Unlike roses, the protected vegetable sector in Kenya is still quite small-scale. On a recent trip there I set out to find some larger nurseries growing vegetables under plastic. Ultimately I found one of 0.5 hectares; most of the others I visited were between 1,500 and 3,000 m2. In Uganda and Kenya I am involved in a project in which we are using sensor technology to make growers more aware of the climate in their greenhouses.
The basic questions we ask are: how hot and humid is it in their greenhouses and what temperature and RH are they aiming for. When we introduce this sensor technology, I notice time and again that people don’t have the faintest idea what the temperature is during the day or night, let alone how humid it really is. If I ask how hot it gets during the day, the answer I usually get is 40°C and that it doesn’t drop below around 20°C at night. But after taking measurements for a while, we discover that the night-time temperature often drops to the ideal level of 17°C and that during the day it never really gets above 37°C and is more likely to be around the 30-32°C mark. So in fact it’s a pretty reasonable climate for growing tomatoes and other fruiting vegetables.
Humidity is much more important, of course. The sensor readings show that with a little wind during the day it soon gets too dry and the vents have to be closed. Many of these greenhouses have side walls that can be opened and closed. The trick is to keep the humidity inside without letting the temperature rise too high. An additional problem is that a lot of polytunnels here are much too low: they are often still built with gutter heights of as little as 2-2.5 metres. Luckily, as European influence spreads, heights of around 4-5 metres are catching on quite quickly. However, you also have to bear in mind that they don’t have cherry pickers, so everything is done by ladder.
Other physical laws come into play too, such as the fact that heat rises to the top of the greenhouse, so you need vents in the ridge as well as in the sides. Local growers and especially greenhouse builders often still need convincing of this. In the meantime, a number of smart new greenhouses are shooting up in various places in East Africa, in which they are growing excellent tomatoes. As a consultant, it makes you proud to see these success stories; passing on knowledge is so satisfying.
Senior Consultant Africa.
A lot of things are unfairly distributed in the world, and rain and drought are no exception, especially in Africa. Last month I was in Rwanda, where it was green and everything was growing well. It’s the rainy season there at the moment, so it’s exactly the right time to grow vegetables. But parts of Kenya and Uganda are still as dry as ever.
Here in KwaZulu Natal it has been pouring with rain again but the dam is now 95% full. Less than two years ago it was empty. So that will keep us going for a while. They are also raising the height of the retaining wall by around 12 metres, which makes you feel good.
But it’s still extremely dry in the Cape Town region. It’s been going on for two years now and drinking water is expected to run out imminently. I read in a Dutch news weekly in early November that the many tourists that visit the Cape province every year will also be affected.
As always, I look for light at the end of the tunnel. When I was in Cape Town in August, I saw a great example set by a big fruit and vegetable farm. The drought has forced the family business to switch to precision irrigation. The transpiration from every individual field is now measured by satellite and they have several sensors in every field measuring soil moisture levels at different depths. If there is any doubt as to whether extra water is needed, the spade or auger goes straight into the ground to see what’s happening. As a result, the company is producing more than ever before, quality is improved and they have fewer diseases.
This family, who originally come from the Netherlands, have been farming in South Africa for several generations and are an excellent example of how to get “more crop per drop”. We are also actively working on getting farmers and growers with scarce water supplies to optimise their production, both in their outdoor and covered crops.
And otherwise, it’s just Africa here. The pace at which decisions get made and things get done is very slow for my still very European taste. I smile every time I drive down two stretches of the motorway which have been narrowed down to one lane for the past 18 months. They want to divert the road slightly but no progress is being made. As someone here taught me: we move forward “slowly but surely”. That’s why we’re looking forward to 2018 full of confidence.
Senior Consultant Africa
In some way or another, Africa and plastic formed a close relationship a long time ago. At the checkout, all your groceries are packed in small plastic carrier bags – you don’t get big shoppers here. But the problem is that most of these bags don’t end up in the rubbish bin but land up somewhere in the environment after only being used once. And most plastic bottles end up on the streets – the deposit system is very European.
Also very European is the idea that the entire system of separate waste processing and recycling should be organised by the government. No, in Africa it’s left to private initiatives to set up these systems. And it’s surprising to see how quickly that can happen. There are already large numbers of small plastic recycling companies making things like garden furniture and rubbish bins out of recycled plastic. But many people still don’t bother to recycle, so substantial volumes of glass, plastic, paper and metal are still ending up in landfill sites. How long do you want to go on filling up your country with your own rubbish? Never mind the fact that less energy is needed to produce things with recycled materials than with new materials. And as a continent, we already have enough trouble providing an adequate and stable electricity supply.
