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The focus of energy savings usually liesin technology. But the crop itself offersnumerous opportunities to economiseon energy consumption. Many researchresults are still waiting to be translatedinto practice.

The focus of energy savings usually liesin technology. But the crop itself offersnumerous opportunities to economiseon energy consumption. Many researchresults are still waiting to be translatedinto practice.

Plants in the greenhouse are increasingly on the move. More attention is being paid to air circulation and mobile cultivation is on the rise. Research shows that movement and touch (also as plants rub against each other) slow down growth. That can be frustrating but you can also use it to your advantage.

The gas carbon dioxide (CO2) is a raw material for photosynthesis. From this, together with water, the plant makes sugars and other compounds. Therefore CO2 is for the plant what food is for man. There is often too little available in the greenhouse air for optimal production. Therefore it makes sense to dose with CO2. The optimum concentration varies over the day and is dependent on many factors.

Calcium is a delicate mineral in the plant. A deficiency can cause problems such as blossom end rot in sweet peppers and tomato, burnt edges in leafy crops and ‘tip burn’ in some ornamental crops. The other way round, excess leads to gold spot on tomatoes and stip (colour spotting) in peppers. Just paying attention to the nutrition is not enough. The distribution in the plant is crucial. This can be regulated but it requires a lot of diligence.

Fungi parasitize plants because they can’t assimilate themselves. They have developed numerous methods of penetrating the plant. In turn, plants have developed a complete arsenal of defences. The latter offers growers some encouragement.

Plants in the greenhouse are increasingly on the move. More attention is being paid to air circulation and mobile cultivation is on the rise. Research shows that movement and touch (also as plants rub against each other) slow down growth. That can be frustrating but you can also use it to your advantage.

Fungi parasitize plants because they can’t assimilate themselves. They have developed numerous methods of penetrating the plant. In turn, plants have developed a complete arsenal of defences. The latter offers growers some encouragement.

The gas carbon dioxide (CO2) is a raw material for photosynthesis. From this, together with water, the plant makes sugars and other compounds. Therefore CO2 is for the plant what food is for man. There is often too little available in the greenhouse air for optimal production. Therefore it makes sense to dose with CO2. The optimum concentration varies over the day and is dependent on many factors.

Calcium is a delicate mineral in the plant. A deficiency can cause problems such as blossom end rot in sweet peppers and tomato, burnt edges in leafy crops and ‘tip burn’ in some ornamental crops. The other way round, excess leads to gold spot on tomatoes and stip (colour spotting) in peppers. Just paying attention to the nutrition is not enough. The distribution in the plant is crucial. This can be regulated but it requires a lot of diligence.

If light penetrates the crop better, it results in higher production. This is because the leaves that are deeper in the crop are a long way from their light saturation point. Diffuse glass or coatings and the distribution of the crop are the most applicable ways to achieve better light penetration. Other methods are usually beyond the reach of the grower

If light penetrates the crop better, it results in higher production. This is because the leaves that are deeper in the crop are a long way from their light saturation point. Diffuse glass or coatings and the distribution of the crop are the most applicable ways to achieve better light penetration. Other methods are usually beyond the reach of the grower

Sweet peppers arrive in waves. New fruits lure so many assimilates towards them that the flowers above them abort. This article provides various suggestions about how to flatten out the peaks and troughs. In the long term, breeding can also play an important role.

No potassium no plant: A huge number of processes are dependent on this element. Luckily, hardly any problems occur because the plant is good at looking after itself in this respect.

No potassium no plant: A huge number of processes are dependent on this element. Luckily, hardly any problems occur because the plant is good at looking after itself in this respect.

Sweet peppers arrive in waves. New fruits lure so many assimilates towards them that the flowers above them abort. This article provides various suggestions about how to flatten out the peaks and troughs. In the long term, breeding can also play an important role.

Een plant heeft te maken met voortdurend wisselende lichtniveaus die soms zodanig hoog kunnen oplopen dat ze schade veroorzaken. Er bestaat een uitgebreid stelsel van verdedigingslinies op alle niveaus: blad, cel, celorganen en moleculair niveau. Soms is de voorbereiding op mogelijke lichtschade zo goed dat het productie kost.

Iron plays a major role in photosynthesis. That’s why a shortage directly affects the production capacity of the plant. The application of chelates has made iron much more easy to absorb. Nevertheless it’s an element that we have to keep an eye on.

It used to be rare to come across plants that bind CO2 mainly at night: CAMplants. But it’s no longer an exception in the horticultural sector. Nowadays the best-selling pot plant in the Netherlands – phalaenopsis – belongs to this group. This then raises questions such as: When do CAM-plants behave according to the book and when don’t they? And when does it make sense to dose with CO2 and provide lighting?

Een plant heeft te maken met voortdurend wisselende lichtniveaus die soms zodanig hoog kunnen oplopen dat ze schade veroorzaken. Er bestaat een uitgebreid stelsel van verdedigingslinies op alle niveaus: blad, cel, celorganen en moleculair niveau. Soms is de voorbereiding op mogelijke lichtschade zo goed dat het productie kost.

It used to be rare to come across plants that bind CO2 mainly at night: CAMplants. But it’s no longer an exception in the horticultural sector. Nowadays the best-selling pot plant in the Netherlands – phalaenopsis – belongs to this group. This then raises questions such as: When do CAM-plants behave according to the book and when don’t they? And when does it make sense to dose with CO2 and provide lighting?

