Citrus fruit dropping in large numbers before maturity, what is wrong (santra)?

Heavy fruit drop in citrus before maturity usually has more than one cause, and finding the right one matters. The most common reasons are moisture stress and uneven irrigation, nutrient shortages especially of potassium and micronutrients, sudden weather swings and heat, hormonal imbalance, and pest or disease attack such as fruit fly, fruit borer, or fungal fruit rots, while citrus greening also causes drop along with its other symptoms. First fix the basics: keep soil moisture even with regular irrigation rather than long dry spells followed by heavy watering, and mulch the basin. Correct nutrition based on a soil or leaf test from your KVK. Cut open some dropped fruit to check for maggots or borer grubs and look for rot, since those point to a pest or disease that needs separate action. Rule out citrus greening if you also see blotchy mottled leaves and lopsided bitter fruit. Some growers use a recommended low-dose plant growth regulator such as a planned NAA spray at the proper stage to reduce drop, but the dose and timing must come from your horticulture department. Please show samples to your KVK to confirm the cause before acting, and mind residue and pre-harvest interval for any spray.