An adult sweet potato whitefly on the underside of a poinsettia leaf with her recently produced group of eggs. Photo: Erfan Vafaie
Erfan Vafaie, Texas A&M AgriLife Extension Service entomologist, recently wrapped up the second year of a three-year study looking at the use of predatory beneficial insects – mites and wasps – to control sweet potato whiteflies in commercial settings.
Vafaie’s research is looking at whether the combination of the two beneficial insect species manage whiteflies can work better than just one for poinsettias in a greenhouse environment.
In the most recent year, Vafaie focused on commercial trials in three locations where poinsettias are being grown – two local commercial growers’ greenhouses and Texas A&M AgriLife Research greenhouses holding poinsettia trials in Overton, Texas. At Location 1, Vafaie said spot sprays were required in addition to the beneficial insects in sections of the greenhouses after whitefly populations moved in. At Location 2, no pesticide applications for whiteflies were necessary in the beneficial insect-managed greenhouse, but fire ant bait was needed to manage the fire ants, which were consuming the beneficial insects. In Overton, two broadcast applications were needed to bring whitefly populations back down to manageable levels for the beneficial insects.
In earlier small-scale trials, Vafaie said the combination of wasps and mites worked as well as either predator alone. “Throughout the small-scale study, the combination of mites and wasps were more reliable in handling simulated whitefly migrations into the greenhouses,” he said. “Mites are thought to wait and intercept incoming whiteflies, while wasps actively move around and encounter new populations of whiteflies.”
Although the cost of beneficial insects was roughly equivalent to the typical cost of pesticide inputs, a full cost comparison between conventional insecticide rotations and the beneficial insect strategy is still pending.
New Ag International JUN/JUL 2020
Robots that use artificial intelligence to recognize the health of fruit and vegetable crops and when they’re ready to harvest are being trialled to help small, organic and greenhouse farmers with weeding and patrolling for pests, according to a story from Horizon, the EU Research and Innovation magazine.
The roving wheeled ‘ROMI’ has one arm for weeding small vegetable farms. According to Jonathan Minchin at the Institute for Advanced Architecture of Catalonia in Barcelona, Spain, to benefit small farmers, the robot had to be inexpensive and lightweight. ROMI’s developers, which includes Minchin along with Dr. Christophe Godin who is a research director in plant modelling and computer science at Inria (the French National Institute for Research in Digital Science and Technology), worked to keep its costs down by fitting it with off-the-shelf electric wheelchair motors and relying on open source hardware and software for AI and navigation, for instance. Once available, it should cost €5,000 or less.
Right now, a ROMI robot is being put through its paces to weed and navigate an organic farm in a forest outside Barcelona. A sister robot is weeding on a commercial organic farm called Pépinières Chatelain close to Paris Charles De Gaulle Airport.
Scientists in the project use a lot of imaging and mapping data with AI to identify and model plants. Godin and computer scientist Dr. Peter Hanappe, at the Sony Computer Science Laboratories in Paris, are working with the weeding robot in France. It has visual software that lets it capture 2D images. Once it takes a picture it must then interpret “this soup of pixels,” says Godin. These images are used to create 3D computer models that the robot then uses to better understand or manipulate its environment. They want to teach the robot to understand what a leaf is, a stem, a fruit and so on.
Godin wants to improve the computer image analysis so that plant scientists can use the data collected by the robot to study crop varieties in growth experiments. The 3D plant models may also be used for programming robots in precise fruit picking or to breed better crops in the future. It may also allow the scientists – and ultimately farmers – to track the health and growth of crops.
In the future, a ROMI could see lettuce start to shoot up and know when it’s time to harvest, says Minchin. Or the technology could allow a new generation of farm robots to identify and pick fruit or vegetables when they are ripe.
Greenhouse robot In another project, María Campo-Cossío Gutiérrez at the Centro Tecnológico CTC in Spain and her team has developed a prototype of a smart roving robot to patrol greenhouses and pinpoint and identify when pests or diseases are present. The robot can operate autonomously, without human intervention.
The robot was trained on the main pest and diseases of tomato and pepper and is being tested in greenhouses in northern Spain. Farmers can access an online application to see the robot’s status and a map of healthy and infected zones with recommended actions.
One of the main challenges is that the robot is in a (semi-) indoor environment, noted Campo-Cossío Gutiérrez. If it were outside, it could use satellite navigation, but greenhouses have roofs with metal reinforcements which degrade signals. Another challenge is that greenhouses change regularly as the crop grows, but also after harvests, when growing materials such as soil are removed. Because of this, robots cannot be programmed to follow defined routes.
“We needed the robot to identity where pests are located and then come back and treat them in a second phase,” said Campo-Cossío Gutiérrez. With the farmer’s instruction, the robot has the ability to spray the plant with pesticide.
