[Objective] To investigate the effects of rooting agents on the growth and photosynthetic traits of Sudan grasses. [ Method] The responses of the growth and some photosynthetic traits of Sudan grasses to three NK II r...[Objective] To investigate the effects of rooting agents on the growth and photosynthetic traits of Sudan grasses. [ Method] The responses of the growth and some photosynthetic traits of Sudan grasses to three NK II rooting agents were determined according to the randomized complete block design. [ Result] Compared to control treatment, the Sudan grass treated by NK 11-298 showed higher chlorophyll a and carotenoid contents, higher chlorophyll fluorescence parameter values （ PSII quantum efficiency： ФPSII; photochemical quenching： qP; and electron transport rate： ETR）, higher maximum photosynthetic rate （Pmax） and respiration rate （ Rd）, and the highest biomass accumulation. The chlorophyU fluorescence parameter values of Sudan grasses treated by NK 11-888 and NK 11-16 were higher than those of control treatment （ P 〈 0.05）, and other indexes had no significant difference. [ Conclusion] The rooting agents should be selected carefully according to their practice aims because of sensibility of Sudan grass to rooting agents.展开更多
We conducted a two-factor experiment in randomized complete block design with four replications during 2004 in El Demokeya Forest Reserve and El Himaira Natural Forest, North Kordofan State, Sudan. The objective was t...We conducted a two-factor experiment in randomized complete block design with four replications during 2004 in El Demokeya Forest Reserve and El Himaira Natural Forest, North Kordofan State, Sudan. The objective was to develop an understanding of the ecological effects of under-story vegetation and tapping date on the productivity of gum arabic from Acacia senegal as over story cover. The first factor was grass cover which was tested in four levels （100% and 50% grass cover in addition to bare and burnt）. The second factor, date of tapping was tested in three levels namely （1st Oct, 15th Oct and 1st Nov）. The first picking was done after 45 days from tapping and the gum yield up to seven pickings was collected at intervals of 15 days. Gum yield from each picking was collected and weighed using sensitive balance. Analysis of variance was carried out using MSTAT-C statistical package, and the Tukey test was applied for mean comparisons. The results showed highly significant differences （p 〈 0.01） of grass cover on gum arabic yield in the two sites for most of the first consecutive pickings （1st–4th out of seven） in addition to total yield （kg/ha）. With exception to the 4th pickings, the interaction effect between the grass densities and tapping date was not significantly different. The total gum yield was significantly （p 〈 0.05） increased in only two pickings （third and fourth） in El Demokeya Forest Reserve and two pickings （1st and 2nd） at El Himaira Natural Forest. The density of grass cover significantly （p 〈 0.05） affected the number of pickings at both sites; the number of gum pickings was directly proportional to grass density. The number of gum pickings was found to be significantly （p 〈 0.05） increased at the early date of tapping.展开更多
基金supported by the Science Research Development Fund of Tianjin Agricultural University(2008D004)the National Natural Science Foundation(30900191)
文摘[Objective] To investigate the effects of rooting agents on the growth and photosynthetic traits of Sudan grasses. [ Method] The responses of the growth and some photosynthetic traits of Sudan grasses to three NK II rooting agents were determined according to the randomized complete block design. [ Result] Compared to control treatment, the Sudan grass treated by NK 11-298 showed higher chlorophyll a and carotenoid contents, higher chlorophyll fluorescence parameter values （ PSII quantum efficiency： ФPSII; photochemical quenching： qP; and electron transport rate： ETR）, higher maximum photosynthetic rate （Pmax） and respiration rate （ Rd）, and the highest biomass accumulation. The chlorophyU fluorescence parameter values of Sudan grasses treated by NK 11-888 and NK 11-16 were higher than those of control treatment （ P 〈 0.05）, and other indexes had no significant difference. [ Conclusion] The rooting agents should be selected carefully according to their practice aims because of sensibility of Sudan grass to rooting agents.
文摘We conducted a two-factor experiment in randomized complete block design with four replications during 2004 in El Demokeya Forest Reserve and El Himaira Natural Forest, North Kordofan State, Sudan. The objective was to develop an understanding of the ecological effects of under-story vegetation and tapping date on the productivity of gum arabic from Acacia senegal as over story cover. The first factor was grass cover which was tested in four levels （100% and 50% grass cover in addition to bare and burnt）. The second factor, date of tapping was tested in three levels namely （1st Oct, 15th Oct and 1st Nov）. The first picking was done after 45 days from tapping and the gum yield up to seven pickings was collected at intervals of 15 days. Gum yield from each picking was collected and weighed using sensitive balance. Analysis of variance was carried out using MSTAT-C statistical package, and the Tukey test was applied for mean comparisons. The results showed highly significant differences （p 〈 0.01） of grass cover on gum arabic yield in the two sites for most of the first consecutive pickings （1st–4th out of seven） in addition to total yield （kg/ha）. With exception to the 4th pickings, the interaction effect between the grass densities and tapping date was not significantly different. The total gum yield was significantly （p 〈 0.05） increased in only two pickings （third and fourth） in El Demokeya Forest Reserve and two pickings （1st and 2nd） at El Himaira Natural Forest. The density of grass cover significantly （p 〈 0.05） affected the number of pickings at both sites; the number of gum pickings was directly proportional to grass density. The number of gum pickings was found to be significantly （p 〈 0.05） increased at the early date of tapping.
