The effects of drought on macadamia nut quality

Macadamia farmers understand risk better than anyone else. The potential impact of uncontrollable risks like weather conditions on the quality of their harvest can keep any farmer up at night. Drought, for one, can cripple an industry, setting back annual harvesting targets and affecting crop yield and quality.


Two years ago, macadamia nut producing regions were brought to their knees by an unrelenting drought that resulted in a 22 per cent drop in harvest the following year.

While the local 2017 macadamia nut-in-shell crop was 42 000 tons, Australia’s was about 47 500 tons. The drought set the industry back by two years. Valley Macadamia Group chairperson, Alan Sutton says while the industry is expecting a 55 000-ton crop for export this year, the industry should have produced this amount two years ago.

‘Luckily, macadamia producing regions in Mpumalanga and KwaZulu-Natal have recovered in the last season to more than average rainfalls,’ says Sutton, ‘While some farmers in the Western Cape are still feeling the effects of dry soil, growth in the industry is looking good.’

While the increased rainfall is a welcome sign of relief, many farmers worry about the legacy of a drought and how it can affect macadamia nut quality in the next harvest.

Legacy of the drough

Macadamia trees can endure extended periods of drought as its tree leaves lose little water regardless of the temperature or rainfall. However, harvests during droughts will be smaller and of poor quality. Water stress at different stages during the nut’s development could affect the yield, kernel recovery and nut quality.

During the premature nut drop and early oil accumulation stages, drought can decrease the crop’s yield. Water stress during the nut maturation period can decrease the kernel recovery and nut quality due to a reduction in photosynthesis during this high energy demanding period. Water stress during this stage also leads to a high percentage of immature kernel.

Quality control and world-class vetting procedures are critically important during harvests that follow a drought. Partnering with global leaders in macadamia processing will also ensure not a single bad nut slips through.

Quality at every stage

Droughts do not condemn the next harvest to the waste disposal. Risk of poor quality can be mitigated by maintaining strict quality control at every stage. Every macadamia should be graded according to set quality criteria.

Valley Macadamia Group is committed to preserving the fresh taste from tree to final product. The group’s unique processing plants are the most sophisticated in Africa, designed to grade, dry, crack and pack macadamia nuts to the highest HACCP standards.

Despite a difficult two years and drought conditions persisting in some parts of the Western Cape, the macadamia industry is booming. The growth prospects for the industry are high with 2000 hectares of trees planted annually and a projected increase of between eight per cent and 10 per cent profit growth.