Crabgrass
Eleusine indica
Poaceae
Crabgrass has a number of uses, some of which include fodder, forage, erosion control, dune stabilisation, medicinal, fibre and food.
Crabgrass is a coarse tufted/stoloniferous annual or sometimes perennial grass. Flowering stems can be up to 0.8 m high and are either ascending or prostrate. The inflorescence (flower structure) contains 3-8 racemes, with each being 5-10 cm long, but rather than originating from a single point, each raceme is separated by about 1 cm. The root system is described as well developed and strong... as anyone that has attempted hand weeding will know - they can be very difficult to pull out. Crabgrass is described as an agricultural and environmental weed, but can be found along roads, disturbed areas, gardens and parks. Crabgrass is a fast-growing C4 plant that thrives in full sun and where soil moisture is adequate. Single plants can produce 40 000 seeds, with seed remaining viable for 2 to 5 years. Seed germination requires light or scarafication. It tolarates a range of soil types, including shallow soils. Allelopathic activity has been reported for crabgrass i.e. reduced growth and/or germination of other plants.
There are a number of natural enemies for crabgrass, some of these include:-Black wheat midge, -Nematode (Heterodera delvi) -Aphid (Sitobion leelamaniae) -smut: finger millet The book (The major arthropod pests and weeds of agriculture in Southeast Asia by Waterhouse, D. F.) provides a more comprehensive list of organisms impacting crabgrass. The website Discover Life, also provides a substantial list of organisms impacting crabgrass - see link below