This is the final part to the article on alien species Destroy Lantana Camara Lantana Camara is originally from South America but came to Africa from Europe as a garden plant. Problems caused by Lantana Camara are: l It replaces indigenous vegetation and reduces the rich vegetation species or biodiversity.
l It is poisonous to livestock.
l It can cause livestock losses.
l It reduces carrying capacity of grazing area by replacing grass and browsing species.
Farmers should control Lantana Camara by mechanical means through clearing and destroying each plant. Simple and safe herbicides which maybe considered more environmental friendly can be used.  
Some of the worst invaders that affect water bodies: Kariba weed, water hyacinth, dodder and water fern.
Many rivers and dams are clogged with water hyacinth, Kariba weeds or water fern. Problems caused by plant invaders such as water hyacinth  include:
l reduced flow of water in the water bodies , this makes irrigation difficult.
l reduced water quality.
l affects aquatic life disturbs recreation activities in water bodies.
What farmers can do to control alien species
l Clear any invasive alien species growing or occurring on your land.
l List and map all invasive alien species in your area.
l Find out how to control each invasive alien species.
l Draw up a report outlining an overall control plan (get specialist advice )and present it to your local authorities, EMA or Agritex.
l Report to the inspector the occurrence of any invasive alien species in your area.
l Abide by the regulations regarding the importation of plant and animal material when returning from abroad and encourage friends to do so
DO NOT
l Move any aquatic plants or animals (including fish) from one water body to another without written authorisation from Parks and Wildlife Management Authority, it is illegal.
l Sell, offer any plant, seed or grain to spread the growth of invasive alien species.
Minimising agricultural pollution
Potential of chemical pollution is high in Zimbabwe as farming relies heavily on herbicides and fertilisers. Pesticides and their degraded products are carried by rainwater and reach water bodies by run off.
Insecticides like Dieldrin used in cotton growing kill fish, birds and small animals.
Other sources of pollution are dip chemicals. Fertilisers in water bodies promote the growth of aquatic plants especially invasive species.
In terms of the EMA Act (CAP 20:27), it is an offence for any person to use or dispose into the environment a pesticide or toxic substance in contravention of standards and measures that will be prescribed by the agency.
Sustainable farming methods
Practice good land husbandry to ensure sustainable farming systems for optimum economic returns and ecological stability. A few examples for recommended practice include:-
l Prepare a farm plan to give guidance on sustainable farming
l Conservation farming
l Afforestation using indigenous species or suitable exotics to meet all timber and fuel needs
l Mechanical conservation by constructing contour ridges and waterways
l Tied ridging
l Ridging
l Minimum tillage
l Mixed cropping
l Crop rotation
l Correct carrying capacity/avoid overstocking
l Construct fire guards
l Land use planning for sustainable agricultural production systems
l Organic farming
l Perma-culture
l Ecotourism and alternative land use on fragile land
l Observe crop pests and disease legislation and regulations
l Apply environmental friendly indigenous knowledge technology where available.

l Please talk to us we are always ready to listen. Email: eep@ema.co.zw or 04 305543 / SMS 0772 951635