Rice production and research in Turkey

H. Sürek

Thrace Agricultural Research Institute, PO Box 16, 22100 Edirne, Turkey

INTRODUCTION

Turkey has great agricultural production potential thanks to its favourable ecological and conditions, climate and land resources. As well as providing food for the growing population, agriculture plays an important role in nation-al development efforts - the country has 65 million inhabitants, 45 percent of whom live in rural areas.

Turkey has a total land area of 76 960 000 ha, and approximately 24 000 000 ha are cultivable (Table 1). The average annual rice-growing area varies between 50 000 and 60 000 ha.

RICE PRODUCTION AND CONSUMPTION

Turkey's rice area varies between 50 000 and 60 000 ha from year to year depending on available irrigation water and market price (Table 2). In the early 1980s the country had more than 70 000 ha of rice-growing area, reaching 77 000 ha in 1982. However, after the mid-1980s it decreased drastically, owing to two factors: a drought occurred between 1985 and 1994, resulting in a shortage of irrigation water; and there was protection against rice imports, for example in the form of taxes. Such protection was lifted or reduced in 1984, thus allowing low-cost rice imports. Domestic production costs were higher than the price of imported rice and so farmers abandoned rice cultivation in some regions, both because of the shortage of irrigation water and because of high production costs. Rice cultivation was also prohibited in some drought-stricken areas so that water supplies could be used for other irrigated crops, such as cotton, maize and vegetables. However, the area planted to rice started to increase again in 1994, rising from 41 000 ha to 58 000 in 1995. An area of more than 60 000 ha was estimated in 1996, an increase owing to a slight increase in rainfall over the previous two years.

Total milled rice production varies between 150 000 and 200 000 tonnes, which is not enough for domestic consumption. Rice consumption per caput is 4 to 5 kg and total milled rice consumption is about 300 000 tonnes. Therefore, some milled rice should be imported to meet total domestic consumption.

Over the last decade, owing to a decrease in domestic rice production, Turkey increased its rice imports, which went from 26 000 tonnes in 1981 to 309 000 tonnes in 1993. In some cases, imports exceeded requirements.

Average rough rice yield in Turkey is currently 5 tonnes/ha, up from about 4.5 tonnes/ha in the early 1980s.

Rice-growing regions

Turkey has seven geographical regions and rice can be cultivated in all of these (Table 3). However, the main rice-growing regions comprise the northwestern (Marmara-Thrace) and northern parts of the country (the Black Sea region).

The Marmara-Thrace region is the largest rice-growing area and makes the greatest contribution to production, followed by the Black Sea region. The drought affected the rice crop in all regions but production decreases were largest in the Mediterranean and Aegean regions. Rice production was forbidden in the Aegean because of a shortage of irrigation water.

Although rice is produced in certain micro- and macroclimatic regions in Turkey, it is a profitable source of income for farmers owing to its very high gross income per unit area. In the main rice cultivation regions, there is no alternative high-income crop. Therefore, farmers continue to cultivate rice in these areas at all costs. On the other hand, in regions where there are alternative crops that give a high profit, such as cotton and maize, if the rice market price drops or a water shortage affects irrigation, farmers prefer to grow other crops.

Cultivated rice varieties

The Rocca variety has the largest growing area in Turkey, followed by Baldo. Local varieties are mostly cultivated in Southeast and East Anatolia regions.

CONSTRAINTS TO RICE CROPPING

The meteorological data of two provinces (Edirne and Samsun) which represent two main rice cultivation regions, Marmara-Thrace and Black Sea, are given in Tables 5 and 6. Edirne Province has an average temperature of 24°C during the panicle formation and heading stages in July and August. Low temperatures sometimes cause spikelet sterility in this region. On the other hand, low temperatures at the germination and seedling stages may cause poor stand establishment.

In Samsun Province, the average temperature is slightly lower than Edirne, but its average relative humidity is higher, thus creating suitable conditions for blast outbreaks in that region.

The meteorological data of Diyarbakýr Province in the Southeast Anatolia region are given in Table 7.

The typical characteristics of the climate in Diyarbakýr are high average temperatures and a low relative humidity during the rice-growing period. This situation causes high spikelet sterility in Southeast Anatolia's rice crop.

Abiotic and biotic constraints

Cold water and weather temperatures. Cold water, especially supplied by water pumped from underground or dams, affects the rice crop in the germination and seedling phases and jeopardizes a good stand estab-lishment. Low temperatures damage the rice crop during the different stages of development, for example during germination and at the seedling, panicle formation, flowering and pollination stages.

