How to Overcome Alternate Bearing in Mango? Detailed Explanation of Cultivation Measures

To overcome alternate bearing in mango, the first requirement is to have an appropriate amount of flowers; the second is to have the flowering period avoid low-temperature rainy weather; the third is to find ways to increase the fruit-setting rate. The measures are:

1. Selection of varieties. According to the characteristics of Guangxi's early spring, which is mostly low-temperature rainy weather, it is ideal for mango to bloom after early April. Therefore, varieties with a late flowering period, strong ability to regrow after the inflorescence freezes to death, and a relatively high proportion of bisexual flowers should be selected, such as Zihua mango, Guixiang mango, Qiu mango and Xiangya mango.

2. Strengthen management. After fruit harvest, more organic fertilizer should be applied, especially phosphorus and potassium fertilizer, and quick-acting fertilizer should be reasonably applied during the autumn shoot growth, flower panicle emergence, flowering period and fruit-bearing period. After fruit harvest, shallow plowing should be carried out, and deep plowing should be carried out around the Beginning of Winter to create a relatively fertile, loose, moist orchard soil environment with coordinated fertilizer, water, air and heat. For mango orchards on barren mountainous and hilly land, special attention should be paid to deep plowing and green manure incorporation to improve the soil; the orchard irrigation and drainage system and soil and water conservation engineering should be well constructed to lay a good foundation for high and stable mango yields.

3. Reasonable pruning. Bearing mango trees generally undergo summer pruning and post-harvest pruning. Summer pruning usually involves removing all summer shoots to regulate the conflict between summer shoots and fruits competing for nutrients; at the same time, inner canopy branches and overly weak or overly dense inflorescences should be thinned; branches in the middle and upper parts that shade the fruit and have no flowers or fruit should be cut away, so that the fruit is exposed, reducing damage from diseases and pests, and promoting fruit enlargement. Post-harvest pruning is generally carried out after fruit harvest and before the autumn shoots sprout. Remove overly dense branches that affect light, weak branches, drooping branches, aged branches with no fruiting capacity, dead branches and diseased and insect-damaged branches, so as to improve light conditions and save nutrients, and promote the growth of the remaining branches. In addition, crossing branches between tree canopies and within the canopy should be cut back so that the canopies maintain a certain distance; the declining branches at the tips, overly long vegetative branches and fruiting mother branches should be cut off to promote the sprouting and growth of autumn shoots.

4. Control diseases and pests. The main mango diseases are: anthracnose, sooty mold, powdery mildew, gummosis, fruit spot disease and scab; the main insect pests are: tail night moth (also known as heart-boring worm, shoot-boring moth), leafhopper, poisonous moth, scarab beetle, etc. For disease control, use carbendazim or thiophanate-methyl at 700-800 times dilution, spraying 1-2 times each when new shoots emerge and during the fruit-bearing period; when new shoots are about 3 cm long, spray trichlorfon plus dimehypo each at 800 times dilution or methamidophos and omethoate at 800-1000 times dilution, once every 7-10 days, 2-3 times per shoot period.

5. Promote flowering and remove flowers. Insufficient flower quantity in an off year is an important cause of reduced yield. For late-flowering varieties, from mid-December to early January, spray the canopy with ethephon at 800-1000 times dilution or ethephon at 1000-1200 times dilution mixed with B9 at 300-400 times dilution, which can increase the panicle emergence rate by 15%-35%. If the inflorescence emerges too early, it can be removed when the inflorescence grows to 3-5 cm to promote the re-sprouting of lateral flower buds.

6. Protect flowers and fruits. Place bees for pollination during the flowering period, with 15 beehives per hectare of orchard; when there are few bees, use artificial supplementary pollination. After flowering, use 0.3% monopotassium phosphate plus 0.2% urea for 1-2 foliar topdressings; spray 0.1% boric acid at full bloom; spray 5-8 PPM 2,4-D 2-3 times or 20-30 PPM “920” etc. during the fruit-bearing period, all of which have obvious effects on protecting flowers and fruits.