SciELO - Scientific Electronic Library Online

vol.7 número8Variabilidad genética y asociación morfológica entre poblaciones nativas de maíz y sus cruzas F1Crisomélidos asociados a recursos forestales maderables y no-maderables en Victoria, Tamaulipas índice de autoresíndice de materiabúsqueda de artículos
Home Pagelista alfabética de revistas  

Servicios Personalizados




Links relacionados

  • No hay artículos similaresSimilares en SciELO


Revista mexicana de ciencias agrícolas

versión impresa ISSN 2007-0934

Rev. Mex. Cienc. Agríc vol.7 no.8 Texcoco nov./dic. 2016



Efficiency of different fungicides to control pink root rot in onions

Rubén Macías Duarte1 

Raúl Leonel Grijalva Contreras1  § 

Fidel Núñez Ramírez2 

Fabián Robles Contreras1 

Arturo López Carvajal1 

1Campo Experimental Costa de Hermosillo, Sitio Experimental Caborca-INIFAP. Avenida S, No. 8 Norte. CP. 83600. Tel: 01 55 38 71 87 00 Ext. 81105. H. Caborca, Sonora, México. (;;

2Universidad Autónoma de Baja California-Instituto de Ciencias Agrícolas. Ejido Nuevo León, Mexicali, Baja California. (


Onion cultivation in Mexico is of great economic importance and during 2014, 48170 ha were established, one of the main problems for its production is the presence of diseases in the soil. The aim of this study was to evaluate different chemicals and biological fungicides to control pink root rot and its effect on yield. The research was conducted at INIFAP in the Experimental field Coast Hermosillo, Sonora, Mexico, during the years 2010 and 2011. The design was randomized blocks with three replications. Treatments applied did not affect statically the incidence percentage of pink root rot nor plant height; however, it had effect on the severity of the disease, bulb weight and yield. In 2010 the incidence ranged from 39 to 73% and severity of damage between 10-34% and fungicides with greater control were methyl thiophanate (MT), benzothiazole tiocianometitio (TB) and the combination of TB + Trichoderma harzianum although without improving yield. In 2011 the incidence of the disease ranged from 22-30% and the severity of damage of 14-30%. The applications of Trichoderma harzianum alone or in combination with TB were those that achieved greater weight bulb and promoted an increase in yield of 16% compared to control. The application of chemical and biological fungicides is a short-term alternative to reduce pink root rot in onions.

Keywords: Allium cepa L.; disease; quality; yield


El cultivo de la cebolla en México representa gran importancia económica y para el año 2014 se establecieron 48 170 ha, uno de los principales problemas para su producción es la presencia de enfermedades en el suelo. El objetivo del presente trabajo fue evaluar diferentes fungicidas químicos y biológicos para el control de la pudrición rosada y su efecto sobre el rendimiento. La investigación se realizó en el INIFAP en el Campo Experimental Costa de Hermosillo, Sonora, México, durante los años 2010 y 2011. El diseño utilizado fue bloques al azar con tres repeticiones. Los tratamientos aplicados no afectaron estadísticamente el porcentaje de incidencia de pudrición rosada ni la altura de planta; en cambio, tuvieron efecto en la severidad de la enfermedad, peso de bulbo y rendimiento. En 2010 la incidencia varió de 39 a 73% y la severidad del daño entre 10 a 34% y los fungicidas con mayor control fueron metil tiofanato (MT), tiocianometitio benzotiazol (TB) y la combinación de TB + Trichoderma harzianum aunque sin mejorar el rendimiento. En 2011 la incidencia de la enfermedad varió de 22 a 30% y la severidad del daño de 14 a 30%. La aplicación de Trichoderma harzianum solo o en combinación con TB fueron los que alcanzaron mayor peso de bulbo y promovieron un incremento en el rendimiento 16% con respecto al testigo. La aplicación de fungicidas químicos y biológicos es una alternativa a corto plazo para reducir la pudrición rosada en cebolla.

