scholarly journals Influence of nitrogen fertilizer and duration of Purple Nutsedge (Cyperus rotundus) interference on Onion (Allium cepa) growth and yield in minor seasons in Batticaloa, Sri Lanka

2020 ◽  
Vol 14 (1) ◽  
pp. 11
Author(s):  
T. Geretharan ◽  
U.R. Sangakkara ◽  
V. Arulnandhy
2004 ◽  
Vol 18 (2) ◽  
pp. 341-345 ◽  
Author(s):  
James P. Gilreath ◽  
Bielinski M. Santos

Field trials were conducted to compare the effect of various soil fumigants along with in-bed pebulate and row-middle metribuzin applications on purple nutsedge control and on tomato and bell pepper growth and yield. Treatments consisted of combinations of soil fumigants, pebulate, and metribuzin. Fumigants levels were (1) untreated control, (2) methyl bromide (MBr) + chloropicrin (Pic) (67 + 33%, respectively), (3) Pic, (4) metham, (5) dazomet, and (6) 1,3-dichloropropene (1,3-D) + Pic (83 + 17%, respectively). Pebulate levels were either applied in-bed or not applied. Row middles were either sprayed with metribuzin or untreated. In both crops, purple nutsedge populations were independently influenced by fumigants and pebulate applications, with the highest number of purple nutsedge plants in the untreated control. The addition of pebulate reduced purple nutsedge populations in all treatments. In tomato trials, the yield was affected by fumigants, with the highest losses (53 and 50% reductions in fruit number and weight) observed in the nonfumigated control. In pepper trials, fruit number and weight were individually influenced by fumigants and metribuzin sprayings. Application of metribuzin to row middles increased yields 10% relative to nontreated plots.


Weed Science ◽  
1977 ◽  
Vol 25 (1) ◽  
pp. 13-17 ◽  
Author(s):  
K.E. Frick ◽  
P.C. Quimby

The degree of control of purple nutsedge (Cyperus rotundusL.) provided byBactra verutanaZeller, a native moth, was evaluated for various stress conditions. Two, three, or four weekly infestations each with three larvae per live shoot, reduced purple nutsedge dry weight an average 77% compared with an average 55% for one infestation. Eight weekly infestations reduced plant dry weight 98%. Neither caging of the larvae on the plants nor osmotic stress with NaCl to −8 bars influenced larval efficacy, but nitrogen deficiency did reduce the effect of the larvae about 75%. Purple nutsedge had no effect on the dry weight of cucumber (Cucumis sativusL., ‘Straight Eight’) after 1 month, whether larvae were or were not present. Purple nutsedge did reduce the plant dry weight of okra (Abelmoschus esculentus(L.) Moench, ‘Clemson Spineless’) 64%, but repeated (eight) weekly infestations of larvae gave a plant weight of okra equal to that of okra grown without purple nutsedge. Purple nutsedge reduced the bulb and root dry weight of onion (Allium cepaL., ‘Big Valley’) 37%, but repeated weekly infestations of larvae gave onion growth equal to that of onion grown without purple nutsedge.


2010 ◽  
Vol 50 (3) ◽  
pp. 274-279 ◽  
Author(s):  
Kowthar El-Rokiek ◽  
Samia El-Din ◽  
Faida Sharara

