Emergence and competition of polla in semi-dry rice
Loading...
Files
Date
1999
Journal Title
Journal ISSN
Volume Title
Publisher
Department of Agronomy, College of Horticulture, Vellanikkara
Abstract
Sacciolepis interrupta (Willd.) Stapf. is a serious weed opthe semi dry rice
in Kerala. An investigation focussing on the emergence pattern and growth
characteristics of Sacciolepis and its management were undertaken at the Agricultural
Research Station, Mannuthy during the early Kharif of 1999.
Sacciolepis interrupta was found to emerge during the first few weeks after
the initial ploughing followed by pre-monsoon showers. Majority of the weed
seedlings (87%) emerged during the first two weeks. The emergence pattern supports
the possibility of practicing a stale seed bed. in the management of the weed. Seeds
collected during July 1998 remained dormant for initial six to seven months. The seed
germination commenced by the month of March and attained a peak during June and
July.
The study on the competitiveness of Sacciolepis interrupta modified by
stale seed bed technique was conducted during the first crop season using split plot
arrangement in randomised block design (early Kharif) of 1999. The study revealed
that competition from Sacciolepis alone could reduce the rice grain yield by 50.1 per
cent. The Sacciolepis compete with the crop and reduced the height, LAI, tiller
production and biomass production of the crop.
Adoption of stale seed bed method reduced the competition from all weeds
including Sacciolepis. Stale seed bed with paraquat application was found to be better
than stale seed with hoeing. Application of oxyfluorfen @ 0.15 kg ai ha-1 as preemergence
spray though reduced the problem of Sacciolepis in the semi-dry rice,
could not prevent germination of other weeds beyond 15 DAS. However, as preemergence
application of oxyflourfen prevented germination of all type of weeds in
the beginning, it could save one hand weeding.
From the study, it could be concluded that the practice of stale seed bed
technique is an efficient tool for the management of Sacciolepis interrupta in semi-diy
rice. The practice was found to be economically viable also.
Description
MSc
Keywords
Citation
171620