Evaluation of pollen production of common male date palms grown in the mexicali valley, Mexico

Authors: SALOMON-TORRES, RICARDO - Universidad De Sonora; ORTIZ-URIBE, NOE - Universidad De Sonora; Krueger, Robert; GARCIA-VAZQUEZ, JUAN CARLOS - Autonomous University Of Baja California; COHEN, YUVAL - Volcani Center (ARO); WRIGHT, GLENN - University Of Arizona; SAMANIEGO-SANDOVAL, LAURA - Universidad De Sonora

Submitted to: Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/14/2022
Publication Date: 8/18/2022
Citation: Salomon-Torres, R., Ortiz-Uribe, N., Krueger, R., Garcia-Vazquez, J., Cohen, Y., Wright, G.C., Samaniego-Sandoval, L. 2022. Evaluation of pollen production of common male date palms grown in the mexicali valley, Mexico. Agriculture. https://doi.org/10.3390/agriculture10020045.
DOI: https://doi.org/10.3390/agriculture12081248

Interpretive Summary: Date palms are dioecious plants; that is, male and female flowers are borne on different plants. This makes artificial pollination critical for good fruit set under cultivation. The quantity, quality, and time of production of pollen are important characteristics of male date palms. This study had the objective of identifying local male date palms with desirable characteristics in Northwestern Mexico. Twelve seedling male date palms with phenotypes similar to common female cultivars grown in the area (Medjool, Deglet Noor, Khadrawy, Zahidi) were evaluated for quantity of pollen produced, timing of production, and viability as measured by an in vivo fruit set assay. Seedling male palms in the groups resembling Deglet Noor and Medjool produced the largest quantity of pollen. All four groups showed good viability and fruit set. This study identified superior local male date palm in Northwest Mexico that should be considered for clonal propagation to produce good pollen sources for the local producers.

Technical Abstract: The aim of this study was the evaluation of date palm (Phoenix dactylifera L.) pollen production during the 2021 and 2022 seasons in the Mexicali Valley, Mexico. Twelve seedling male palms of 20 years of age and similar vigor were selected and grouped into four groups with phenotypic characteristics of the common female cultivars in the area (Medjool, Deglet Noor, Khadrawy, and Zahidi). The pollen was extracted manually, with average production among all individuals of 780.94 and 777.11 g, in 26 and 24 inflorescences, respectively for each year. Likewise, the flowering period on average was 47 and 41 days for each year. The pollen extracted from the earliest four inflorescences averaged 38.7 and 32.55 g, while that of the latest one produced 10.70 g and 18.28 g for each year, respectively. Seedling male palms with a phenotype similar to the Deglet Noor cultivar produced the greatest amount of pollen with 1,250.98 and 1,114.26 g on average for each year, produced during a late, short flowering period. Likewise, those palms with phenotype similar to the Medjool cultivar produced the second highest amount of pollen with 851.28 and 866.43 g on average for each year, produced during an early, long flowering period. Finally, an in vivo viability test through the fruit set percentage, revealed that the use of any of these four pollen sources would be suitable for pollination of the recipient female cultivar Medjool, the most widely cultivated variety in Mexico. These results will allow date producers to select and propagate better pollen-producing male palms.