“Tum-thang” (<Emphasis Type="Italic">Crotalaria tetragona</Emphasis> Roxb. ex Andr.): a little known wild edible species in the north-eastern hill region of India

Crotalaria tetragona Roxb. ex Andr., locally known as “Tum-thang” was collected from Mizoram state of north-eastern hill region of India during 2008. Its flowers were being sold by the tribal communities in local markets. The buds and flowers are cooked as vegetables and used in garnishing of local food preparations especially in non-vegetarian recipes. This species is reported here as little known Edible type in Indian region and may be considered as a multi-purpose species with potential. Edible uses of some of the Crotalaria species in different regions of world have also been included in the present communication.     

A new trimethoxychalcone from Crotalaria ramosissima

A new trimethoxychalcone (1) was isolated from the aerial parts of Crotalaria ramosissima. The structure was elucidated on the basis of (1)H NMR, (13)C NMR and MS methods.     

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为优良野生猪屎豆种质资源的开发利用和耐盐育种提供理论依据,通过对种子萌发期的相对发芽率、相对发芽势、胚根胚芽比值等指标测定,运用隶属函数法综合评价野生猪屎豆种质材料的耐盐性.结果表明:低浓度的盐溶液对野生猪屎豆的萌发具有一定的促进作用,高浓度盐对种子萌发存在抑制作用.盐浓度越大,对相对发芽率、相对发芽势的影响越大;在相同盐浓度下,不同材料间的相对值也存在显著差异.随着盐浓度的增加,胚根胚芽比值呈上升的趋势.盐溶液对胚根的抑制作用小于胚芽.芽期耐盐性最强的材料是采自陵水的C22以及三亚的C27,耐盐性最差的材料是采自乐东的C1、海口的C31和澄迈的C23,其余材料的耐盐性介于二者之间.     

超声提取和气相色谱-质谱联用测定 猪屎豆种子中“百合碱含量

采用超声提取方法对猪屎豆种子中的“百合碱进行提取,并使用气相色谱-质谱法测定“百合碱的含 量。超声提取的最佳提取条件为提取温度75益、提取时间60 min、提取功率255 W、料液比25颐1（V颐M）。建立气相色 谱-质谱联用测定“百合碱含量的方法,采用毛细管气相色谱柱DB-5MS (30 m伊0.25 mm伊0.25 滋m),进样口温度 250益,离子源为EI 源,电离电压为70 eV,GC-MS 接口温度为280益,离子源温度为220益,采用选择粒子扫描模式, 选择m/z 120 和236 作为定性离子,m/z 120 为定量离子。“百合碱在上机液浓度0.10耀2.00 滋g/mL 与峰面积值线性 关系良好（R2越0.9994）,最低检测浓度为0.05 滋g/mL。在试验所选择的3 个样品测定中,平均回收率为96%~112%, RSD 为3.7%~6.7%。     

猪屎豆丛枝病植原体的分子检测与鉴定

植原体(phytoplasma),原称类菌原体(MLO),在植物和昆虫中广泛分布,为无细胞壁原核微生物,尚不能在人工培养基上离体培养.迄今,世界各地已统计有1000多种植物自然感染植原体病害(Seemüller et al.,1998),我国也报道了100多种植物植原体病害(赖帆等,2008).     

Integrated management of Striga hermonthica, stemborers,and declining soil fertility in western Kenya

Striga hermonthica (Delile) Benth., stemborers, and declining soil fertility are serious threats to sustainable food production in the Lake Victoria zone of Kenya. To address these constraints, promising integrated crop management technologies were evaluated, using a multi-locational design in four sub-locations in Siaya and Vihiga district (western Kenya) for six cropping seasons. Technologies evaluated consisted of the traditional maize (Zea mays L.) – bean (Phaseolus vulgaris L.) intercrop, maize – Desmodium (Desmodium uncinatum (Jacq.) DC.) push–pull intercrop, Crotalaria (Crotalaria ochroleuca G. Don) – maize rotation, and soybean (Glycine max (L.) Merr) – maize rotation. Within each of these systems, imazapyr-coated herbicide-resistant maize (IR-maize) and fertilizer were super-imposed as sub-plot factors. The push–pull system was observed to significantly reduce Striga emergence and stemborer damage from the second season onwards. IR-maize reduced and delayed Striga emergence from the first cropping season. Differences in Striga emergence and stemborer damage between the other systems were not significantly different. After five cropping seasons, the Striga seedbank was significantly higher in the maize-bean intercrop system than in the push–pull system under both maize varieties while the rotational systems had intermediate values not different from the day zero values. Under IR-maize, the Striga seedbank was significantly lower than under local maize for all cropping systems. Maize yields varied between seasons, districts, and cropping systems. Yields in the push–pull system were higher than in the maize-bean intercrop after two seasons and in the absence of mid-season drought stress. Both maize and soybean responded significantly to fertilizer application for both districts and for most seasons. The various interventions did not substantially affect various soil fertility-related parameters after five seasons. In the short term, IR-maize integrated in a push–pull system is the most promising option to reduce Striga while the rotational systems may need a longer timeframe to reduce the Striga seedbank. Finally, farmer-led evaluation of the various technologies will determine which of those is really most acceptable under the prevailing farming conditions.     

