The unusual profuse flowering of mango trees in Kerala ahead of the summer this year could be due to the cool night temperature, water stress condition and poor crop during the previous year, according to the preliminary observations of the phenomenon by scientists at Kerala Agricultural University (KAU).

Last week, the government had asked the KAU to study the factors behind the abundant blooming of mango trees across the State.

According to P. Indira Devi, Director of Research, KAU, the unprecedented drop in night temperature early January could be the most important factor that triggered the sudden profuse flowering. The minimum night temperature across the State in January was 16-20 degrees Celsius whereas it was 20-24 degrees C last year. Relative humidity was also lower during the period (40-60% in January 2019 compared to 60-80% in 2018).

Though the State had received unusually heavy rain during the southwest monsoon last year, the northeast monsoon was poor.

The report noted that groundwater depletion had been reported from all parts of the State soon after the rains. “Further there were no rains since December 2018,” Prof. Indira Devi said. Water stress is another factor that triggers flowering in mango.

Heavy rain during the flowering season last year had resulted in a poor crop. According to scientists, flowering is governed by a proper balance between carbohydrate reserves and nitrogen in the mango shoots.

“Poor crop during 2018 would have increased the carbohydrate reserves, contributing to the profuse flowering in 20l9,” says the report, which indicates the need for a detailed study to analyse the factors.

Farmers, however, are hoping that the unusual phenomenon would lead to a bountiful harvest.