Fertigation in Papaya

Fertigation, i.e., the application of water-soluble fertilizers through drip irrigation, has become an efficient method in papaya cultivation. It ensures uniform distribution, higher nutrient-use efficiency, and better crop performance. Fertigation programs generally include urea or calcium nitrate as nitrogen sources, mono-ammonium phosphate or phosphoric acid for phosphorus, and muriate of potash or sulphate of potash for potassium. Fertilizers are applied 2–3 times per week depending on the growth stage, and micronutrients are often supplemented through foliar sprays.

Micronutrient Management

Micronutrients are essential for balanced papaya nutrition, and their deficiencies can significantly reduce yield and fruit quality. Boron deficiency leads to deformed fruits and poor seed development, while zinc deficiency causes small leaves and stunted growth. Iron deficiency results in leaf chlorosis, particularly in calcareous soils. Regular foliar sprays of micronutrient mixtures are therefore recommended. A common practice is to spray zinc sulfate (0.5%) and boric acid (0.1%) during the flowering stage to improve fruit set, and ferrous sulfate (0.5%) to correct chlorosis. Calcium nitrate (1%) sprays during fruit enlargement prevent fruit cracking and improve firmness.

Integrated Nutrient Management (INM)

For sustainable papaya cultivation, integrated nutrient management is highly recommended. This approach combines organic manures, biofertilizers, and chemical fertilizers in a complementary way. For example, 50% of the nutrient requirement can be met through inorganic fertilizers, while the remaining 50% is supplemented by farmyard manure, green manures, and biofertilizers. Such integration improves soil health, enhances microbial activity, reduces the risk of nutrient leaching, and ensures long-term sustainability of papaya production.

Nutrient Deficiency Symptoms

Identification of nutrient deficiency symptoms is critical for corrective management. Nitrogen deficiency appears as yellowing of older leaves and stunted growth. Phosphorus deficiency causes a purplish discoloration on leaf undersides and delays flowering. Potassium deficiency manifests as leaf-edge scorching and poor fruit development. Calcium deficiency leads to fruit cracking, while boron deficiency results in misshapen fruits. Zinc deficiency is identified by rosette formation and chlorosis of young leaves. Recognizing these symptoms early and correcting them through soil or foliar applications prevents significant yield losses.

Best Practices for Fertilizer Application

To maximize fertilizer use efficiency, certain best practices must be followed. Fertilizers should be applied in a circular band 20–30 cm away from the plant stem to prevent stem rot. Mulching with organic materials or plastic film helps conserve soil moisture and reduce nutrient losses. Soil testing should be conducted regularly to determine pH, electrical conductivity, and nutrient status, ensuring that fertilizer recommendations are based on scientific data. Where soils are saline, sulphate of potash should be used instead of muriate of potash. Furthermore, fertilizers should always be applied in split doses rather than a single heavy application.