Dialium guianense es una especie tropical arbórea de bosques perennifolios utilizada por su madera y frutos comestibles. Estos ecosistemas son amenazados, por lo que el objetivo del estudio fue evaluar el crecimiento inicial de la planta con miras a establecer programas de propagación. Las plántulas fueron cultivadas en bolsas de vivero y se empleó un diseño completamente aleatorio con una población inicial de 200 plantas durante 10 meses. El tallo y la raíz alcanzaron longitudes de 32.8 y 28.9 cm, respectivamente. El número de hojas compuestas fue de 12.3 con siete folíolos. La acumulación de biomasa fue de 2.5 g en el tallo, 1.6 g en la raíz y 3.7 g en las hojas. La relación vástago/raíz mostró, aproximadamente, cuatro veces mayor biomasa en el vástago. La TRC media fue de 15 mg g-1 día-1. El crecimiento de D. guianense resultó lento, indicando que es una especie tardía sucesionalmente.

<p><strong>Background:</strong> In Mexico, 164 species of whiteflies have been reported in different crops, among which are citrus varieties. <strong>Objective:</strong> In the present work, the whitefly species was identified and determined the population size of the nymphal state and adults in citrus trees. As well as, the severity of the sooty mold (<em>Capnodium citri</em>) in the leaves and fruits was quantified in a citrus orchard in the municipality of Victoria, Tamaulipas, Mexico. <strong>Methodology:</strong> Nymphs and adults of the whitefly were sampled in the citrus trees selected at random in a 500-hectare orchard. The specimens were identified with taxonomic keys of the whitefly species. Then, the size of the nymphal and adult population of the identified fly species was determined, and the percentage of severity of sooty mold in the leaves and fruits was quantified. <strong>Results:</strong> In the orchard, the whitefly species present on the trees was identified as <em>Tetraleurodes ursorum</em> Cockerell, 1910. Of this species, more than 75 adults were recorded on the leaves and fruits per tree, and an average of 20 nymphs per developing shoot per tree. In the case of the severity of <em>C. citri</em>, this was greater than 80% in 95% of the fruits and leaves per tree. <strong>Implications:</strong> The results of this study are very useful for the development of sampling and control strategies for <em>T. ursorum</em> that help prevent the spread of this pest insect in the citrus zone of Tamaulipas state. <strong>Conclusion:</strong> Based on the results, the focus of <em>T. ursorum</em> infestation in the study area represents a risk for citrus production in the municipality of Victoria, Tamaulipas. Said infestation may be related to the presence of insect host weeds, and possibly to the biological control of the pest insects and to the organic management of some citrus varieties in the orchard.</p>