Gooseweed

Scientific name: Sphenoclea zeylanica
Synonym: Chickenspike



Photo courtesy of IRRI and University of Queensland

Habitat

Irrigated rice fields, swamps, and stagnant waters

Affected crops

Mostly irrigated rice

Description

The stem is erect, branched, smooth, and hollow. The leaves are smooth and spoon-shaped and grow opposite each other. The flower head is a distinctive cylindrical crowded terminal spike that bears whitish to greenish flowers. The roots are long and have cord-like appearance. The plant has a fleshy appearance. It is propagated by seeds. n

Effects and impacts

Gooseweed competes with rice for soil nutrients and sunlight. It can lower the yield by up to 50% when left uncontrolled (Rice IPM, 2001).

The young plants and leaves are eaten as vegetables.

Studies show that the weed is found resistant to 2,4-D on some rice fields in Malaysia, Thailand, and the Philippines (Weed Science, 2005).

Methods of control

1. Proper seed selection
2. Thorough land preparation by plowing and harrowing
3. Rice seedbeds should be free of weeds
4. Regular plant monitoring
5. Proper water and fertilizer management
6. Closer plant spacing to prevent the germinating seeds of the weeds being exposed to sunlight
7. Hand weeding
8. Crop rotation

External links

• Weed Science. Herbicide resistant gooseweed globally. http://www.weedscience.org/Summary/USpeciesCountry.asp?lstWeedID=167&FmCommonName=Go

References

• CABI. (2001): Crop protection compendium. Global module, 3rd edition. CAB International Publishing. Wallingford, UK.
• IRRI & Queensland University. (2001): Rice IPM. An interactive information and identification system for integrated pest management in rice. University of Queensland and IRRI.
• Moody, K.; Munroe, C.; Lubigan, R.; Paller , E. (1984): Major weeds of the Philippines. University of the Philippines, Los Baños. Laguna, Philippines.
• Reissig, W.; Heinrichs, E.; Litsinger, J.; Moody, K.; Fiedler, L.; Mew, T.; Barrion, A. (1986): Illustrated guide to integrated pest management in rice in tropical Asia. IRRI. Los Banos, Laguna, Philippines.