Imperata management strategies used in smallholder rubber-based farming systems

A large proportion of global natural rubber production takes place in Southeast Asia. The majority of this rubber is produced by smallholders. Thailand, Indonesia and Malaysia are the three principal countries involved. In Malaysia and Indonesia the smallholder sector accounts for 72% and 84% of total rubber production respectively. In other countries rubber plays a significant role on a more local basis. Imperata is a serious problem for the smallholder rubber farmer in most of Southeast Asia in three respects: the high cost (labour and/or capital) of opening Imperata-infested land, its competitive effect on rubber and annual intercrops, and the fire hazard that it poses during the dry season as a major source of combustible material. The costs of Imperata to smallholders are substantial in terms of a direct loss through fire and revenue foregone or delayed as a result of competition. Most smallholders intercrop their rubber during the first 1–3 years after planting it, and during this period Imperata is reasonably well controlled. Intercropping is only feasible for a limited period because of limited soil fertility and/or the shading effect of the rubber trees. After intercropping, Imperata tends to establish itself for a few years until it too is shaded out by the rubber. This is the problem period, during which farmers practise only limited weed management, if any.A large amount of research has been done on methods of controlling Imperata, but the recommended methods have been generally spurned by smallholders unless they have been given subsidies to apply them. This paper describes the precise nature of the Imperata problem, with reference to some of the smallholder rubber-based farming systems within Southeast Asia; the different Imperata control strategies currently practised in these farming systems; and some of the constraints on the adoption of currently and recently recommended practices. It then proposes a ten-point agenda for research on Imperata control, including two ways in which current research programmes could be usefully reoriented: first, they need to take greater account of smallholder farming systems and constraints; and second they should shift their emphasis from single-method to integrated control systems.     

Protein improves health and performance of molted layers

禽业是巴基斯坦最大且仍在增长的行业.据巴基斯坦经济调查(2008 ～ 2009)的信息显示,家禽的总数已经由2006～2007年度的8.95亿增加至2008 ～ 2009年度的10.61亿,其中包括2 842万羽的蛋鸡.     

艾丁湖极端嗜碱菌碱性纤维酶的初步研究

从吐鲁番艾丁湖地区６４种土样中筛选到一株能产细胞外嗜碱性纤维素酶的极端嗜碱菌Ａ０４,细胞杆状,革兰氏染色阴性。该菌在ＣＭＣ培养基中产生细胞外纤维素酶,产酶的最适ＰＨ和ＮａＣｌ浓度分别为９．５和０．５％。酶反应最适温度为４０℃,在ＰＨ９．５条件下产生较高的碱性纤维素酶。     

Gastrointestinal parasites of dogs in Iran

Summary The results are described of a survey on the incidence of intestinal helminths and protozoa in house-dogs in Teheran, Iran. Eleven species of adult helminths, six species of eggs and two species of protozoa were recovered.Toxocara canis, Taenia multiceps andSpirocerca lupi were the most common helminths in dogs.Toxascaris leonina, Physaloptera preputialis, Trichuris vulpis, Isospora bigemina andI. rivolta are reported for the first time from Iran.

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Sumario Se describen los resultados de una encuesta sobre la incidencia de helmintos intestinales y protozoarios en perros “caseros” en Teherán, Iran. Se recuperaron once especies de helmintos adultos, seis especies de huevos y dos especies de protozoarios. Los helmintos mas comunes en los perros fueron encontrados serToxocara canis, Taenia multiceps ySpirocerca lupi. Por primera vez se reportan en IranToxascaris leonina, Physaloptera preputialis Trichuris vulpis, Isospora bigemina eIsospora virolta.

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Résumé Cet article donne les résultats d'une étude sur l'incidence des helminthes et des protozoaires intestinaux chez les chiens de particuliers à Téhéran. Onze espèces de vers adultes, six espèces d'oeufs et deaux espèces de protozoaires furent recensés.Toxocara canis, Taenia multiceps etSpirocera lupi étaient les helminthes les plus courants chez les chiens.Toxascaris leonina, Physaloptera preputialis, Trichuris vulpis, Isospora bigemina etI. rivolta sont cités pour la première fois en Iran.

     

天山南北坡植物种-面积关系

通过对天山南北坡25个样地的物种-面积关系的研究,结果发现:①所有样地种-面积关系斜率的平均值为0.21±0.02,低于全球平均水平;②草甸、草原和荒漠的种-面积关系的斜率分别为0.14±0.02,0.13±0.01和0.28±0.02.草甸和草原的种-面积关系斜率无显著差别,但两者显著低于荒漠的种-面积关系斜率;③天...     

新疆山地针叶林植物物种组成与丰富度研究

通过对新疆阿尔泰山、天山北坡、天山南坡和昆仑山西部11个地点122个样方的调查,发现阿尔泰山针叶林植物(包括乔木、灌木和草本)丰富度显著高于天山南坡和昆仑山;天山南坡和昆仑山物种组成相似,阿尔泰山和天山北坡物种组成相似.全疆针叶林物种丰富度随年平均气温和海拔的增加显著下降,随纬度的升高显著升高.在不同区域,物种丰富度随...     

