Publication:
Efectividad de fungicidas sistémicos y de contacto para el control de Sigatoka negra (Mycosphaerella fijiensis Morelet) en guineo en Isabela, Puerto Rico
Efectividad de fungicidas sistémicos y de contacto para el control de Sigatoka negra (Mycosphaerella fijiensis Morelet) en guineo en Isabela, Puerto Rico
Authors
Prieto-Figueroa, José A.
Embargoed Until
Advisor
Chavarría-Carvajal, José A.
College
College of Agricultural Sciences
Department
Department of Crops and Agro-Environmental Sciences
Degree Level
M.S.
Publisher
Date
2010
Abstract
Sigatoka negra Mycosphaerella fijiensis (anamorfo Pseudocercospora fijiensis) es la enfermedad más limitante para la producción de guineos en Puerto Rico. Un experimento de campo se estableció en la estación Isabela para estudiar un programa de aspersión a base de los fungicidas sistémicos y de contacto con registro en Puerto Rico para el control de la Sigatoka negra. El diseño experimental fue de bloques completos aleatorizados con cuatro repeticiones y seis tratamientos. Los tratamientos evaluados fueron: 1. Rotación azoxistrobina (Abound) + mancozeb (Dithane M-45) o clorotalonil (Bravo weatherstik), 2. rotación de propiconazol (Tilt) + clorotalonil o mancozeb, 3) rotación de azoxistrobina (Abound) + propiconazol (Tilt) + clorotalonil o mancozeb, 4. fungicidas de contacto clorotalonil o mancozeb, 5. Aceite de huerta BVA # 15 y 6. Control absoluto (parcelas sin tratar). Las aplicaciones de fungicidas se realizaron desde el nivel del suelo con un pulverizador de mochila de motor calibrado para asperjar un volumen total de 85-110L/ha. Los fungicidas fueron aplicados en una emulsión de aceite-agua, en aceite, o en una emulsión de agua, a intervalos de 14 días durante la temporada de lluvias y 21 días durante la estación seca. Un total de ocho aplicaciones se llevaron a cabo durante el primer ciclo del cultivo. Dos de estas aplicaciones se hicieron con fungicidas sistémicos (Tilt o Abound) y el resto con fungicidas de contacto (mancozeb y clorotalonil) Los resultados indicaron que la temperatura desempeñó un papel importante en el desarrollo de la enfermedad en Puerto Rico. La humedad Relativa (HR) obtuvo un buen valor del coeficiente de Spearman (rho = 0,62) con la hoja más joven enferma, indicando que la HR es importante durante las primeras etapas de desarrollo de la Sigatoka negra. Los valores rho para precipitación fueron en general bajos, lo que indica que esta variable no fue adecuada para predecir el desarrollo la Sigatoka negra, durante el desarrollo de la plantilla en Isabela, Puerta Rico. El programa de aspersión de mancozeb y clorotalonil (tratamiento 4) alcanzó los mejores valores para peso del racimo en comparación con los otros dos programas de aplicación estudiados. Una reducción del 44.7% en el peso del racimo fue observada cuando se comparó el control absoluto, tratamiento 6 (16.11 kg/racimo) con el tratamiento 4 (29.15 kg/racimo), lo que demuestra la importancia del control químico de la Sigatoka negra para la producción de guineos en Puerto Rico.