• High temperatures. High temperatures cause spikelet sterility in the southeastern part of Turkey, where rice is grown in several different microclimatic zones.
• Drought or water shortage. Rice is grown under continuous irrigation with full water control. The crop can suffer from drought or water shortages owing to other causes. The reasons for this problem are: i) farmers sow rice over too wide an area when rice prices are very high and profitable - thus, there is insufficient irrigation water for good growth; and ii) low water accumulation in dams or less river flow owing to low rainfall.
• Salinity and alkalinity. Salinity and alkalinity affect the rice crop in areas where the soil has a high salt content. Irrigation water may also contain a high level of salt. However, this is not a major problem in Turkish rice production.
• Rice diseases. Some fungal diseases damage the rice crop in Turkey, for example blast disease (Pyricularia oryzae), brown leaf spot (Helminthosporium oryzae) and bakanae and foot rot (Fusarium moniliforme). The most important disease is blast. A heavy incidence of blast disease occurred in some rice growing areas in northwest Turkey (Thrace) in 1995. This was the most harmful disease outbreak observed in this region in the last 25 years, causing a 20 percent yield loss in 25 000 ha of rice area of the region. Some farmers left their crop in the field without harvesting. The reasons for the outbreak were heavy rainfall in July and August in 1995, excessive nitrogen application, late planting, high seed density and cold irrigation water.
• Weeds. The most important weed in rice fields is Echinochloa spp. Other species observed include: Cyperus spp., Scirpus spp. and Alismacea spp. Weed control consists of chemical applications during the pregermination or postgermination stages.

RICE PRODUCTION POTENTIAL

The average rice yield in Turkey is about 5 tonnes/ha, which is low compared with other temperate countries such as Australia, California, Spain, Italy, Japan and the Republic of Korea. It could be increased, however, using improved modern rice varieties and new growing techniques, since Turkey has the same rice-growing conditions as those countries.

Increasing rice cultivation area in Turkey depends on irrigation water. Since the climate and soil structure are suitable for rice cultivation in many micro- and macroclimatic regions, if irrigated area is increased, it will be possible to increase rice area as well. Some irrigation projects have been conducted in Turkey, especially in Southeast Anatolia. Rice cultivation area may increase after finishing these projects.

RICE RESEARCH ACTIVITIES

The rice research programme in Turkey was initiated in 1970 at the Thrace Agricultural Research Institute. Until 1982, the institute concentrated its research activities on regional problems. After 1982, a National Rice Research Project was established, and the institute became the coordinating centre. Other research institutes involved in the project are Samsun and Diyarbakýr. Some of Turkey's agricultural university faculties are also involved rice research, for example at Ýzmir, Samsun and Adana.

Major achievements in rice research up to 1995

Varietal improvement. Since the rice research programme began in 1970, much germplasm has been introduced from Italy, Bulgaria, Spain, France, Hungary and the Russian Federation. Four Italian varieties (Rýbe, Rocca, Baldo and Venerýa), three Bulgarian varieties (Plovdýv, Rodýna and Ranballý) and one Russian variety (Krasnodarsky-424) have been released in different regions of Turkey.

As a result of the crossing programme which started in 1979, seven rice varieties have been developed and released for different rice-growing regions. The main traits of these varieties are given in Table 8.

Agronomic research

In addition to breeding activities, studies have been carried out on production techniques. Selected results are given below:

• Rice planting time. It was found that rice can be planted after mid-April in major rice-growing areas, even though the planting time varies from region to region. In the main growing regions it is planted in May.
• Appropriate fertilizer rates. In general, the appropriate rate was found to be N150 P80 kg/ha and it was determined that the rice crop gives better results if nitrogen is applied as NH⁺₄. Regarding the time of application, nitrogen should be applied in two or three doses using one of the following options:

- 1/3 as a basal application, 1/3 at tillering stage and 1/3 at panicle initiation;

- 1/2 at tillering stage and 1/2 at panicle initiation;

- 1/2 as a basal application and 1/2 at panicle initiation.

The results of this study indicate that the most critical stage for nitrogen application is panicle initiation. As mentioned above, to obtain a good yield, part of the nitrogen application must be done at panicle initiation.

