These challenges have not deterred litchi producer Pieter Luus, however. Although he has also ventured into macadamia production, his 10ha of 18-year-old Mauritius litchis are still very much part of the farm’s success.
Since litchi trees produce fruit only on new branches, they have to be pruned both for production and to keep them at an optimal size.
“The trees must be maintained in an umbrella shape, with light able to penetrate the middle of the tree,” explains Luus. “Litchi trees grow very quickly, and windows for sunlight must be cut regularly to ensure that the tree doesn’t die off on the inside.”
Branches are removed to prevent the tree from producing excessive wood.
“A litchi tree bears fruit only on new branches. So to ensure it doesn’t keep getting bigger and bigger, producing litchis only on its outer branches, we break off old branches, and the crop then grows on the new branches that appear,” explains Luus.
“Every three or four years we do a drastic prune, using electric cutters, to get the trees back to a manageable size. The yield takes a bit of a knock that year, but it’s better in the long run, as the tree then has the right shape and can be hand-pruned thereafter.
“Keeping the trees shorter also makes harvesting far easier. We aim for around 5m in height, but if they’re on a slope, they can be more difficult to reach, so we keep them even shorter here.”
Luus says that getting the fertiliser programme right and timing the applications correctly make all the difference to yield. Some nutrients are especially time-sensitive.
“以前，我们在1月修剪后立即施用氮，但这产生了过度增长。现在我们等到六月申请氮。这为树提供了足够的能量来通过冬天来看待它。在这个阶段，树没有足够的能量来产生过多的木材，因此额外的氮气只是通过寒冷的月份提高它。我们在6月和7月以90kg / ha的速度施用氮。“
随访10月份磷酸盐2kg / ha磷酸盐施用，达到65kg / ha和140kg / ha钾，这取决于土壤和叶片分析的结果。低钾水平会导致果实突发，特别是当它暴露于长时间的高温时。
Luus says that boron also plays an important role in litchi nutrition and he applies 5kg/ ha annually, spread across four doses.
Keeping the pH of the soil at the correct level of 5,5 is of particular concern to Luus. As his soil averages 6,8, he applies calcitic lime at a rate of 1,2t/ha to 1,3t/ha each year.
He also applies extra compost, consisting of composted macadamia nut husks and cattle manure, to increase the organic matter in the soil. This is done at a rate of 8kg/tree/year.
“It aids moisture retention and soil conservation. We slash the grass under the trees when we start harvesting to make it easier to get into the orchards. The grass between the rows is cut and [the cuttings] are placed under the trees.”
“一些农民相信水在某些限制times to put the tree under stress and hence induce flowering. I don’t follow this practice; I prefer applying water throughout. We’re already quite marginal, so I don’t want to stress the trees further.”
Pollination is carried out via bee pollination services, which up until now have been provided at no cost. “Litchi honey has always been in high demand, but now that macadamia farmers are paying for pollination services, the companies have indicated that they will start charging us in future too.”
“I don’t do any chemical applications and fertiliser inputs are fairly low. This means that despite litchis not achieving huge prices on the market, it’s still a profitable crop.”
About 60 labourers are employed for the harvest. In addition to professional workers, Luus employs students who want to earn a holiday income.
“I foresee that in future we’ll need to use a labour contractor to source labour for us. This will make the harvest more expensive, but it seems to be the only way forward,” he says.
Litchis are said to be alternate-bearing, but Luus has found that with careful management, a more evenly balanced yield can be obtained from year to year.
“The trees produce a flush as soon as they’re pruned. Spraying ethephon after pruning stops the vegetative growth and forces the tree to start producing flowers instead. It holds the tree back a bit, but ensures a more even yield.”
Oversupply and low prices
Another challenge of litchis is that the harvest must be started and completed within the four-week December-January period.
“The market is effectively flooded for a short time and prices are low. Prices also depend on how much volume Komatipoort’s litchi producers send to the market, and when. We can’t compete with them.
Unfortunately, the value of the litchis is still high enough to keep thieves active. When the fruit starts ripening, Luus employs security to patrol the orchards at night.
“I don’t need to apply any chemicals for pests, as fruit flies are controlled with fly traps and pheromones, and litchis have very few pests, anyway.”
All things considered, Luus has no intention of replacing the litchis with another crop over the next few years.
“At least not until I know that macadamias can replace that income.”
Email Pieter Luus at[email protected].