Colombia is the Latin American country with the second-largest area planted with OxG hybrid cultivars, covering more than 120,000 hectares Various health problems can affect yield, especially those affecting fruit. Since 2021, white fruit rot has been reported in the northern, central, and southwestern palm-growing areas. Therefore, the objective of this study is to identify associated symptoms and their causal agent. To this end, a total of six locations in the three palm-growing regions were visited, and 36 samples of affected fruits were collected to obtain microorganisms. These microorganisms were inoculated into detached fruits under in vitro conditions, and seven isolates were inoculated into bunches in the field. They were morphologically and molecularly characterized by partial sequencing of the ITS and TEF1 regions. Symptoms of white rot were observed, starting from the base of the fruit to the apex, with the development of a cottony mycelial mass, followed by the formation of sclerotia. A total of 33 organisms were obtained, 30 isolates identified as Agroathelia rolfsii, one Fusarium sp., one Rhizoctonia sp., and one Pestalotiopsis sp. isolate. The Agroathelia isolates exhibited white, cottony growth adhering to the surface of the PDA culture medium. After four days of growth, they developed globose to ellipsoid sclerotia (average 1.00 ± 0.26 (0.46–2.20 mm)). These were initially white and turned brown as they developed, with the average number of sclerotia per plate ranging from 4 to 449 (n = 6). In the in vitro pathogenicity test, only A. rolfsii isolates were pathogenic, with a 100% incidence, an average severity ranging from 10 to 40% infection, and a range of 10 to 100%. In field inoculations, 100% of the inoculated bunches exhibited symptoms similar to those observed under natural field conditions. In all cases, the pathogen was recovered, fulfilling Koch’s postulates and confirming that A. rolfsii is the causal agent of white fruit rot. This constitutes the first record of Agroathelia rolfsii in oil palm in Colombia.

Weeds and economically important crops (tomato, pepper and passion fruit) in Valle del Cauca are currently affected by viruses of the Begomovirus genus, including PLDV, RhGMCV, PRMV, PYMV, and CroGMV. This study aimed to identify weed species associated with crops of agronomic interest that may serve as natural reservoirs of these viruses. Leaf samples were collected from various weeds in crop fields across Candelaria, Cerrito, and Palmira, and total DNA was extracted. Virus detection was performed by PCR using both universal Begomovirus primers and specific primers for PLDV, RhGMCV, PRMV, PYMV, and CroGMV. The incidence of each Begomovirus was analyzed by host species. Among the 16 samples collected, RhGMCV was the most prevalent virus (31.25%), followed by PRMV (25%) and PLDV (12.5%). PYMV and CroGMV were not detected. Corchorus orinocensis was found to be singly infected with RhGMCV, marking, to the best of our knowledge, the first report of this species as a host for Begomovirus. Tithonia diversifolia, Malvastrum coromandelianum, and Solanum nigrum were also identified as new reservoirs in Colombia, each exhibiting single infections with RhGMCV, PRMV, or an uncharacterized Begomovirus. Macroptilium lathyroides presented a mixed infection with PRMV, PLDV, and RhGMCV. These findings expand the known range of natural Begomovirus reservoirs in Valle del Cauca and contribute valuable data for the development of targeted management strategies to mitigate viral disease in crops of agricultural importance.