• Suitable harvesting time. It was found that rice should be harvested 49 days after flowering in Edirne in order to give a high paddy and milled yield and less chalky and broken grains.
• Seed rates per unit area for different rice cultivars. The recommended rate is 200 kg/ha for long and large grain varieties such as Baldo, Rocca, Trakya and Ýpsala.
• Irrigation. In a comparison between continuous flooding and various methods of interval flooding, continuous flooding was found to give the highest yield, followed by three-day flooding and two-day interval irrigation. A study carried out on the amount of water needed for a given unit area revealed that 1 800 to 2 000 mm of water was necessary for a good yield. The height of standing water in a rice-field should be 15 cm at the maximum vegetative stage. Rice cultivation using sprinkler irrigation was studied and the results showed that it was possible to obtain a considerable rice yield and save irrigation water with this method.
• Seed treatment to control bakanae and foot rot (Fusarium moniliforme) disease. A study showed that these diseases could be controlled by treating seeds with fungicides.

Varietal improvement

A varietal improvement programme is being carried out in the Edirne, Samsun and Diyarbakýr institutes, with the aim of developing high-yielding varieties with one or more of the following traits:

• high yield;
• lodging resistance to mechanical harvesting;
• low spikelet sterility;
• resistance to blast and food rot;
• cold-tolerance at different growing stages;
• early or medium to early maturation (120 to 140 days);
• long and translucent grain type;
• high milled rice yield;
• low or medium amilose content and medium to high gelatinization temperature;
• response to high nitrogen rates.

A short plant height (90 to 100 cm) and strong stem have become an important target in the selection programme since farmers have started using combine harvesters for rice. On the other hand, the rice farmers are used to applying high nitrogen doses in Turkey. Thus, new improved varieties should have a short plant height. To achieve this, three breeding procedures are used:

i) Hybridization. Hybridization is carried out using local varieties or strains, and local material is also crossed with introduced material to incorporate genes and obtain an improved plant type. About 100 single and multiple crosses are conducted annually. F₂ is planted and harvested in bulk and F₃ material is planted as bulk and selectively harvested as a single plant, after which the pedigree selection method is used. More than 1 500 pedigree lines (F₄-F₆) are studied annually.

ii) Introduction. In addition to the hybridization programme, varieties or promising lines are introduced from other rice-growing countries or institutes. First, this material is tested in an observation nursery and then selected lines are included in the yield trials or are used in hybridization. The variety or lines adaptable to Turkish growing regions are those released as a commercial variety.

iii) Mutation breeding. A mutation breeding was set up in 1996 to improve characteristics of the commercial varieties Baldo, Ýpsala and Rocca. These varieties were treated with gamma rays to obtain early-maturing, short-stature, high-yielding, high grain quality and disease-resistant mutants. For this purpose, 5 000 seeds of each variety were treated with 25 and 30 grade gamma rays.

Observation nurseries and yield trials

More than 150 promising lines selected from segregating material or introduced from other sources are tested in observation nurseries every year.

The selected lines from observation nurseries are included in the preliminary yield trials and single-location and multiple-location yield trials are then conducted. The most promising lines are tested in a national registration trial. About 200 lines are tested in yield trails annually. Promising lines are also evaluated under different stress conditions (e.g. drought and disease).

Growing technology

Experiments have been conducted to determine fertilizer requirements of newly released varieties or promising lines.

Plant protection

A study has been carried out to find a chemical control mechanism for blast disease. Different fungicides have been used as seed treatment in this experiment.

Technology

The technological characteristics of all lines in preliminary and yield trials are examined in laboratory tests.

Seed production

Every year, breeder and foundation seeds of some commercial varieties are produced in the Thrace Agricultural Research Institute. The following amounts of seed are produced:

Breeder seed: 2 tonnes

Foundation seed:  50 tonnes

Foundation seed is given to state farms or private companies for multiplication.

Research constraints

The major constraints to rice research in Turkey are:

• a lack of facilities to test breeding material under controlled conditions for stress tolerance, for example in the event of drought, disease or cold;
• a lack of machinery for field experiments - most fieldwork is done manually, resulting in high-cost experiments;
• insufficient trained scientists and technicians.

Rice production policy

The current strategy is to:

• increase the level of mechanization, as it is not used as widely in rice cultivation as for other crops in Turkey;
• increase rice yield per unit area through new improved varieties and innovative growing tech-niques;
• expand the area under rice cultivation. Irrigation water is the main obstacle to the expansion of rice cultivation area in Turkey. However, the land structure and climate are suitable for rice cultivation in many micro- and macroclimatic regions and the country has the water potential to increase irrigated areas. Therefore, the area planted to rice could be expanded.

Finally, Turkey's policy is to reduce rice imports as much as possible and eventually to become self-sufficient in rice production.

REFERENCES

IRRI. 1995. World Rice Statistics (1993-1994). Los Baños, the Philippines.

