Abstract:
The objective of this study was to determine the best doses of organic fertilizers for sweet potato yield increase. Specific targets to be achieved is to improve the productivity of sweet potato in West Papua over 20 tonnes/ha compared to the current productivity of 10.13 tonnes/ha. The study was conducted over eight months starting in January 2015. The experiment was set up as a randomized block design factorial, consisted of 2 treatment with three replications. The first treatment consists of seven formulations of organic fertilizer, namely: husk ash (F1), compost (F2), manure (F3), compost+husk ash (F4), manure+husk ash (F5), compost+manure (F6), and husk ash+compost+manure (F7). While the second treatment in the form of organic fertilizer dose optimization consists of four dose levels, namely: 0 kg per hectare (D0), 2000 kg per hectare (D1), 4000 kg per hectare (D2), and 6000 kg per hectare (D3). The experiments were performed in the field with experimental unit in the form of plot with a size of 2 x 3 meters. In one plot made two mounds. The parameters observed was scab disease intensity, a long tendril, number of branches, number of tubers and tuber weight . Some soil chemical characteristics were also analyzed before and after planting. The data analysis was performed using varian analysis and continued with Duncan Multiple Test at the level of 95%. 144 Eko Agus Martanto, Adelin Tanati, Samen Baan & Irnanda AF Djuuna The result showed that formulations and doses of fertilizers applied cause different responses in long tendrils parameters and the number of branches of sweet potato cultivars. Long tendrils and the number of branches increased to a third observation , then on the fourth observation there is decreased and there were increases. The best formulation of fertilizer to do a production is husk ash with the production of 9.8 kg/plot (equivalent to 16.33 tonnes/ ha). The best dose of fertilizer for generating dose of fertilizer production is 6 tonnes/ha with a production of 9.71 kg/plot (equivalent to 16.18 tonnes/ha). The best combination treatment of fertilizer to do a production is husk ash by dose of 4 tons/ha and husk ash + compost at a dose of 6 tonnes/ha production of 11.0 kg/plot (equivalent to 18.33 tonnes/ha).