Palabras claves: Allium cepa L.; calidad; enfermedades; rendimiento


The area planted with onion (Allium cepa L.) in Mexico during 2014 was 48 170 ha with a production of 1 368 183 t, with an average yield of 28.9 t ha-1 and production value of 5 665 million pesos. The main producing states are Baja California, Guanajuato, Tamaulipas, Chihuahua and Puebla (SIAP, 2014).

One of the problems affecting onion production in Mexico is the presence of the disease called 'pink root rot' which is caused by a fungus from the soil Pyrenochaeta terrestris (Hansen) Gorenz, Walker and Larson. The fungus is present in most soils where onions are grown, being one of the few fungal diseases that infects only the root without causing damage to the bulb. Symptoms include root rot accompanied of a pink color; the plant shows signs of moisture deficit, as well as an aspect of burns on the tips of the leaves, slow growth of bulbs, consequently yield loss and quality bulb. The fungus remains dormant without causing infections during the months of low temperature like December and January, but as the temperature increases, root infestation becomes evident in the roots of susceptible crops because of this pathogen (Netzer et al., 1985; Aragones, 1988).

The optimum soil temperature for this patogen to attack is 28 °C, situation that coincides with the growth stage of the onion bulb; as soil temperature increases, the degree of infection increases. The attack of the fungus is more severe in white onions. Short photoperiod varieties mature earlier and are less affected by this fungus compared to varieties with intermediate or long photoperiod (Wall and Corgan, 1993).

Among the main control measures to reduce the problem of pink root rot include the use of resistant varieties (Lacy and Roberts, 1982; González et al., 1985; Thornton and Mohan, 1996), crop rotation (Davis and Aegerter, 2008; Nishwitz and Dhiman, 2012), soil solarization (Katan, 1980; Pulido-Herrera et al., 2012), to maintain vigorous plants with different management practices (Thornton and Mohan 1996; Nishwitz and Dhiman, 2012) fungicides (Porter et al., 1989; Pages and Nottegehem, 1996; Biesiada et al., 2004).

Disease management that originates in the soil is commonly done with chemicals (Oezer and Oemeroglu, 1995; Zavaleta- Mejía, 1999). The main chemical fungicides that have shown to reduce the incidence and severity of pink root rot in onions are Dazomet and Thiophanate methyl causing an increase in yield, quality and shelf life (Porter et al., 1989; Pages and Nottegehem, 1996; Biesiada et al., 2004; Sander et al., 2006; Pulido-Herrera et al., 2012). Other products that have shown disease control are Benomyl, Thiram, Zineb, Captan, Cyprodinil and Iprodione, among others (Adams, 2003; Biesiada et al., 2004; Sander et al., 2006).

Other alternatives to disease control with less impact on the environment is bio-fumigation through the toxic effect of gases released during the decomposition process of organic matter incorporated into the soil (Bello et al., 2002). The implementation of ecological practices like solarization is another alternative to control soil diseases with reduced effects on the environment (Katan, 1980).

The antagonistic microorganisms are also used as biological control agents such is the case of the fungus Trichoderma spp., which is recognized as a biological control agent against diseases caused by phyto-pathogenic soil fungi (Harman, 2006). The applications of Trichoderma harzianum strain A (Macias-Duarte et al., 2004; Pulido-Herrera et al., 2012) and Trichoderma viride (Biesiada et al., 2004) have shown a reduction between 10 and 13% the incidence of the fungus compared to treatments not applied. Solarization with clear plastic and biological control, are viable alternatives to control pink root rot in onion, as it increases yield from 24 to 34% and reduces the incidence and severity of the disease (Pulido-Herrera et al., 2012).

On the other hand, mycorrhizal associations have shown to reduce damage by soil pathogens (fungi, bacteria and nematodes) and the response varies from the type of pathogen and environmental conditions (Azcón-Aguilar and Barea, 1997). Similarly, to submerge the roots before transplanting in garlic extract 2% provides significant control of the fungus (Biesiada et al., 2004) as well as application to the foliage of Neem extracts (Pulido-Herrera et al., 2012).

