'Litchi farmers should adopt climate-smart practices'

Bihar commands the litchi landscape of India, contributing nearly 40% of the national output. Cultivation spans around 32,000 hectares across the state with Muzaffarpur alone holding 12,000 hectares famous for its GI-tagged Shahi Litchi. However, the sector is experiencing significant disruptions from climate variability and pest infestations. To understand these challenges and explore viable solutions, TOI’s Madan Kumar spoke with Bikash Das, dDirector of the ICAR-National Research Centre on Litchi (NRCL), Muzaffarpur. In this interview, Das breaks down the current production crisis, the impact of the destructive litchi stink bug, and strategies to safeguard the crop.Could you provide an overview of the current litchi production scenario in Bihar this season?It is a critical period for our litchi sector. Under normal conditions, Bihar produces approximately 300,000 metric tonnes of litchi annually. However, this year has been exceptionally difficult. Farmers across key hubs like Muzaffarpur and Vaishali are reporting massive crop reductions, with losses reaching up to 70 per cent in a few pockets like the Minapur block. Currently, many orchards are yielding only 60 to 65 per cent of their normal capacity. This represents one of the most severe production drops we have seen in recent history.What specific climatic anomalies have caused such a severe drop in production this year?Litchi is a microclimate-sensitive fruit crop that requires specific temperature and humidity bands. Three sequential weather anomalies disrupted the crop cycle this season: In November and December, minimum temperatures were 1.8°C and 0.8°C higher than normal, respectively. Litchi trees require a distinct winter chill to transition from vegetative growth to reproductive growth. Due to the warmer winter, trees put out new vegetative flushes (leaves) instead of floral panicles, resulting in poor flowering. During the late winter flowering window, sudden cloudy skies and rain stimulated severe outbreaks of the flower webber pest. This directly damaged the blossoms and prevented proper fruit setting. In April, temperatures skyrocketed past optimal limits alongside dry, westerly winds. Litchi fruits cannot tolerate extreme heat at early development stages, triggering massive premature fruit drop.Moving to the biological threat, the litchi stink bug has been making headlines. How severe is this pest?The invasive litchi stink bug is an existential threat to our orchards. While it was historically a minor pest in India, it was first detected in Bihar around 2018 in East Champaran district. It likely entered the state via logwood transport vehicles coming from other states, where the bug feeds on its native host, the Kusum tree. Since 2018, it has spread aggressively. Both adult bugs and nymphs use their mouthparts to pierce and suck the sap out of tender vegetative shoots, flower panicles, and young fruits. This feeding causes immediate panicle blight, shoots to dry up, and severe fruit drop. In severely infested orchards where no controls are applied, the damage can reach 90 to 95 per cent, giving it the potential to completely wipe out profitable litchi farming in affected zones if left unchecked.What is your final message to the litchi growers of Bihar facing these overlapping crises?While the current climate and pest challenges are severe, they are not insurmountable. By adopting Good Agricultural Practices (GAP), maintaining strict pest surveillance, and migrating toward climate-smart orchard management, we can fully protect Bihar's litchi wealth. The ICAR-NRCL stands fully committed to supporting our farmers with technical know-how and resilient technologies.