Studying of dynamics of oil flax flowering in south Portuguese conditions

Studying of dynamics of oil flax flowering in south Portuguese conditions. Brach N. B. "OIL CROPS" Scientific bulletin, VNIIMK, 2005, is. 2 (133) The evaluation of flowering and pollination dynamic of the crop is very important for the development of crossing technique. The speed of flax buds and flowers development depends on the genotype and weather conditions. Normally fibre flax varieties give petals cone above sepals on the eve of flowering. Intermediate ones show petals 2 days before flowering. Low temperatures increases the period of buds development. Fibre varieties are more stable to this influence, then intermediate ones. Also in low temperatures decreases the total number of opening flowers. Cold rainy weather causes the prolongation of flowers life. Petals can be preserved in intermediate varieties even for 7-8 days, and pollen remains on the anthers for 2 days. The ovary becomes mature the day before flowering independently of previous time of bud's development. The pollen is alive only one day. In hot temperature (more then 30C) in fibre varieties the fertilization could happen in the bud in the evening before petals opening. According to all these data, the most suitable flax crossing technique for Portuguese conditions is following (it probably can be used in other regions with hot climate). Hybridization must be done in moderate temperatures (usually they coincide with flax flowering in winter sowing trials). On mother plants buds, completely ready for tomorrow flowering, must be taken. From father plants only first day living flowers must be used.