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Temperature is The Biggest Challenge For Cultivation in The Maldives
They currently import 95% of their food. Fruit and vegetables are brought in from afar to provide food for the many tourists as well as the local
A pearly white beach and a vast blue ocean. This is the picturesque location for which many tourists travel to the Maldives every year. However, these islands in the Indian Ocean are tiny and are highly dependent on imports for fresh produce. They currently import 95% of their food. Fruit and vegetables are brought in from afar to provide food for the many tourists as well as the locals.
That could be done more efficiently, according to a group of university students from TU Delft. As part of an assignment, they designed a modern self-sufficient greenhouse in order to produce food locally. And where most study assignments remain a plan on paper, this greenhouse actually might be realized on one of the islands in the near future.
Biggest challenge is temperature
The plans of the Maldives Matter Project are already very advanced, says Carmen Jansen op de Haar of Resilient Island. "It will be a semi-closed greenhouse of one hectare in size. Two-thirds of it will be used to grow lettuce, there will be tomatoes in one-third and possibly strawberries at a later stage. There will be a hydroponic system for lettuce cultivation, for which we collaborate with Van der Hoeven. There is plenty of sunlight and an occasional shower. The biggest challenge for growing in the Maldives is the temperature and the high humidity. On the islands it is between 25 and 30 degrees Celsius all year round, both during the day and at night. Because this temperature difference is so small, many fruits and vegetables cannot grow in that climate, so that the Maldives become highly dependent on imports."
"In order to keep the temperature in the greenhouse at the right level, we need cooling technology. We are also looking at Deep Water Source Cooling, where you use the temperature differences in the water. A new technique that we certainly will not apply immediately, but that is worth investigating.”
Test greenhouse
To investigate the feasibility of the thought out plans, the group will first set up a miniature version of the greenhouse. “We have already done a test with tomatoes. The cultivation results in those circumstances were very positive. With a mini greenhouse, we mainly want to test the techniques.”
Growers from the Netherlands
According to Carmen, so far there is little horticulture to be found on the sun-drenched islands. “There is some cultivation in simple plastic tunnels without cooling or other techniques. The products on the field are sprayed a lot. Agricultural training is available, but currently only six people have completed the university horticultural training. Because there is little work to be found in it, that number will not grow anytime soon."
At the end of last year, Resilient Island made an appeal to find a Dutch grower who, once the greenhouse is completed, will start the cultivation. “We have found two growers who are currently helping us to answer technical cultivation questions and who also give advice on setting up an education program. Eventually, a Dutch grower will head over there to train the Maldivian growers. We are also going to bring local growers to the Netherlands to show them our horticulture here. Ultimately, they will have to manage cultivation independently, with the help of Hoogendoorn climate computers and some advice from the Netherlands.”
Supply to resorts
The choice of crops will be tailored to the demand of resorts. “Our market research showed that there was a great need for lettuce, however, if we would produce only lettuce then it would be too much. Lettuce and strawberries are fragile in transport and therefore very suitable for local cultivation. The intention is to supply various resorts with fresh produce packages."
The exact location for the greenhouse has not yet been determined. “We have selected three islands, each of which has potential in a different way. All three are local islands, which ensures that the local population can easily work in the greenhouse later on. "Although the Maldives have many luxury resorts, not every resort will be supplied." We are looking for resorts that share our vision. Some say that they strive for sustainability, but in practice, nothing much is achieved. It is important that the resorts with which we work support our principles."
Chain reaction
Further in the future, the Resilient Island team hopes to broaden the project. “Our goal is to make the Maldives less dependent on the rest of the world. We are hoping for a chain reaction to other Small Island Developing States, as these countries are called that are highly dependent on the mainland. The corona crisis once again made it very clear that it is important that countries and islands can meet their own needs. Air traffic almost came to a standstill, making it even more evident why it is so important that these kinds of countries can be self-sufficient."
