Authors:
Asmanizar
1
;
Aldy Waridha
2
;
Edy Sumantri
2
and
Rizky Budiarto
2
Affiliations:
1
Faculty of Agriculture, Universitas Islam Sumatera Utara, Jl. S.M.Raja
;
2
Keyword(s):
herbicide application, Asystasia gangetica, Ottochloa nodosa, young oil-palm plantation
Abstract:
A field study was conducted to evaluate the effect of herbicide application on Asystasia gangetica and Ottochloa nodosa in young oil-palm plantation. Experimental plots with the size of 3 x 3 m2 each were laid in a randomized complete block design with 3 replications. The summed dominance ratio of A. gangetica and Ottochloa nodosa were 32 and 37%, respectively. The treatments were Glyphosate-isopropyl ammonium 1.5 l/ha + Metsulfuron-methyl 150 g/ha; paraquat dichloride 2 l/ha and 2,4-D Dimethyl amine 2.5 l/ha and untreated control (water). The percentage of weed yellowing, weed killed, weed re-growth and wet weight and dry weight of weed was found to be significantly affected by herbicide application compared to untreated control. The result showed that Paraquat dichloride (2 l/ha) caused high weed yellowing on A. gangetica and O. nodosa (88.66 and 85%) at 4 Days After Treatment (DAT). Glyphosate-isopropyl ammonium 1.5 l/ha + Metsulfuron-methyl 150 g/ha caused low effect on A. ga
ngetica and O. nodosa killed at initial (7 DAT) observation (21.66 and 13.33 %, respectively), but the percentage of weed killed increased consistently until 28 DAT (100 and 68.33%, respectively). Application of 2,4-D Dimethyl amine 2.5 l/ha caused weed re-growth to be low on A. gangetica (2.66%) whilst, Glyphosate-isopropyl ammonium 1.5 l/ha + Metsulfuron-methyl 150 g/ha and Paraquat Dichloride 2 l/ha was 17.66 and 38.33%, respectively. Paraquat dichloride 2 l/ha showed good effect at 7 DAT on O. nodosa, but there was high weed re-growth at 58 DAT (95%).
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