ISSN: 0041-3216

ISSN: 0041-3216 (Online), 0041-3216 (Print)
Volume 78 Number 3
Research Papers
Effect of mulch on weed infestation, soil temperature, nutrient concentration, and tuber yield in Ipomoea batatas (L.) Lam. in Papua New Guinea. (144)
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Four mulching materials were evaluated in sweetpotato [Ipomea batatas (L.) Lam.] plots in a highland region of Papua New Guinea (PNG) to assess the influence of mulch on weed infestation, soil temperature, soil nutrient concentration, and tuber yield. Grass mulch gave the most effective weed control; treatment differences were significant (P ? 0.05) at 4 weeks after planting (WAP) but not at 20 WAP. Grass mulch also gave the lowest soil temperatures, significant (P ? 0.05) temperature differences being observed at 5-cm, 10-cm, and 15-cm depths. Coffee pulp mulch resulted in increased concentration of K, Ca, and Mg and reduced soil acidity. Sawdust mulch gave a higher, although not significant, tuber dry matter (DM) yield at 16 WAP whereas the grass mulch gave the lowest tuber DM yield. Of the yield components investigated, none was significantly correlated with tuber yield. Sweetpotato farmers in the highlands of PNG are encouraged to mulch their gardens with coffee pulp or with coffee husk to obtain high yielding tubers, and to assist in reducing coffee waste in the environment.
Keywords: Mulch; Weed infestation; Soil temperatures; Sweetpotato