For more information:
Carmen Jansen op de Haar
Resilient Island Foundation / Resilient Island B.V.
info@resilientisland.com
www.resilientisland.com
Publication date: Mon 6 Jul 2020
© HortiDaily.com
Breaking News: Europe Braces For Peak of A Record Heatwave
Europeans braced Thursday for the expected peak of a sweltering heatwave that has sent temperatures soaring above 40oCelsius (104 Fahrenheit), with schools in France closing and wildfires in Spain spinning out of control
Europeans braced Thursday for the expected peak of a sweltering heatwave that has sent temperatures soaring above 40oCelsius (104 Fahrenheit), with schools in France closing and wildfires in Spain spinning out of control.
Governments warned citizens to take extra precautions, with the high temperatures also causing a build-up of pollution, and emergency calls to hospitals increased. Exceptional for arriving so early in summer, the heatwave will on Thursday and Friday likely send thermometers above 40oC in France, Spain and Greece.
A forest fire in Torre del Espanol in Spain's northeastern Catalonia region raged out of control, devouring land despite the efforts of hundreds of firefighters who worked through the night.
French Health Minister Agnes Buzyn said people had to be prepared for the peak of the heatwave and expressed irritation that some appeared not to be taking the advice on board.
Possible all-time high
The average maximum temperature recorded Wednesday in France of 34.9oC was already a record for the month of June, said state weather forecaster Meteo France. Even higher temperatures are expected on Friday, where areas in the south could see peaks of 42 to 44oC.
Meteo France said France's all-time record could be broken; an August 12, 2003 reading of 44.1oC in Saint-Christol-les-Ales and Conqueyrac in the southern Gard region.
Source: phys.org
Publication date: 6/28/2019
Northern Italian Trial Greenhouse To Test Floating Systems In Winter
"Water temperature essential element in growing on floating systems"
"Growers have been using floating systems for years, but not always in the right way. We verified that an essential element is the temperature of water." Speaking is Gian Paolo Menarello with Idromeccanica Lucchini. The company set up a testing area in a company located in northern Italy to grow lettuce using a floating system in winter. "They proved that it is not so much air temperature, but rather the water temperature that determines crop development."
Idromeccanica Lucchini is continuously experimenting with hydroponic cultivation and, specifically, with floating systems.
Non-heated greenhouse
Tests are still being carried out in a non-heated greenhouse (45 meters long, 8 meters wide and 3.5 meters high) protected with a plastic film. A heat exchanger helps maintain the temperature within a suitable range without wasting too much energy, so that the crop can be economically viable.
"Another fundamental aspect is the monitoring of oxygenation. While the floating system technique helps make a better use of the space, it cannot be improvised and all materials must be chosen accurately. For example, supports are made of PVC suitable for young plants."
Lucchini focuses on innovation working alongside entrepreneurs to make sure all steps are verified and all components are checked. For example, while the temperature in tanks must be regulated in winter to obtain sustainable productivity, the environment needs to be cooled down in summer.
"The first winter harvest was excellent and economic results were very positive for growers. Heads were large, weighing around 450 grams each. Thanks to our tests, we proved that, in theory, lettuce could be cultivated throughout the year in northern Italy too, but the cycle becomes too long in central winter months, so it is not worthwhile. Anyway we are also carrying out tests with parsley, celery and endive."
This type of cultivation leads to many advantages: there are no soil fatigue problems, a lot of water can be saved and there is no need to weed or prepare the soil. In addition, producers can make more precise plans and spend less money on labor.
Contacts:
Idromeccanica Lucchini S.p.a.
Via Cavriana 4B
46040 Guidizzolo (MN)
Tel.: (+39) 0376 818433
Fax: (+39) 0376 819498
Email: info@lucchiniidromeccanica.it
Website: www.lucchiniidromeccanica.it
Publication date: 5/8/2019
© HortiDaily.com
The Best Temperatures For An Indoor Grow Room
Finding the ideal operating temperature is one-way growers can help ensure growth rates and bountiful harvests. But as Goldilocks found out, determining ideal temperatures can sometimes take some experimentation.
