Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/7/2007
Publication Date: 12/12/2007
Citation: Derksen, R.C., Vitanza, S., Welty, C., Miller, S., Bennett, M., Zhu, H. 2007. Field Evaluation of Application Variables and Plant Spacing for Bell Pepper Pest Management. Transactions of the ASABE. 50(6):1945:1953. Interpretive Summary: Successful bell production depends on the appearance of the fruit, fruit size, and overall yield. Little information exists on how different application methods influence pest control, especially in different production schemes. The objective of this research was to determine the effect of plant population density and pesticide application techniques on spray deposition in a pepper canopy. Air-assist, low-drift (air-induction), conventional, and electrostatic nozzles were used in theses field studies at different travel speeds to determine the quantity and quality of spray deposited on foliage and fruit. Foliar spray deposits were lower in the more dense canopies of twin-row plantings than single-row plantings. Despite differences in atomization characteristics, the performance of the twin-fan and air-induction treatments were similar. Air-assisted delivery provided no advantage in the amount of spray retained on the foliage. The twin-fan nozzle and air-induction nozzle treatments deposited the greatest amount of spray material on foliage in the middle area of the canopy. However, air-assisted delivery resulted in more spray being deposited on fruit, higher foliar spray coverage, and higher dried droplet density on foliage lower in the canopy and on the lower leaf surfaces. Travel speed between 6.44 and 12.87 km/h did not significantly affect sprayer performance; however, differences could be expected in taller, denser canopies. This research aids producers in selecting application techniques that put material where it is most needed in pepper pest management and which will reduce costs and the impact on off-target areas and help ensure high quality and yield pepper production.
Technical Abstract: Pepper production in Ohio is affected by several insect and disease pests. Previous studies have documented that higher plant population densities usually result in greater pepper yields; however, there is little information on the interaction between pesticide efficacy and yield. The objective of these studies was to determine the effect of pesticide application techniques and plant stand density spray deposits in the pepper canopy. Application techniques evaluated included conventional nozzles, low-drift (air-induction) nozzles, air-assist delivery, and charged sprays. 2004 field trials examined the effect that travel speed had on spray deposits on the pepper plants. The 2005 field trials included three different application techniques, two within-row spacings, and three population densities. Foliar spray retention was lower in twin-row plantings compared to single-row plantings. Spray retention in the middle and the bottom of the canopy was similar for air-induction and twin-fan nozzle treatments. The air-assist sprayer produced the highest spray deposits on fruit compared to conventional treatments. The air-assist sprayer also produced significantly higher spray coverage deeper in the canopy and on underside leaf surfaces. There were no significant differences in foliar spray deposits between treatments applied at 6.44 and 12.87 km/h. These results indicate that plant population can affect canopy penetration and deposits lower in the canopy. Producers can use these results to choose application techniques that put material where it will be most efficacious and which reduce the impact of vegetable pesticide applications on the off-target environment.