PRODUCTION AND RESEARCH PROGRAMMES
PROGRAMMES DE PRODUCTION ET DE RECHERCHE
PROGRAMAS DE PRODUCCIÓN E INVESTIGACIÓN
National Agricultural Research Foundation (NAGREF), Cereal Institute, Thermi-Thessaloniki, Greece
Rice has been known in Greece as a plant, as a foodstuff and as an adequate cure for diseases of the digestive tract since the time of Theophrastus (370-285 bc), Dioscurides (first century) and Galenos (ad 130-200). There is no clear information about when rice cultivation began in Greece, although it is known that it has been cultivated for the last two centuries. The importance of rice as a foodstuff was very minor before the Second World War. After then, rice cultivation became more intensive and rice consumption started to increase gradually. In 1958, the State's interest in this crop became apparent with the foundation of a department specifically devoted to rice research at the Cereal Institute of Thessaloniki.
The area under rice cultivation was less than 1 000 hectares (ha) annually before 1931, fluctuated between 1 000 and 4 000 ha during the period 1931-48, increased to 10 000 ha in the year 1950 and fluctuated between 12 000 and 30 000 ha annually during the period 1951-99 (Figure 1). The shortage of water for irrigation was the most restrictive factor against expanding rice cultivation.
Until 1969, when the indica varieties were introduced, only the japonica type was cultivated (Figure 1). In 1999 the main regions of rice cultivation were in Thessaloniki (67.3 percent) and Serres (18.1 percent), both situated in northern Greece (Makedonia), which has five rivers. There were 11 further areas (five of them in Makedonia) under rice cultivation (14.6 percent) in different regions of Greece, although rice is not cultivated every year.
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FIGURE
1 Areas under rice cultivation in Greece: total, japonica and indica |
The proportion of different rice categories cultivated changed greatly as the years went by. The short-grain japonica varieties were grown on about 80 percent of the rice area in 1961. Their importance then decreased dramatically and they stopped being cultivated in 1988. The medium-grain japonica varieties accounted for about 4 percent of the rice area in 1961, increasing to over 25 percent in the 1970s and 1980s, then decreasing to an average of 10 percent in the 1990s. The long-grain japonica varieties represented about 15 percent of the area under rice cultivation in 1961, increasing to an average of 60 percent during the 1980s, then falling to an average of 43 percent in the 1990s. The long-grain indica varieties did not exceed an average of 12 percent of total cultivated area in the period 1969-89, while during the years 1996-99 they rose to an average of 60 percent (Table 1).
TABLE 1
Distribution of different grain types in Greece, 1961-99 (percentage of area under rice cultivation)
Japonica |
Indica | |||
Year |
Short grain |
Medium grain |
Long grain |
Long grain |
Mean 1961-65 |
73.0 |
6.3 |
20.7 |
- |
1966-70 |
47.8 |
22.1 |
28.5 |
1.6 |
1971-75 |
27.2 |
27.3 |
29.9 |
15.6 |
1976-80 |
27.6 |
25.0 |
33.7 |
13.7 |
1981-85 |
8.0 |
24.1 |
61.6 |
6.3 |
1986-90 |
0.3 |
21.5 |
64.4 |
13.8 |
1991-95 |
- |
10.2 |
46.6 |
43.2 |
1996-99 |
- |
6.2 |
34.0 |
59.8 |
Source: NAGREF, Cereal Institute.
Yields increased by an average of 10.2 and 2.4 percent per year for the periods 1931-50 and 1950-99, respectively (Figure 2). For the period 1995-99 the average yield was 7.67 tonnes/ha at the country level, 8.40 tonnes/ha in Thessaloniki and 5.87 tonnes/ha in the other rice regions. The increased yields were achieved through the release and distribution of new high-yielding varieties and application of appropriate new technologies to improve crop management and monitor production constraints. There is a significant variance in yields in the regions under rice cultivation because of incomplete information from rice growers regarding the new cropping methods, and the lack of permanent irrigation and drainage systems in some regions.
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FIGURE 2 Evolution of rice grain yields in Greece since 1930 |
The creation of a rice gene bank was the priority at the beginning of the breeding programme in 1958. Twenty years later there were about 200 entries, 97 percent of which were japonica type and only 3 percent indica type. By 1995 the total number of entries had increased to 360, with the same percentages for both types; the total has now reached 550, 94 percent japonica type and 6 percent indica type.
