INTERVIEW: Cacao Undercover – Optimizing Cacao Orchard Systems using the CI-110 Plant Canopy Imager

Application Scientist, Eric Munoz sits down with Agronomy Scientist, Rany Agustina Susanti to discuss her research using the CI-110 Plant Canopy Imager and what it means for the cacao industry today.

ABOUT RANY

Rany Agustina Susanti is a former Senior Agronomy Scientist at Mars Inc. and final year PhD student, specializing in cacao physiology at the School of Agriculture, Policy, and Development at University of Reading, UK. Her current research investigates the potential to improve the efficiency of high productivity cacao farms using orchard-intensive cropping systems. This project is a collaboration between Mars Global Plant Science & Technology and the University of Reading, UK.

Related to my research :
One research question that needs to be investigated is related to the effect of clonal differences in vigour on yield in a trellis system. Several canopy characteristics parameters, such as leaf area index, extinction coefficient, and light interception, which are important to correlate between vegetative vigour between different clones and treatment, were measured using CI-110 from CID Bioscience (The results cannot be published at this moment).

Another interesting result observed that the light-saturated photosynthetic rate of leaves was significantly higher after pruning. A possible explanation for this increase in photosynthetic rate is that pruning stimulates new leaf growth, thereby altering the source-sink ratio. The results suggest that cacao might be able to increase its assimilation rate in response to demand for carbohydrate by stimulated leaf growth. 

[INTRO]

Eric:    So, my name is Eric Munoz Garcia. I’m an application scientist here at CID Bio-Science. I’ve been with the company for 2 years. I have a background in molecular biology and chemistry. And so yeah, I’d love to hear about you Rany.

Rany:    Yeah, I’ve been following your webinar a couple of times actually. So, that’s why I’m familiar with your name and your face. So…

Eric:    Oh, great, yeah. That’s great.

Rany:    So, my name is Rany. So now I’m a PhD student in the University of Reading in the UK. But now I live with my husband in the Bay Area in the US. And previously I was working for a chocolate company, for Mars. This project is under collaborations with the University of Reading, also Mars.
So I just resigned last November from Mars. So my last role is Senior Agronomy Scientist for Southeast Asia. And then now I’m just focusing on finishing my PhD dissertations. And then, I was experiencing using your equipment, the CI-110, since 2015 maybe. Or 2016? Maybe 2016. So, previously I was using the old CI-110.

Eric:    Yeah.

Rany:    And then in 2018 I got the latest model CI-110. So I can compare the difference between the old version and the latest version. And then, now my research project is about maximizing the efficiency of efficiency of a novel cropping system on cacao production in intensive growing systems. So, long story short, it’s like making a vineyard system for cacao.

Eric:    Oh, okay.

Rany:    Yeah. So then with manipulating that architecture we are hoping to get more efficient, and then maximize yield on cacao. For having that analysis I need to have an instrument for measuring the light interceptions and then leaf area index. So all the characteristics which is involving CID equipment, the CI-110.

[THE TREATMENTS – Density]

Eric:    Yeah. Oh, I understand. Yeah, that sounds so exciting. So, if you don’t mind, could we talk a little bit about some of the treatments maybe? I would love to hear about the treatments that you use. 

Rany:    Okay. So, we use two local Sulawesi clones. We call it MCC-02 and MCC-01. And then, both of the clones, they have different vigorosities. One is really vigorous and one is quite small — related to the trunk diameter. And then they were planted in different architectures from 1, 2, 3, 4 branches. So can you imagine that normally cacao trees has 4 branches, but we cut all the main branches into 1, 2, 3, 4. Some of them are shaped in a trellis, and some of them are in just conventional planting or architecture. And then some of them are in high  planting density, from 2,000, 3,000 and also 5,000 trees per hectare. And them some of them are also planted in different row orientations, in east/west and south row orientations. So why we have different row orientations, because in a previous experiment in apple – you can refer to Jackson 72 – so when Jackson and Palmer planted the apple orchard in different row orientations in temperate locations, that they observed the estimate percentage interceptions by the east/west hedgerow is varied over the seasons. However, for the north/south hedgerows it was reasonably constant. So that’s why there’s different results that they had with different row orientations. So, that’s why we want to see whether it will influence the light interceptions, and then later on influence the yield that we have.
And then for higher planting densities—So, higher tree densities improving the efficiency of light interception per unit area. Usually in other species or crops this has other favorable effects on the higher harvest index. So that’s why we want to see beyond the conventional planting density—that is usually 1,100 trees per hectare. That’s the conventional way to grow cacao—So then we want to go beyond that; 2,000, 3,000 and then 5,000. So we hope that with this higher planting density not only it will improve in the productivity per hectare area, because we multiply it by the numbers of the tree, right?

Eric:    Yeah.

Rany:    But also it improves the efficiency of the light interceptions. But another challenge, another possible challenge that will occur, it might be the efficiency or the productivity per tree, whether it will be decreasing with the higher planting densities since it has nutrient competition between the trees. So we will want to see about that. So, the latest results show that there’s limitations of planting density. So, until now we cannot go in 5,000 trees per hectare planting density with certain cacao clones.