Effects of legume green-manuring on nitrogen mineralization and some microbiological properties in an acid rice soil

We studied N mineralization of legume green manures under laboratory and field conditions, and the effects of field green-manuring on the microbiological properties of an acid Alfisol soil. No significant differences were found in the mineralization rates of Sesbania (Sesbania cannabina), sunnhemp (Crotalaria juncea), and cowpea (Vigna unguiculata) green manure. Mineralization was higher in field-capacity moist soil than water-saturated soil. The decomposition of sunnhemp under field wetland conditions, in the absence of a rice crop, was a rapid as it was under in vitro conditions. The decomposition released considerable amounts of mineral N and the level of NH ₄ ⁺ -N was significantly higher than NO ₃ ^– -N. Significant improvements were observed in the microbial biomass, dehydrogenase activity, and bacterial populations in the field soil green-manured for rice for 3 years, compared with fertilized soil.     

Sesbania spp., Aeschynomene indica and Crotalaria spp. are amide-exporters

Abstract

Extract

Leguminous plants consist of two groups, amide-exporting and ureide-exporting plants. The former legumes export a large fraction of fixed-N in the form of amides (asparagine and glutamine), and the latter legumes in the form of ureides (allantoic acid and allantoin). Another characteristic of the nodules is the enrichment in ¹⁵N. There are two types of legumes: one characterized by the enrichment with ¹⁵N in N₂-fixing nodules, in contrast to the other where the enrichment does not occur. The first investigation by Shearer et al. (1982) suggested that the nodules exporting fixed-N in the form of ureides were enriched in ¹⁵N unlike those exporting it in the form of amides. Soybeans, mungbean, and cowpea belong to the former group and groundnut, alfalfa, white clover to the latter. Although pea and faba bean were first classified into the latter group (Shearer et al. 1982), a recent investigation (Yoneyama 1988) showed that these nodules were also enriched in ¹⁵N.     

Green manures for maize—bean systems in eastern Uganda: Agronomic performance and farmers' perceptions

Researchers worked with farmers in eastern Uganda to develop alternatives for soil management using crotalaria (Crotalaria ochroleuca), mucuna (Mucuna pruriens var. utilis), lablab (Dolichos lablab), and canavalia (Canavalia ensiformis) as green manures in short-term fallows. The participatory research was part of a community-based approach for systems improvement. Grain yields of maize (Zea mays) and bean (Phaseolus vulgaris) following one season of crotalaria fallow were 41% and 43%, respectively, more than following a two-season weedy fallow. Grain yields of maize following a one-season fallow with mucuna and lablab were 60% and 50% higher, respectively, as compared with maize following maize. Maize and bean yield were more, although effects were small, during the second and third subsequent seasons, indicating probable residual effects of the green manures. Mucuna and lablab were successfully produced by intersowing into maize at three weeks after sowing maize, although the yields of the associated maize crop were reduced by 24% to 28%. Farmers estimated the labor requirements for mucuna and lablab to be less than for crotalaria. Farmers independently experimented on how these species can be integrated into banana (Musa spp.), coffee (Coffea robusta), sweet potato (Ipomoea batatas), and cassava (Manihot esculenta) production systems. Farmers reported that the beneficial effects of the green manures included higher food-crop yields; weed suppression; improved soil fertility, soil moisture, and soil tilth; and erosion control. Mucuna and lablab were preferred because of reduced labor requirements and increased net benefits compared with continuous cropping. Farmer participation in the green manure research resulted in efficient generation and adaptation of green manure technology now being promoted in eastern and central Uganda.This revised version was published online in November 2005 with corrections to the Cover Date.     

Effect of plant age on in-soil decomposition and nitrogen content of sunn hemp tissue

ABSTRACT

The effects of plant age at the time of mowing on sunn hemp (Crotalaria juncea L.) tissue decomposition, nitrogen (N) release, and fiber content in Krome very gravelly loam were assessed. Combined leaf and stem tissue from 42-, 77- or 112-day-old sunn hemp plants was placed in mesh bags and buried below the soil surface in the field. Bags were removed bi-weekly and dry weights, N concentration, acid detergent fiber (ADF) and neutral detergent fiber (NDF) concentrations in buried sunn hemp tissues were determined. There was a rapid decrease plant tissue dry weight during the first 14 days after tissue was buried, followed by a slow gradual decrease. The amount N per hectare was much lower for 42-day-old than 112-day-old sunn hemp. Tissue of the youngest plants decomposed the quickest. Forty two-day-old tissue had a higher N concentration, N mineralization rate, and lower NDF and ADF than 77- or 112-day-old tissue. Mowing and soil incorporation of a 42-day-old instead of a 77- to 112-day-old sunn hemp cover crop prior to planting a cash crop can be beneficial for a fast-growing cash crop planted soon after soil incorporation of the cover crop.