Prior to 1965 most varieties cultivated in Greece were imported from Italy and, to a lesser extent, from the United States. At the beginning of the breeding programme, emphasis was given to the release of japonica-type varieties with the following characteristics: semi-dwarf stature (85-100 cm), short-medium maturity (125-145 days), resistance to pests and diseases, and high yield. The breeding programme has been accelerated since 1965 for both the japonica type (with an emphasis on quality characteristics) and the indica type. Constraints against the release of indica-type varieties have been the late maturity of the genetic material used for crosses, their low sprouting ability, the tall plant height and low yield potential. In recent years efforts have focused on releasing new varieties of both types that combine productivity and quality. A specific priority is the release of new long-grain japonica varieties.
Aromatic rice is not yet cultivated in Greece. The most serious problem encountered in aromatic rice breeding is the loss of aroma intensity in crosses between scented and local varieties. Attempts have been made to grow foreign aromatic rice genetic material, but it has shown poor adaptability to local climatic conditions.
During the period 1958-2000 19 varieties were released, 16 japonica type and 3 indica type. Mass, classical pedigree and honeycomb pedigree selection methods were used for releasing eight, ten and one varieties, respectively. The last method proved to be the most effective. Biotechnological methods, based on in vitro culture, have not yet been used.
In 2000, of the 11 main varieties under cultivation seven (six japonica and one indica) were Greek. These were the following: L-202, Dion, Makedonia, Olympiada, Melas and Ariete in the Thessaloniki region; Axios, Eyropi, Dion, Makedonia and Lido in the Serres region; and L-202, Strymonas, Dion and Turbo in the other regions. Approximately 58 percent of the total rice area is cultivated with the variety L-202.
Sowing direct into water has been the only sowing method used in Greece since 1930. This was done by hand until 1982, after which it became fully mechanized. Low temperatures in April are a limiting factor for sowing and germination. Therefore, sowing begins during the last few days of April and finishes at the end of May. Japonica-type varieties are sown first, followed by the indica-type varieties.
The irrigation method used for rice is flooding. The water distribution programme involves irrigation for four days followed by a gap of four to five days. Fifteen days before harvesting, as the rice is reaching its physiological maturity, the water is drained from the fields. A permanent irrigation and drainage system has existed since 1961 in Thessaloniki and three other regions nearby, together covering about 75 percent of the cultivated rice area in Greece. Since 1988 the use of laser techniques for land levelling has made possible significant economies in water for irrigation, which have enabled the cultivated rice areas to be maintained at a level sufficient to cover domestic needs.
The most serious weeds affecting the rice crop are barnyard grass (Echinochloa crusgalli), red rice (Oryza sativa), Scirpus maritimus, Scirpus mucronatus, Cyperus difformis, Cyperus longus, Paspalum distichum, Typha angustifolia, Ammania spp., Polygonum persicaria and Cirsium arvense. Prior to 1965, the most important weed, barnyard grass, was controlled by maintaining a high water level in the rice fields and removing the weed by hand; this method was then replaced by the herbicides molinate and propanil. The herbicides pretilachlor and quinclorac were used in 1993, azimsylfuron in 1998 and cyhalofop butyl in 2000. The control of barnyard grass has become very difficult during the last decade, because it has developed resistant biotypes, probably caused by the application over 35 years of the first two herbicides. Its control is also hampered by the newer rice varieties' low ability to compete and the low depth of water in the field during the first stages of development. Red rice is partially controlled by using certified seed, working the ground mechanically through ploughing and harrowing, and also rotation. Since 1965, the weeds of the Cyperaceae family and broad-leaved weeds have been controlled by a mixture of the herbicides propanil and MCPA, with the addition of bentazon from 1985. The cost of weed control currently represents 10 percent of the total production cost, whereas 15 years ago it accounted for about 5 percent.
After many years of experimentation it was concluded that the rice crop in Greece needs the following fertilization rates: N 140-160 kg/ha, P2O5 40-60 kg/ha and K2O 60-80 kg/ha. Nitrogen is applied at three increments: 40-45 percent before planting, 30-35 percent during tillering and the rest at panicle initiation stage. Because 90 percent of the cultivated rice area is characterized by high salinity soils, the application of nitrogen acid fertilizers is required. Phosphorus and potassium are applied before planting. Potassium has only been used for the last ten years. It is estimated that it has contributed to a yield increase of about 5 percent.