But there is light at the end of the tunnel. There has been a Recycling Day in South Africa for several years now, and International Coastal Clean-up Day took place on 16 September. All the plastic waste that blows out to sea has a significant impact on the ecosystem and on life in our oceans. I am actually writing this column in the week in which the Kenyan government announced that anyone stopped on the street with a plastic bag in hand can expect an exorbitant fine of thousands of dollars. I happened to be in Kenya this week and it was amazing to see everyone walking around holding their shopping in their hands or carrying it in big packages. Not a single plastic bag in sight. Well – at least they can no longer blow out to sea.
Whether that’s really the way to do it, I’m not sure, but it certainly works. A great lesson on how to put environmental awareness on the daily agenda of your entire population in one fell swoop.
Senior Consultant Africa
I am writing my second column having just returned to South Africa after two weeks in the Netherlands. It’s always good to keep in touch with my motherland and catch up with family, friends and colleagues. But it always feels like coming home when we are back in South Africa. This is where our mission lies: to be there for the children of Africa, to improve food production and to create jobs. Last time I promised to tell you more about what we are doing to boost food production and quality here.
First of all, the shift from open field to protected cultivation is an important step. Here in South Africa we have various regions where crops are grown in tunnels. The size of the nurseries is usually anything from 2-3 hectares upwards, with one or two major players operating 10-12 hectares. These nurseries usually grow tomatoes, cucumbers and sweet peppers, but also lettuce and herbs. These are the crops I specialise in. We grow on the ground in coconut and cucumbers are often still grown in wood chippings. But a lot of tomatoes and sweet peppers are still grown outdoors. When you see this product in store you can tell that the weather hasn’t done the fruit’s appearance any favours. So it’s high time to tackle quality – although having said that, the quality of tomatoes in stores has improved enormously since 2014. Colour and presentation are also starting to become important here, as is segmentation: for example, you’ll see cherry tomatoes, snack tomatoes and tomatoes in other colours apart from red – like yellow and orange – in neat little packs on the shelves.
In the other African countries I work in, such as Kenya, Tanzania and Uganda, almost all vegetables are still grown in open fields. The growers I visit have small, 300 m2 tunnels. So a grower with six of these tunnels next to each other is a big one. The crops are grown in the soil, which means that pests like nematodes and soil diseases are a big problem. Of course we’re all familiar with the big cut flower nurseries in these countries, so it's only a matter of time before vegetables are grown in large-scale tunnels too.
I will tell you about the kinds of diseases that occur and how we treat them another time.
Senior Consultant Africa
I’m writing my first column for In Greenhouses sitting in the departure lounge at Schiphol Airport in Amsterdam. The reason for my three-day trip to the Netherlands was a joyous one: our daughter Wendy turned 30 yesterday, and as her proud father, naturally I had to be there. All the children and grandchildren were there this afternoon, and now I’m already on my way back to South Africa.
South Africa has been our home since 2014. After many years of travelling and deliberating, we ultimately decided to follow our dream: to be there for the people of Africa. We live and work in South Africa. Anne, my wife, is involved in development work for disadvantaged children, and I am a consultant for Delphy specialising in covered vegetable growing in eastern and southern Africa. Basically that means advising and training people in safe food production to enable them to create jobs and produce safer food.
Horticulture, and in particular covered crop production, has been gaining rapidly in significance in Africa in recent years. There are many reasons for this, with water shortages topping the list. As many people are aware nowadays, it takes five times less water to grow a kilogram of tomatoes in a greenhouse or tunnel than it does in the open air. Protection against wind and rain and keeping pests out are other reasons for growing crops under cover.
It’s much easier to grow food safely and sustainably under cover. Funnily enough, it has mainly been private initiatives and not government ones that have set this movement in motion here. Supermarket chains like Woolworths have been setting the trend for years with the Farming for the Future programme. As a result, growing in an environmentally sound way now tends to be the rule rather than the exception for modern GlobalGAP certified growers. But there are still a lot of smallholder farmers growing for the wholesale markets where certification is not yet a requirement, although it is a USP for them. In my next column I will be looking at how this works in practice and what role I can play in it myself.
Senior Consultant Africa