Horse purslane (Trianthema portulacastrum Linn.)
After you finish reading this, you will be able to:
- Identify Horse Purslane.
- Know the habitat of Black Pigweed.
- Know the best cultural and chemical options to control Horse Purslane.
Black Pigweed has negative allelopathic effects on seed germination, seedlings, and productivity in soybeans.
How to Identify Horse Purslane.
Horse purslane is a strong competitor. Research shows it reduces the yield of mung bean by 50 to 60% if you do not control it. Significant losses also occur in maize, soybean, and peanut yields are also attributed to this weed.
Category: Broadleaf (Dicot)
Flower: Flowers are white, pink, or purple.
Height: Prostrate.
Leaf length: The leaves of Black Pigweed are 1—5 cm long, have a purplish colour along their edges, and have a petiole. They are opposite, unequal, and the lower pair is much smaller than the other. Leaves are ovate to almost circular, with slightly wavy margins.
Leaf width:
Reproduction: After it emerges, Horse purslane grows vegetatively for 35–40 days, and then both the vegetative growth and reproductive growth continue simultaneously. Horse purslane seeds germinate at 20°C–45°C, with maximum germination occurring at 35°C.
The seeds of Black Pigweed do not exhibit dormancy and will emerge from 1 cm depth. However, seed emergence declines with increasing soil depth. The production of flowers and seeds of Black Pigweed starts 20-30 days after germination of the seeds.
Each plant produces 52,000 seeds in its life span. Seeds have a hard coat, and persist for many years. The low dormancy period, and enormous seed production, result in a large seed bank, and enables the plants to survive in adverse condition.
Comments: Horse Purslane is thick, and flat at the nodes. Its taproot is white or brown in colour with fibrous hairs that reach to a depth of 30-50cm. Stems are maroon-purple, hairy, and erect.
Habitat: The plant grows in sunny and dry areas along roadsides, wastelands and in lawns. Seedlings prefer rich and moist soil but are sensitive to flooding.
For more information on weeds check out our weed ID Chart.
How to control Horse Purslane in your lawn.
You can control Horse Purslane by cultural and chemical means, but successful management of this weed can only be achieved by an integrated approach.
Cultural control:
Chemical control:
Non selective options for use on public rights of way and domestic and urban areas include Glyphosate (Rapid Fire 800) under APVMA Permit 9907. If you use glyphosate and water quality is an issue then we recommend the use of ProForce Manta Ray.