Although onion breeding programs aim to increase resistance to this disease, in recent years the problem has been accentuated in the producing regions causing yield losses and to leave this crop. For this reason, the alternative to control through fungicides is still viable. The aim of this study was to evaluate different chemical and biological fungicides to control pink root rot and its effect on yield and bulb quality in onion variety ‘Morada Regional’.

Materials and methods

Description of the study area

The research was conducted during 2010 and 2011 in the region from Magdalena de Kino, Sonora at the Experimental field Coast of Hermosillo, belonging to the National Institute of Forestry, Agriculture and Livestock (INIFAP), whose coordinates are: 110° 55’ 42’’ west longitude and 30° 39’ 41’’ north latitude and an altitude of 780 masl. Annual average evaporation of 1 493 mm. Annual average temperatures of 19.4 °C, the coldest month is January with monthly average of 1.8 °C and the hottest month is June with 37.8 ° C (INIFAP, 1985; Ruiz et al., 2005).

Soil characteristics

The experiment was conducted in a field whose previous crop was onion and with history of presence of the fungus in the soil Pyrenochaeta terrestris. The main soil characteristics are: sandy loam with an electrical conductivity of 1.2 dS m-1, pH 7.8 and organic matter content of 0.70%. Fertility, soil had 58 kg ha-1 of nitrogen, 43 kg ha-1 phosphorus and 170 kg ha-1 of potassium, which indicates that the soil is suitable for onion production (Castellanos et al., 2000).

Agronomic management

In 2010, seedbed planting took place on October 25th and transplanted on January 21st of the following year. In 2011, planting was performed October 19th and transplantation on January 11th of the following year. In both years, the onion variety was ‘Morada Regional’ which is considered susceptible to pink root rot (Macías and Grijalva, 2005). The traditional irrigation system (flooding) with row spacing at 0.8 m and two planting rows was used in the first year (230 000 plants ha-1). The fertilization formula applied was 180N-80P-00K. In the second year drip irrigation system with 1m beds and four planting rows were used (350 000 plants ha-1). Fertilization was done through irrigation with the formula 250N-150P-100K. For weed control in both years applied Trifluralin (1 kg ha-1) before sowing and two applications oxyfluorfen, the first during transplant at dose of (250 g ha-1) and the second at 40 days using (150 g ha-1). The main pest was thrip (Thrips tabaci) and to control it Lambda-cyhalothrin (42 g ha-1) was applied. The other cultural practices were performed as recommended by Macías and Grijalva (2005).

Treatments evaluated

In both years 6 treatments of which three biological, two chemicals and a combination of biological and chemical were evaluated and were as follows: 1) Trichoderma harzianum strain A, from the study area 1.4 x 107 g-1 colony forming units (CFU); 2) ceres® (liquid inoculant with beneficial microorganisms and humic and fulvic acids) + liquicomp® (liquid compost with beneficial microorganisms) both produced by BIO®; 3) mycorrhizal (PHC Hortic Plus® endomycorrhizal inoculant) at sowing the seed (S) and transplantation in the root (R); 4) methyl thiophanate (MT); 5) benzothiazole tiocianometitio (TB); 6) TB + Trichoderma harzianum; and 7) the control without application. The number of applications and the dose for each product are described in Table 1. The products were applied to the soil and incorporated through irrigation. In the combined treatment, chemical fungicides were applied at the time of transplantation and biological 30 days later.

Table 1 Treatments, number of applications and doses applied to control the fungus Pyrenochaeta terrestris in onion. 

