Frequently asked questions?

Rice Research

Q. What is meant by the Green Revolution?
A. The Green Revolution is a term used to describe an event which was launched in the 1960s throughout Asia, when modern scientific methods were applied to agriculture.

Q. What happened during the Green Revolution?
A. Production of various crops, including rice, increased dramatically.

Q. Why is this important?
A. There was not enough food being produced in some countries and the Green Revolution saved millions from famine.

Q. Why biotechnology in rice production?
A. It enables breeders to solve problems that currently cannot be solved by traditional methods. And also, it enables breeders to move characters between rice cultivars more quickly and efficiently. It will enhance pest and diseases resistance, increase tolerance to flooding and drought, raise yield potential, improve nutritional value, and reduce production costs.

Q. What is genetic conservation?
A. It is the collection, maintenance, and preservation of all segments of germplasm in a crop species and its wild relatives.

Q. What do you mean by genetic resources?
A. Genetic resources refer to germ plasm that includes the entire array of cultivars in the crop species, related wild species in the genus, and hybrids between the wild and the cultivated species.

Q. How much water is needed to produce 1 kilogram of rice?
A. By traditional irrigation method, it takes about 5,000 liters of water to produce 1 kilogram of rice.

Q. What do you refer to as the "miracle rice"?
A. It is the term given to IR-8-288-3, or simply IR-8, by newsmen because of its high yield. IR-8 is the first high-yielding variety developed at IRRI. It is the result of the crosses between Peta, a tall Indonesian variety with high vigor, seed dormancy, resistance to several insects and diseases; and Dee-geo-woo-gen, a high yielding, heavy tillering, short statured variety from Taiwan.

Q. What is hybrid rice?
A. Hybrid rice is a new sort of rice developed by China noted for its vigor and yield potential. Half of China's rice land is planted to such rice and two-thirds of all the rice harvested in China are hybrids. First generation hybrids produce seeds in very high quantities. But this seed, while good for eating, is not good for planting; it would produce a poor crop.

Q. When did China achieve its first research breakthrough in hybrid rice?
A. In 1973. And in 1990, more than a quarter of China's rice land was under hybrid rice, and yields were running up to 13.5 tons per hectare.

Q. What is the difference between the seeds of hybrid rice and IRRI seeds?
A. Hybrid seeds cannot be replanted and you will need a fresh supply of first-generation hybrid seeds from a nursery to grow a good crop. Seeds of IRRI rice varieties, on the other hand, can be replanted again and again.

Q. What is called "super rice"?
A. This is a new plant type developed by IRRI that can produce yields of 12.5 tons per hectare. This new plant type, dubbed by media as "super rice," has fewer tillers than the currently grown high-yielding varieties, but the number of grains per panicle is 2 to 3 times greater. It has thicker and sturdier stems to prevent the rice plant, now with more grains, from toppling over.

Q. Is the new plant type available to farmers?
A. No. It is still being field tested at IRRI. After fine-tuning, field evaluation, and seed multiplication, the first new plant type seed is expected to be available to farmers in 3 to 4 years.

Q. What is Bt rice? What can it do?
A. Bt rice is rice that has been modified, through biotechnology techniques, with genes from a soil bacterium, Bacillus thuringiensis (Bt). These genes produce crystalline (Cry) proteins that are highly toxic to specific insect groups but are nontoxic to humans and other animals. The insecticidal protein accumulates in the leaves and other green tissues of the plant but not in the grain. Bt rice is targeted at controlling stem borers, which are chronic pests in all rice-growing countries of Asia.

Q. What can be done about insects?
A. In rice production, insects can be categorized into two: the harmful and the friendly insects. In the rice field, these insects and other organisms are linked in an intricate food web. Based on scientific evidence, it is questionable whether routine insecticide treatment of rice is needed to protect the crop. In one of the surveys, untreated fields yield as much as fields treated with one to five or more insecticide applications.

Q. What do you refer to as integrated pest management (IPM)?
A. It is the mixture of biological, physical, and chemical methods integrated into one cohesive strategy. IPM combines resistant cultivars, agronomic practices known to reduce losses due to pests, and conservation practices that preserve and increase natural enemies. Pesticides are applied only when necessary.

Q. How can IPM help farmers?
A. By promoting IPM, farmers will be equipped with information and tools to make better decisions about how to control insects, weeds, diseases, and other pests without relying solely on chemical inputs that can damage the environment and cause health problems.

Q. What are considered pests in rice production?
A. The term rice pests refers to all organisms that can cause economic loss in rice production, including anthropods, pathogens, viruses, weeds, mollusks, and vertebrates. Pests are characterized by the damage or illness they cause and by the value placed on these consequences by society.

