Managing Flower and Fruit Drop in Mango

Understanding Mango Flower and Fruit Drop

It is normal for mango trees to shed a large number of flowers and young fruits. A healthy mango tree produces thousands of flowers, but only a small percentage (often less than 1%) develop into mature fruits. This natural shedding helps the tree manage its resources and ensures the remaining fruits grow well. However, when the drop is excessive, it can significantly reduce your mango yield, requiring careful attention and management.

Key Causes of Excessive Drop

Several factors can lead to an abnormal loss of mango flowers and young fruits:

Environmental Stress: Sudden changes in temperature (very high or very low), strong winds, hailstorms, or unseasonal heavy rains during flowering and fruit set can cause significant drop. High humidity can also hinder pollination.
Water Imbalance: Both insufficient water (drought stress) and excessive water (waterlogging) can stress the tree, leading to flower and fruit drop. Consistent moisture is vital during critical stages.
Nutritional Deficiencies: Lack of essential nutrients, especially Boron, Zinc, Nitrogen, and Phosphorus, can weaken the tree and impair fruit development.
Pests and Diseases: Pests like mango hoppers, thrips, and fruit flies, along with diseases such as powdery mildew and anthracnose, directly damage flowers and young fruits, causing them to drop.
Poor Pollination: Inadequate activity of pollinators (bees and other insects) or unfavorable weather conditions during flowering can lead to unfertilized flowers, which then drop.
Hormonal Imbalance: Internal hormonal factors within the tree can also influence shedding.

Effective Management Strategies

To minimize excessive flower and fruit drop, a combination of cultural practices and timely interventions is necessary:

Nutrient Management

Ensure your mango trees receive balanced nutrition. Soil testing can help identify specific deficiencies. Apply fertilizers as per recommendations, focusing on critical nutrients during flowering and fruit development stages.

Nutrient	Role in Fruit Set	Application Timing
Nitrogen (N)	Vegetative growth, overall tree health	Before flowering (e.g., Sept-Oct)
Phosphorus (P)	Flower and fruit development, root growth	Before flowering and fruit set
Potassium (K)	Fruit quality, disease resistance	During fruit development
Boron (B)	Pollination, fruit set	Foliar spray before flowering (e.g., 0.1-0.2% Borax solution)
Zinc (Zn)	Hormone production, enzyme activity	Foliar spray before flowering (e.g., 0.2-0.5% Zinc Sulphate)

Water Management

Maintain consistent soil moisture, especially from flowering until fruit development. Avoid both water stress and waterlogging. Irrigate regularly during dry spells, but reduce irrigation during peak flowering to encourage fruit set, then increase it as fruits develop. Drip irrigation is highly effective.

Pest and Disease Control

Regularly monitor your orchard for pests and diseases. Apply appropriate fungicides (e.g., Carbendazim for powdery mildew, Mancozeb for anthracnose) and insecticides (e.g., Imidacloprid for hoppers) at recommended dosages and timings, particularly before and during flowering. Consult local agricultural extension for specific recommendations.

Hormonal Sprays

Plant growth regulators like Naphthalene Acetic Acid (NAA) at very low concentrations (e.g., 10-20 ppm) can be sprayed after fruit set to reduce fruit drop. This should be done carefully, following expert advice, as incorrect dosages can be harmful.

Best Practices for Prevention

Orchard Hygiene: Keep the orchard clean by removing weeds and fallen debris to reduce pest and disease reservoirs.
Pruning: Light pruning after harvest can improve air circulation and sunlight penetration, leading to healthier flowering.
Pollinator Attraction: Encourage natural pollinators by planting flowering plants around the orchard or by placing bee hives.
Windbreaks: Plant tall trees as windbreaks around the orchard to protect flowering trees from strong winds.
Timely Interventions: Act quickly at the first sign of pest or disease issues, or during adverse weather conditions.

By implementing these management practices, farmers can significantly reduce excessive flower and fruit drop in mango trees, leading to improved yields and better quality fruit. Regular monitoring and a proactive approach are key to a successful mango harvest.