喀喇昆仑山-西昆仑山苔藓植物区系及物种多样性1）

对喀喇昆仑山—西昆仑山苔藓植物区系成分进行了划分,并对该区系与邻近9个地区的地理成分进行了聚类分析。经查阅有关资料和标本鉴定,确定新疆喀喇昆仑山共有苔藓植物32科、76属、178种（含5变种）,其中苔类为7科、8属、11种,藓类25科6、8属、167种。喀喇昆仑山—西昆仑山苔藓植物区系成分可划分为10种类型,其中北温带成分居主导地位,占该地区苔藓植物总种数的71．81％,东亚成分次之,占8．85％,热带成分甚微。地理成分区系谱及聚类分析结果表明,新疆喀喇昆仑山—西昆仑山与东部天山苔藓植物区系关系最为接近,与贺兰山密切相关。对喀喇昆仑山—西昆仑山10个样点中苔藓植物多样性指数的分析结果表明,西合休和果萨斯苔藓植物分布较丰富。     

Synergistic effect of arbuscular mycorrhizal fungi and Bacillus subtilis on the biomass and essential oil yield of rose-scented geranium (Pelargonium graveolens)

Four different arbuscular mycorrhizal (AM) fungi, Glomus aggregatum, Glomus fasciculatum, Glomus intraradices and Glomus mosseae, were used alone and in combinations with Bacillus subtilis to evaluate their capability to increase the productivity of geranium. Mycorrhizal treatment increased the growth and total biomass invariably over non-mycorrhizal control plants. In AM alone treatment, the best result was obtained for G. mosseae treatment, where 380.9 and 335.3 g fresh herb yield per pot was recorded in 2005–2006 and 2006–2007, respectively, an increase of 75.3 and 85.9% over controls. Plants inoculated with B. subtilis alone yielded 287.8 and 252.3 g fresh herb, an increase of 32.4 and 39.9% over uninoculated controls. However, B. subtilis in combination with G. mosseae produced the highest herb yield, i.e. 410.8 and 347.8 g herbs pot^?1, an increase of 89.4 and 92.9% over untreated controls. The field experimental data validated the results of the pot experiment. Treatment with G. mosseae alone increased herb yield by 49.4%, whereas in combination with B. subtilis, it increased herb yield by 59.5%. Treatment with AM fungi and B. subtilis did not affect the essential oil content of the plant, but total oil yield was significantly increased because of the increase in biomass production.     

The nature of organic matter in soil organo-mineral complexes

“The union of mineral and organic matter to form the organo-mineral complex is a synthesis as vital to the continuance of life as, and less understood than, photosynthesis.”(JACKS) (1).     

Evaluation of nitrogen status of agricultural soils in Java,Indonesia

Abstract

To evaluate the content of nitrogen (N) fractions of agricultural soils in Java, Indonesia, in relation to soil type and land use, 46 surface soil samples, 23 from paddy and 23 from upland, were collected throughout Java to include various types of soils. Soil N was separated into four fractions according to form and availability: inorganic extractable nitrogen (Iex-N), fixed ammonium nitrogen (Ifix-N), organic mineralizable nitrogen (Omin-N) and organic stable nitrogen (Osta-N). The total-N content was determined by the dry combustion method. The Iex-N content was determined by extraction with a 2 mol L^?1 potassium chloride (KCl) solution and the Ifix-N content by extraction with an hydrofluoric and hydrochloric acid (HF-HCl) solution after removal of organic-N. The Omin-N content was evaluated as the potentially mineralizable N based on a long-term incubation method. The Osta-N content was calculated as the difference between the contents of total-N and the three other fractions. The total-N content was 2.06 g kg^?1 on average. The contents of Iex-N, Ifix-N, Omin-N and Osta-N were 25.8, 99.1, 103 and 1,832 mg kg^?1, respectively, and corresponded to 1.3, 4.8, 5.0 and 88.9% of the total-N. Hence, available (Iex-N and Omin-N) and stable (Ifix-N and Osta-N) fractions accounted for 6.3% and 93.7% of the total-N, respectively. Correlation analysis indicated that the contents of total-N and Osta-N had positive correlation with (Alo + 1/2Feo) as an index of amorphous minerals (p < 0.01), suggesting strong influence of volcanic materials for the accumulation of organic matter in Java soils. The content of Ifix-N had a positive correlation with nonexchangeable potassium (K) content (p < 0.01), suggesting the contribution of 2:1 clay minerals which can fix both ammonium (NH₄⁺) and K⁺ in their interlayer sites. On the contrary, Omin-N did not have any significant correlation with soil properties, implying the importance of management for the improvement of the available N level in soils, rather than intrinsic soil properties. Soil N status further showed strong topographical trends depending on the elevation where soil developed. The contents of total N, Iex-N, Ifix-N, Omin-N and Osta-N in Java soils were on average 80, 69, 90, 65 and 80% of those in Japanese soils, respectively, suggesting that the soil N level in Java was lower than that in Japan, probably due to accelerated decomposition of organic matter, especially degradable fractions, reflecting high temperature, but that the level was relatively high for tropical soils due to the effect of volcanic materials. In conclusion, these results should be taken into account for the sustainable management of soil N in agricultural fields in Java, Indonesia.