Controlled environment experiments showed that velvetleaf plants grown under drought stress or low temperature (LT) treatments had greater leaf epicuticular wax (ECW) deposition compared to plants grown in soil with moisture at field capacity (FC) or a high temperature (HT) regime. Light intensity did not affect ECW deposition; however, increasing light intensity decreased the leaf ECW ester content and increased the secondary alcohol content. Plants grown at an LT regime or under FC had leaf ECW with fewer hydrocarbons and more esters than those grown at an HT or drought stress regime. Velvetleaf absorption of acifluorfen increased as light intensity decreased for plants grown in adequate soil water content, while the opposite was true for drought-stressed plants. Velvetleaf absorption of acifluorfen was approximately 3 and 10 times greater, respectively, with the addition of 28% urea ammonium nitrate (UAN) in comparison to crop oil concentrate (COC) or no adjuvant, regardless of the environmental treatments. Plants absorbed more acifluorfen when subjected to the LT regime in comparison to the HT regime when UAN was the adjuvant, while the opposite was true when COC was the adjuvant. Velvetleaf absorption of acifluorfen was not affected by drought stress when COC or no adjuvant was used and varied between studies when UAN was used. Velvetleaf absorption of bentazon was greatest for plants grown under HT/FC or high light/FC treatments and least with plants grown under HT/drought stress or low light/drought stress treatments, regardless of the adjuvant. However, bentazon absorption was higher with the addition of an adjuvant and for plants grown at a high light intensity or FC condition compared with medium to low light intensity or drought stress treatments.

Controlled-environment experiments were conducted to determine giant foxtail epicuticular wax (ECW) deposition and fluazifop-P absorption under different environmental conditions and with two adjuvants. Drought stress and low temperature increased leaf ECW content, whereas low light intensity decreased ECW content compared with medium light intensity. Drought stress conditions decreased the fatty acid and primary alcohol content of ECW and increased the hydrocarbon content compared with field capacity. Compositional changes would make the ECW more hydrophobic and reduce leaf wetting by herbicide spray. Increasing air temperature decreased the aldehyde content of ECW, whereas decreasing light intensity increased ECW fatty acid and aldehyde content while decreasing primary alcohols and esters. Compositional changes under low light intensity would make the ECW more hydrophilic and increase leaf wetting by a herbicide spray. Drought stress reduced fluazifop-P absorption regardless of the temperature but could not further reduce fluazifop-P absorption under low light intensity. Fluazifop-P absorption by plants under low light and drought stress conditions was similar to plants under low or medium light intensity and field capacity conditions. Similarly, the rate of fluazifop-P absorption was less under drought stress and low light conditions. Fluazifop-P absorption was greater when crop oil concentrate was added compared with 28% urea ammonium nitrate or no additive. Crop oil concentrate, added to the herbicide solution, overcame reduced fluazifop-P absorption under the low light conditions and in one of the two drought stress regimes but could not overcome reduced fluazifop-P absorption with the high temperature regime.

Seeds of green foxtail [Setaria viridis(L.) P. Beauv. # SETVI] and giant foxtail (S. faberiHerrm. # SETFA) were collected from mature plants in the field and recovered from three soil depths under two types of tillage. Fungi colonizing the caryopses were isolated to determine the effect of tillage and soil depth on fungal colonization and the field flora.Alternaria alternata(Fr.) Keissler andEpicoccum purpurascensEhrenb. ex Schlecht. were the two fungi most frequently isolated from the hand-harvested seeds. Percentages of fungal colonization were directly related to size of the caryopses. The most frequently isolated fungus species recovered from seeds from soil wereA. alternata, Cladosporium cladosporioides(Fresen.) de Vries,E. purpurascens, and two unidentified fungi with sterile mycelium. One sterile fungus had white rough mycelium, and the other had dark mycelium. These two sterile fungi had a detrimental effect on foxtail seed germination in the laboratory. Caryopsis colonization seems to be related to the placement of the crop residues in the soil. In reduced-tillage plots, more caryopses were colonized in the top soil layer (0 to 7.5 cm) than in the 7.5- to 15-cm layer. In plowed soils, greater colonization occurred at the lower depth.

Pitty, Abelino, "Effect of environmental conditions on velvetleaf and giant foxtail epicuticular wax quantity and quality and the relationship to herbicide penetration " (1988). Retrospective Theses and Dissertations. 9716.

El Centro para el Control Biológico en Centro América (CCBCA) fue creado en 1989 por  la Escuela Agrícola Panamericana, financiado por la United States Agency for International Development (USAID) en Honduras. El CCBCA se enfocó en el control biológico clásico, el aumento y la conservación de enemigos naturales. En el 2000 cambió el nombre de Laboratorio de Control Biológico y se enfocó en el aprender haciendo de los estudiantes de la Escuela Agrícola Panamericana y la producción y comercialización de enemigos naturales de plagas agrícolas. El único parasitoide conocido que ataca al picudo de las bromelias (Metamasius quadrilineatus), fue encontrado en las investigaciones del CCBCA; resultó una especie nueva nombrada Lixadmontia franki que fue liberada en Florida en el 2007 para el control biológico del picudo mejicano de las bromelias (Metamasius callizona). Se determinaron los organismos parasíticos de las plagas Plutella xylostella, Mocis latipes, Spodoptera frugiperda, Leptophobia aripa y Liriomyza spp. Cuatro especies de avispas parasíticas exóticas, un baculovirus, un hongo y tres picudos fueron introducidos a Honduras para control biológico clásico: Cotesia plutellae (parasitoide asiático de P. xylostella); Diadromus collaris (parasitoide pupal de P. xylostella); Telenomus remus (parasitoide que ataca a los huevos de 30 especies de lepidópteros); una especie de Eretmocerus (originaria de India, para controlar Bemisia tabaci); los picudos Neochetina bruchi y Neochetina eichhorniae y el hongo Cercospora piaropi (para el control de la maleza acuática lirio de agua (Eichhornia crassipes); y el picudo Neohydronomous affinis (controlador biológico de la maleza acuática lechuga de agua (Pistia stratiotes). En el 2000, Zamorano cambió la estrategia del uso de control biológico y empezó a incursionar en la producción comercial de microrganismos para el control de plagas, debido a una demanda no satisfecha. Los controladores biológicos que ha producido son el hongo antagonista Trichoderma harzianum (Trichozam™) para combatir hongos en el suelo, Beauveria bassiana (Bazam™) para controlar lepidópteros y coleópteros, Lecanicillium lecanii (Verzam™) para el control de áfidos y mosca blanca, Metarhizium anisopliae (Metazam™) para el control de salivazo (Aeneolamia spp.) y larvas de coleópteros en caña de azúcar, y Purpureocillium lilacinum (Pazam™) para controlar nematodos. Además, ha reproducido y vendido la chinche depredadora Orius insidiosus para el control de trips, áfidos y mosca blanca, el ácaro depredador Neoseiulus longispinosus para el control de la arañita roja (Tetranychus spp.) y el nematodo entomófago Heterorhabditis bacteriophora para el control de insectos del suelo, especialmente contra Phyllophaga spp., Cosmopolitus sordidus, larvas de lepidóptera, picudo del camote (Cylas formicarius) y termitas en el suelo. Posiblemente, el mayor aporte es en la enseñanza de las técnicas y tecnologías del control biológico de plagas que se han distribuido por América Latina a través de los graduados de Zamorano que estudiaron y fueron entrenados en Zamorano.DOI: http://dx.doi.org/10.5377/ceiba.v52i1.966