The effect of pruning and the use of a growth regulator on initial flowering in mangos.
Avilán L., Azkue M., Soto E., Rodriguez M., Ruiz J., Escalante H.
Author Affiliation: Instituto Nacional de Investigaciones Agrícolas (INIA), Centro Nacional de Investigaciones Agropecuarias (CENIAP), Instituto de Investigaciones Agronómicas (IIA), Maracay 2101, Estado Aragua, Apdo. Postal 4653, Venezuela.
Revista de la Facultad de Agronomía, Universidad del Zulia 20 : 430-442
Abstract : The mango cultivars Haden, Tommy Atkins, Springfels and Edward grafted on Criollo stalks were planted at 6×6 m (278 trees ha-1) to evaluate the effects of pruning at a height of 2 m; of paclobutrazol (PBZ) when applied to the soil (2.5 g per tree); and of the flowering promoter potassium nitrate (KNO3), at 6% on the vegetative growth, flowering and yield of the cultivars. The treatments comprised: control (T), T + PBZ, pruning (P) and P + PBZ. P + lateral branch pruning at a radius of 2 m (P + L); and P + pruning of internal primary branches (P + E). The results indicate that initiation of flowering is associated with the increment of the number of days with night temperatures under or equal to 20°C. The results also suggest the existence of different number of days required under 20°C among cultivars, independent of the annual-production cycle. With the exception of the 1998-99 cycle, flowering started first in the treatment with T and T + PBZ in Edward with an anticipation of 2-3 weeks in relation to the other cultivars and treatments considered. P delayed the beginning of flowering, regardless of its intensity and the cultivar. The occurrence in all cycles of a marked diminishing of rain, which preceded the beginning of flowering, propitiated a lower vegetative development and leaf maturation, which created conditions that favoured the leaf maturing process.