[Objective] With a rice variety ＂Long Rice 11＂ as a test cultivar,an experiment of raising rice seedlings with the new substrata prepared from biochar,and maize stalks,rice husks,organic fertilizer,turf,zeolite,fine...[Objective] With a rice variety ＂Long Rice 11＂ as a test cultivar,an experiment of raising rice seedlings with the new substrata prepared from biochar,and maize stalks,rice husks,organic fertilizer,turf,zeolite,fine river sand and arable layer soil by mixing according to certain volume proportions was caried out,in order to investigate the physical and chemical properties of different organic-material seedling-raising substrata and the effects of these substrata on seedling growth.[Method] The experiment raised seedlings in greenhouses and adopted randomized block arrangement.[Result] The substratum of biochar mixed with maize stalks and rice husks could increase the maximum water-holding capacity of the substratum,reduce the volume weight of the substratum and improve the buffering effect of the substratum.It also had great effects on the contents of alkali-hydrolyzale nitrogen and rapidly available potassium in the substratum,and could improve the root number and substantial degree of rice seedlings.[Conclusion] Biochar with maize stalks and rice husks（the treament HC） is the optimal substratum in this study.展开更多
Root-knot nematodes （Meloidogvne spp.） constrain the production of high value vegetable crops, such as tomato, on smallholder farms in Kenya. For several years, control of root-knot nematodes largely depended on the...Root-knot nematodes （Meloidogvne spp.） constrain the production of high value vegetable crops, such as tomato, on smallholder farms in Kenya. For several years, control of root-knot nematodes largely depended on the use of synthetic nematicides, most of which have been banned due to their toxicity to humans and the environment. Farmer-participatory trials were established, for two consecutive growing seasons on farmers＇ fields infested with root-knot nematodes （A4eloidogvne javanica and Meloidogyne incognita）, at two sites in central Kenya （Maragua and Kirinyaga districts）, representing two contrasting group of farmers （low-input and high-input）. The trials aimed at evaluating the potential of using biological control agents （BCAs）, i.e. Poehonia ehlamydosporia and Pasteuria penetrans, antagonistic plants （Crotalaria grahamiana and Tagetes minuta）, ＂＇trash burning＂ and chemical control （dazomet 98% = Basamid~ Granular） in the management of root-knot nematodes in tomato nursery beds, and quantify the associated net benefits, compared to an untreated control. Crotalaria grahamiana, ＂trash burning＂ and dazomet, significantly （P 〈 0.05） reduced the number of second-stage juveniles （J2s） of the root-knot nematodes in the soil in nursery beds during the first season at Karigui-ini, but there was no significant （P 〉 0.05） increase in yield after transplanting tomato seedlings from the respective treatment. Similarly, one of the BCAs （P. ehlamydosporia）, was effectively transferred to the field with seedlings from the BCA-treated nursery beds, but there was no significant （P 〉 0.05） increase in yield due to slow proliferation of the BCA, after transplanting. Participatory partial budgets were successfully developed with srnallholder farmers, and proved to be a vital tool in making informed decisions on management options for root-knot nematodes. In general, labour was considered by all farmers as the major input that contributed to the overall additional cost of the different treatments at both sites. This necessitates improvement in efficiency of labour resource use.展开更多
[Objective] This study was conducted to characterize the seed germination and seedling growth of Idesia polycarpa. [Method] After 3-5 h of soaking in 5% baking soda solution, the waxy outer layer of the seeds was rubb...[Objective] This study was conducted to characterize the seed germination and seedling growth of Idesia polycarpa. [Method] After 3-5 h of soaking in 5% baking soda solution, the waxy outer layer of the seeds was rubbed off. Then, the seeds were mixed with fine sand and evenly sown on seedbeds. Germinated seeds were counted to calculate germination rate. Seedlings at two-or three-leef stage were transplanted, and their phenophases were observed and recorded. Height and ground diameter of the seedlings were monitored in the following three years. [Result] The seed germination rate was increased to 20% by soaking in 5% baking soda solution. The yearly seedling height growth of L polycarpa increased with the increase in seedling age. The monthly seedling height growth from August to October was much higher than in other months in the first year, and the growth in seedling height in the three months accounted for 79% of the total increase in that year. The seedling height grew rapidly from May to July in the following two years. In detail, the increase in seedling height from May to July accounted for 87.94% of the total increase in the second year, and 74.16% of the total increase in the third year. The monthly seedling height growth peaked in May in the two years. The yearly growth in ground diameter of I. polycarpa seedlings also increased with the increase in seedling age. The monthly growth in ground diameter from July to September was much higher than in other months in the first year, and the increase in ground diameter in the three months accounted for 80% of the total increase in that year. In the second and third years, the monthly growth in ground diameter from July to October was much higher than in other months. The increase in ground diameter in the two months accounted for 76.89% of the total increase in the second year, and 61.23% of the total increase in the third year. The monthly growth in ground diameter peaked in August in the two years. [Conclusion] The results will provide a theoretical basis for the development and popularization of L polycarpa in Chongqing and surrounding provinces and cities.展开更多
The effects of extracts from five Albizia （Fabaceae） endemic species from Madagascar （A. arenicola, A. boivini, A. bernieri, A. polyphylla and A. tulearensis） were tested on vegetable seedling development. Crude e...The effects of extracts from five Albizia （Fabaceae） endemic species from Madagascar （A. arenicola, A. boivini, A. bernieri, A. polyphylla and A. tulearensis） were tested on vegetable seedling development. Crude extracts were obtained through cold or hot extraction methods on dried powdered seeds, seed teguments, leaves or empty pods. They were thereafter purified using techniques based on physicochemical properties of active substances. Assays were carried out on seedling growth of Monocotyledons and Dicotyledons representatives. Results showed that all extracts exerted significant dose dependent inhibition on epicotyl and hypocotyl growth. However, some extracts exhibited a slight stimulation effect at low doses. Moreover, A. arenicola crude extract （E23） slightly inhibited axillary bud growth, while A. tulearensis crude extract （ET1） showed a stimulation effect. According to preliminary phytochemical screening results, these effects might be due to saponins or alkaloids.展开更多
文摘[Objective] With a rice variety ＂Long Rice 11＂ as a test cultivar,an experiment of raising rice seedlings with the new substrata prepared from biochar,and maize stalks,rice husks,organic fertilizer,turf,zeolite,fine river sand and arable layer soil by mixing according to certain volume proportions was caried out,in order to investigate the physical and chemical properties of different organic-material seedling-raising substrata and the effects of these substrata on seedling growth.[Method] The experiment raised seedlings in greenhouses and adopted randomized block arrangement.[Result] The substratum of biochar mixed with maize stalks and rice husks could increase the maximum water-holding capacity of the substratum,reduce the volume weight of the substratum and improve the buffering effect of the substratum.It also had great effects on the contents of alkali-hydrolyzale nitrogen and rapidly available potassium in the substratum,and could improve the root number and substantial degree of rice seedlings.[Conclusion] Biochar with maize stalks and rice husks（the treament HC） is the optimal substratum in this study.