Black Sigatoka (BS) Mycosphaerella fijiensis (anamorph Pseudocercospora fijiensis) is the most limiting disease for banana production in Puerto Rico. A field experiment was established at Isabela Station to study a spray program based on the systemic and contact fungicides registered in Puerto Rico for BS control. The experimental design was a RCB with four replicates and six treatments. Treatments evaluated were: 1. Rotation azoxystrobin (Abound) + Contact Fungicides mancozeb (Dithane F-45) or chlorothalonil (Bravo weatherstik); 2. Rotation propiconazole (Tilt) + chlorothalonil or mancozeb; 3) Rotation azoxystrobin (Abound) + propiconazole (Tilt) + chlorothalonil or mancozeb; 4. Contact Fungicides chlorothalonil or mancozeb; 5. Orchard oil BVA #15 and 6. Absolute control (untreated plots). Fungicide applications were conducted from ground level with a motorized backpack sprayer calibrated to deliver a total volume of 85-110L/ha. Fungicides were sprayed in an oil-water emulsion, an oil mixture, or in a water-emulsion, at intervals of 14 days during rainy season and 21 days during dry season. A total of eight sprays were applied during the banana plant crop. Two of these sprays were made with systemic fungicides (Tilt or Abound) and the rest were with the contact fungicides (mancozeb and chlorothalonil ) Results indicated that temperature played an important role on disease development in Puerto Rico. Relative Humidity (RH) had a good Spearman’s coefficient value (rho=0.62) with YDL; indicating that RH is important during the first stages of BS development. Rho values for rainfall were in general low, indicating that this variable is not very good to predict BS development during the development of the banana plant crop at Isabela, Puerto Rico. The spray program with mancozeb and chlorothalonil (treatment 4) reached the best values for bunch weight when compared with the other treatments studied. A bunch weight reduction of 44.7% was observed when the absolute control, treatment 6 (16.11 kg/bunch) was compared with treatment 4 (29.15 kg/bunch), indicating the importance of BS control on bananas in Puerto Rico.
Black Sigatoka (BS) Mycosphaerella fijiensis (anamorph Pseudocercospora fijiensis) is the most limiting disease for banana production in Puerto Rico. A field experiment was established at Isabela Station to study a spray program based on the systemic and contact fungicides registered in Puerto Rico for BS control. The experimental design was a RCB with four replicates and six treatments. Treatments evaluated were: 1. Rotation azoxystrobin (Abound) + Contact Fungicides mancozeb (Dithane F-45) or chlorothalonil (Bravo weatherstik); 2. Rotation propiconazole (Tilt) + chlorothalonil or mancozeb; 3) Rotation azoxystrobin (Abound) + propiconazole (Tilt) + chlorothalonil or mancozeb; 4. Contact Fungicides chlorothalonil or mancozeb; 5. Orchard oil BVA #15 and 6. Absolute control (untreated plots). Fungicide applications were conducted from ground level with a motorized backpack sprayer calibrated to deliver a total volume of 85-110L/ha. Fungicides were sprayed in an oil-water emulsion, an oil mixture, or in a water-emulsion, at intervals of 14 days during rainy season and 21 days during dry season. A total of eight sprays were applied during the banana plant crop. Two of these sprays were made with systemic fungicides (Tilt or Abound) and the rest were with the contact fungicides (mancozeb and chlorothalonil ) Results indicated that temperature played an important role on disease development in Puerto Rico. Relative Humidity (RH) had a good Spearman’s coefficient value (rho=0.62) with YDL; indicating that RH is important during the first stages of BS development. Rho values for rainfall were in general low, indicating that this variable is not very good to predict BS development during the development of the banana plant crop at Isabela, Puerto Rico. The spray program with mancozeb and chlorothalonil (treatment 4) reached the best values for bunch weight when compared with the other treatments studied. A bunch weight reduction of 44.7% was observed when the absolute control, treatment 6 (16.11 kg/bunch) was compared with treatment 4 (29.15 kg/bunch), indicating the importance of BS control on bananas in Puerto Rico.
Keywords
Fungicidas sistémicos,
Guineos
Guineos
Usage Rights
Persistent URL
Cite
Prieto-Figueroa, J. A. (2010). Efectividad de fungicidas sistémicos y de contacto para el control de Sigatoka negra (Mycosphaerella fijiensis Morelet) en guineo en Isabela, Puerto Rico [Thesis]. Retrieved from https://hdl.handle.net/20.500.11801/1365