Published Date: 2003-10-12 23:50:00
Subject: PRO/PL> Vector repellent mulches
Archive Number: 20031012.2563
VECTOR REPELLENT MULCHES
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A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the
International Society for Infectious Diseases
<http://www.isid.org>
Date: 10 Oct 2003
From: Mark D. Laing <laing@nu.ac.za>
Re: Use of UV-reflective mulches to reduce infection by Tomato spotted wilt
tospovirus [see ref. below]
With virology colleagues (da Graca, Cradock & Budnik), we have shown that UV-
reflective mulches also repel aphids, drastically reducing both feeding and
probing by them in sweet pepper (capsicum) and baby marrow (zucchini). Given
that potyviruses are a big problem for both these crops in South Africa (PVY
and Zucchini yellow mosaic virus or Watermelon mosaic virus, respectively),
these repellent mulches resulted in increases in yields of about 100 percent
in most trials, relative to a susceptible control with no mulch, for both
sweet peppers and baby marrow.
Interestingly, organophosphate insecticide applications resulted in increased
aphid probing and therefore increased virus disease levels, relative to the
control. This phenomenon will probably hold true for most non-persistent
viruses that are transmitted during plant probing.
--
Mark D. Laing
Professor and Chair of Plant Pathology
Director, ACCI
University of Natal, PBag X01, Scottsville, 3209
South Africa
Tel/Fax 27-33-260 5524 Cell 082 3724 945
<laing@nu.ac.za> or <mdl@sai.co.za>
[I thank Mark Laing and his colleagues for providing this information.
Plastic UV-reflective mulches have been demonstrated to reduce the incidence
of plant virus diseases transmitted by aphids, thrips, and whiteflies.
Clearly, IPM has much to offer for management of vector-borne plant viruses
and the diseases they cause. - Mod.DH]