Mature onion thrips are about 0.05 inch (1.3 mm) while western flower thrips are slightly larger at 0.06 inch (1.5 mm). The most distinctive characteristic of thrips is two pairs of wings that are fringed with long hairs. Adults are pale yellow to light brown.
Yellowing of leaf tips with white areas in upper portions of the leaf blade, stunting of affected plants, twisting or distortion of the flag leaf and distortion and discoloration of panicles and florets.
Tall, succulent plant with soft stems and spiked, waxy leaves that often release milk when broken. Produces a large number of seeds and commonly encountered across soil types and farming systems.
Fast growing, prostrate annual weed with reddish stems and very succulent leaves. Prefers warmed climates and lower altitudes. Most likely to be found around Naivasha and surrounding areas.
Large, upright plant that grows over a meter tall and produces poisonous seeds in a thorn-covered fruit at the centre of the main stem. Very common in most areas and soil types. Grows up to 1.5m high in fallows.
Highly aggressive, fast growing annual with a red upright stem and soft green triangular leaves. Germinates all year-round and produces very high numbers small black seeds very quickly. Very quick to develop resistance to several common herbicides which makes it often very difficult to control.
Hard to control with Group A herbicides post emergence in cereals. C4 plant, normally annual but in absence of frost survives two years. Seeds borne on short stalks arranged in a star, but seeds are much smaller and hairier than Rhodes grass.
Small yellow flowers on a tall stem, and strong smell that can contaminate the grain sample at harvest. Leaves vary from long oval to fern-like. One of the few weeds that is resistant to atrazine. Competitiveness Moderate
These are perennial plants that are commonly found in shallow water or moist soils and can reach 4 feet in height. They resemble grasses and often grow in thick clusters.
