Yangyel Lhaden

Bhutan’s horticulture sector has grappled with escalating challenges, witnessing a significant downturn in fruit yields attributed to diseases and pests over the past decade. Key cash crops like oranges and apples have seen a production decline exceeding 50 percent between 2012 and 2022.

In 2012, there were 306,181 apple trees, out of which 243,967 were bearing trees, producing 7,666 metric tonnes (MT) of apples. In 2022, the number of apple trees decreased to 175,331, with 119,688 being bearing trees, and the production dropped to 2,222.94MT, according to agricultural statistics.

The yield per tree also plunged to 18.6kg per tree in 2022 from 31.42kg yield per tree in 2012.

An agriculture officer attributes the loss in production in the horticulture industry to climate change. “Apple orchards are suffering from woolly aphids, brown rot, collar rots, and apple scab diseases being reported in almost all apple-growing northern districts.”

“Unlike field crops, fruits are highly vulnerable and sensitive to climate change because of their longer duration for establishment,” an agriculture officer said. “With climate change the country is experiencing frequent extreme weather events causing widespread damages to crops and livelihoods of people.”

He said that the issue with global warming had a dramatic effect on the chilling requirement of temperature fruits such as apples. “Studies have projected a decline in the winter chill which is crucial for many fruits and nuts grown in temperate countries.”

Studies have revealed that the Himalayas and Hindukush regions were climatically very sensitive to climate change owing to our topography, an agriculture officer said. “Bhutan being one of the smallest countries whose economy is largely based on agriculture, livestock, and forests is particularly vulnerable to climate change.”

In citrus cultivation, climate change has compelled growers to shift to higher altitudes, retreating from pests and diseases prevalent at lower altitudes, an agricultural officer said. “This shift is driven by an increase in temperature and water scarcity.”

The main citrus fruit grown in Bhutan, native mandarin production, has seen a 62 percent decrease in 2022 compared to 2012. In 2022, there were 1,361,691 mandarin trees, with 714,250 bearing trees producing 18,466.6MT. In 2012, there were over two million mandarin trees, with more than a million bearing fruit, yielding close to 50,000MT. The productivity of mandarins in 2012 was 44.8kg per tree, while in 2022, it dropped to only 25.8kg.

Farmers cultivating mandarins at lower altitudes, such as those in Chukha, have shifted to growing areca nuts after losing their orchards to diseases. In Dagana, farmers have turned to cultivating cardamom as mandarin growth has ceased in their region.

The shift among farmers towards cultivating areca nuts is evident in the agricultural statistics report. In 2022, there were over two million more areca nut trees than in 2012, with over one million bearing trees that produced 11,106MT of areca nuts. However, in 2012, the productivity of areca nuts was 11.56kg per tree, while in 2022, it decreased to 7.8kg per tree.

The cardamom cultivation has also increased from about 5,000 acres in 2012 to 10,926 acres in 2022. In 2022, 1,693MT of cardamom was harvested whereas 643MT of cardamom was harvested in 2012. The yield per area of cardamom has also increased in 2022 with 178.8kg per acre from 126kg per acre in 2012.

However, an agricultural officer said that  the cardamom cultivation was also under pressure now due to widespread wilt disease. Wilt disease is caused by Phytophthora fungus and warming temperature creates favourable conditions for the fungus to thrive.

The Department of Agriculture is working towards identification of right citrus varieties for particular production zones along with scientific management of existing citrus orchards with application of the right amount of nutrients.

The department is also encouraging farmers in citrus declining areas towards fruit diversification. “We are encouraging farmers to grow high value fruit crops such as avocado, Irwin mango, macadamia nut and dragon fruits in places where citrus production is declining under Million Fruits Trees Plantation Project,” an agricultural official said.