This monitoring period covers the harvest of the main rice crop and the start of the second rice season. According to CropWatch agroclimatic indicators, Thailand experienced average weather conditions compared to the last 15 years. The rainfall (RAIN, +3%) was slightly above average, while radiation (RADPAR-7%) and temperature (TEM, -0.5°C) were below average. Low radiation resulted in insufficient biomass accumulation (BIOMSS). According to NDVI development graph, the crop conditions were slightly below average. The NDVI departure clustering and the corresponding profiles show that for 83.4% of the cropland the crop conditions were slightly above average from late October to late November and deteriorated to below average afterwards. These patches appear in the Central double and triple-cropped rice lowlands, Single-cropped rice north-eastern region and South-eastern horticulture area. The crop conditions in Southern Thailand and Northwestern Thailand were always below average during this monitoring period.  Most affected regions were located in the Western and southern hill areas (including Surat Thani, Nakhon Si Thammarat et.al) and Loei, Udon Thani, Nong Bua Lamphu, Phichit, Kampaeng Phet and Nakhon Sawan. National VCIx value was at 0.90 and CALF remained near average. Considering the favourable conditions described in the November 2020 bulletin and the conditions of this monitoring period, the crop outputs are assessed as average. However, wetter conditions and less sunshine may have caused slightly unfavorable conditions for harvest and storage.

Regional analysis

The regional analysis below focuses on some of the already mentioned agro-ecological zones of Thailand, which are mostly defined by the rice cultivation typology. Agro-ecological zones include Central double and triple-cropped rice lowlands (115), South-eastern horticulture area (116), Western and southern hill areas (117) and the Single-cropped rice north-eastern region (118).

Compared to the 15YA, Central double and triple-cropped rice lowlands experienced cooler and wetter conditions. Temperature (TEMP -0.5°C) and radiation (RADPAR -9%) were below average accompanied by higher rainfall (RAIN +12%). Lower radiation led to a below-average estimate for BIOMSS (BIOMSS -35%). Although the NDVI development graph shows that crop condition were below the five-year average for most of the monitoring period, the  above-average conditions in November and high VCIx value at 0.93 indicate that crops were in favorable conditions during the main growing season and the peak growth period.

Indicators for the South-eastern horticulture area follow the same patterns as those for the Central double and triple-cropped rice lowlands: Temperature (TEMP -0.7°C) and radiation (RADPAR -11%) were below average accompanied by higher rainfall (RAIN +29%). They led to a below-average estimate for BIOMSS (BIOMSS -19%). According to the NDVI development graph, however, the crop conditions were close to average during this monitoring period except for the start and end of this monitoring period when the crop conditions were below average. Considering the favorable VCIx value of 0.93, the crop conditions were favorable.

Agroclimatic indicators show that the conditions in the Western and southern hills were slightly below average: temperature (TEMP -0.2°C), rainfall (RAIN, -9%), and radiation (RADPAR -6%) were below average, while the BIOMSS decreased by 18%. According to the favorable VCIx value of 0.93, crop conditions were assessed as close to average.

In the Single-cropped rice north-eastern region precipitation was above average by 23%, while temperature and radiation were below average by 0.2°C and 6%, respectively. According to the NDVI development graph, the crop conditions were slightly above average as contributed by the above-average rainfall. Considering the favorable VCIx value of 0.95, the crop conditions are assessed as favorable.

Figure 3.39 Thailand’s crop condition, October 2020- January 2021

(a). Phenology of major crops

(b). Time series temperature profile. (c). Time series rainfall profile

(d) Crop condition development graph based on NDVI  (e) Maximum VCI

(f) Spatial NDVI patterns compared to 5YA   (g) NDVI profiles

(h) Crop condition development graph based on NDVI (Central double and   triple-cropped rice lowlands (left) and Western and southern hill  areas (right))

(h) Crop condition development graph based on NDVI (South-eastern horticulture   area (left) and Single-cropped rice   north-eastern region (right))

Table 3.67 Thailand's agroclimatic indicators by sub-national regions, current season's values and departure from 15YA,October 2020- January 2021

Table 3.68 Thailand's agronomic indicators by sub-national regions, current season's values and departure,October 2020- January 2021