Agriculture.ph Blog

Why Enhance Readiness to Flower in Carabao Mango?

Bugante and his colleagues began the project with the objectives of increasing the number of trees flowering and the flowering intensity. Mr. Bugante considers flower induction as the first step in the production process. Flowering response to potassium nitrate (KNO3) spray is dependent on tree “condition”, climate, and time of application.

The kind of response to KNO3 application could be either flowers, leaf flush or none. However, a good response is if over 60% of the trees flower, and over 30% of the shoots flowering spread over the entire tree canopy. To obtain flowering response, the relationships between and among the several factors have to be considered – the TREE, CLIMATE and CULTURAL PRACTICES.

The Carabao mango cultivar has a long juvenile period, strong dormancy characteristics, and responds to chemical/ smoke induction.

Juvenility refers to the period between planting and first flowering, usually ranging from 3-14 years. Juvenile trees/ shoots do not flower when induced but may flush instead. Cutting of large branches produces juvenile shoots, which have relatively large twigs and leaves, long internodes and retain leaves at the last 3 or more previous flushes. Regular fertilization and irrigation during the dry months induce frequent flushes thus shortening the juvenile period.

Juvenile trees attain “phase change” before flowering and still undergo a “transition” period from young to mature stage. Young trees have smaller, shorter shoots than the juveniles. Their leaves are retained at the last 2-3 internodes. Young trees respond only occasionally and usually limited to December to May period of induction. Early (October-November) and late (May-June) induction may result in leaf flush or no response in young trees.

The mature Carabao mango tree, on the other hand, can be induced to flower any month of the year. A mature tree is ready to flower 4-9 months from flushing, though a minimum of 6 months is needed for good fruit set and retention. Flowering intensity increases with shoot age, and initiated buds may stay dormant for 2 years. Leaf color changes from light green at 4 months to dark green at 6 and coppery bronze at over 9 months.

There are factors and cultural practices that may insure vigorous flush.

Flowering response is dependent on the vigor of the tree/ flush. Flush is vigorous when it occurs fast, old leaves are shed and covers the entire canopy. Factors and cultural practices that may insure vigorous flush are regular fertilization / manuring; irrigation if the soil is dry at flowering, fruit set, fruit maturation and after harvest; deep and well-drained soil; and protection of new flushes from pest injury.

Climate affects flowering response. Flowering response is good if rainfall prior to and during months of induction is less than 200 mm/mo. Extended rainy period in October to December (late dry season) and early onset of rainy season in April to May induce flushing in juvenile, young and mature trees

Therefore, the project’s recommended ways to increase readiness to flower in mango are by inducing vigorous flush by fertilization, manuring and irrigation, and by protecting flush from pests. You could also offset the tendency to flush in young trees due to excess soil moisture by chemical means (use of Cultar –drench 4 months before induction), root pruning/ cultivation/ intercropping, bark ringing (cutting a strip of bark around the trunk 4 months after flush), and bending of branches.

Bibliography:

Bugante, Restituto D. Jr., Protacio, Calixto M., Quinto, Julita E., and Gerardo G. Paelmo. Enhancement of readiness to flower in mango. Postharvest Horticulture Training and Research Center and Department of Horticulture. University of the Philippines Los Baños, College, Laguna.

For details of the study, please contact:

Dr. Calixto M. Protacio
Flowering/Physiology
Associate Professor
Department of Horticulture
College of Agriculture
U.P. Los Baños, College, Laguna
Tel. No. (049) 536-2448, 2478