The Agriculture Ministry cut its growth forecast for Thailand's agricultural sector from 4% to a range of 1.5% to 2.5% after only a slight expansion in the first half of the year.
After the sector expanded by only 0.4% in the first six months, the ministry blamed the drop on the severe drought that hit widespread plantations from late last year until May, said ministry spokesman Apichart Jongskul.
Early mortality syndrome (EMS), which ravaged Thai shrimp farming for several months and cut production by over 40%, was the main reason behind the drop in the fisheries sector.
Other fisheries products were affected by the drought, causing the fisheries sector to contract by 7.1% year-on-year.
Operators estimated revenue losses of 16 billion baht from falling shrimp shipments in the first half, a year-on-year decrease of about 30%.
The export situation is expected to continue to decline due to the weak global economy, with the Thai Shrimp Association braced for a 40% fall in shipments this year.
Crops were the only strong sector in the first half, with a 1.9% expansion from last year thanks to higher production of rice, cassava, oil palm, rubber, durian and mangosteen, said Mr Apichart.
Besides proper irrigation that promotes rice output, the state's rice-pledging scheme has encouraged farmers to expand production and push the crop sector towards growth of 3.3% to 4.3%.
The livestock sector also performed well, especially pigs, thanks to the reduced impact of porcine reproductive and respiratory syndrome.
High demand for chicken meat in Europe and Japan will help shipments to rise by 5% this year. As of May, Thailand exported 219,000 tonnes of chicken products, up 4.7% year-on-year.