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Abstract

La cebada es afectada por la Escaldadura (EC) producida por Rhynchosporium secalis, y el salpicado necrótico (SN) por Ramularia collo-cygni siendo enfermedades prevalente y emergente en el Sudeste Bonaerense, respectivamente. Ambas afectan el área foliar provocando pérdidas de rendimiento y calidad de grano. El control químico es una herramienta eficaz de control y requiere de ajustes para el momento oportuno de aplicación. El objetivo fue identificar la ventana de protección (VP) para garantizar bajos niveles de SN y EC. Se realizó un ensayo en la EEA INTA Balcarce (Cultivar: Andreia). Se establecieron diez tratamientos según periodos de protección/desprotección fúngica mediante aplicaciones de fungicida (Isopyrazam 12,5g + azoxistrobina 20g) distribuidas diferencialmente en cinco fechas a lo largo del ciclo del cultivo (entre 0 y 132 días después de la siembra, dds). Se usó un DBCA con cuatro repeticiones. Se incluyó un tratamiento de protección completa (PC; cinco aplicaciones) y otro desprotegido (sin fungicida). En el estadio de grano lechoso (126 dds) se evaluó la incidencia de EC y SN. Los periodos de protección/desprotección que no difirieron de la PC fueron ≥0-84/≤0-27 dds y de ≥0-84/≤0-52 dds para EC y SN respectivamente. La VP para EC va desde dos o tres hojas (27dds) hasta aristas visibles (84 dds) y para SN desde inicio de elongación de tallo (52 dds) hasta aristas visibles. Dosis y nº de aplicaciones en las VP, dependerán de la presión del patógeno, condiciones ambientales y genotipo.
0
20
40
60
80
100
020 40 60 80 100 120
Incidencia de EC (%)
Periodo de protección/desprotección
(días después de la siembra)
I. A. Erreguerena1, F. J. Quiroz1, M. R. A. Montoya1, C. A. Maringolo1, N.
Lazzaro3, F. Giménez2. EEA INTA 1Balcarce / 2Bordenave; 3FCA, UNMdP.
erreguerena.ignacio@inta.gob.ar
INTRODUCCIÓN
La cebada es afectada por la Escaldadura (EC) producida por Rhynchosporium secalis, y el salpicado
necrótico (SN) por Ramularia collo-cygni entre otras, siendo enfermedades prevalente y emergente en el
Sudeste Bonaerense, respectivamente. Ambas afectan el área foliar provocando pérdidas de
rendimiento y calidad de grano importantes. Dentro de las medidas de manejo, el control químico es
una herramienta eficaz de control y requiere de ajustes para determinar el momento oportuno de
aplicación.
MATERIALES Y MÉTODOS
OBJETIVO
0
20
40
60
80
100
020 40 60 80 100 120
Incidencia SN (%)
Periodo de protección/desprotección
(días después de la siembra)
RESULTADOS
Identificar la ventana de protección para
garantizar bajos niveles de Salpicado
Necrótico y Escaldadura de la cebada.
Cultivar: Andreia
Diez tratamientos según periodos de protección/desprotección fúngica (aplicaciones de Isopyrazam 12,5g + azoxistrobina 20g).
Cinco fechas de aplicación a lo largo del ciclo del cultivo (entre 0 y 132 días después de la siembra, dds).
T: tratamiento
E: emergencia
DBCA con cuatro repeticiones.
En el estadio de grano lechoso (126 dds) se evaluó la incidencia de ambas enfermedades.
VENTANA DE PROTECCIÓN PARA EL
CONTROL QUÍMICO DE Ramularia collo-cygni
y Rhynchosporium secalis EN CEBADA EN EL
SUDESTE BONAERENSE
VP
= 0.96
= 0.83
VP
EEA INTA Balcarce
CONCLUSIONES Y DISCUSIÓN
Los periodos de protección/desprotección que no difirieron de la protección completa
(tratamiento 2) fueron 0-84/≤0-27 dds y de 0-84/≤0-52 dds para EC y SN, respectivamente.
La Ventana de Protección para la EC va desde dos o tres hojas (Z: 12-13) (27dds)
hasta aristas visibles (Z: 47-49) (84 dds) y para SN desde inicio de elongación de
tallo (Z: 29-30) (52 dds) hasta aristas visibles. Dosis y de aplicaciones en las
VP, dependerán de la presión del patógeno, condiciones ambientales y genotipo.
Análisis de varianza (ANOVA) y
comparación de medias (Test de
Duncan).
Ajuste de modelos de regresión.
Protección
Desprotección
Protección
Desprotección
= 0.97
= 0.98
BIBLIOGRAFÍA
ZADOKS, J. C., CHANG, T. T., & KONZAK, C. F. (1974). A decimal code for the growth stages of cereals. Weed research, 14(6), 415-421.
... Most studies indicate that the best effects from late treatments come from sprays at awns peeping (GS49). In Argentina, a protection window of barley against RLS by the application of an azoxystrobin + isopyrazam mixture between barley stem elongation (GS30) and first awns visible (GS49) was determined by Erreguerena et al (2014). The GS 49 treatment has also been recommended for RLS control in Switzerland (Peter Frei, personal communication), Germany (Hess et al. 2007) and UK ). ...
... Farklı araştırmalarda RLS kontrolünde sentetik fungisitlerin potansiyeli görülmüştür [111]. Erreguerena ve ark., [112] [18]. Havis ve ark. ...
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... Most studies indicate that the best effects from late treatments come from sprays at awns peeping (GS49). In Argentina, a protection window of barley against RLS by the application of an azoxystrobin + isopyrazam mixture between barley stem elongation (GS30) and first awns visible (GS49) was determined by Erreguerena et al (2014). The GS 49 treatment has also been recommended for RLS control in Switzerland (Peter Frei, personal communication), Germany (Hess et al. 2007) and UK ). ...
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