Número Tratamientos Aplicaciones Dosis total
1 Trichoderma harzianum 4 0.8 kg ha-1
2 Micorrizas 2 60 g kg-1 (S) y 30 g L-1 (R)
3 Ceres + liquicomp 3 + 3 12 L ha-1 + 12 L ha-1
4 Metil tiofanato (MT) 2 1.5 kg ha-1
5 Tiocianometitio benzotiazol (TB) 2 6 L ha-1
6 TB + Trichoderma harzianum 1 + 4 6 L ha-1 + 0.8 kg ha-1
7 Testigo

Characteristics evaluated and statistical analysis

Variables evaluated to determine treatments efficiency to control the fungus were the incidence rate and severity of the disease, which were determined only at harvest time for which a random sample of 75 bulbs was taken. The incidence rate was calculated with the following formula: Incidence (%)= number of diseased plants*100/ total plants observed. Disease severity was assessed visually using an arbitrary scale where: 1= 1-15% root damage; 2= 16-40%; 3= 41-65; and 4= 66-100%. To calculate the percentage of severity the townsend and Heuberger formula (1943) was used: p= [Σ(n*v)/CM*N]*100.

Where: P= weighted average of severity; n= number of plants per each level of the scale; v= numerical value of each class; CM= higher category and N= total number of plants assessed. The remaining variables were vegetative growth based on plant height (cm), yield (t ha-1), bulb weight (g). The experimental design was a randomized block with three replications. The size of the experimental plot in 2010 was 16 m2 and useful plot 6.4 m2. In 2011 the experimental plot was 20 m2 and useful plot 8 m2. For mean separation Tukey test at 0.05was used. The analysis of variance and means tests were performed with the FAUNAL (Olivares, 1994) statistical package.

Results and discussion

Incidence and severity of the fungus

There were no statistical differences in the incidence of pink root rot between treatments in any of the two years evaluated. In 2010, the highest incidence of the disease was observed, with an average of 51.6%. Values between treatments ranged between 45 and 73%, whereas in 2011 the average was 25% with values of 13 to 30% incidence (Table 2). The incidence rate of pink root rot and efficiency of fungicides in 2010 are similar to those previously reported (Adams, 2003; Duarte et al., Macías-2004; Sander et al., 2006). While other studies report up to 100% disease incidence at the end of the crop (Pulido-Herrera et al., 2012). The difference in disease incidence between years can be explained by two factors, first to temperature difference between years. In 2011, the maximum monthly temperature in March and April (period where growth bulb is present and the first symptoms of the disease are detected) were lower (Figure 1) which favor a decrease in soil temperature, since the presence of the disease decreases as soil temperature is lower (Wall and Corgan, 1993). The second factor is that in 2011 water management was through drip irrigation which favors lower soil temperature, better drainage and root development of the onion and thereby able to reduce the problem of pink root rot (Alvarado, 1983; Luong et al., 2008).

Table 2 Incidence and severity of pink root rot Pyrenochaeta terrestris in onion with the application of different chemical and biological fungicides in 2010 and 2011. 

Tratamientos Incidencia del hongo (%) Severidad (%)
2010 2011 2010 2011
Trichoderma harzianum 49 az 22 a 33 ab 14 b
Micorrizas 53 a 23 a 34 ab 18 b
Ceres + liquicomp 53 a 27 a 34 ab 27 a
Metil tiofanato (MT) 49 a 25 a 15 c 16 b
Tiocianometitio benzotiazol (TB) 45 a 27 a 12 c 15 b
TB + Trichoderma harzianum 39 a 21 a 10 c 13 b
Testigo 73 a 30 a 41 a 30 a
Significancia ns ns 0.01 0.01
CV 24.6 28.4 28.5 26.5

zMedias con la misma letra dentro de cada columna son estadísticamente iguales (Tukey 0.05).

Figure 1 Monthly maximum and minimum temperatures recorded during the years 2010 and 2011 in the region of Magdalena de Kino, Sonora. 