Q. What are the most serious insect pests of rice?
A. Stem borers, green leafhoppers, brown planthoppers, and gall midge.

Q. What are stem borers?
A. Stem borers have been conventionally considered the most serious insect pest of rice throughout Asia. Stem borers cause severe losses during the vegetative and reproductive stages of the plant. When the vegetative tillers attacked by the stem borer larvae die, a condition known as "dead heart" results. If the attack occurs after the panicle emergence stage, the entire panicle dies without producing any grain. This condition is referred to as "white head." Some of the most important species of stem borers are the striped borer (Chilo suppressalis), yellow borer (Tryporyza incertula), the white borer (Tryporyza innotata), the dark-headed borer (Chilotraea polychryza), and the pink borer (Sesamia inferens).

Q. Are pesticides a problem?
A. Yes. Indiscriminate pesticides use can result in health impairment due to direct or indirect exposure to hazardous chemicals, environmental contamination, transmittal of pesticides residues through the food chain to the rural and urban consumers, an increase in the resistance of pest populations to pesticides causing pests outbreaks, and the reduction of beneficial parasites and predators.

Q. How can farmers reduce their use of pesticides without seeing their harvest diminish?
A. Increasingly, farmers are using more modern methods of protecting their crops from predators, such as biocontrol or IPM.

Q. What happens if the farmers are too poor to buy insecticides?
A. If the farmers are too poor to buy insecticides, spiders and other predators will control the pests.

Q. How can spiders help farmers?
A. Spiders are naturally voracious predators. One spider can immobilize five brown planthopper nymphs or adults in 2 or 3 minutes. Among the 300 diverse kinds of spiders, the wolf are the best predators.

Q. How do you control golden snails?
A. Golden apple snails have become a serious problem in the Philippines and other countries causing high losses, but there has not been an intensive and well-targeted research on these pests. It is necessary to first understand the ecological relationships of golden snails and other biotic and abiotic factors in the rice ecosystem in order to design management strategies. IRRI, meanwhile, has designed a counter-weapon -- a kitchen strainer and scraper-blade on a long handle -- to control these pests.

Q. What about weed management?
A. Just as with insect pests of rice, a mixture of approaches for weed management needs to be applied.

For more than 2,000 years, water and the physical removal of weeds have been the dominant components of weed management. To date, herbicide application is the solution. But other approaches needs to be developed. Good land management with level fields can be combined with minimum water use for effective weed control, use of clean seeds can prevent new weed species from being introduced; and mechanization of planting, both for transplanting and for direct seeding, allows for easier weed management. Long- term solutions to weed management will include developing rice cultivars that outcompete weeds for resources (light, nutrients, and water) and that interfere with weed growth. Weeds have their own pests: insects, diseases, and nematodes. Opportunities exist to use these indigenous natural control agents as biological weed management tools.

Q. What are the major diseases of rice?
A.  Among the major diseases are blast, bacterial leaf blight, tungro virus, and sheath blight.

Q. What is Oryza nivara?
A. It is a wild species of rice which is the only known source of resistance to grassy stunt virus. This species has many undesirable agronomic traits, such as fragile rachis (shattering), weak stems, droopy leaves, squatty and spreading growth habits, long awns, red pericarp, and a high level of sterility. Its desirable traits, besides resistance to grassy stunt, include high tillering capacity, grain dormancy, and resistance to bacterial leaf streak.

Q. Why do some farmers prefer transplanting rather than direct seeding?
A. So the rice will have a head start over the weeds. This will minimize the cost of weeding and expensive chemicals.

Q. In fertilizer application, what does topdressing mean?
A. Topdressing means applying fertilizer to the soil or water surface after seeding or transplanting or after the crop has been well established (usually at the panicle initiation stage about 3 weeks after flowering).

Q. What is meant by basal application?
A. Basal application means applying fertilizer into the soil before seeding or transplanting the crop.

Q. What is the effect of global climate change to rice production?
A. A warming of 2°C promotes sterility in rice, reducing the yield 25% or more. A similar rise in temperature could also greatly affect wheat. Consequently, the effect of low temperature to rice production is that the growth duration of rice will be prolonged.

Q. What will be the effect of low temperatures during the ripening stage of the rice plant?
A. Rice grains shatter easily from the panicle and grain dormancy is shorter when the temperatures during ripening are low. The rice plant produces more straw than grains.

Q. What will be the effect of high temperatures during the ripening stage of the rice plant?
A. High temperatures accelerate grain ripening, resulting in prematurity. Prematurity may result in partially chalky and milk-white kernels and thicker bran and aleurone layers.

Q. What do you refer to as allelopathy?
A. Allelopathy is the phenomenon of suppressing the growth of one plant species by another through the production and release of toxic substances.

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