The ‘GreenPatrol’ robot as it is called uses novel algorithms which allows it to successfully exploit stronger signals from the Galileo global navigation satellites as well as orientation sensors and lasers to help guide its manoeuvres under the greenhouse roof. It can obtain a position inside the greenhouse with an accuracy better than 30cm. The robot uses AI and image libraries to spot pest invaders and also harmless insects.
“It is able to distinguish the degree of infestation and tell if it is an egg, or a larva or full adult insect,” said Campo-Cossío Gutiérrez. It can then send growers real-time heat map updates of insect infestations to their smartphones.
Flying companion Rover bots are not the only solution for growers. The ROMI project has also developed a flying companion for its rover – a drone that can scrutinize the plants from the air. ROMI scientists also constructed a cable bot to glide across crops and perform a similar job.
The ROMI team ultimately envisage their design not as a single weeding robot, but as platform to which farmers can attach sensors, cameras and tools and then take them off again. “You can imagine a farmer getting up in the morning and going to the tool shed. Putting tools onto the robot and turning it on,” said Minchin.
This robot might then set about weeding or scanning for pests. If the farmer wishes to view the information, they could look at their phones or later that day on a computer back at home.
The ROMI robot has an arm for weeding on small vegetable farms. Photo: Sony computer science laboratories
The Dutch horticultural sector aims to be climate-neutral in 2040. So, Wageningen University and Research (WUR) researchers have built a low-emission demo-greenhouse for the cultivation of vegetables, fruit and flowers in an effort to find ways to reduce CO2 emissions as well as the use of crop protection agents and artificial fertilizers to zero.
The water used for irrigation is completely conserved. Photo: WUR
In the demo-greenhouse, situated in Bleiswijk, WUR researchers are currently growing strawberries, the houseplant anthurium and the flowers gerbera and freesia. “The demo-greenhouse offers us the opportunity to experiment in ways that are impossible in actual practice,” says Frank Kempkes, researcher Energy and Greenhouse Climate.
Dutch horticulturalists sorely need this help since the sector has agreed to be fully CO2-neutral by the year 2040. The CO2-emissions produced by the sector totalled 5.7 megatonnes in 2017, which they aim to reduce to 2.2 megatonnes of CO2 by 2030.
Reducing energy usage is key in creating a climate-neutral greenhouse. In the winter, heating is generated through the use of natural gas and this produces CO2-emissions. Better insulation can contribute to lower energy use, but this can cause unwanted levels of humidity.
“Plants will always evaporate, so we must take measures to stop fungi from taking over. The plants in the demo-greenhouse are cultivated at relatively low temperatures. In combination with the improved isolation, this makes it more challenging to dehumidify the greenhouse which consumes a lot of energy,” says Kempkes. “For this reason, we maintain a higher temperature in the winter, while using special installations to extract moisture from the air. With these dehumidification installations, we reclaim heat at the same time.” In summer the greenhouse is open and there is little or no heating.
Renewable energy An increasing number of horticulturalists are now using alternative sources of heating such as geothermal heat or a heat pump rather than heating with natural gas, according to Kempkes. A heat pump also heats the demo-greenhouse. “But even an energy-efficient greenhouse still needs heating. In the future, this heat will be obtained from renewable energy sources instead of fossil fuel.”
The researcher stresses the possibilities of storing the energy generated by the greenhouse as a solar collector are expected to increase in the future. He is researching how the energy generated in the summer can be collected and stored. Energy is currently stored in a layer of groundwater. “In the summer, it is usually possible to harvest sufficient energy to get through the winter.”
Another way to minimalize energy usage it to intensify cultivation, notes Kempkes. “Through technical innovations, we can generate a larger harvest using the same resources. This motivates horticulturalists to invest in improved greenhouses.”
Traditionally, for example, rows of strawberry plants are placed sufficiently far apart for a person to move in between them. “An intelligent system that lifts rows of plants individually allows us to increase the number of plants by 20 per cent in the same space.” Light-loving gerberas are provided with light from LED lamps during the winter. Unlike the previous generation of lighting, LED’s do not generate as much heat, preventing the temperature from rising above desired levels. “This leads to a continuous harvest, allowing businesses to employ a stable and experienced workforce, which contributes to the quality of the product.”
Clean water The demo-greenhouse is also efficient with water. The water used for irrigation is completely conserved, even if it has evaporated and has been removed from the air by the dehumidifier. The water is then treated with ozone to kill any germs. Rainwater is the best available source of irrigation water. “By primarily using rainwater, you prevent the accumulation of elements that are harmful to the plants. Tap water contains too many salts for plants. Even spring water requires some treatment to be used for irrigation, because the coastal areas are silted, or because it contains too much iron. Re-using clean water is thus very important in greenhouse cultivation,” says Kempkes.