The severity of damage in onion roots by pink root rot, showed statistically significant differences in both years (p≤ 0.01). In 2010 plants treated with Tiocianometitio benzothiazole (TB) + Trichoderma harzianum, benzothiazole tiocianometitio and methyl thiophanate (MT) were those that showed lower degree of severity of the disease with 10, 12 and 15%, respectively, being statistically different from the rest of the treatments, whose values ranged from 33 to 41%. In 2011, control plants and where Ceres + Liquicomp was applied had greater severity of damage with 30 and 27%, in the rest of the treatments, the percentage ranged from 13 to 18% with no statistical difference between them. The severity of the disease in both years is lower than that reported in other studies (Pulido-Herrera et al., 2012). In general, chemical fungicides (MT and TB) reduced the severity of damage during the two years; while the application of Trichoderma harzianum and mycorrhizae were effective only in 2011. The application of biological and chemical fungicides although did not reduce the incidence of the fungus, it managed to reduce the intensity of root damage probably because the fungicides have an effect on the delayed onset of the fungus (Alvarado, 1983 and Porter et al., 1989).

Plant height

In both years of evaluation, plant height showed no statistical difference between treatments. In 2010 ranged from 69 to 73 cm and in 2011 ranged from 70 to 74 cm between treatments. Plants inoculated with mycorrhizal did not improve vegetative growth, contrary to the statement by AzcónAguilar and Barea (1997) who point out that associations with these organisms provide an improvement in nutrition, which promotes greater leaf development.

Bulb weight

Bulb weight showed statistically significant differences (p≤ 0.05) in both years. In 2010, the treatment where tiocianometitio benzothiazole was applied achieved the highest bulb weight with 234 g. This value was statistically different to the treatments where Trichoderma harzianum and control were applied obtaining the lowest weight bulb with 205 g for each. In 2011, the treatments where only Trichoderma harzianum was applied excelled and when combined with TB, which achieved the highest bulb weight of 212 and 206 g, respectively. The lowest bulb weight was obtained with the control treatment with 181g. In previous work using only biological fungicides, pink root rot incidence was reduced but it showed no difference in yield or bulb weight (Macias-Duarte et al., 2004).

Table 3 Plant height and bulb weight in onion with the application of different chemical and biological fungicides on pink root rot Pyrenochaeta terrestris during 2010 and 2011. 

Tratamientos Altura de planta (cm) Peso de bulbo (g)
2010 2011 2010 2011
Trichoderma harzianum 70 az 72 a 205 b 212 a
Micorrizas 73 a 73 a 213 ab 198 b
Ceres + liquicomp 73 a 74 a 215 ab 193 b
Metil tiofanato (MT) 72 a 71 a 212 ab 189 c
Tiocianometitio benzotiazol (TB) 73 a 71 a 234 a 195 b
TB + Trichoderma harzianum 70 a 72 a 207 ab 206 a
Testigo 69 a 70 a 205 b 181 d
Significancia ns ns 0.05 0.05
CV 6.5 7.1 4.8 3.2

zMedias con la misma letra dentro de cada columna son estadísticamente iguales (Tukey 0.05).


In 2010, there was no statistical difference in yield between treatments, and a production between 36.2 and 40.9 t ha-1was obtained. In contrast, 2011 showed statistical differences (p≤ 0.05). Treatments where Trichoderma harzianum and combination of TB + Trichoderma harzianum were applied obtained the highest yields with 76.8 and 73.4 t ha-1, respectively. The lowest yields were obtained with control 62.5 t ha-1 and where methyl thiophanate was applied obtained 65 t ha-1 (Table 4). Studies performed by Pulido-Herrera et al. (2012) indicated that the application of Trichoderma harzianum increased onion yield in 14.6% compared to those where chemical fungicides were applied. On the other hand, other researches indicate that the application of sterilizing agents to the soil like Dazomet (750 kg ha-1) plus solarization to the soil significantly increased yield, besides improving postharvest quality (Porter et al., 1989; Pages and Notteghem, 1996). Similarly, solarization with clear plastic, with organic amendments increased yield between 22 and 34% (Pulido-Herrera et al., 2012). The difference in yield between years in this study is due to in 2010 a low-density planting and conventional irrigation was used, while in 2011 was planted with high density and drip irrigation and with this technology is possible to increase yields between 50 and 100% (Macías and Grijalva, 2005).