Eric:    I see. So you see a drop off at 5,000 trees?

Rany:    Yes.

Eric:    Okay. Conventional is 1,100 you say?

Rany:    Yes. So the convention is 1,100. It’s usually 3×3 or 4×4. But what I use is the minimal of the high planting density and that’s 2,000 trees per hectare. So, the trees that grows in 2,000 trees per hectare planting density seems to be growing quite well with that cacao clones. But as you may know, there are also interactions between clone and planting density, so not always. Although I say that the cacao trees that are growing in a density of 2,000 trees per hectare could grow well in certain clones. It might not be suited for other clones.

[THE TREATMENTS – Row Orientation]

Eric:    I see. Okay. So, north/south to east/west, are you able to talk about that? Any of the results.

Rany:    So, yes. I can share about that. Until now, we cannot see any difference, whether it’s growing in row orientations of east/west or north/south. Whether it’s located in Indonesia, or I have also some results from my colleague in Latin America, in Ecuador–they also found the same thing. So, why are the results in apple different than in cacao? Maybe it’s because of the location itself, since the apple research is located in the UK, and we are located in a tropical area. So my trial is located 3 degrees from the equator, to be exact.

Eric:    I was about to say, yeah.

Rany:    Yeah.

Eric:    Closer to the equator you know you’re getting much more stable sunlight.

Rany:    But there’s one effect that we see—it’s about the sun damage on the pods. All the east/west and north/south, they have more or less the same light interceptions or light intensity, but during the day in the north/south the pods will have received, more or less, constant light compared to east/west. In east/west, since we are located 3 degrees from the equator, there is some area that is quite shaded in the afternoon. So, the pods will not receive the same exposure as in the north/south. So that’s why in north/south we found some pods that look burned, because of that sun damage. And it will induce pre-germinations since each clone has different characteristics of pulp. Some of them are quite humid. Some of them are quite dry. So, if the pulp is dry or drying, it will induce the germination process. So, this sun damage process will induce pre-germinations for certain clones if it’s exposed to the sun in the longer exposure time. So, for instance, in the north/south certain clones will have pre-germinations because of that light exposure.

[CACAO CULTIVATION TODAY]

Eric:    I see, okay. That’s interesting. For myself, and any viewer as well who’s not super familiar with cacao, can you talk a little bit more about the sample itself?

Rany:    So, cacao is a perennial tree. In the conventional way it is planted in a tropical area, and then in conventional way it usually is planted with distance 3×3 or 4×4, in Africa or Southeast Asia usually one family farm only has two hectares. They planted it in 3×5 or 4×4, so then, in one area they more or less have 1,000 trees. Since most of the cacao producer countries are in tropical areas, as you said–so the biggest producer is Ivory Coast and then Ghana, and then continue with some countries from Latin America. But, as we know, most of them are coming from the small holder farms. Productivity, it really varies within the country. In Africa the highest that’s recorded is around 600kgs per hectare. While in Southeast Asia usually it’s quite higher. More or less 800. Then in Latin America, in a bigger farm, the highest that I heard is about 2 tons per hectare.

Eric:    Wow.

Rany:    Mmhmm.

Eric:    Interesting that you mention small stakeholders in production of cacao.

Rany:    Yeah, so it’s tied also the culture itself. How in Africa and Southeast Asia it’s really difficult for industry to have a large cacao farm, compared to in Latin America, because the culture in Latin America is they have – they are used to having big farms for coffee or for cacao. So, that’s why it’s quite easy for them to continue that culture, that big farm culture. While in Southeast Asia or in Africa normally one person or one family farmer who just has like two hectares farm, and yeah, it’s difficult to have a bigger farm because the culture is like “family-owned farm.” So, it’s difficult to gather all the family into one big farm. And then the equipment itself, it’s quite… it’s really easy to use in the field, the CI-110. So, that’s why, even though there’s like drone equipment now that can facilitate to also measuring the same thing, like leaf area index measurement or light interceptions, but the CI-110 equipment, I think it’s still the best approach to measure that parameter that we need, especially if we work with really small farm.
My project is actually located in Indonesia. So, that’s why we want to see how local Indonesia clones will cope with that intensive growing system in that vineyard or orchard systems. Meanwhile, as you know that in Latin America most of the cacao farm is in a big farm, just like 200 hectares area. So, yeah, if we are working with a larger farm – so for instance if I had my trials, we will cover like a hundred hectares farm. And then I want to have an idea about the leaf area index or light interceptions data, so I will choose a drone imaging one. But if I need to have a project that will go deeper into the analysis about the possibility of using certain clones to have specific measurement, so I will use this handheld equipment ones. Because the point of this research is to maximizing the productions in orchard system. So, then we will use smaller vegetative growth, so then we hope that the harvest index will go up to reproductive if we’re decreasing the productions of the vegetative growth. So, that’s why leaf area index parameter will be one indicator to see whether this clone is vigorous or not. So… so that’s why it’s become one of the most critical equipment in my trial.

Eric:    And with that I think, I really appreciate your time, all your wonderful work in cacao, and we look forward to seeing the publication.

Rany:    Thank you also for today.

Feature image courtesy of Jenni Miska.