Wide-row Seeding Cultivation of the Nematode-suppressive Forage Crop Palisade Grass (Urochloa brizantha) cv. MG5 in the Southern Kyushu Region of Japan

We conducted a serial field experiment study with row seeding cultivation (RSC) of palisade grass (a nematode-suppressive forage crop) and machine intertillage for weed and nematode control. We aimed to examine RSC of palisade grass under several inter-row spacing (IRS) conditions using intertillage with a view to the use of palisade grass in crop rotation for nematode control on cultivating farms, as well as use of the shoots as forage on regional livestock farms. In Field Experiment 1, RSC with IRSs of 60, 80, and 100 cm showed no significant differences in yield between these IRS conditions. In Field Experiment 2 and Field Experiment 3, IRSs were set at 80 and 120 cm, and plant-parasitic nematode densities were suppressed to suitably low levels in Field Experiment 2. There was no significant difference in yield between the 80 and 120 cm IRS treatments after three months of cultivation in Field Experiment 3. Comparing RSC with a 120 cm IRS with broadcast seeding cultivation (BSC) in Field Experiment 4, the yield from RSC tended to be higher than that from BSC. Weed dry weight was higher in the BSC system than in the RSC system after two rounds of intertillage in RSC until 127 days after sowing. In Field Experiment 5, an RSC treatment with a 120 cm IRS was constructed in a farmer’s field, and the root-knot nematode density was clearly suppressed on the palisade grass yield survey date. We concluded that wide-row seeding cultivation with an IRS of 120 cm is one of the practical choices for the combined utilization of palisade grass for forage production and as a nematode-suppressive crop.