Table 4 Onion yield with the application of different chemical and biological fungicides to control pink root rot Pyrenochaeta terrestris during 2010 and 2011. 

Tratamientos Rendimiento (t ha-1)
2010 2011
Trichoderma harzianum 36.2 az 76.8 a
Micorrizas 38.5 a 68.6 b
Ceres + liquicomp 38.8 a 67.7 bc
Metil tiofanato 40.9 a 65 cd
Tiocianometitio benzotiazol (TB) 40.4 a 69.7 b
TB + Trichoderma harzianum 37.1 a 73.4 a
Testigo 36.3 a 62.5 d
Significancia ns 0.05
CV 10.3 12.8

zMedias con la misma letra dentro de cada columna son estadísticamente iguales (Tukey 0.05).


Chemical and biological fungicides did not significantly affect incidence rate of pink root rot, but reduced the severity of damage to the roots.

The application of Trichoderma harzianum alone or in combination with tiocianometitio benzothiazole improved yield in 2011 as a result of an increase in the size of the bulb.

Incidence and severity percentage of pink root rot was different between years, as well as fungicides efficiency.

Literatura citada

Adams, A. I. 2003. Use of different methods for the control of pink root rot disease (Pyrenochaeta terrestris) ‘Hansen’ of onion (Allium cepa L.) in Nyola Province. Thesis (Ph. D). Faculty of Agriculture- University of Khartoum, Shambat (Sudan). htpp:// [ Links ]

Alvarado, H. G. 1983. Distribución, incidencia y características de la enfermedad raíz roja de la cebolla causada por Pyrenochaeta terrestris (Hansen) en la región Centro Occidental de Venezuela. Agron. Trop. 33:123-141. [ Links ]

Aragonés, A. M. 1988. Desarrollo y control de las enfermedades de las plantas. National Academy of Science. Ed. Limusa. México, D. F. 212 p. [ Links ]

Azcón, A. C. and Barea, J. M. 1997. Arbuscular mycorrhizas and biological control of soil-borne pathogens an overview of the mechanisms involved. Mycorrhiza 6:457-464. [ Links ]

Bello, A.; López, L. A. J. y Díaz, V. 2002. Biofumigación y solarización como alternativas al bromuro de metilo. Departamento de Agroecología. Madrid, España. 50 p. [ Links ]

Biesiada, A.; Kolota, E.; Pietr, S.; Stankiewicz, M. and Matkowski K. 2004. Evaluation of some biological methods of pink root rot control on leek. Acta Hortic. 635:187-194. [ Links ]

Castellanos, J. Z.; Uvalle, B. J. X. y Aguilar, S.A. 2000. Manual de interpretación de análisis de suelos y aguas. Colección INCAPA. 150 p. [ Links ]

Davis, R. M. and Aegerter, B. J. 2008. Management guideline of onion and garlic pink root. Publication 3452. Agric. Nat. Res. University of California. 25 p. [ Links ]

González, A. H.; García, G. A. and Abreu, S. 1985. Comportamiento de cultivares de cebolla en suelos infestados con el hongo de la raíz roja Pyrenochaeta terrestris (Hansen). Agron. Trop. 35:105-114. [ Links ]

Harman, G. E. 2006. Overview of mechanism and uses of Trichoderma spp. Phytopathology 96:190-194. [ Links ]

INIFAP. 1985. Guía para la asistencia técnica agrícola. Área de influencia del Campo Experimental Región de Caborca. Caborca, Sonora, México. 10 p. [ Links ]

Katan, J. 1980. Solar pasteurization of soils for disease control: status and prospect. Plant Dis. 64:450-454. [ Links ]

Lacy, M. L. and Roberts, D. L. 1982. Yields of onion cultivars in midwestern organic soils infested with Fusarium oxysporum f. sp. cepae and Pyrenochaeta terrestris. Plant Dis. 66:1003-1006. [ Links ]

