La agroindustria cítrica argentina, que incluye producción, empaque, transporte, tratamiento por frío y producción de jugos concentrados, aceites esenciales, etc.; constituye una de las actividades de fundamental importancia en la economía nacional y regional. Los mercados importadores del mundo y consumidores de productos frescos o industrializados en general, han incrementado considerablemente sus exigencias respecto a los niveles de tolerancia de residuos de agroquímicos en los productos, lo que demanda controles y estrategias de producción adecuadas. Dentro de la amplia gama de plaguicidas de uso corriente en la producción citrícola, los benzimidazoles constituyen un grupo importante de fungicidas sistémicos, que son empleados para el control y tratamiento de enfermedades en citrus. El contenido de residuos de estos fungicidas, constituye un importante parámetro de calidad a controlar al momento de comercializar los frutos, tanto para el consumo fresco como para su empleo como materia prima en la industria cítrica. Las metodologías analíticas tradicionales para la determinación de benzimidazoles, son en general complejas, de elevado costo y tiempo de análisis; lo que llevó a plantear como objetivo del presente trabajo el desarrollo de metodologías alternativas para el análisis de fungicidas benzimidazólicos en matrices cítricas. La propuesta incluyó la aplicación y optimización de metodologías analíticas para la determinación de tiofanato, metiltiofanato y thiabendazole por microextracción en fase sólida y cromatografía gaseosa con detector de nitrógeno-fósforo en frutas, jugos concentrados y productos cítricos fermentados; y la determinación de thiabendazole y carbendazim por extracción en fase sólida y cromatografía líquida de alta resolución con detector de arreglo de diodos en aceites esenciales cítricos. / Visciglio, SB. (2011). Desarrollo de metodologías alternativas para el análisis de fungicidas benzimidazólicos en matrices cítricas [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/14978

A study was initiated in the spring of 2003 to evaluate the response of lemons to soil and foliar applied micronutrients for two growing season (2003-2005). Soil applied Fe, Zn, Mn, and Cu was applied in sulfate form and B as Solubor in shallow holes around the skirt of each tree. Foliar applied micronutrients were all applied as “Metalosate” products. Lemon leaf tissue analyses show marginal levels of Zn, Mn, and Cu throughout the study. In 2003-2004, soil fertilization sometimes increased leaf nutrient composition but there was no effect to foliar fertilization. In 2004-2005, ,leaf B and Zn increased to soil fertilization and leaf Mn and Cu increased to foliar fertilization Overall, there were no significant differences in yield or quality to micronutrient fertilization in either growing season.

This experiment was established in January 2000 in a block of ‘Washington’ navel orange trees at Verde Growers, Stanfield, AZ. Treatments included: normal grower practice, winter low biuret (LB) urea application, summer LB urea application, winter LB urea application plus winter and spring potassium phosphite, winter LB urea application plus summer potassium phosphite, and normal grower practice plus spring potassium phosphite. Each treatment was applied to approximately four acres of trees. For 2000-01, yields ranged from 40 to 45 lbs. per tree, and there was no effect of treatments upon total yield, and only slight effect upon fruit size, grade and quality. For 2001-02, there was a slight effect of treatment upon yield as LB urea led to improved yield, while potassium phosphite led to reduced yield. Normal grower practice was intermediate between these two extremes. For 2002-03, we noted a large increase in yield, however the yield data was lost when the block was inadvertently harvested. For 2005, there was no effect of treatments upon total yield.

Four 'Lisbon' lemon selections, 'Frost Nucellar', 'Corona Foothills', 'Limoneira 8A' and 'Prior' were selected for evaluation on Citrus volkameriana rootstock. 2004-05 results indicate that the 'Limoneira 8A Lisbon' and ‘Corona Foothills Lisbon’

Two orange cultivar trials have been established in Arizona, one at the Yuma Mesa Agricultural Center, Yuma, AZ and one at the Citrus Agriculture Center, Waddell, AZ. For the navel orange trial in Yuma, all the selections had improved yields in 2004-05. ‘Fisher’ navel continues to have the greatest yield, but is quite granulated. Of the rest in the Yuma trial, ‘Lane Late’ had the best quality and yield. For the Waddell trial, the fourth year data has been collected, and suggests that ‘Fisher’, ‘Beck-Earli’, ‘Chislett’ and ‘Lane Late’ are outperforming the other cultivars tested to date.

Three lemon cultivar selection trials are being conducted at the Yuma Mesa Agriculture Center in Somerton, AZ. Data from these trials suggest that ‘Limonero Fino 49’ selections may be a suitable alternative for the varieties most commonly planted in Southwest Arizona today. ‘Femminello’ and ‘Villafranca’ might also be planted on an experimental basis.

In a rootstock evaluation trial planted in 1993, five rootstocks, ‘Carrizo’ citrange, Citrus macrophylla, ‘Rough Lemon’, Swingle citrumelo and Citrus volkameriana were selected for evaluation using 'Limoneira 8A Lisbon' as the scion. 1994-2004 yield and packout results indicate that trees on C. macrophylla, C. volkameriana and ‘Rough Lemon’ are superior to those on other rootstocks in both growth and yield. C. macrophylla is outperforming C. volkameriana. For the second year in a row, ‘Rough Lemon’ trees performed similarly to C. macrophylla and better than C. volkameriana. ‘Swingle’ and Carrizo’ are performing poorly. In two other rootstock evaluation trials, both planted in 1995, C. macrophylla and/or C. volkameriana are outperforming other trifoliate and trifoliate-hybrid rootstocks under test.

Bioassay with Dimethoate, Carzol, Danitol, Baythroid and Success were conducted on citrus thrips collected from the Yuma Mesa to determine if insecticide resistance to these insecticides occurred. Low to moderate levels of resistance were detected for Dimethoate, Carzol and Danitol, and one population exhibited a high level of resistance to Baythroid. No resistance was evident for Success. Susceptibility to Success was much higher for the Yuma populations relative to populations previously reported in California.

In a rootstock evaluation trial planted in 1993, five rootstocks, ‘Carrizo’ citrange, Citrus macrophylla, ‘Rough Lemon’, Swingle citrumelo and Citrus volkameriana were selected for evaluation using 'Limoneira 8A Lisbon' as the scion. 1994-2005 yield and packout results indicate that trees on C. macrophylla, C. volkameriana and ‘Rough Lemon’ are superior to those on other rootstocks in both growth and yield. C. macrophylla is no longer outperforming C. volkameriana. ‘Swingle’ and Carrizo’ are performing poorly.

Three lemon cultivar selection trials are being conducted at the Yuma Mesa Agriculture Center in Somerton, AZ. Data from these trials suggest that ‘Limonero Fino 49’ selections may be a suitable alternative for the varieties most commonly planted in Southwest Arizona today. ‘Femminello’ and ‘Villafranca’ might also be planted on an experimental basis.