Selection of high productivity combinations of hybrid melaleuca varieties experimentally planted on boggy soil and semi-flooding soil in Ninh Binh province
2011
Hoang Vu Tho
The results evaluated of experiments on hybrid Melaleuca verieties in Ninh Binh province show that, averaghheight growing rates of combinations V43L53, V43L24, L23Ca3, V43L7 and L22V43 have indicated the increase of 1.95, 1.92, 1.54, 1.59 and 1.68 times in comparison at the age of 5 with 3 year ago from that time, respectively. Volume growing rates have also increased of approximate 6-8 times in comparison with that of 3 year ago from that time. The combination L23Ca33, V36L25, L48Ca61, V36L24, L16V66, L7Ca61, L22V66 and L7V66 have always performed positive heterosis in diameter and height growing. Meanwhile that of V43V66, Q40V43, V19Ca61 and Q40Ca61 have always show negative heterosis in all comparing criteria. At growing stage of age 5, it was possible to choose 12 hybrid combinations which have exceeded their best parents by more than 20% in volume growing, of which 4 choosen combinations V43L53, V43L24, L23Ca33 and L42Ca31 have been able to give wood yield of 41.0, 35.5, 31.8 and 31.1m3/ha per year, respectively (exceeding the threshold of 30,0m3/ha per year). Among these combinations, 8 individuals would be selected as the best hybrid trees. These are materials valuable to subsequent steps of Malaleuca breeding, taking part to supply new forest varieties with high productivity to afforestation, especially to production and protection forests which are having similar conditions throughout the country.
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