Faculty and research guide

Laboratory of Vegetable Crop Science

Katsumi Suzuki, Yoshikazu Kiriiwa

In the Laboratory of Vegetable Crop Science, researches are conducted to develop techniques that are useful at sites which can produce succulent vegetables reliably, without any investment of effort.

1) The study of laborsaving hydroponic system
Research on profitable automated and laborsaving cultivation that does away with the need to invest a lot of effort laborsaving farming becomes possible with soilless culture * because fertigation (irrigation and fertilization) can be controlled automatically. This means that the manual work that humans previously performed on the basis of observation, by responding to the existing plant growing conditions, is left to a control device like a computer. To bring this about requires the development of a horticultural robot which grows plants with the desired capability. Rigorous management that meets the needs of the crop leads to the stable production of succulent and healthy vegetables.
* Soilless culture: a technique in which an organic or inorganic medium is used instead of soil and vegetables are cultivated by applying a nutrient solution containing fertilizer.

Research on high quality melon cultivation using D-tray hydroponic system

2)The study on environmental control of protected horticulture
Environmental control is very important with cultivation in protected horticulture. We are investigating effected CO2 enrichment methods to increase yield of horticultural crops in greenhouse. We developed new technique that measure CO2 concentration in house, and now we make a local CO2 enrichment system using that methods.

CO2 enrichment in strawberry house

3) The study of environment-friendly agriculture for the future
Environmental problems, including global warming and so on, have become serious worldwide concerns, and we cannot neglect them, even at agricultural production sites. In soilless culture, the fertilizer that nourishes the plants is provided by drip irrigation. However, since the fertilizer that is not taken up by the plants is sometimes discharged into the soil or groundwater unmodified, we are also trying to develop a zero-emission cultivation system as a way of helping to prevent environmental pollution.

Tomato grown in D-tray circulated hydroponic system

4) The study of high-quality vegetable production
Consumers have a lot of concerns about food and health, and nowadays, in addition to being delicious and safe, consumers want their food to be healthy (i.e., contributing to good nutrition). We are engaged in research that aims to improve the quality of vegetables raised by soilless culture, taking advantage of the fact that in a soilless culture system nutrient control can be accomplished more completely.
Recently we study about tomato disorder, for example, cracking, yellow shoulder color, blossom-end rot, blossom-inner rot and abnormal flower in tomato, and abnormal flower and fruits in strawberry.
We make a condition that those injuries occur easily, and we use biological, morphological and chemical technique to clarify to incidence of injuries and develop control technology to stop those injuries.

Tomato cracking, blossom-end rot, yellow shoulder, check

Strawberry flower injury

5)The study good quality nursery
We study the good quality nursery of tomato, kale and strawberry. It is possible to manage seedling intensively. We produce high quality seedlings by using fertilizer, environmental control and so on.

Some vegetables grown in closed plant production system

Seedlings of kale were improved under some environment conditions

6) The establishment of advanced cultivation methods that use new and different field techniques
When it is possible to cultivate plants without using soil, crops can be produced without regard to location. A typical example of this concept is the plant factory. In plant factories, technological developments are needed to maximize crop productivity by combining various techniques. Companies that up to now were not interested in agriculture are also considering technology transfers to agricultural sites to gain a wider use of their technology. To support such companies, we are also studying methods for different field techniques that can then be disseminated to production sites.

Experiments of irradiation of LED light