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Purdue Methods: Rice

Rice is a major food crop of the world and a great deal of global research efforts are dedicated to its improvement. Greenhouse production of rice has proven problematic at many institutions due to special nutritional and watering needs of this annual grass, and methods to address these problems are not uniform between research institutions. Rice is unforgiving of water stress, often kept in a tray of water continuously to simulate a rice paddy. Micronutrient deficiencies, particularly iron, hamper early growth, requiring supplemental or corrective applications of fertilizers. Field soils are often used to alleviate these nutritional problems. Locally dug, they are not uniform between institutions and require digging, drying, grinding, cleaning and heat-treatment. Whether using field soil or not, many root media used for greenhouse-grown rice require special equipment for mixing, or labor-intensive mixing by hand. We conducted two studies using Oryza sativa japonica 'Nipponbare' to optimize greenhouse rice production by achieving as many of these goals as possible:

-Optimized growth and yield

-No requirement for using a mineral soil dug from a field

-No supplemental or corrective fertilizer applications

-Limited mixing of soil components

-Repeatable, reportable methodology using readily available materials

-Scaleable production system, for large research projects

Below, you can find the most frequently asked questions that researchers inquire over. Some of the questions we answer with the results from our studies; others from references or surveys of university greenhouse curators. An in-depth description of our materials and methods is provided in the 'Technical Information' section below. A printable, single-page summary of recommendations is also provided, as well as technical analyses of irrigation solutions and root media.

Printable, Single-page of Recommendations

Advice by Question:

Click "GO" to see photographs and description of the experimental results. Click ".pdf", where available, to open printable document format from Purdue Libraries e-Pubs.

[GO]		What is the best temperature?
[GO]		Are short days required for flowering?
[GO]	[.pdf]	What is the best root medium?
[GO]	[.pdf]	What is the best pot size?
[GO]	[.pdf]	What is the best watering method?
[GO]	[.pdf]	What is the best fertilization schedule?
[GO]	[.pdf]	What is the best plant spacing?
[GO]	[.pdf]	How do I avoid leaf yellowing?
[GO]	[.pdf]	Do I need to use field soil?
[GO]		Does water HAVE to left in trays underneath plants?
[GO]		Is reverse-osmosis water required?
[GO]		What if roots need to be cleaned and analyzed?
[GO]		How do I control algae in trays?
[GO]		How long does it take until flowering?
[GO]		How long before seeds can be harvested?
[GO]		How do I control Two-spotted spider mites?
[GO]		Can these results be applied to corn and other grasses?

Related References

• Halevy (Ed.), 1989, CRC Handbook of Flowering. CRC Press, Boca Raton, Florida, pp. 83-91
• International Rice Research Institute homepage
• Article: Photothermal Responses of Flowering in Rice
• Plant Growth Chamber Handbook (plant information table)

Technical Information

• [.pdf] Printable, Single-page of Recommendations
• [.pdf] Materials & Methods

HGRH / WSLR Technical Analyses

• [.pdf] Solution Analysis: Fertilizer Water
• [.pdf] Solution Analysis: Clear Water (tap)
• [.pdf] Media Analysis: Promix BX
• [.pdf] Media Analysis: Profile Greens
• [.pdf] Media Analysis: Mineral Soil
• [.pdf] Media Analysis: Turface MVP