Floración y rendimiento con inhibidores de giberelinas alternativos al paclobutrazol en mangos ‘Tommy Atkins’

The ‘Tommy Atkins’ mango is the second most important fruit cultivated in Nayarit, Mexico.
It has an irregular harvest whenever warm and damp autumns occur which affects its yield more than 50%. That being said it has been handled with the assistance of paclobutrazol (PBZ), nevertheless there are some negative effects with the use of this product.
The main objective of this investigation was to evaluate other inhibitors to paclobutrazol (PBZ) during the flowering process and production of the ‘Tommy Atkins’ mango.
The study was done within two production cycles of commercial orchard fields.
In both years were evaluated the following: 1) calcium prohexadione (P-Ca) 500 mg L^‑1, three times (3×); 2) P-Ca 1500 mg L^‑1 one time (1×); 3) P-Ca + uniconazol (UCZ) 750 + 250 mg L^‑1 (3×); 4) UCZ 1000 mg L^‑1 3×; 5) chlormequat chloride (CC) 1000 mg L^‑1 75; 6) PBZ 2500 mg L^‑1 (1×); y 7) control.
Percentage of bud differentiation was tested and bud development stage; percentage of flowering, fruit fresh weight and yield.
The results were analized using a total randomized design with 6 repetitions and a tree as experimental unit.
Percentage of differentiated buds was different (P=0.0001) in all treatments, gibberellin inhibitors surpassed the control, coming on top P-Ca and PBZ comparing with the UCZ and control treatments in year 1. In the above treatments, the percentage of buds than reached E4 was minor.
In the second cycle, there were no differences found between the GA inhibitor treatments but was not the case with the control which was easily overtaken for the rest of the treatments.
Percentage of flowering: there were significant differences between treatments in both years (P=0.0023 and 0.0001, Year 1 and 2, respectively). All GA inhibitor treatments were greater than the control, although in Year 1 P-Ca (1500 mg L^‑1) matched the PBZ effect.
In Year 2, the PBZ treatment went over 15 and 160% flowering according to the treatments.
Nevertheless, the control got less flowering in this two years tested.
Fruit fresh weight (FFW): during Year 1 FFW was lower during the CC and PBZ treatment while the greatest FFW was registered with the use of P-Ca 500 (3×) and the control.
During Year 2, P-Ca 750+UCZ 250 (3×) and PBZ decreased the fruit size but nevertheless no significant differences were observed except with P-Ca 1500 (1×), in which the fruit weight was greater (P=0.0001) compared to all the treatments, including the control.
Yield: the P-Ca treatments within both concentrations registered the best performance in Year 1; meanwhile PBZ and the control got a reduction of 16 and 40%, respectively.
In Year 2, with the best yield was observed with P-Ca 1500 (1×) treatment while the least best was registered with PBZ even though it was no different to the rest GA inhibitor treatments but it did surpassed the control.
Conclusions: calcium prohexadione, 1500 mg L^‑1 (1×) stimulate floral differentiation, percentage of differentiated buds, and floral budbreake.
All inhibitors used increase yield as compared to control.
The above results indicate than P-CA could be used instead of PBZ without significant effect on flowering and yield.

XIII International Mango Symposium

M.H. Pérez-Barraza, I.J. González-Acuña, J.J. Velázquez-Monreal, R. Cano-Medrano

Mangifera indica L., flowering, GA inhibitors, calcium prohexadione, yield

https://doi.org/10.17660/ActaHortic.2025.1415.33