Thrace Agricultural Research Institute. 1982 to 1995. Annual Report of National Rice Research Projects. Edirne, Turkey, Thrace Agricultural Research Institute.

Sürek, H. 1990. Rice production and research activities in Turkey. Meeting of Interregional Cooperative Research Network on Rice, 11-14 September 1990, Arles, France.

Production de riz et recherche en Turquie

La Turquie dispose d'une superficie terrestre totale de 76 960 000 ha, dont environ 24 millions sont cultivables. L'étendue moyenne des rizières varie entre 50 000 et 60 000 ha selon les années, en fonction des pénuries d'eau d'irrigation et de l'instabilité des cours. La production intérieure est inférieure à la demande, ce qui fait que la Turquie importe du riz tous les ans. Depuis quelques années, les importations augmentent en fonction de la baisse de la production locale. La consommation de riz par habitant est de 4 à 5 kg et la consommation totale de riz usiné est d'environ 300 000 tonnes.

Le riz peut être cultivé dans sept régions géographiques en Turquie, mais les principales zones productrices sont les régions de la Marmara-Thrace et de la mer Noire. Les variétés cultivées sont essentiellement italiennes (Rocca, Baldo et Ribe). Certaines variétés nouvelles et locales sont également produites. On signale habituellement dans ce pays des contraintes biotiques et abiotiques, telles que la température froide de l'eau et de l'air, les fortes températures, la sécheresse et le manque d'eau, la salinité et l'alcalinité, les maladies et les mauvaises herbes.

Le programme de recherche sur le riz a été entrepris en Turquie en 1970 à l'Institut de recherche agricole de Thrace. Depuis lors, ces recherches se poursuivent. D'autres instituts ont également pris part à ce programme. Ces activités de sélection ont permis d'introduire des variétés en Turquie et d'en créer de nouvelles qui sont cultivées dans différentes régions. Outre les techniques de sélection, des recherches sont effectuées sur des techniques de production. Les principaux objectifs de l'amélioration variétale sont l'augmentation du rendement, la résistance à la verse et aux maladies, la tolérance au froid, la maturation précoce ou moyennement précoce, un rendement usiné élevé, une teneur faible ou moyenne en amylose et une température moyenne à élevée de gélatinisation, et une réaction aux engrais à forte teneur en azote.

En Turquie, les politiques de production rizicole visent à promouvoir la mécanisation des cultures, à accroître le rendement par unité de terrain, à étendre l'étendue des rizières, et à parvenir à l'autosuffisance ou à réduire le plus possible les importations.

Producción e investigación del arroz en Turquía

Turquía tiene una superficie total de 76 960 000 hectáreas, de las que 24 millones son cultivables. La superficie media destinada al cultivo del arroz varía de un año a otro entre 50 000 y 60 000 ha, debido a la escasez de agua de riego y a la inestabilidad de los precios del mercado. La producción interna no es suficiente para cubrir el consumo. Por ello, las importaciones de arroz aumentaron en los últimos años al disminuir la producción local. El consumo de arroz per cápita es de 4 ó 5 kg y el consumo total de arroz elaborado asciende a unas 300 000 toneladas.

El arroz puede cultivarse en siete regiones geográficas de Turquía. Sin embargo, las zonas principales son Mármara-Tracia y la región del mar Negro. Se cultivan las variedades italianas (Rocca, Baldo y Ribe), y también algunas variedades nuevas y locales. En el país se comunican habitualmente limitaciones abióticas y bióticas, como baja temperatura del agua y de la atmósfera, temperatura atmosférica elevada, sequías o escasez de agua, salinidad y alcalinidad, enfermedades y malas hierbas.

En 1970 se inició en Turquía un programa de investigación sobre el arroz en el Instituto de Investigación Agrícola de Thrice. Otros institutos participan también en este programa. Como resultado de las actividades de mejoramiento del arroz se distribuyeron variedades introducidas u obtenidas en Turquía para su cultivo en las diferentes regiones. Además de los estudios sobre mejoramiento, se han realizado investigaciones sobre técnicas de producción. Los objetivos principales son obtener variedades mejoradas del alto rendimiento, resistentes al encamado, a las enfermedades y al frío, con un contenido de amilosa entre bajo y mediano y una temperatura de gelatinización entre media y alta, y que respondan a altas dosis de fertilizantes nitrogenados.

Las políticas de producción arrocera tienen como finalidad promover la mecanización del cultivo del arroz, aumentar el rendimiento por superficie unitaria, ampliar la superficie cultivada de arroz y lograr la autosuficiencia en la producción de arroz o reducir las importaciones de este cereal.