| Popis: |
Five Egyptian clover cultivars were evaluated for the fertility traits, open pollinated seed set/ floret%, no. of floret/ inflorescence. no. of inflorescences/ plant, the weight (gm) of 1000 seeds, productivity of seed per m2 and vital pollen grain under different heat treatments oC, relative humidity % and wind speed m/sec, for four blooming periods. The study was conducted in Randomize Complete Block Design with three replications at Agricultural Research Center (ARC) in Giza Station during winter 2008-2009 and 2009/2010 seasons. Three cuts were taken during the two seasons and total forage and dry yield were analyzed as a total yield over the two seasons. Affect the temperature and relative humidity on many of the attributes of plant flowering (the speed of dispersal of pollen, matured pollen, pollination and fertility and increased use of seeds), while affecting the wind speed, the movement and the activity of pollinators, especially honey bees and its role in floret pollination, which leads to increase seed production. Helaly-1 cultivar was demonstrated high seed set, over the two seasons, 17.77%, 29.10%, 42.48% and 56.65% in all blooming dates except for the fourth date followed by Giza-6 cultivar was the superior seed set of the fourth blooming date (58.35%). The four blooming dates set seed over the two seasons recorded 13.70% of the first date, 28.30% of the second date, 39.78% of the third date and 55.12% for the fourth date. Heritability over two seasons indicated 94.78%, 93.20%, 91.34% and 81.50% of the first, second, third and fourth blooming dates, respectively. The local cultivars Helali-1 and Giza-6 were generally higher than Sakha-4, Gemmiza-1 and the cultivar Serw-1 was lower one in the most flowering traits. The same performance showed in forage and dry yield t/fed. Whereas Helali-1 and Giza-6 cultivars were insignificantly different in number of inflorescences per plant, but both of them were significantly higher than for both cultivar in all trail. Helaly-1, cultivar followed by Giza-6 cultivar was classified as the highest productivity of seed per m2 compared with the other cultivars under study. This study has shown that early blooming date has low seed set, but the latest blooming date produce the highest percentage of seed setting under Giza environmental conditions of commercial berseem cultivars. It could be concluded that cultivation of Helaly-1 and Giza-6 cultivars produced the maximum of seed setting in July and produced highest forage and dry yield under Giza environmental conditions. Vital pollen grain ranged from 75% to 90% of third and fourth bloom. Temperature (28 - 32oC), relative humidity (45 -55%) and wind speed (1.2- 2 m/sec.) and their interactions may be the best environmental conditions, in Giza, for setting seeds and regulating the movement of pollinators, increase the pollination efficiency and increase seed yield. The current study may be need for more studies on pollinators' densities and activities to determine pollination practices for berseem clover commercial seed production in all Egypt regions. |
