTTEDWILTVIRUS
In the realm of virus diseases, another problem dreaded by industrial and ta-
ble tomato producers is a disease known as tomato spotted wilt virus, caused by
several strains of tospoviruses. Agronomist Mirtes Lima clarifies that the virus is
transmitted by insects like thrips, and there are two main strains of them in Brazil.
“The name of the disease stems from the fact that the initial symptoms appear on
the highest portion of the plant”, she explains. The fruits are affected by necrotic
and chlorotic ring spots, and lose their commercial value.
According to Mirtes, one of the most efficient manners of keeping these vi-
ruses under control is to carry out the so-called insect management procedure.
Nonetheless, she recalls that in the case of thrips this is more complicated, once
they affect several plant species, like vegetables, ornamental plants and even we-
eds – there are upwards of one thousand host plants in the world. Furthermore,
as these insects are very small, they hide between the leaves, and find protection
against the pesticides. An efficient alterative for those who produce tomatoes is
to grow cultivars that have resistance to tospovirus infections.
Vegetables has work in progress on several
Virology fronts, with the identification of the
virus, evaluation of their diversity, manage-
ment and epidemiologic studies and studies
that lend support to research on enhance-
ment in pursuit of more resistant cultivars.
“It takes years of dedication to achieve the
results expected by the farmers”, she argues.
While science is doing its job, other mea-
sures could be implemented by the tomato
farmers to find a way around the problems
brought about by the whitefly. One of the
possibilities could be the introduction of the
so-called sanitary gap (total absence of any
tomato plant), from November to January,
intended to reduce the source of viruses at
tomato planting time.
