Extreme weather adversely affecting fruit, veggie crops

In a worrisome trend pointing towards global warming, Western Disturbance-induced extreme weather conditions are coming to fore in the region reflecting an increased amount and frequency of rainfall received from March to May.

During the first week of May, 66.8 mm of rainfall pounded Solan within three days from May 2 to 5. This is nearly the month’s normal of 67.7 mm rain received in the earlier years. The incessant rain accompanied by hailstorm events and gusty winds caused substantial damage to the standing crops across several regions. Similar affects were also noticed in other neighbouring districts, especially in Shimla, observed Dr Satish Bhardwaj, Head of Department of Environmental Sciences, Dr YS Parmar University of Horticulture and Forestry, Nauni in a study conducted by scientists.

“Similar findings have been corroborated in various studies conducted across the nation with high frequency of hailstorm occurring during May,” explained Dr Bhardwaj.

“Global warming is contributing to warmer atmosphere capable of holding more moisture, thereby increasing the frequency of extreme weather events such as intense rainfall and hailstorms,” observed the weather scientist. In India, hailstorms are typically a summer phenomenon. In mountainous regions, orographic lifting of warm, moist air along the slopes leads to formation of large cumulonimbus clouds, which are responsible for moderate to heavy rainfall and hailstorm. This process is particularly active during the summer/pre-monsoon season due to strong atmospheric instability over the Himalayan foothills.

Moderate rainfall coupled with hailstorm events in these months had a significant adverse impact on horticultural crops. Fruit crops such as apple and stone fruits like plum, apricot, peach, etc, have suffered from fruit drop and scarring, particularly in mid hill sub humid zone of the state. Hailstorms severally impact mango and litchi crops in the low hills. In mango, hailstorms often lead to premature fruit drop, significantly affecting its yield and quality.

Litchi fruits are equally vulnerable with hail causing cracking, shedding and damage to the tender foliage, resulting in considerable losses to farmers.

Vegetable crops, including tomato, capsicum, French beans, etc, at their vegetative stage have faced foliage damage and stem breakage, especially in the open field conditions. Farmers have been advised to adopt pre and post-hailstorm management strategies to minimise crop damage and follow weather forecast advisory. Measures like timely installation of hail nets to protect fruits plants from damage has been advised.

Wounds caused by hail provide entry point for pathogens both fungal and bacterial and plants weakened by hailstorm are more susceptible to pests and secondary infection. Farmers have been advised to remove the infected branches and other parts, including fruits from the orchard.