Sri Lanka cultivates maize and rice as its two main crops and two growing periods are rotated in one year for every kind of crop. The main Maha season lasts from October to March while the remaining months belong to the second Yala season. The reporting period covers the entire sowing and growing season of Yala rice and maize. According to the CropWatch indicators, crop condition is assessed as roughly  up to May, it dropped sharply bas as much as 0.2 NDVI units after mid-June.

The interpretation which assigns the NDVI drop to persistent cloudiness is not incompatible with the prevailing below average RADPAR (4% below average, nationwide), abundant rainfall (+45% compared with average) and relatively cool weather (TEMP 0.9℃ below average).  The fraction of cropped arable land (CALF) remained stable compared with the five-year average. Except for the effects of cloud in late monitoring period, crop production performed well under the abundant precipitation, with BIOMASS increasing 18% compared to the five-year average.

There were some spatial differences according to NDVI profile clusters and map. The whole country suffered a minor departure from average in April. Thereafter, crop condition fluctuated around the average in northern and eastern Sri Lanka while all other regions experienced departures from average to different extent. The North-western Province suffered bad conditions since May, especially in mid-May and mid-June. In the south-east of the country, the crops did unsatisfactorily since May and recovered to average in July in the  Western Province. VCIx patterns tend to disagree with NDVI profiles, with low values distributed over the eastern and northern coast, and high values occurring throughout the country. The average VCIx value for Sri Lanka is rather high at 0.93.

Regional analysis

Based on the cropping system, climatic zones, and topographic conditions, three sub-national, agro-ecological regions can be distinguished for Sri Lanka. They are the Dry zone, the Wet zone, and the Intermediate zone.

The Dry zone shows the most favorable agroclimatic and crop conditions for the country. The crop condition was slightly below average in April and above average after that. The agroclimatic indices show that rainfall was markedly over average (RAIN +51%) while temperature and radiation was poor (TEMP -0.9℃, RADPAR -4%). 

The Wet zone (the northeast of the country) shows the least favorable values among the three sub-national regions discussed here. The crop condition was below average all the time and reached its lowest value in May and June. Less precipitation excess (RAIN +34%) compared with other two sub-national regions and constant cloud cover may substantially impacted the second maize and rice.

The Intermediate zone is located between the Dry and Wet zones, and therefore has the most comfortable weather condition over Sri Lanka. Temperature and radiation anomalies were close to those in the Dry zone (TEMP -0.9℃, RADPAR -4%) but rainfall was relatively more abundant (RAIN +57%). According to the NDVI development graphs, this region suffered below average crop condition but recovered to above average in July.

CropWatch puts the production of maize and rice during 2018 slightly below those of 2017.

                      Figure 3.21. Sri Lanka crop condition, April - July 2018

                                                                             (a) Phenology of major crops

                                                                                                    (c) Maximum VCI

(b) Crop condition development graph based on NDVI

(d) Spatial NDVI patterns compared to 5YA                                                          (e) NDVI profiles

(f) Crop condition development graph based on NDVI(Dry zone (left) and Wet zone (right))

(g) Crop condition development graph based on NDVI (Intermediate zone)

Table 3.50. Sri Lanka agroclimaticindicators by sub-national regions, current season's values and departure from15YA, April - July 2018

Table 3.51. Sri Lanka agronomicindicators by sub-national regions, current season's values and departure from5YA, April - July 2018

Table 3.52. CropWatch-estimated maizeand rice production for Sri Lanka in 2018 (thousand tons)