Fall armyworm (Lepidoptera: Noctuidae), southwestern corn borer (Lepidoptera: Pyralidae) and sugarcane borer (Lepidoptera: Pyralidae) damage and grain yield of four maize hybrids in relation to four tillage systems

Zero tillage can be used tactic to prevent soil erosion and save the top soil for maize production.The effects of tillage systems on the growth, grain yield and resistance of maize hybrids against fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), sugarcane borer (SCB), Diatraea saccharalis Fabricius and southwestern corn borer (SWCB), Diatraea grandiosella (Dyar) were examined. Four single cross hybrids used were: Ki3×CML139 (resistant), Ki3×CML131 (susceptible), CML67×CML135 (resistant) and Ki3×CML69 (susceptible). These hybrids were sown on land with conventional tillage, minimum tillage and zero tillage, with and without mulch, in infested and insecticide—protected plots. The resistance/susceptibility of these hybrids against FAW, SCB and SWCB was not altered by the tillage systems. Hybrids planted under zero-tillage+mulch suffered significantly higher damage by SCB and FAW probably because of the retention of moisture in the mulch, which provided optimum conditions for larval feeding. Damage by SWCB on hybrids was the same in different tillage systems because of relatively dry conditions prevailing in the trial. Grain yield of the four hybrids was generally higher in zero-tilled plots in comparison to conventional or minimum tillage systems. These observations support the use of zero-tillage for maize production. Data also show that FAW infestation at 4–5 leaf stage caused grain yield reduction of 10–13% across all tillage systems in the tropical environment but in a subtropical environment, yield reduction was only 1–2%. Grain yield of the hybrids Ki3×CML139 and Ki3×CML69 was affected by SCB infestation in all the tillage systems but that of CML67×135 and Ki3×CML131 was not affected. SWCB infestation on the hybrid Ki3×CML131 was less in the infested plots but that of remaining hybrids was the same in infested and protected plots in different tillage systems. Thus, zero-tillage can be used on community-wide basis to prevent the soil erosion and save our dwindled soil resources.