In a two growth-cycle survey, 30 annual and 13 perennial weed species
were determined in different sweet pepper ( Capsicum annuum L.)
growing areas of the Limari and Elqui valleys of Coquimbo Region of
Chile (29\ub0 to 30\ub0 S lat). The samples were randomly taken in
and outside tomato fields, with and without crops present, in winter
and spring. A total of 676 weed plants were collected, with a total of
379 samples being analyzed. DAS-ELISA was used to test the presence of
Cucumber mosaic virus (CMV), Tomato spotted wilt virus (TSWV), Alfalfa
mosaic virus (AMV), Potato virus Y (PVY) and Impatients necrotic spot
virus (INSV). A 17% (64) of all collected samples were positive to at
least one virus, of which 7.4% (28) came from symptomatic weeds and
9.4% (36) were from symptomless hosts. Jimsonweed (Datura spp.) was
positive to CMV and PVY; apple-of-Peru ( Nicandra physalodes ) to
AMV, CMV and PVY; black nightshade ( Solanum nigrum ) to CMV and PVY;
sowthistle (Sonchus spp.) to AMV and TSWV; small-flower galinsoga (
Galinsoga parviflora ) to AMV, CMV, TSWV and INSV; common
lambsquarters (Chenopodium spp.) to AMV, CMV, TSWV, PVY and INSV, among
the principle species. Using a relative potential infection index
(IPIR), weeds having highest values were small-flower galinsoga (74.7),
apple-of-Peru (11.2), black nightshade (6.3) and lambsquarters (6.0).
Species such as sowthistle, jimsonweed, bristly mallow ( Modiola
caroliniana ), chickweed ( Stellaria media ) and pigweed (Amaranthus
spp.) had indexes lower than 1.0. Small-flower galinsoga and
apple-of-Peru had more than one virus, and these multiple virus
infections were prevalent over single infections. It is imperative to
control host weeds within cultivated areas and surroundings to reduce
the incidence and dispersal of the viruses in sweet pepper plants.En prospecciones de malezas realizadas durante dos temporadas
agr\uedcolas, 30 especies anuales y 13 perennes fueron determinadas
en cultivos de pimientos ( Capsicum annuum L.) de los Valles de Elqui
y Limar\ued, Regi\uf3n de Coquimbo (29\ub0 a 30\ub0 lat. Sur).
Los muestreos fueron aleatorios dentro y fuera de los potreros, con y
sin cultivo presente, en invierno y primavera. Se recolectaron 676
plantas de malezas, analiz\ue1ndose un total de 379 muestras.
Utilizando la prueba DAS-ELISA se determin\uf3 Virus del mosaico del
pepino (CMV), Virus del bronceado del tomate (TSWV), Virus del mosaico
de la alfalfa (AMV), Virus Y de la papa (PVY) y Virus INSV (Impatients
necrotic spot virus). Un 17% (64) de las muestras fueron positivas al
menos a un virus, de las cuales 7,4% (28) provinieron de plantas con
s\uedntomas y 9,4% (36) fueron hospederos asintom\ue1ticos. Chamico
(Datura spp.) hosped\uf3 a CMV y PVY; nicandra (Nicandra physalodes)
a AMV, CMV y PVY; tomatillo ( Solanum nigrum ) a CMV y PVY;
\uf1ilhue (Sonchus spp.) a AMV y TSWV; pacoyuyo ( Galinsoga
parviflora ) a AMV, CMV, TSWV y INSV; quing\ufcilla (Chenopodium
spp.) a AMV, CMV, TSWV, PVY e INSV, entre las principales. Usando un
\uedndice potencial de infecci\uf3n relativa (IPIR), los mayores
valores se obtuvieron con pacoyuyo (74,7), nicandra (11,2), tomatillo
(6,3) y quing\ufcilla (6,0). Especies como \uf1ilhue, chamico,
pila-pila ( Modiola caroliniana ), quilloi-quilloi ( Stellaria media
) y bledo (Amaranthus spp.), tuvieron \uedndices inferiores a 1,0.
Nicandra y pacoyuyo portaron m\ue1s de un virus y estas infecciones
m\ufaltiples prevalecieron sobre las simples. Controlar malezas
portadoras tanto dentro como en las inmediaciones de los potreros,
resulta imperioso para poder minimizar la incidencia y dispersi\uf3n
de las enfermedades virales en pimientos