Takeaway: Finding the ideal operating temperature is one-way growers can help ensure growth rates and bountiful harvests. But as Goldilocks found out, determining ideal temperatures can sometimes take some experimentation.
The atmospheric conditions in an indoor garden have a tremendous impact on the quality and quantity of the finished crop. Growers of all skill levels are continuously trying to master the subtle environmental factors that can make a significant difference in growth and yield over the course of a plant’s life cycle.
When discussing the atmospheric conditions of an indoor garden, people are often referring to humidity and temperature. Although humidity is an important aspect, this article will focus on temperature, which plays a vital role in the way a plant is able to process light and intake water and nutrients.
Temperature affects a plant’s ability to photosynthesize, and it also plays a key role in seed germination and fruit and flower development. If temperatures fall outside the desired range, the garden becomes less efficient. Over time, these inefficiencies can lead to smaller, lower-quality yields.
Maintaining a Consistent Temperature Inside Your Grow Room
One of the most important things a grower can do is maintain a uniform and consistent temperature. A uniform temperature means the growroom’s temperature is the same in all areas, from one end to the other.
Most growers use high-intensity lighting equipment in their growrooms, which produces excess heat from one focal point. If this is not addressed, the temperature around the light source will be much warmer than in the other areas.
Maintaining a uniform temperature can normally be achieved by creating adequate air flow within the room. Oscillating fans will continuously move the air around the room so the heated air underneath the light fixtures will mix with the cooler air in the room.
Consistency is also important when it comes to growroom temperatures. Plants love consistency and respond well to it. The better growers can maintain a consistent temperature range, the better their yields will be.
To achieve a high level of consistency, a grower will usually invest in a climate controller with ventilation fans or an air conditioner.
For ultimate control, air conditioners are the way to go. Mini-split air conditioners allow growers to maximize control over temperature consistency. Those who choose to invest in a properly sized mini-split air-conditioning system will not regret it—nothing is better than being able to simply push a button and have absolute control.
The Ideal Temperature Range for Indoor Gardens
To maximize efficiency, try to determine the garden’s ideal temperature range, which is the temperature at which plant growth is maximized. The ideal temperature is crop-dependent because plants differ greatly in their responses to temperature.
For most fast-growing annuals, a good initial range at which to operate a garden is 70-80°F (21.1-26.6°C). Most varieties will prefer the upper end of this range. This temperature range can be used for both the vegetative stage and the fruiting/flowering stage.
Growers with climate-controlled rooms can use the temperature range as a starting point when trying to figure out the room’s best operating temperature.
When experimenting, consider the way the air temperature will affect the root mass of the plant. In most indoor gardens, plants are grown in hydroponic systems or planting containers, and these plants are more affected by changes in the air temperature than plants that are planted directly into the ground.
For this reason, growers must always be aware that higher air temperatures can lead to higher temperatures around the plant’s root mass.
Growers with climate-controlled rooms can set up an experiment to find the ideal temperature by slowly increasing the temperature and monitoring vegetative growth. By using this method, a grower can measure plant growth as it correlates to temperature and then determine the optimal temperature for the vegetative growth of that plant variety.
Remember that different varieties of the same plant will have different optimal temperatures. For that reason, growers with multiple plant varieties will have to shoot for a happy medium to keep all plant varieties as content as possible.
For most plants, the ideal temperature range for vegetative growth will also be the ideal temperature range for the fruiting stage, although some varieties prefer slightly cooler temperatures for flowering.
Many plant varieties I have grown performed best at 78°F (25.5°C), although I have had a few varieties that liked it a bit warmer (80-84°F). For novice growers or those without an air-conditioning system, a thermostat controller and fan can still get the garden close to the 70-80°F (21.1-26.6°C) range.
"In a semi-enclosed environment, a significant drop in temperature can lead to condensation and moisture issues in the growroom and on the plants themselves."