Luong, T. M.; Huynh, M.T.; Tran, U.; Dau, V. T.; Burgess, L. W.; Phan, H. T.; Aveskam, M. M. and Vo, A. D. 2008. First report of phoma terrestris pink root rot of chinese onion in Vietnam. Austr. Plant Dis. 3:147-149. [ Links ]

Macías, D. R.; Grijalva, C. R. L.; Valenzuela, R. M. and Robles, C. F. 2004. Chemical control in the soil fungus (Pyrenochaeta terrestris) in onion production. HortSci. 39:804. [ Links ]

Macías, D. R. y Grijalva, C. R. L. 2005. Tecnología de producción de hortalizas, frutales y forrajes en la región de Magdalena de Kino, Sonora. 2005. SAGARPA-INIFAP-CIRNO-CECAB. Publicación Técnica Núm. 8. 110 p. [ Links ]

Netzer, D.; Rabinowitch, H. D. and Weintal, C. 1985. Greenhouse technique to evaluate onion resistance to pink root. Euphytica 34:385-391. [ Links ]

Nischwitz, C. and Dhiman, C. 2012. Pink root of onion. UTAH State University Cooperative Extension. Fact Sheet 017. 1-5 pp. [ Links ]

Oezer, N. and Oemeroglu, M. 1995. Chemical control and determination of fungal causal agents of wilt disease of onion in Tekirdag Province. Turkish. Phytopathology 24:47-55. [ Links ]

Olivares, S. E. 1994. Paquete de diseños experimentales FAUANL. Versión 2.5. Facultad de Agronomía UANL. Marín, N. L., México. [ Links ]

Pages, J. and Notteghem, L. 1996. Effects of soil treatment practices on pink root disease of onion in the Senegalese cultivation system. Inter. J. Pest Manag. 42:29-34. [ Links ]

Porter, I. J.; Merriman, P. R. and Keane, P. J. 1989. Integrated control of pink root (Pyrenochaeta terrestris) of onions by dazomet and soil solarization. Austr. J. Agric. Res. 40:861-869. [ Links ]

Pulido, H. A.; Zavaleta, M. E.; Cervantes, D. L. y Grimaldo, J. O. 2012. Alternativas de control en la pudrición radical de cebolla para el Valle de la Trinidad, Baja California. Rev. Mex. Cienc. Agríc. 3:97-112. [ Links ]

Ruiz, C. J. A.; Medina, G. G.; Grageda, G. J.; Silva, S. M. M. y Díaz, P. G. 2005. Estadísticas climatológicas básicas del Estado de Sonora. (Periodo 1961-2003). INIFAP-CIRNO-SAGARPA. Libro Técnico Núm. 1. 92-93 pp. [ Links ]

Sander, F.; Langston, D. and Foster, M. 2006. Effect of fungicide dip treatment on fungal disease and yield of transplanted sweet onion. htpp:// [ Links ]

Thornton, M. K. and Mohan, S. K. 1996. Response of sweet Spanish onion cultivars and numbered hybrids to basal and pink root. Plant Dis. 80:660-663. [ Links ]

Towsend, G. R. and Heuberger, J. V. 1943. Methods for estimating losses caused by diseases in fungicide experiments. Plant Dis. Report. 24:340-343. [ Links ]

SIAP. 2014. Cierre de la producción agrícola por estado. htpp:// [ Links ]

Wall, E. S. and Corgan, J. 1993. Onion disease in New Mexico. Cooperative service. Circular 538. College of Agriculture and Home Economics. University New Mexico State. Las Cruces New Mexico. USA 5 p. [ Links ]

Zavaleta, M. E. 1999. Alternativas de manejo de las enfermedades de las plantas. Terra. 17:201-207. [ Links ]

Received: September 2016; Accepted: November 2016

Creative Commons License Este es un artículo publicado en acceso abierto bajo una licencia Creative Commons