The disease Pyricularia oryzae was known before 1968. It is currently the most common disease affecting rice in Greece. However, the climatic conditions mitigate its effects, such that it rarely causes damage to the crop. Moreover, the cultivation of foreign varieties sensitive to this disease means that farmers remain vigilant and respond quickly to its appearance.
The stem-borer Sesamia nonagrioides is the insect that causes the most damage to rice in Greece. It attacks the plants and damages more than 10 percent of the late-maturing cultivars. It is not controlled by the use of insecticide. The crustacean Triops cancriformis and the insects Chironomus spp. and Ephydra attica had been serious pests in the past, prior to the introduction of the laser technique for land-levelling. Previously, levelling with conventional machines did not achieve the desired water height. The resulting excess water in the rice fields was conducive to the movement and development of these pests, hampering their control. The regulation of water height made possible by the laser technique enabled their effective control. Hydrellia spp. has been known to attack the rice plants only once, in 1986. Expenditure on insecticide has fallen by 50 percent over the last ten years.
Twenty years ago harvesting was done relatively late, when the grain moisture content was 14-17 percent, to avoid the expense of paddy drying. As a consequence, high breakages occurred during milling, due to the "sun-crack" phenomenon (where the grains dry relatively quickly during the day and then reabsorb moisture during the night, leading to fissures and subsequent breakages). Harvesting is now done earlier, when the grain moisture content is 18-22 percent, resulting in a lower percentage of breakages. Harvesting has been fully mechanized since 1968.
Fifty years ago it was difficult to apply an ideal system of crop rotation, because of the very high salinity of the soil. Continuous leaching of soil salts over an extended period of rice cultivation in the same fields has created conditions where a three-year rotation (with maize, sugar beet or cotton) can now be applied in about 80 percent of the area under cultivation.
An average rice farm was about 3 ha in size in 1980 and is now about 5.6 ha. The average farm size will increase over time, because new rice growers rarely enter the sector, while old rice growers - owners of small farms usually lacking proper mechanical equipment for rice cultivation - are renting their land to others when they retire. The number of rice growers has fallen from about 6 200 in 1980 to about 4 300 in 2000.
The rice milling industry plays a significant role in marketing terms because it directs consumers to certain types of product. In 1950 there were eight small-scale milling companies, all of which produced white rice; there are now 28 companies, each with greater capacity. Most are relatively old and equipped with old machinery. Twenty of the milling companies produce only white rice and the remaining eight both parboiled and white rice. The parboiling process was used for indica-type rice when it was first cultivated. The same process has been used for japonica-type rice over the last two decades. Its adoption grew year by year as millers found they obtained a higher milling yield due to the lower grain breakage during milling and could convert the rice bran to rice products, both leading to higher profits.
Rice consumption in Greece has remained at the same level for the last ten years (6.5 kg per capita per year), although this level is 26 percent higher than in 1981. In terms of rice quality, however, consumer preferences have changed significantly. Japonica rice seems to be preferred by most Greek consumers; nevertheless, indica rice consumption accounts for 35 percent of total domestic consumption. As for the japonica-type, Greek consumers show a higher preference for long-grain rather than short- or medium-grain rice. This trend is expected to continue in the next decade. Requests for aromatic rice are also increasing in Greece.
Greece was an importing country for rice until 1960. Since then and until 1983 the exports-imports balance was positive only in the years in which the rice area was greater than 20 000 ha. During this period the imported rice was usually indica-type milled rice, while the exported one was japonica-type, paddy and broken. Greece became self-sufficient in rice in 1984 (Figure 3). Although the exports-imports balance was positive in the late 1980s, indica-type rice production did not cover Greek consumption needs until 1993. Since 1993 indica production has more than doubled while there has been a 15-20 percent deficit of japonica-type rice. The objective now is to achieve a balance between the production of both rice types to achieve self-sufficiency in each.
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FIGURE
3 Evolution of rice imports and exports in Greece since 1980 (rice = paddy ´ 65 percent, brown, milled, broken, flour) |
Source: EUROSTAT.
Évolution de la recherche et de la production rizicoles en Grèce
L'étendue des cultures de riz est passée de quelques milliers d'hectares avant 1931 à 10 000 ha en 1950 et varie depuis entre 12 000 et 30 000 ha. Pendant la période 1969-1989, la superficie cultivée en riz long grain Indica n'a pas dépassé 12 pour cent du total, mais durant les quatre dernières années (1996-1999) elle a atteint environ 60 pour cent. Au cours des cinq dernières années, le rendement national a été de 7,67 tonnes/ha. On a privilégié récemment les variétés du type Japonica semi-naines, à maturité de brève à moyenne, résistantes aux maladies et aux insectes et à haut rendement.
