subject: Japanese Weed Showing Flourishing Effects On Adults [print this page] Japanese weed is a large, herbaceous perennial plant, native to eastern Asia in Japan, China and Korea. In North America and Europe the species is very successful and has been classified as an invasive species in several countries. Japanese weed has hollow stems with distinct raised nodes that give it the appearance of bamboo.
Japanese weed is an invasive rhizomes perennial introduced to the UK from Japan between 1825 and 1841 as an ornamental plant and as cattle fodder. In its native habitat, Japanese weed is a pioneer species found in volcanic larva, river gravels and managed pastures. In the UK it was reported as a garden escape in the late 19th century and naturalized populations were recorded in the early 20th century. Initially it was most prevalent in South Wales, perhaps due to the moist climate, but it is now widespread. Japanese weed is established alongside railways, canals, rivers, streams and roadsides.
Annual Broad-leaved Weeds
A wide range of annual broad-leaved weeds can emerge from the soil seed bank and compete with crops. These plants normally reproduce by means of seeds, and in some respects they are therefore the easiest weeds to deal with as their life cycle is complete in one year. The main objective should be to remove plants before they compete with the crop early in the season and later in the year before they set seed, or impair the harvesting process.
Annual Grass Weeds
Annual grasses germinate from seed and reproduce in one year. These weeds can spread through contamination of crop seed and preventative cultural control methods may often be important.
Biennial weeds
Biennials normally reproduce by means of seed but, unlike annuals, they rarely flower and set seed in their first year. The first year growth represents a vegetative phase during which the plant grows and accumulates food reserves followed by flowering and seed production in the second year. After the plant flowers and sets seed it normally dies. The vegetative phase might last more than one year in unfavorable conditions or, conversely, flowering may occur in the first season under favorable conditions.
Perennial Broad-leaved Weeds
Perennial broad-leaved weeds generally reproduce through seed, but also through various vegetative structures. Many only set seed in the second year, and some may die back after setting seed. Weed management can therefore be aimed at one or more phases of the life cycle such as prevention of seed setting or exhaustion of underground roots
Miscellaneous weeds
The weeds in this section don't fall into any obvious category and have been grouped together here for convenience. They represent a diverse collection of blue cheese weed types and management strategies will generally be specific to the weed.
Volunteer weeds
Volunteer weeds are generally crop plants that are growing out of place or in subsequent crops. They obviously compete with the crop, can be a nuisance, but also, can provide a carry-over for pests and diseases