文摘Root-knot nematodes （Meloidogvne spp.） constrain the production of high value vegetable crops, such as tomato, on smallholder farms in Kenya. For several years, control of root-knot nematodes largely depended on the use of synthetic nematicides, most of which have been banned due to their toxicity to humans and the environment. Farmer-participatory trials were established, for two consecutive growing seasons on farmers＇ fields infested with root-knot nematodes （A4eloidogvne javanica and Meloidogyne incognita）, at two sites in central Kenya （Maragua and Kirinyaga districts）, representing two contrasting group of farmers （low-input and high-input）. The trials aimed at evaluating the potential of using biological control agents （BCAs）, i.e. Poehonia ehlamydosporia and Pasteuria penetrans, antagonistic plants （Crotalaria grahamiana and Tagetes minuta）, ＂＇trash burning＂ and chemical control （dazomet 98% = Basamid~ Granular） in the management of root-knot nematodes in tomato nursery beds, and quantify the associated net benefits, compared to an untreated control. Crotalaria grahamiana, ＂trash burning＂ and dazomet, significantly （P 〈 0.05） reduced the number of second-stage juveniles （J2s） of the root-knot nematodes in the soil in nursery beds during the first season at Karigui-ini, but there was no significant （P 〉 0.05） increase in yield after transplanting tomato seedlings from the respective treatment. Similarly, one of the BCAs （P. ehlamydosporia）, was effectively transferred to the field with seedlings from the BCA-treated nursery beds, but there was no significant （P 〉 0.05） increase in yield due to slow proliferation of the BCA, after transplanting. Participatory partial budgets were successfully developed with srnallholder farmers, and proved to be a vital tool in making informed decisions on management options for root-knot nematodes. In general, labour was considered by all farmers as the major input that contributed to the overall additional cost of the different treatments at both sites. This necessitates improvement in efficiency of labour resource use.
基金Supported by Key Technology Research and Development Program of Chongqing(KL1401)~~
文摘[Objective] This study was conducted to characterize the seed germination and seedling growth of Idesia polycarpa. [Method] After 3-5 h of soaking in 5% baking soda solution, the waxy outer layer of the seeds was rubbed off. Then, the seeds were mixed with fine sand and evenly sown on seedbeds. Germinated seeds were counted to calculate germination rate. Seedlings at two-or three-leef stage were transplanted, and their phenophases were observed and recorded. Height and ground diameter of the seedlings were monitored in the following three years. [Result] The seed germination rate was increased to 20% by soaking in 5% baking soda solution. The yearly seedling height growth of L polycarpa increased with the increase in seedling age. The monthly seedling height growth from August to October was much higher than in other months in the first year, and the growth in seedling height in the three months accounted for 79% of the total increase in that year. The seedling height grew rapidly from May to July in the following two years. In detail, the increase in seedling height from May to July accounted for 87.94% of the total increase in the second year, and 74.16% of the total increase in the third year. The monthly seedling height growth peaked in May in the two years. The yearly growth in ground diameter of I. polycarpa seedlings also increased with the increase in seedling age. The monthly growth in ground diameter from July to September was much higher than in other months in the first year, and the increase in ground diameter in the three months accounted for 80% of the total increase in that year. In the second and third years, the monthly growth in ground diameter from July to October was much higher than in other months. The increase in ground diameter in the two months accounted for 76.89% of the total increase in the second year, and 61.23% of the total increase in the third year. The monthly growth in ground diameter peaked in August in the two years. [Conclusion] The results will provide a theoretical basis for the development and popularization of L polycarpa in Chongqing and surrounding provinces and cities.
文摘The effects of extracts from five Albizia （Fabaceae） endemic species from Madagascar （A. arenicola, A. boivini, A. bernieri, A. polyphylla and A. tulearensis） were tested on vegetable seedling development. Crude extracts were obtained through cold or hot extraction methods on dried powdered seeds, seed teguments, leaves or empty pods. They were thereafter purified using techniques based on physicochemical properties of active substances. Assays were carried out on seedling growth of Monocotyledons and Dicotyledons representatives. Results showed that all extracts exerted significant dose dependent inhibition on epicotyl and hypocotyl growth. However, some extracts exhibited a slight stimulation effect at low doses. Moreover, A. arenicola crude extract （E23） slightly inhibited axillary bud growth, while A. tulearensis crude extract （ET1） showed a stimulation effect. According to preliminary phytochemical screening results, these effects might be due to saponins or alkaloids.
