FAQ

Thousands of hectares of macadamia plantings have in the recent years been established, and hundreds of hectares are coming into production each year. When will the markets be saturated, or in other words, is there still scope for new plantings?

It is always risky to speculate about future market trends. However, macadamia nuts make up less than 1% of the global tree nut production (this excludes peanuts). In the past few years, there has been very strong growth in nut consumption in China. China is South Africa’s fastest growing market for macadamia nuts. China currently consumes about 30% of South African macadamia production. Growth in the Chinese market is expected to continue for the foreseeable future. SAMAC is currently investing funds on scientific research which focus on the health benefits associated with consumption of macadamia nuts, in collaboration with the Australian Macadamia Society. This would then be incorporated in the marketing strategies of macadamia nuts. Another factor to consider is the fact that macadamia plantings in China are on the increase; nevertheless, it is speculated that there would still be a demand for macadamia nuts for several years.

At which altitudes can I plant macadamia nuts? Some say macadamia nuts grow only at altitudes of 600 m AMSL or lower. Which temperature extremes suit macadamia production and what is the optimal temperature for macadamia production?

It is well known that better crack outs (kernel as a percentage of dry nut in shell weight) are usually achieved at lower altitude due to the nuts developing thinner shells at lower altitudes, where it is generally warmer. Even at low altitudes, macadamias grown in warmer areas will have thinner shells. Nuts from the North Coast of KwaZulu-Natal have thinner shells than nuts from the cooler South Coast. Macadamia plantings in Mpumalanga and Limpopo range between 600 and 1200 m AMSL. It is however probably not the altitude that determines the kernel percentage, but the climatic conditions associated with the altitudes. The higher the humidity, the better, and moderate temperatures in combination with high humidity seems to be ideal. When the plants are under less stress, less energy is used for shell production with resultantly thinner shells. Macadamia trees are susceptible to both heat and frost damage. Young trees are readily killed by frost, whereas older trees usually survive. Frost can still damage flowers and result in lower fruit (nut) set. Temperatures above 35 ˚C on the other hand become too high and reduce photosynthesis. Therefore tropical and subtropical regions are more suitable; however there are areas in highlands that produce macadamia nuts, and microclimate will play a more vital role in these areas, for instance using micro- as opposed to drip irrigation to increase humidity, or planting on the cooler or hotter slopes etc.

There is a high demand for macadamia trees, and nurseries have waiting lists of between two to three years. Where can I buy trees? Is it feasible to produce my own trees?

There are many growers that produce their own trees with success, but due to the relatively small quantity of trees, together with the inexperience, it would usually cheaper to buy trees from a SAMAC-accredited nursery. SAMAC performs annual audits on these nurseries to ensure that trees are of highest quality. It is important to keep in mind that although one might be able to produce trees quicker than a nursery with a waiting list, the quality of a tree will determine the “quality of service” it returns. Our recommendation is thus to rather wait for good quality trees. There is a list of SAMAC-accredited nurseries on the SAMAC website (https://www.samac.org.za/nurseries/).

Which cultivars should I plant?

This is a challenging question to answer because we do not have all the answers, since not all cultivars perform the same everywhere, and under different production practices. SAMAC is currently conducting a cultivar trial where various “old” and newly imported cultivars are evaluated across all production regions. This is unfortunately a long term project, but once this project is completed we will be able to provide more specific information. At this stage there is a tendency to plant ‘849’, ‘A4’, ‘A16’, ‘816’ and ‘814’. ‘Beaumont’ and ‘Nelmak 2’ are also still widely planted. There is an indication that Nelmak D might perform well at higher altitudes. It is however recommended to do a bit of risk distribution by planting at least two to three cultivars. Cross pollination is an important factor to consider and in the past it was recommended to interplant a specific cultivar block with another cultivar every 6th to 8th row (eg in a ‘Beaumont block’ to have every 7th row a ‘816’ row). However the recent trends are towards mechanisation to reduce labour and labour cost, and one of the areas in reducing labour cost is in harvesting by means of ethapon sprays. Unfortunately not all cultivars can be sprayed with ethapon and the grower needs to wait for the nuts to drop naturally, for instance the case of ‘816’. These mixed-cultivar blocks make it difficult or impossible to use ethapon, and recent trends are to plant single-cultivar blocks, but to try and get some cross-pollination effect from neighbouring blocks. The choice of cultivar thus comes down to choice of farming practices.

What is the optimal planting density?

Some macadamia cultivars have an upright growth pattern, whereas other cultivars tend to have more lateral growth. The cultivar choice could influence tree spacing. In Mpumalanga the average planting density is 7.4 m x 4 m. Many growers are moving to lower density plantings, for instance 9 m x 5 m. Lower density plantings will still require pruning, and perhaps 8 m x 4 m or 8 m x 4.5 m will provide a good balance between pruning intensity and optimal yield per hectare.

What is the potential yield per tree, and when will the trees start bearing? What yields could be expected at the different ages?

Some cultivars like ‘Beaumont’, ‘A4’ and ‘A16’, ‘791’ and ‘Nelmak 2’ are considered precocious and sporadic trees could bear nuts from about three years of age. SAMAC has funded and has been involved in several cultivar trials. In year four approximately 0.6 kg – 0.8 kg per tree for ‘Beaumont’ could be achieved. In year five, between 2 kg and 10 kg of nuts (Wet In Shell; WIS) can be expected per tree. In year 8, approximately 16 kg can be expected and maximum yield is perhaps as late as year 13-14, yielding as high as 35 kg per tree (WIS). These are rough indicators, but these figures are guaranteed to differ between areas. More details are on the SAMAC website under the member’s section: technical info – orchard establishment.

What are the water requirements for macadamia trees?

One hectare of mature macadamia trees, from approximately 7 years and older, will need approximately 9500 m3 water per annum, which equates to between 40 and 120 litres of water per tree per day. This amounts to between approximately 13000 and 37000 litres per hectare per day, depending on the cultivar and time of the year. August and September are the periods with the highest irrigation requirements due to low rainfall, high temperatures and low relative humidity. Furthermore a high water demand arises in August and September, which are the months when most cultivars flower and nuts set.

How much does it cost to establish one hectare of macadamia trees?

This really depends on location and of course there are many variables. A rough guide would be to budget for approximately R100 000 per hectare of orchard establishment. This excludes any implements. After orchard establishment, it could cost up to R25 000 per hectare per year for general running costs (weeding, fertilising and irrigation). Also take into consideration that as soon as trees start bearing you will need a dehusker and drying bins for the nuts.

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