CHARACTERISTICS OF WEEDS COMMONLY FOUND IN KATAMBORA RHODES GRASSES SEED PRODUCTION IN ZIMBABWE PRESENTED BY MONICA MUTSA ZANA

INTRODUCTION KRG (Chloris gayana) is a sub humid tropical and sub tropical perennial grass used primarily in pastures for grazing, hay and silage. The grass is nematode resistant and suppressive. It restores the soil structure, improves soil organic levels, creates a good ground cover and effectively controls soil erosion. The grass has a high salt tolerance, fire tolerant and establish easily.

INTRODUCTION In Zimbabwe, KRG is grown in rotation with tobacco and irish potato to control the root knot nematode (Meloidogyne javanica). It is a good seed producer and the seed exported to mostly Arab countries that can hardly produce their own seed due to unfavourable climatic conditions, (Ibrahim, 2013) .

JUSTIFICATION When a new and superior variety is developed, some form of planned production must be followed to protect its genetic and identity purity. So it is generally recognised by plant breeders that, without seed certification, much of their work will be wasted if the seed purchased by the farmer did remain true to its description.

JUSTIFICATION As with all seed certification scheme, the maintenance of varietal purity of the seed released by plant breeders is of paramount importance. In the Zimbabwean Seed Certification Scheme, the production of grass seed is carried out by selected farmers who are interested in this type of farming. The regulatory measures are the responsibility of the NDA which is GVT body.

BRIEF HISTORY OF KRG CERTIFICATION Certification of KRG used to be done long back and has since stopped. What was being done and still going on is seed testing in the laboratory for germination and purity by few companies who are exporting the seed. A few farmers are growing the grass without following the full certification process.

OBJECTIVES To identify and describe the characteristics of KRG plant in the field. To identify and characterise common weeds that are found in KRG production in Zimbabwe. To find out different methods that can be used to manage weed infestations in KRG production.

MATERIALS AND METHODS Collection of seeds of different rhodes grasses. Collection of seeds of common weeds found in Katambora. International Union on the Protection of Plant Varieties (UPOV) descriptors.

METHODOLOGY Experimental designs RCBD – Randomised Complete Block Design