Productivity stability of some sunflower varieties

12 O.P. varieties, 13 interline hybrids and 14 self-pollinated sunflower lines lune been studied. Trials of breeding material were carried out in 2001-2002. in contrasting soil-climatic conditions in central zone of Krasnodar region in All-Russia Research Institute of Oil Crops (VNIIMK) by V.S. Pustovoit (Krasnodar) and in the zone of risky agriculture (Novoanninskii. Volgograd region). Significant differences in cultivars reaction to the changes of environment conditions have been noted. The highest productivity stability was characteristic of the O.P. varieties. which absolute differences in yield 0.53 t/ha that is in percentage to average yield of two locations was 26.8 % with fluctuations from 10.2 to 46.0% depending on exact variety. Interline hybrids were notable for higher (in 1.6 times) productivity variation. Absolute quantity difference of this trait was 0.92 t/ha. in percentage in average - 44.6 % with fluctuations from 22.2 to 77.9 %. Reaction character of self-pollinated lines was mainly the same as the one of interline hybrids. On the basis of conducted researches a scale of sunflower ecological stability estimation was suggested. In accordance with this scale, only cultivars, which productivity differences in trial under certain soil-climatic conditions do not exceed 15 %. can be referred to the cultivars of high stability. The varieties with productivity variation within 15.1-25.0 % arc suggested for inclusion in good stability category; varieties with productivity variation from 25.1 to 35.0 %-in average stability category; varieties with productivity variation within 35.1-45.0 % - in low stability category and varieties with productivity variation over 45.0 % - in very low stability category. Group of high stability cultivars includes varieties Stepnyak. Voronezhskii 638 and self-pollinated line BK-464, Varieties Rodnik, Meteor, Photon, Lakoinka and VNIIMK 8883; hybrid Kubanskii 48 - possessed good stability level. Average stability group comprises variety Jubileiny 60, hybrid Kubanskii 371, Kubanskii 930. Temp and self-pollinated line BK-830. Varieties SPK, SUR, Master; hvbrids Kubanskii 480, Kubanskii 941, Kubanskii 341, Kubanskii 93; self-pollinated lines BK-483, BK-639, BK-499 and BK-653 have low stabilіty level. Very low productivity stability - is characteristic of variety Krepysh; hybrids Kvant, Garant. NS-H-32. Signal. NS-H-52; self-pollinated lines BK-541, BA-93, BK-276, BK-572, BK-591, BK-571, BK-580 and BK-808.