Using Chinese cabbage and rape as test material and examining the same soil conditions at different seasons（spring and autumn）, the effects of mixed rare earth fertilizer on the yield and nutrient quality of leafy v...Using Chinese cabbage and rape as test material and examining the same soil conditions at different seasons（spring and autumn）, the effects of mixed rare earth fertilizer on the yield and nutrient quality of leafy vegetables were studied to provide a theoretical basis for the application of mixed rare earth fertilizer in agriculture. Results showed a seasonal difference in the nutrient quality of Chinese cabbage and rape. For crops planted in autumn, the soluble sugar and vitamin C content were higher, the titratable acid and nitrate content were lower, and the sugar acid ratio was higher relative to crops planted in spring. Mixed rare earth treatments promoted growth of both crops during both seasons. The plot yield, stem and leaf fresh and dry matter weight, and dry and fresh ratio increased. These increases for Chinese cabbage were greater in autumn than in spring while for rape, the increases were greater in spring than autumn. The soluble sugar content, titratable acid content and sugar acid ratio were increased and the nitrate content decreased, in autumn the effects were more obvious than in spring. In spring, the vitamin C content was increased, and the increase was greater for Chinese cabbage than rape. In autumn, the vitamin C content decreased, and the decrease was greater for rape than Chinese cabbage. At the same time, the content of heavy metals such as Cu, Zn, Cd, Pb and Ni in stems and leaves decreased. This decrease was greater in spring for Chinese cabbage and in autumn for rape.展开更多
[ Objective] The paper was to screen out ideal biological pesticides, in order to provide guidance for pollution-free control against Pieris rapae Linne. [Method] Taking Chinese cabbage variety Taiyuan Erqing as the t...[ Objective] The paper was to screen out ideal biological pesticides, in order to provide guidance for pollution-free control against Pieris rapae Linne. [Method] Taking Chinese cabbage variety Taiyuan Erqing as the test material, the field control efficiencies of four pesticides including PrGV · Bt WP 1 000 times dilution, NPV · Bt SC 750 times dilution, 0.5% azadirachtin EC 750 times dilution, and 0.3% matrine AS 500 times dilution against P. rapae were studied, and their impacts on yield and planting benefits of Chinese cabbage were also determined. Using foliar spray method, the pesticides were sprayed for the first time when the second or third instar larvae of P. rapae first occurred in fields, and sprayed for the second time with the interval of 15 d. The fields sprayed with beta-cypermethrin EC （organic chemical pesticide） and water were set as control. [ Result] NPV · Bt SC 750 times dilution had the best effect after spraying for two times： the control efficiency against P. rapae at 15 d after spraying was 90.11% ; the damage rate of Chinese cabbage was only 0.21%, while the commodity rate reached 100% ; compared with chemical pesticide spraying, the commodity yield （177 262.5 kg/hm2 ） and the income after deducting spraying cost （48 858.5 yuan/hm2 ） were increased by 14.7% and 13.75%, respectively. [ Conclusion] Although biological pesticides are more expensive, they have long persistence and good control effect, resulting in green and safe Chinese cabbage with high commodity rate and yield, and higher eventual economic benefit after deducting spraying cost.展开更多
基金Project supported by Items of Institution of Higher Education Scientific Research of Hebei Province(ZD20131020)Hebei Vegetable Innovation Projects of Modern Agricultural Industry Technology System and Academy of Agricultural Sciences of Qinhuangdao City
文摘Using Chinese cabbage and rape as test material and examining the same soil conditions at different seasons（spring and autumn）, the effects of mixed rare earth fertilizer on the yield and nutrient quality of leafy vegetables were studied to provide a theoretical basis for the application of mixed rare earth fertilizer in agriculture. Results showed a seasonal difference in the nutrient quality of Chinese cabbage and rape. For crops planted in autumn, the soluble sugar and vitamin C content were higher, the titratable acid and nitrate content were lower, and the sugar acid ratio was higher relative to crops planted in spring. Mixed rare earth treatments promoted growth of both crops during both seasons. The plot yield, stem and leaf fresh and dry matter weight, and dry and fresh ratio increased. These increases for Chinese cabbage were greater in autumn than in spring while for rape, the increases were greater in spring than autumn. The soluble sugar content, titratable acid content and sugar acid ratio were increased and the nitrate content decreased, in autumn the effects were more obvious than in spring. In spring, the vitamin C content was increased, and the increase was greater for Chinese cabbage than rape. In autumn, the vitamin C content decreased, and the decrease was greater for rape than Chinese cabbage. At the same time, the content of heavy metals such as Cu, Zn, Cd, Pb and Ni in stems and leaves decreased. This decrease was greater in spring for Chinese cabbage and in autumn for rape.
基金Supported by Science and Technology Research and Development Program of Chengde City in 2011(201121167)
文摘[ Objective] The paper was to screen out ideal biological pesticides, in order to provide guidance for pollution-free control against Pieris rapae Linne. [Method] Taking Chinese cabbage variety Taiyuan Erqing as the test material, the field control efficiencies of four pesticides including PrGV · Bt WP 1 000 times dilution, NPV · Bt SC 750 times dilution, 0.5% azadirachtin EC 750 times dilution, and 0.3% matrine AS 500 times dilution against P. rapae were studied, and their impacts on yield and planting benefits of Chinese cabbage were also determined. Using foliar spray method, the pesticides were sprayed for the first time when the second or third instar larvae of P. rapae first occurred in fields, and sprayed for the second time with the interval of 15 d. The fields sprayed with beta-cypermethrin EC （organic chemical pesticide） and water were set as control. [ Result] NPV · Bt SC 750 times dilution had the best effect after spraying for two times： the control efficiency against P. rapae at 15 d after spraying was 90.11% ; the damage rate of Chinese cabbage was only 0.21%, while the commodity rate reached 100% ; compared with chemical pesticide spraying, the commodity yield （177 262.5 kg/hm2 ） and the income after deducting spraying cost （48 858.5 yuan/hm2 ） were increased by 14.7% and 13.75%, respectively. [ Conclusion] Although biological pesticides are more expensive, they have long persistence and good control effect, resulting in green and safe Chinese cabbage with high commodity rate and yield, and higher eventual economic benefit after deducting spraying cost.
