THE EFFECT OF TEMPERATURE, HUMIDITY AND WIND SPEED ON SEED SETTING AND FERTILITY OF FIVE EGYPTIAN CLOVER (Trifolium alexandrinum, L.) CULTIVARS

Abstract

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 m 2 and vital pollen grain under different heat treatments o C, 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 m 2 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 -32 o C), 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 pr...

Enhancing performance of berseem clover genotypes with better harvesting management through farmers’ participatory research at smallholder farms in Punjab

“…1) were unfavourable for pollination resulting in a significant reduction in seed yields of cutting treatments T3 and T4 (Table 1) compared to T2 when environmental conditions were more favourable for pollination. These findings were in line with the studies that reported temperatures of 28-32 °C with a relative humidity of 45-55%, which were favourable for maximum pollination in berseem clover crops 32,33 . The timing of the last forage cut prior to seed harvesting can also impact on the efficiency of pollinators, namely honeybees.…”

“…The Agaitti Berseem-2002 variety performed well for both seed and forage production and so is likely to be favoured by farmers. Selection of genotypes with early seed set were favourable for high temperature and low relative humidity areas 33 . These were linked with the regulation of the movement of pollinators, which set the genotypes for early blooming and high pollination efficiency and thus increased seed yield of berseem clover.…”

Berseem Clover (Trifolium Alexandrinum L.) Seed Yield and Seed Quality Response to Irrigation Frequency and Foliar Spray of Plant Bio-Regulators

“…1). The synchronization of pollination and fertilization time with hot air temperature, low humidity, and hot desiccating winds can severely reduce seed settings in Berseem clover, as reported in several studies (El-Naby et al, 2011;El-Naby et al, 2012). Factors contributing to low seed setting may include pollen sterility, post-fertilization abortion of developing seeds due to high temperature, and reduced pollen viability under high-temperature and low-humidity conditions (El-Naby et al, 2011;Vijay et al, 2017).…”

“…The synchronization of pollination and fertilization time with hot air temperature, low humidity, and hot desiccating winds can severely reduce seed settings in Berseem clover, as reported in several studies (El-Naby et al, 2011;El-Naby et al, 2012). Factors contributing to low seed setting may include pollen sterility, post-fertilization abortion of developing seeds due to high temperature, and reduced pollen viability under high-temperature and low-humidity conditions (El-Naby et al, 2011;Vijay et al, 2017). The direct application of plant bio-regulators through foliar spray during pre-flowering stages might have been more effective in altering the life processes or structure of seed plants, improving seed yields, sizes, and quality, as reported by Nickell (1982).…”

Egyptian Clover Genotypic Divergence and Last Cutting Management Augment Nutritive Quality, Seed Yield and Milk Productivity

“…As per our trial's findings, the last harvesting taken late resulted in a lower 1000-seed weight and yield, presumably owing to a shorter time available for seed setting under quickly hiking temperatures. Moreover, a rising air temperature coincides with low humidity, which results in a decline in pollination activity and fertilization rate [66][67][68][69][70]. Furthermore, lesser bee activity causes poor pollination, the infertility of pollen and seed development termination, leading to weak seed setting [63,65,71].…”