Les semis effectués directement dans l'eau d'irrigation sont largement utilisés. Depuis 1988 on nivelle la terre en appliquant une technique au laser qui accroît l'efficacité de l'utilisation de l'eau. Avant 1965, on luttait contre l'échinochloa en maintenant l'eau à une grande hauteur et en pratiquant l'arrachage à la main, mais durant les dix dernières années on a eu recours
Des taux de fertilisation de 140-160 kg/ha de N, 40-60 kg/ha de P205 et de 60-80 kg/ha de K20 ont été recommandés aux riziculteurs. La principale maladie est la pyriculariose du riz (due à Pyricularia oryzae), qui provoque rarement beaucoup de dégâts dans les cultures. Les pires ennemis sont le foreur des tiges Sesamia nonagrioides, les crustacés Triops cancriformis et Chironomus sp. et Ephydra attica. La meilleure maîtrise de l'eau a eu des effets positifs sur la lutte contre les insectes. Par conséquent, les dépenses d'insecticides ont baissé de 50 pour cent par rapport aux chiffres d'il y a 10 ans. Il est recommandé de récolter le grain lorsque sa teneur en humidité atteint 18 à 22 pour cent.
En 1999, les principales régions de riziculture étaient la Thessalonique (67,3 pour cent) et Serres (18,1 pour cent) dans le nord de la Grèce. En 1980 la superficie moyenne d'une exploitation était de 3 ha, elle est à présent de 5,6 ha. Il existe 20 rizeries ne produisant que du riz blanc et huit qui produisent du riz étuvé et du riz blanc. La consommation de riz en Grèce est toujours de 6,5 kg/habitant/an.
Evolución de la investigación y producción del arroz en Grecia intensivement aux herbicides.
La superficie dedicada al arroz pasó de ocupar unos miles de hectáreas antes de 1931 a 10 000 ha en 1950 y, desde entonces, ha fluctuado entre 12 000 y 30 000 ha. Entre 1969 y 1989, la superficie cultivada con variedades de grano largo Indica no superó el 12 por ciento de la superficie total, aunque en entre 1996 y 1999 representó aproximadamente el 60 por ciento. El rendimiento nacional fue de 7,67 t/ha entre 1995 y 1999. Se ha prestado una especial atención a la difusión de variedades Japónica, cuyas características son: un tamaño semienano, madurez corta o media, resistencia a las plagas e insectos, y un rendimiento elevado.
La siembra directa en agua de riego es de uso generalizado. La nivelación del terreno mediante técnicas láser desde 1988 ha aumentado la eficacia en el uso del agua. Antes de 1965, el control del mijo japonés, una mala hierba, se realizaba manteniendo el alto nivel de agua y extrayéndolo manualmente, pero durante el último decenio se han utilizado de forma intensiva los herbicidas. A los arroceros se les recomendó unos índices de fertilización de 140-160 kg/ha de N, 40-60 kg/ha de P2O5 y 60-80 kg/ha de K2O. La Pyricularia oryzae es la plaga principal, aunque en pocas ocasiones provoca daños importantes en la cosecha. El barrenador Sesamia nonagrioides, los crustáceos Triops cancriformis y Chironomus sp., y Ephydra attica constituían enemigos peligrosos. Una mejor ordenación del agua ha repercutido de forma positiva en la lucha contra los insectos. Como consecuencia, los gastos en insecticidas han disminuido un 50 por ciento en comparación con los de hace 10 años. Se recomienda recoger la cosecha cuando el porcentaje de humedad del grano es del 18-22 por ciento.
En 1999, las principales regiones en que se cultiva arroz eran Tesalónica (67,3 por ciento) y Serres (18,1 por ciento) en el norte de Grecia. En 1980, la plantación media de arroz ocupaba unas 3 ha, pero en la actualidad abarca unas 5,6 ha. Existen 20 empresas molineras que producen exclusivamente arroz blanco y 8 empresas que elaboran tanto arroz blanco como arroz sancochado. El consumo anual de arroz en Grecia continúa siendo de 5,6 kg por habitante al año.
