Seokil Lee Department of Agricultural Economics Oklahoma State University 411 Agriculture Hall Stillwater, Oklahoma, USA
Email: zubair.1300@yahoo.com
Jeffrey Vitale Department of Agricultural Economics Oklahoma State University 418 Agriculture Hall Stillwater, Oklahoma, USA
Email: zubair.1300@yahoo.com
Dayton M. Lambert Department of Agricultural Economics Oklahoma State University 411 Agriculture Hall Stillwater, Oklahoma, USA
Email: dayton.lambert@okstate.edu

Abstract:

Sugarcane aphids Melanaphis sacchari (Aphididae: Hemiptera) cause significant economic damage to sorghum production. This study measures the effects of weather, geographic, and biological characteristics of sugarcane aphid (SCA) on the infestation of sorghum fields in Oklahoma. Infestation likelihood curves suggest there is a difference in the infestation probability between the high- and low-density wing/un-winged sugarcane aphid groups. The larger the ratio of winged to un-winged sugarcane aphid, the more likely their movement to other sorghum fields. Proportional hazard regression results affirm that weather is an important factor in determining infestation hazards. This study uses information on field-level infestations of sorghum by sugarcane aphis. Data were collected by scouting sorghum fields for SCA infestation during the 2017 growing season in Oklahoma. Field location, the distance between sampled fields, and the day SCA were observed was recorded. Field location and the distance between sampled fields was not a significant factor affecting the likelihood of field infestation. The total population of sugarcane aphid per plant in the most recently infested field was negatively correlated with infestation hazard. These findings may contribute to development of early warning infestation alarms through the coordination of farm-to-farm pesticide use and harvest timing. Increased investments in real-time pest monitoring including on-farm detection, report transmission, and forecasted movements could improve the accuracy of early warning SCA system for producers, thereby mitigating the negative economic impacts caused by infestation.

Keywords:Geography, precipitation, sorghum, sugarcane aphids, temperature, time-to-infestation.