An intelligent system that lifts rows of plants individually allows us to increase the number of plants by 20 per cent in the same space. Photo: WUR
Pest control The demo-greenhouse has a standing army of biological exterminators such as Linopodes, Reduviidae and parasite-wasps. These prevent the spread of insects such as thrips, whitefly and plant louse. The greenhouse contains plants that house these insects and that they use for breeding, and they are fed.
Kempkes says normally, a horticulturist will only order biological exterminators once an infestation has started. “This takes time, and meanwhile, the plague can spread. So, our team of entomologists is now researching what conditions we need for a continuous presence of biological exterminators, and what effect this has. The conditions in the greenhouse must be favourable to the survival of the exterminators. Besides, not every insect has a known natural enemy.”
Smart windows Greenhouse 2030 is funded through the programme Greenhouse as an Energy Source (Kas als Energiebron), which stimulates energy conservation and use of renewable resources in greenhouse farming and which is funded by Glastuinbouw Nederland (Greenhouse Horticulture Netherlands) and the Ministry of Agriculture, Nature and Food Quality.
In the Netherlands, fruit, flowers and vegetables are grown in some 9,500 hectares of greenhouses, and 300 of those hectares are renewed annually in the form of replacement of obsolete greenhouses. Kempkes says a simple calculation shows this pace is too low to use all possibilities to be completely emission-free in 2040. The knowledge and insights gained through the demo-greenhouse can hasten this process, according to the researcher.
By the time 2030 nears, this greenhouse will likely be obsolete.
A team of researchers from Tomsk Polytechnic University (TPU) in central Russia – along with scientists from other universities and research institutes in the region – recently developed a prototype for an orbital greenhouse. Known as the Orbital Biological Automatic Module, this device allows plants to be grown and cultivated in space and could be heading to the International Space Station (ISS) in the coming years.
According to Aleksei Yakovlev, head of the TPU School of Advanced Manufacturing Technologies, numerous orbital experiments have confirmed the possibility of cultivating agricultural plants under microgravity conditions.
“Currently we are preparing an application for the experiment, and working through the preliminary design and technical solutions. In 2020, we should complete the application and submit it. Then, a coordination council will evaluate its relevance and importance,” said Yakovlev in a TPU news release.
The smart greenhouse project will incorporate technologies developed at TPU, which includes smart lighting that will accelerate plant growth, specialized hydroponics, automated irrigation and harvesting solutions. At present, TPU is constructing a new testing ground so they can expand production on the smart greenhouse.
“In Tomsk, we will conduct interdisciplinary studies and solve applied problems in the field of agrobiophotonics,” said Yakovlev. “At the same time, the research team includes scientists from Tomsk, Moscow, Vladivostok, and international partners from the Netherlands specializing in climate complexes including one from Wageningen University.”
In the end, Yakovlev and his colleagues envision an autonomous module that would be capable of supplying food for astronauts and potentially even docking with the ISS. They also indicated that the module would contain a cultivation area measuring 30 m² (~320 ft²) and that it would be cylindrical in shape. As Yakovlev indicated, this would allow the module to be spun up to simulate different gravity conditions.
The design and engineering that goes into the module will also take into account the kinds of conditions that are present in space, such as solar and cosmic radiation and extremes in temperature. Beyond that, the module will investigate what kinds of crops grow well in orbit.
“Another important issue is the selection of necessary and most suitable agricultural crops and their protection against pathogens in microgravity. We offer various types of lettuce, leeks, basil, and other crops for cultivation in the module,” said Yakovlev.
Plants, cultivated in smart TPU greenhouse Photo: TPU
As the global population increases and climate change threatens traditional farming methods, sustainable food production becomes more crucial, reducing dependence on natural soil and large open fields. Several solutions have been proposed, such as hydroponics, vertical farming and cultivating crops on orbital stations or on ships during interplanetary missions. However, all face technical challenges, particularly in how the plants interact with their environment.
Researchers at Imperial College London in the UK are pushing the boundaries of science by investigating a project that aims to grow plants without soil a different way. A team led by Dr. Giovanni Sena (Life Sciences) along with Dr Conor Myant (Design Engineering), Dr. Gunnar Pruessner (Mathematics) and Professor Chris Braddock (Chemistry) will develop new 3D-printed materials that interact with plants and especially their roots.
The new materials would be embedded with water and nutrients and structured to allow oxygen to diffuse throughout, while promoting root growth. Instead of the roots aligning their growth to gravity, the team also plan to make use of electrotropism – where plant roots align with external electric fields. Modules made from these materials could be used in vertical or 3D farming, and even in microgravity environments.
This project, along with two others (teach computers to check mathematical proofs, and use nanoparticles for cancer detection) will each receive £250,000 for three years from Imperial College’s President’s Excellence Fund for Frontier Research.
