The worry earlier this year that Ivory Coast’s cocoa mid-crop harvest (April to September) was getting insufficient rainfall just flipped on its head. Too much rainfall - inhibiting drying of the beans so far picked - is now a problem in some key cocoa areas.
Meanwhile in some of the main corn and soybean states of the US, emerging plants are showing mild signs of heat stress and lack of rain.
Too much rain in west Africa, too little in north America - these could be early indications of an impending La Nina event, with fairly predictable consequences for certain crops.
At the end of May the World Meteorological Organisation (WMO) said that sea surface temperatures in the tropical Pacific were neutral. That means neither El Nino nor La Nina weather patterns were emerging.
The inclination of several of the world’s leading weather agencies however is towards there being a reasonable chance of La Nina developing in the second half of 2020 - a distinct contrast to 2019.
2019 was relatively mild El Nino year. Yet although not as severe as that of 1997-98 it nevertheless contributed to (among other things) extreme drought in Australia, which set the stage for the devastating bushfires in New South Wales and Victoria at the end of the year.
The 1997-98 El Nino contributed to widespread disruptions of normal weather patterns, ushered in Indonesia’s severe drought and massive flooding along the western parts of south and north America, and spurred an outbreak of the mosquito-borne Rift Valley fever in east Africa.
Both El Ninos and La Ninas usually peak in their intensity during October to January.
If a La Nina develops there are certain crops that will be more affected, largely to the good.
The world’s biggest cocoa-producing region, west Africa, will have greater rainfall, which may disrupt the mid-crop harvest this season but will benefit the flowering and development of next season’s main crop. The likely above-average rainfall across south-east Asia will also benefit Indonesia’s main cocoa region of Sulawesi.
Generally, crops throughout the equatorial region should benefit from the heavier-than-usual rainfall, so long as flooding does not wash away plantations. Palm oil in Indonesia and Malaysia, and in India - where the annual monsoon is progressing well - all major crops will benefit this season and the extra soil moisture will give a boost to the next.
And a few losers
There will be losers. In a typical La Nina drier-than-usual conditions occur in the south of the US, and along the eastern half of Argentina. Ethiopian and Ugandan coffee output could be hurt by the lack of rainfall that typically comes to east Africa.
Development of this season’s corn and spring wheat in the US is already falling behind, as a result of the dry conditions.
If we are in for a La Nina then some hasty revisions to global crop balances will follow in the months to come. The time lag between clear evidence of the weather condition setting in and its consequent crop impacts will give scope for some astute investment decisions.