Ecology and management of an exotic weed Phalaris minor - Invasive Plants: Ecological and Agricultural Aspects - page 167

harvest during the fallow period. In addition to being used for P. minor con-
trol, herbicides such as metsulfuron and atrazine are also used to control weeds
in a wheat-rice cropping system, including weeds of the fallow crop. Kaushik
and Inderjit [56] found that isoxaflutole reduced shoot growth of mung bean,
while isoxaflutole and metsulfuron reduced chlorophyll concentration.
Therefore, before recommending a herbicide for P. minor management, it is
important to assess its potential effect on succeeding crops.
Conclusion
P. minor is an alien weed with serious environmental and economic conse-
quences. Although there is appreciable progress in the area of P. minor man-
agement through herbicides, its ecology still needs to be explored. Vilà et al.
[57] suggested that there is a need to assess and quantify the impact of alien
species at several levels of ecological complexity in order to gain influence in
their management and control. Several herbicides are available for P. minor
control (Tab. 2); however, the joint action of herbicides with different molecu-
lar targets to P. minor management has not been well investigated.
There is a need to utilize an integrated approach that combines ecological
and agronomic aspects to design better P. minor management. Possible avenues
of future research are: 1) use of novel selective herbicides, 2) mixtures of her-
bicides with different molecular targets, 3) crop rotation, zero tillage, narrow
row spacing, early sowing, and improved straw management, and iv) allelo-
pathic wheat cultivars. Questions addressing the ecology of P. minor include: 1)
what makes a habitat favorable for P. minor ; 2) what characteristics of P. minor
make it successful in wheat fields; and 3) why it is not escaping its field bound-
aries?
Acknowledgements
We thank Drs Barbara Booth, Douglas D. Buhler, William J. Grichar, Calvin G. Messersmith, and
John Wilcut for their constructive comments on the earlier version of the manuscript. S. Kaushik
acknowledges the Council of Scientific & Industrial Research (CSIR) for financial assistance.
References
1 Singh S, Kirkwood RC, Marshall G (1999) Biology and control of Phalaris minor Retz. (littleseed
canarygrass) in wheat. Crop Prot 18: 1-16
2 Holms LG, Doll J, Holms E, Pancho JV, Harbinger JP (eds) (1997) World weeds: natural histo-
ries and distribution. John Wiley, New York
3 Shad R, Siddiqui S (1996) Problems associated with Phalaris minor and other grass weeds in
India and Pakistan. Exp Agric 32: 151-160
4 Afentouli CG, Eleftherohorinos (1996) Littleseed canarygrass ( Phalaris minor ) and short spiked
canarygrasss ( Phalaris brachystachys ) interference in wheat and barley. Weed Sci 44: 560-565
5 Cudney DW, Hill JE (1979) The response of wheat grown with three population levels of canary-
grass to various herbicides treatments. Proc Western Weed Sci Soc (USA) 32: 55-56
6 Mehra SP, Gill HS (1988) Effect of temperature on germination of Phalaris minor Retz. and its