Presencia de diferentes virus del pimiento ( Capsicum annuum L.) en especies de malezas asociadas al cultivo

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

Tolerancia del Tomate (Lycopersicon EsculentumMill.) a Aplicaciones Post Trasplante del Herbicida Halosulfuron-metil

During the 1998/99 season at La Platina Research Regional Center of the National Agricultural Research Institute (INIA) (33\ub034' S lat, 70\ub038' W long, altitude 625 m.o.s.l.), on a loamy-clay soil, field trials were conducted to determine crop tolerance of tomatoes (Lycopersicon esculentum Mill.) of the industrial cultivars H-993, P-76, APT-127, APT-410, and fresh consumption cultivars Cal Ace, and XPH-12221, to post transplant applications of halosulfuron-methyl (Sempra\uae 75 WG) at the recommended rate 75 g ha-1 and at an overdose of 150 and 300 g ha-1. At all of the doses halosulfuron-methyl did not produce any significant adverse effects on the foliage. The greatest levels of foliar discoloration were observed on cv. P-76 at 300 g ha-1 seven days after treatment (DDA). This phytotoxicity was temporary, restricted to 7-15 DDA, disappearing almost completely at 21 DDA. There was no reduction in plant height and width to 30 DDA, except the width of cv. P-76 treated at 300 g ha-1. Single plant and total tomato yield of the varieties Cal Ace, XPH-12221, H-993, APT-127 y APT-410 were not affected by any herbicide applications of halosulfuron-methyl. No dose produced adverse effects on the polar and equatorial fruit diameter. The industrial hybrid P-76 had a significant reduction in total fruit yield and number of fruit per plant at 150 and 300 g ha-1, but not at 75 g ha-1. Tomato plants were tolerant to early post transplant applications at the normal recommended rate of halosulfuron-methyl.Durante la temporada 1998/99 en el Centro Regional de Investigaci\uf3n La Platina del Instituto de Investigaciones Agropecuarias (INIA) (33\ub034' lat. Sur, 70\ub038' long. Oeste, 625 m.s.n.m.), en un suelo franco-arcilloso, se realizaron ensayos para determinar la tolerancia de tomate (Lycopersicon esculentum Mill.) de los cultivares industriales H-993, P-76, APT-127, APT-410 y cultivares de consumo fresco Cal Ace y XPH-12221 a aplicaciones de post trasplante de halosulfur\uf3n-metil (Sempra 75 WG) en la dosis recomendada 75 g ha-1 y en sobredosis de 150 y 300 g ha-1. En todas las dosis halosulfur\uf3n-metil no produjo s\uedntomas adversos importantes sobre el follaje. Los mayores niveles de decoloraci\uf3n foliar se observaron en la sobredosis 300 g ha-1 en el cv. P-76 siete d\uedas despu\ue9s de la aplicaci\uf3n (DDA). Esta fitotoxicidad fue temporal, restringida a 7-15 DDA, desapareciendo casi completamente 21 DDA. No hubo reducciones en alto y ancho de las plantas 30 DDA, a excepci\uf3n del ancho del cv. P-76 a 300 g ha-1. 0El rendimiento individual y total de frutos en los cvs. Cal Ace, XPH-12221, H-993, APT-127 y APT-410 no fueron afectados por las aplicaciones de halosulfur\uf3n-metil. Ninguna dosis produjo efectos adversos en el di\ue1metro ecuatorial y polar de los frutos. El h\uedbrido industrial P-76 tuvo una baja significativa en rendimiento y n\ufamero de frutos planta-1 a 150 y 300 g ha-1, pero no con la dosis de 75 g ha-1. Las plantas de tomate fueron tolerantes a aplicaciones tempranas de post trasplante en la dosis m\ue1xima recomendada de halosulfur\uf3n-metil