Unfortunately, temperature control is only as good as the equipment, but don’t get frustrated if the ventilation system isn’t perfect to begin with. Instead, do your best to maintain consistent and uniform temperatures with the equipment that is on hand and work towards maximizing climate control in the future.
Temperature Differential
The temperature differential, or the temperature change between the lights-on (daytime) and lights-off (nighttime) periods, is an important aspect of controlling temperature that often gets overlooked. Once growers determine the temperature of the lights-on stage in the garden, they can start to determine what temperature is needed for the lights-off period.
The best lights-off operating temperature is generally about 10-15°F (5-7°C) cooler than the lights-on operating temperature. This temperature drop is significant enough to allow a plant to go through its normal process of rest and transpiration, but is not so great that problems are caused.
Keeping the lights-off temperature within 10-15°F of the lights-on operating temperature serves as a safeguard against pathogens, especially molds and fungi. In a semi-enclosed environment, a significant drop in temperature can lead to condensation and moisture issues in the growroom and on the plants themselves.
Over time, this will result in a perfect environment for molds, fungi, and other plant pathogens. For most indoor gardens, the ideal temperature for the lights-off period is 55-70°F (12.8-21.1°C). Adding an electric heater to warm up the garden at night goes a long way towards preventing problems and maintaining healthy growth rates. (Read More: Tips for Avoiding Mold Growth in the Grow Room)
CO2 Enrichment and Temperature Inside a Sealed Grow Room
Growth rates can be increased by enriching the garden’s environment with carbon dioxide, but to gain maximum benefits, growers need to increase the room’s operating temperature.
The increase in temperature enables plants to properly process the additional CO2 in the atmosphere and increase the rate of photosynthesis, which increases plant growth.
When operating a garden with CO2 levels of 1,200-1,500 parts per million (ppm), it is a good idea to increase the temperature range to 80-90°F (26.6-32.2°C). From there, slowly increase the temperature and monitor plant growth to find the ideal operating temperature.
Best Temperatures for Clones and Seeds
Just like fully established plants, clones and seedlings thrive on consistency. In fact, most seed varieties will only germinate once the temperature is consistently over the seed’s threshold temperature for sprouting.
For many plants, this is a temperature range of 60-70°F (15.5-21.1°C). In indoor gardens, a good temperature range for the seedling and cloning stage is usually around 72-82°F (22.2-27.8°C). Seedling heat mats or small electric heaters are great ways to maintain a consistent temperature warm enough to promote germination and early root development.
Again, each plant variety is different. When starting from seeds, check the seed packet for instructions. Some cold-weather plants can be germinated in relatively cold conditions, whereas some summer plant varieties may require much warmer temperatures for germination.
Experiment to Find the Ideal Temperature
Every indoor garden is different and there are many variables that can affect the way a crop performs. Although growers can use the general operating temperature range of 70-80°F ((21.1-26.6°C) as a starting point, finding the ideal temperature for an indoor garden is something that can only be done through experimentation.
As with most horticultural experiments, finding the ideal operating temperature will take time. It is hard to determine how a small change in the garden will affect the overall results until the garden’s harvest can be measured.
For that reason, it may take multiple garden cycles before a grower is able to collect enough data to make a solid conclusion about the ideal operating temperature.
Although the process can be a bit tedious, committed indoor gardeners should have no problem documenting temperatures and how they relate to the growth of the garden. After all, growers are always in search of ways that will increase their return on investment.
Finding the ideal operating temperature for an indoor garden is just one-way growers can help ensure their gardens have consistent growth rates and repetitive, bountiful harvests.
Written by Eric Hopper
Eric Hopper’s past experiences within the indoor gardening industry include being a hydroponic retail store manager and owner. Currently, he works as a writer, consultant and product tester for various indoor horticulture companies. His inquisitive nature keeps him busy seeking new technologies and methods that could help maximize a garden’s performance.