Journal of Tropical Crop Science
Vol. 13 No. 02 (2026): Journal of Tropical Crop Science

Yield Components Response in ‘Barhi’ Dates Phoenix dactylifera to Organic Fertilization, Foliar Gibberellin, and Tryptophan

Sarah R. M. Alzamili (Department of Horticulture and Landscape, Faculty of Agriculture, University of Kufa, Najaf, Iraq)
Ghalib B. A. Al-Abbasi (Department of Horticulture and Landscape, Faculty of Agriculture, University of Kufa, Najaf, Iraq)



Article Info

Publish Date
29 Jun 2026

Abstract

 A two-season was conducted in the palm tissue culture station of orchard/horticulture department in Najaf Governorate, Iraq, from February 1st to October 1st 2024 for the first season and from February 1st to October 1st 2025 for the second season. The organic fertilization (sheep manure) at 0, 15, and 20 kg per tree, foliar spray with gibberellin at 0, 200, and 300 mg/L, and tryptophan at 0, 50, and 100 mg/L, were evaluated for their effects on ‘Barhi’ date palm growth and yield indicators. The results indicated that organic fertilization produced the greatest increase in leaf auxin and gibberellin content. In contrast, treatments with gibberellin and tryptophan resulted in comparatively smaller increases. Hormone levels in the control were approximately 20% lower than those observed in the lowest treatment. The fruit size was larger in the total interactions, but was not significantly affected by the individual treatment. However, fruit weight and cluster weight differed among the experimental factors. In general, the interaction treatment of organic fertilizer 20 kg per palm and gibberellins 300 mg/L in the presence of tryptophan 100 mg/L significantly resulted in the highest plant content of auxins (34.911 μg/g FW) and gibberellins (35.181 and 35.173 μg/g FW), fruit weight (13.020 and 11.573 g), fruit size (11.670 and 11.720 cm³), cluster weight (9.527 and 10.873 kg) and the total yield (38.109 and 38.780 kg per tree).

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Journal Info

Abbrev

agro

Publisher

Subject

Agriculture, Biological Sciences & Forestry

Description

Journal of Tropical Crop Science is an international journal publishing research related to tropical crops. Articles in the journal focus on in-vivo and in-vitro production and production environment, breeding, seed technology, physiology, postharvest, pest and pathology of cereals, vegetables, ...