Heat stress causes scalding, fruit drop in mango orchards

Panaji: Mango growers in Goa are facing a difficult season marked by unusual spotting on the fruits during the peak fruiting season, with early assessments pointing to environmental stress rather than pest or disease as the primary trigger.According to horticulture scientist AR Desai, who recently retired from ICAR Goa, the symptoms being observed — depressed, discoloured patches on the fruit surface — are typically associated with physical or climatic injury.“Generally, this kind of symptom is seen when fruits are struck by hailstones. The impact causes injury, and those damaged spots later appear as depressed lesions,” Desai told TOI. “However, there has been no hailstorm activity in Goa recently, so that is unlikely to be the cause in this case.”Instead, Desai pointed to intense sunlight exposure as a more probable factor. “At times, fruits exposed to the highest intensity of sunlight, particularly on the northern side during certain periods of the day, can suffer localised cell death. This results in patches that later develop into visible spotting,” he said.This condition, commonly referred to as sunburn or sunscald, is seen in tropical fruit crops during spells of high temperature and strong solar radiation.

While initially a physiological disorder, the affected areas can become vulnerable to secondary infections.“Such damaged spots may later be colonised by pathogens, leading to diseases like anthracnose,” Desai added, warning that it could escalate into fungal infection if conditions remain conducive.Farmers have been advised to monitor orchards closely, especially fruits exposed directly to harsh sunlight.“Because of the heat, fruits are dropping even before harvest,” retired agriculture officer-turned-farmer Sanjeev Mayekar said, referring to orchards in and around Bicholim.He further said that the crop has been impacted at multiple stages this year. “First, flowering was affected. Then the fruit setting was low. After that, there was fruit drop. Now, even the mature fruits are falling.”A Sattari-based farmer said that such changes could have long-term consequences for fruit cultivation. “These pressures are influencing farming decisions over time. If worsening climate conditions continue, mango cultivation could face deeper setbacks,” he added.