The photosynthetic process can hardly be bettered. But the utilisation of natural or artificial light certainly leaves room for improvement. In recent years our understanding of light has grown considerably and this has major implications on how we deal with light in horticulture.

Nitrogen is found in almost all parts of the plant. It’s one of the plant’s most essential nutritional element. There’s a tendency in greenhouse horticulture to over-fertilise. In most situations it’s difficult to get around this. However, more precise application offers more possibilities to control production.

The photosynthetic process can hardly be bettered. But the utilisation of natural or artificial light certainly leaves room for improvement. In recent years our understanding of light has grown considerably and this has major implications on how we deal with light in horticulture.

Nitrogen is found in almost all parts of the plant. It’s one of the plant’s most essential nutritional element. There’s a tendency in greenhouse horticulture to over-fertilise. In most situations it’s difficult to get around this. However, more precise application offers more possibilities to control production.

Tomaten bijbelichten heeft alleen zin als de vraag naar assimilaten (sink) groter is dan de productie ervan (source). Anders is het weggegooid geld en kan het extra licht zelfs averechts werken. Dit speelt in het begin van de teelt, zeker bij plantdata vroeg in de herfst. Voor drie tomatenrassen is de source/sink balans in beeld gebracht.

Tomaten bijbelichten heeft alleen zin als de vraag naar assimilaten (sink) groter is dan de productie ervan (source). Anders is het weggegooid geld en kan het extra licht zelfs averechts werken. Dit speelt in het begin van de teelt, zeker bij plantdata vroeg in de herfst. Voor drie tomatenrassen is de source/sink balans in beeld gebracht.

Temperature influences plant processes. But the different organs – root, stem, leaf, flower, fruit – all react differently. This is something to take into account with new cultivation systems such as (semi) closed greenhouses, where an essential aspect is cooling.

Good light interception is the first step to good production. For that you need sufficient leaf area in the greenhouse. But it’s difficult for a grower to determine how much leaf surface area is present. Research is shedding new insight into this aspect.

A high EC results in loss of production and reduces growth. However, for quality reasons it can be beneficial to maintain a higher EC. In doing so a grower can take advantage of the difference between the plant’s day and night mechanisms.

Temperature influences plant processes. But the different organs – root, stem, leaf, flower, fruit – all react differently. This is something to take into account with new cultivation systems such as (semi) closed greenhouses, where an essential aspect is cooling.

A high EC results in loss of production and reduces growth. However, for quality reasons it can be beneficial to maintain a higher EC. In doing so a grower can take advantage of the difference between the plant’s day and night mechanisms.

The Netherlands sets the standard for high-tech greenhouses worldwide. But increasingly suppliers are looking too at possibilities within the mid-tech and even the low-tech market segments. The Dutch government is supporting demonstration projects, for example in Mexico, East Africa and Malaysia. Technically it’s all going well.

Good light interception is the first step to good production. For that you need sufficient leaf area in the greenhouse. But it’s difficult for a grower to determine how much leaf surface area is present. Research is shedding new insight into this aspect.

Imagine 200 kg of tomatoes per square metre greenhouse, 310 kg cucumbers, 120 kg peppers, 1,100 roses and 1,300 chrysanthemums. The plant is capable of producing much more than we currently achieve. However, to actually get closer to this potential production each step has to be improved.

Dry, brown areas (blossom end rot) on tomatoes and peppers; tipburn on lettuce and Chinese cabbage; dry edges on the young leaves and flower leaves of poinsettias; malformed spathe leaves on anthurium. Many such physiogene deviations are related to calcium. They aren’t always caused by a deficiency but can be due to poor calcium distribution in the plant. Many sorts of circumstances influence the dispersal of calcium.

Will a top rose variety perform just as well in Kenya as in the Netherlands? Can you predict how it will perform based on its genetic characteristics? A large trial which tested 20 varieties from five plant breeders at ten locations in the Netherlands and abroad gives many new insights, but still no definitive answers.

The use of LED’s in horticulture is still progressing. And the increasing number of control possibilities is staggering. But the speed at which our knowledge is being transferred into new developments could be faster, certainly when it comes to the influence of light colour. Here is the current situation.

Dry, brown areas (blossom end rot) on tomatoes and peppers; tipburn on lettuce and Chinese cabbage; dry edges on the young leaves and flower leaves of poinsettias; malformed spathe leaves on anthurium. Many such physiogene deviations are related to calcium. They aren’t always caused by a deficiency but can be due to poor calcium distribution in the plant. Many sorts of circumstances influence the dispersal of calcium.

Imagine 200 kg of tomatoes per square metre greenhouse, 310 kg cucumbers, 120 kg peppers, 1,100 roses and 1,300 chrysanthemums. The plant is capable of producing much more than we currently achieve. However, to actually get closer to this potential production each step has to be improved.

The Next Generation Growing is about technologies working together. In addition to significant energy savings, the aim is to develop new methods of growing, which look more at systems rather than individual climate factors. Understanding how a plant will react is therefore essential.

Will a top rose variety perform just as well in Kenya as in the Netherlands? Can you predict how it will perform based on its genetic characteristics? A large trial which tested 20 varieties from five plant breeders at ten locations in the Netherlands and abroad gives many new insights, but still no definitive answers.