TY  - BOOK
AU  - Ameena M 
AU  - Geetha Kumari V L (Guide)
TI  - Integrated Management of Purple Nutsedge
U1  - 630 
PY  - 2003///
CY  -  Vellayani
PB  - Department of Agronomy, College of Horticulture
N2  - An investigation entitled "Integrated management of purple 
nutsedge (Cyperus rotundus L.)" was conducted during 1999-2002 at 
College of Agriculture, Vellayani, Thiruvananthapuram. It comprised of 
one pot study, two field experiments and three laboratory experiments. 
Pot experiment was conducted to study the biology of purple nutsedge 
under various seasons and stage of tuberisation. Field experiments were 
conducted to evolve an integrated management strategy for purple 
nutsedge control in cropped area and a long-term control strategy in non- 
cropped area. Laboratory experiments were conducted to assess the 
allelopathic influence of purple nutsedge root exudates on early growth 
of crop seeds and nutsedge extracts on weed seeds. An attempt has been 
made to identify the allelochemicals present in tubers of nutsedge by 
employing HPLC (High Performance Liquid Chromatography) technique. 
In pot study, the growth and development of purple nutsedge was 
observed for a period of one year. Results of the study indicated that 
chain tuber took more time for sprouting compared to shoot tubers or 
bulb. The time required to sprout varied with seasons in the case of 
chain tuber and August and March planted tubers took lesser time for 
sprouting. March and May planting tecorded more tuber production 
compared to August and November planting. August planted tubers 
recorded very early tuberisation and November and May planted tubers 
took more or less double the time for tuberisation compared to August 
planted tubers. 
Field studies in cropped area indicated that the growth characters 
of okra were significantly influenced by the weed management practices. 
Flowering was early by about 7-10 days in mulched plots under both 
stale seed bed and soil exposure treatments compared to weedy check 
plots. Stale seed bed coupled with mulching registered maximum leaf 
area index during both the years. All the weed control treatments except 
 
where cowpea was raised as smother crop resulted in significantly more 
fruits per plant and fruit yield per hectare. Maximum productivity of 
5.24 t ha" was realised by stale seed bed with eucalyptus mulched plots 
which was 171.5 and 11 per cent more than weedy check and weed free 
plots respectively. The treatments had no significant influence on 
quality attributes of okra like vitamin C, keeping 'quality, protein and 
fibre content of fruits. Regarding soil fertility status, minimum 
depletion of nutrients occurred in completely weed free and mulched 
plots. 
Stale seed bed with polythene mulching or pre and post emergent 
glyphosate application were identified as the best nutsedge control 
measure in cropped area. Post emergent glyphosate application after stale 
seed bed has found to show spectacular inhibitory effect on nutsedge 
multiplication and spread and this treatment recorded the highest 
percentage reduction values for nutsedge control. Lowest rate of 
regeneration was recorded by this treatment with lower viability of 
tubers. The most economical treatment was stale seed bed with 
glyphosate application integrated with eucalyptus mulching and it 
recorded the highest net returns (Rs.18,2701-) and B:C ratio (2.01). 
In non-cropped area. results of two seasons study indicated that 
the effective stage for glyphosate spraying was identified as before tuber 
initiation. The degree of inhibition exerted by glyphosate on regeneration 
of nutsedge tubers was higher thanthat of 2.4-0. Among the summer 
season treatments stale seed bed with irrigation followed by glyphosate 
application was the best in achieving higher level of control. 
In allelopathic studies. nutsedge root exudates collected at 
sprouting stage inhibited the germination and growth of all the crop 
seeds tested vi : .. rice. co wpea. sesamum. okra and brinjal. Also the 
nutsedge extracts collected at different stages inhibited the growth and 
development of Gomphrena de cumbe nse and Syne drell a nodij7ora. 
 
The allelochemicals present in tubers of purple nutsedge was 
identified by High Performance Liquid Chromatography (HPLC) and it 
indicated the presence of p-hydroxy benzoic acid, p-coumaric acid, m- 
coumaric acid, vanillic acid and gentisic acid. 


UR  - http://krishikosh.egranth.ac.in/handle/1/5810015099
ER  -