Evaluación de patógenos en clones de lulo (Solanum quitoense Lam.)

Abstract

En el noroccidente de Popayán, Colombia, se evaluó la presencia de plagas causadas por patógenos en 42 clones de lulo (Solanum quitoense Lam.). Los clones fueron plantados en bolsas plásticas, donde se desarrollaron por 3 semanas antes de ser trasplantados al campo. Se utilizó un diseño de bloques completos al azar con cuatro repeticiones, la parcela útil estuvo conformada por 6 plantas, las cuales se sembraron a 'tresbolillo' a 2.5 m entre surcos y 2 m entre plantas. Para determinar el efecto de las plagas en el cultivo, se calculó el porcentaje de incidencia y severidad del ataque. La incidencia se evaluó como porcentaje de plantas afectadas, y la severidad como porcentaje de tejido afectado por el patógeno. Las enfermedades más limitantes para los 42 clones fueron: gota (Phytophthora infestans) que provocó una mortalidad de plantas superior a 40%; fusarium (Fusarium oxysporum) que se presentó en 12 de los clones evaluados; antracnosis (Colletotrichum sp.) que afectó 21 clones, los cuales se clasificaron entre tolerantes y medianamente tolerantes; y mancha clorótica (Cladosporium sp.) que afectó 21 clones, clasificados como susceptibles. Los clones PL19, PL24, PL11, PL35 fueron medianamente tolerantes. Se seleccionaron por supervivencia los clones: JY E1 (52.2%), PH E 1 (45.8%), VM E2 (45.8%); por supervivencia y por tolerancia a Fusarium oxysporum los clones PL35, PL11, PL24, PL8, PL19, 120052, 120043, ORE1, AGE1. Los clones SER 7, SER 15, SER 9, SEC 31, SEC 27 presentaron alta mortalidad pero se seleccionaron por ser medianamente tolerantes a gota, tolerantes a antracnosis y medianamente resistentes a nematodos, con buen vigor y producción.

Presence of plant disease caused by pathogens on 42 clones of Solanum quitoense Lam. were evaluated in the north-western region of Popayán, Colombia. The seed of the clons were planted in plastic bags during three weeks and afterwards transplanted to the field. The statistical design consisted of a complete randomized block design with 4 repetitions, the working sampling plot consisted on 6 plants arranged in triangles at distances of 2 m within rows, the inter row distance was 2,5 m. The incidence and severity percentages of damage were evaluated to determine the disease effects. The first incidence was evaluated as the affected plants percentage and severity, as percentage of plant tissue affected by the pathogen. The most limiting diseases for the 42 clones were Phytophthora infestans, which produced mortality more than 40%; Fusarium oxysporum affected 12 of the evaluated clons; Colletotrichum sp. affecting 21 clones which were classified as tolerant and fairly tolerant; and Cladosporium sp., affecting 21 clones and were classified as susceptible, while the clons PL19, PL24, PL11, PL35 were considered fairly tolerant. The clones JY E1 (52.2%), PH E 1 (45.8%), VM E2 (45.8%) were selected by survival; by tolerance to Fusarium oxysporum the clones PL35, PL11, PL24, PL8, PL19, 120052, 120043, ORE1, AGE1; and the clones SER 7, SER 15, SER 9, SEC 31, and SEC 27, were selected due to their fair tolerance to Phytophthora infestans, and Colletotrichum sp and their fair resistance against nematodes, proving to be vigorous and productive.