Imperata

About: Imperata is a research topic. Over the lifetime, 525 publications have been published within this topic receiving 6344 citations.

The Imperata grasslands of tropical Asia: area, distribution, and typology

Abstract: The rehabilitation or intensified use of Imperata grasslands will require a much better understanding of their area, distribution, and characteristics We generated estimates of the area of Imperata grasslands in tropical Asia, and suggested a typology of Imperata grasslands that may be useful to define the pathways toward appropriate land use intensification We conclude that the area of Imperata grasslands in Asia is about 35 million ha This about 4% of the total land area The countries with the largest area of Imperata grasslands are Indonesia (85 million ha) and India (80 million ha) Those with the largest proportion of their surface area covered with Imperata are Sri Lanka (23%), the Philippines (17%), and Vietnam (9%) Laos, Thailand, Myanmar, and Bangladesh evidently all have similar proportions of their land area infested with Imperata (about 3 to 4%) Malaysia (< 1%), Cambodia (1%), and the southern part of China (2%) have but a minor proportion of their total land area in Imperata The species was found widely distributed on the full range of soil orders It occupied both fertile (eg some of the Inceptisols and Andisols) and infertile soils (Ultisols and Oxisols) across a wide range of climates and elevations Imperata lands fall into four mapping scale-related categories: Mega-grasslands, itmacro-grasslands, meso-grasslands, and micro-grasslands The mega-grasslands are often referred to as ‘sheet Imperata’ They are the large contiguous areas of Imperata that would appear on small-scale maps of say 1:1,000,000 We propose that this basic typology be supplemented with a number of additional components that have a key influence on intensification pathways: land quality, market access, and the source of power for tillage The typology was applied in a case study of Indonesian villages in the vicinity of Imperata grasslands We propose an international initiative to map and derive a more complete and uniform picture of the area of the Imperata grasslands This should include selected studies to understand conditions at the local level These are critical to build the appreciation of change agents for the indigenous systems of resource exploitation, and how they relate to local needs, values and constraints

Weed management in rice‐based cropping systems in Africa

Abstract: Weed competition is a major constraint in all the rice production systems in Africa. In addition to the costs of weed control, weeds account for yield losses estimated to be at least 2.2 million tons per year in sub‐Saharan Africa, valued at $1.45 billion, and equating to approximately half the current total imports of rice to this region. Important weeds in upland rice include the perennial species Cyperus rotundus, Imperata cylindrica and Chromolaena odorata, the annual species Euphorbia heterophylla, Digitaria horizontalis, and the parasitic weeds Striga spp. In lowland rice the perennial weeds: Cyperus rotundus, C. esculentus and Oryza longistaminata and annual weeds Sphenoclea zeylanica, Echinochloa spp., Cyperus difformis, C. iria, Fimbristylis littoralis, Ischaemum rugosum, and O. barthii cause serious losses. Common weed management practices in rice‐based cropping systems include soil tillage, clearance by fire, hand‐ or hoe‐weeding, herbicides, flooding, fallow and crop rotations, and these are often used in combination. Labor shortages and lack of access to information, inputs, and credits are widespread constraints for African farmers. To optimize financial, social and environmental costs and benefits, integrated and ecological management approaches are advocated. Locally adapted and affordable combinations of preventive measures and interventions should be targeted. Future weed research should aim to deliver the information and tools for the implementation of these approaches. This requires the generation of knowledge on weed biology and ecology and on the consequences of changes in management and the environment on weed populations. To address the diversity of rice‐based cropping systems in Africa, priorities need to be set and products and information delivered that take full account of local conditions. This will require farmer participatory approaches that are inclusive with respect to resource‐poor farmers and gender.

Cogongrass (Imperata cylindrica)—Biology, Ecology, and Management

Abstract: Cogongrass is considered to be one of the ten most troublesome and problematic weedy species in the world. This species is found throughout tropical and subtropical regions, generally in areas dist...

Restoration of natural vegetation in degraded Imperata cylindrica grassland: understorey development in forest plantations

Abstract: Reclamation of former, degraded forest lands occu- pied by Imperata cylindrica is one of the crucial environmen- tal and forestry issues in the humid tropics, notably Southeast Asia. We suggest that it is possible to gradually restore the original natural forest cover with the help of a sacrifice fallow crop of fast-growing exotic tree species. Recently, a set of suitable fast-growing plantation tree species has been identi- fied and stand establishment methods developed for this pur- pose. We assessed the regeneration of natural vegetation in stands of different plantation tree species and evaluated the ecological impact of species composition in the plantation understorey. PCA ordination, regression analysis and analysis of covariance were applied at different stages of the study. We found a marked vegetational resemblance between stands dominated by Acacia mangium: they had the highest number of indigenous trees in their understorey, whereas stands of other plantation trees supported more diverse grass and herb vegetation. A high proportion of evergreen woody vegetation reduces the risk of fire and grass competition and enhances secondary succession towards natural forest.