Evaluation of Drum Cavity Size and Planter- Tip on Singulation and Plant Emergence in Maize (Zea mays L.).

Average maize grain yields in developing countries are 1.8 Mg ha^-1 compared to 9.9 Mg ha^-1 in the USA, with much of this due to planter technology. Oklahoma State University has developed a hand planter which can help developing world maize producers. Two field experiments were established under conventional tillage (CT) and no-tillage (NT) to investigate the effect of drum cavity size and depth control on emergence, seed singulation and maize grain yields using the current OSU-Hand Planter. A randomized complete block design was used, where treatments included two drums with different cavity sizes (450S and 260-20), two seed sizes (2651 and 3962 seeds/kg), two tips, normal (N) and a tip with a weld-stop (WS), two hand planted checks using a stick planter and two tractor planted checks using a John Deere vacuum planter. In CT, emergence was significantly similar for all four checks (98 to 100%) and HP 450S, 3962 seeds/kg with WS tip (98%). Emergence was better with drum 450S (94% and 98%) than with drum 260-20 (82 and 77%), both with WS tip in CT. This observation is substantiated by increased misses with drum 260-20. Singulations was better with 2651 seeds/kg, drum 260-20 (98%) and drum 450S (59%), both with N tip. Under NT, emergence was improved for the HP 450S, 3962 seeds/kg with N tip (87%) and HP 450S, 3962 seeds/kg with WS tip (84%) over the John Deere check, 3962 seeds/kg (82%). Emergence with the John Deere check 2651 seeds/kg (89%) was significantly better than HP 450S, 2651 seeds/kg (81%). No significant differences were seen with depth control on emergence under NT. Singulation was better with drum 260-20 with smaller seed 3962 seeds/kg (88% versus 72%), whereas drum 450S had better singulation with larger seed 2651 seeds/kg (72% versus 44%).