Allelopathic Behaviour ofCyperus RotundusL. On BothCHORCHORUS OLITORIUS(BROAD LEAVED WEED) ANDECHINOCHLOA CRUS-GALLI(GRASSY WEED) ASSOCIATED WITH SOYBEANPurple nutsedge (Cyperus rotundus) foliage and tubers were tested for allelopathic potential against the following weeds; juteChorchorus olitorius(broad leaved weed), and barnyard grassEchinochloa crus-galli(grassy weed) associated with soybean. In the greenhouse, during 2008 and 2009, foliage and tubers ofC. rotunduswere mixed with soil surface at 20, 40, 60 and 80 g/kg.C. rotundusnegatively affected those of jute and barnyard grass particularly at 80 g. Jute was more susceptible to allelopathy byC. rotundusthan barnyard grass. Inhibition in weed dry matter was higher with tuber than foliage residues. Tuber residues reduced the dry weight of jute and barnyard grass by 85.96% of the control and by 58.28% with 80 g, respectively. On the other hand, soybean growth and yield showed a high significant increase compared with unweeded pots. A high-performance liquid chromatography analysis showed thatC. rotundusfoliage contained the following phenolic acids: caffeic, ferulic, coumaric, benzoic, vanelic, chlorogenic and cinnamic. Tubers contained hydroxybenzoic, caffeic, ferulic, vanelic and chlorogenic.


2015 ◽  
Vol 28 (2) ◽  
pp. 56-66
Author(s):  
Kifah A. J. Al-Dogachi ◽  
Kadim K. Al-Asady ◽  
Manal A. Askar

Weed Science ◽  
1971 ◽  
Vol 19 (6) ◽  
pp. 701-705 ◽  
Author(s):  
R. J. Burr ◽  
G. F. Warren

Several herbicides were tested in the greenhouse on ivyleaf morningglory (Ipomoea hederacea(L.) Jacq.), green foxtail (Setaria viridis(L.) Beauv.), purple nutsedge (Cyperus rotundusL.), and quackgrass (Agropyron repens(L.) Beauv.) to determine the degree of enhancement in activity that could be obtained with an isoparaffinic oil carrier applied at 140 L/ha. The enhancement varied with the herbicide and with the species, ranging from 16-fold enhancement with 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine) and 2-sec-butyl-4,6-dinitrophenol (dinoseb) on ivyleaf morningglory to no enhancement of atrazine activity on purple nutsedge and quackgrass or (2,4-dichlorophenoxy)acetic acid (2,4-D) activity on quackgrass and ivyleaf morningglory. An oil adjuvant was less effective in enhancing dinoseb and 3-(3,4-dichlorophenyl)-1-methoxy-1-methylurea (linuron) activity than was the isoparaffinic oil carrier. Also, the isoparaffinic oil carrier emulsified in water was less effective than the undiluted oil in enhancing dinoseb activity on green foxtail, even though equal volumes of the isoparaffinic oil were applied.


2000 ◽  
Vol 14 (1) ◽  
pp. 1-6 ◽  
Author(s):  
JUGAH B. KADIR ◽  
R. CHARUDATTAN ◽  
WILLIAM M. STALL ◽  
BARRY J. BRECKE

2015 ◽  
Vol 33 (2) ◽  
pp. 165-173 ◽  
Author(s):  
R.S.O. Lima ◽  
E.C.R. Machado ◽  
A.P.P. Silva ◽  
B.S. Marques ◽  
M.F. Gonçalves ◽  
...  

This work was carried out with the objective of elaborating mathematical models to predict growth and development of purple nutsedge (Cyperus rotundus) based on days or accumulated thermal units (growing degree days). Thus, two independent trials were developed, the first with a decreasing photoperiod (March to July) and the second with an increasing photoperiod (August to November). In each trial, ten assessments of plant growth and development were performed, quantifying total dry matter and the species phenology. After that, phenology was fit to first degree equations, considering individual trials or their grouping. In the same way, the total dry matter was fit to logistic-type models. In all regressions four temporal scales possibilities were assessed for the x axis: accumulated days or growing degree days (GDD) with base temperatures (Tb) of 10, 12 and 15 oC. For both photoperiod conditions, growth and development of purple nutsedge were adequately fit to prediction mathematical models based on accumulated thermal units, highlighting Tb = 12 oC. Considering GDD calculated with Tb = 12 oC, purple nutsedge phenology may be predicted by y = 0.113x, while species growth may be predicted by y = 37.678/(1+(x/509.353)-7.047).


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