Recording within-cotton distribution of plant bug injury using plant mapping computer-based tools

Abstract

Plant mapping has been included and evolving in cotton (Gossypium hirsutum L. [Malvales: Malvaceae]) research and management for over 100 years. Here we describe the structure and use of a plant mapping program (PMAPplus) that includes capabilities to record and manage insect injury to fruiting bodies by position and branch, compare it to existing programs (COTMAN and PMAP), and illustrate its use in cotton research that includes an assessment of insect injury. PMAPplus was modified from PMAP to allow entry of additional data on insect injury to squares and bolls and cotton boll rot and to produce output in a numerical and graphical format that can be customized to user specifications. Comparing use side-by-side, protocols of PMAPplus required more mapping time per plant than PMAP and COTMAN due to observing the additional insect injury data. But the added data were found useful in a planting date experiment that included evaluation of verde plant bug (Creontiades signatus Distant [Hemiptera: Miridae]) feeding on cotton that results in injury to bolls and is associated with cotton boll rot. PMAPplus graphical displays and output that was further analyzed statistically indicated that first position bolls in the middle branches of later planted cotton had the higher insect injury scores and incidence of boll rot, despite similar verde plant bug densities occurring on both plantings. The within-cotton distribution of verde plant bug insect injury helped explain the significantly higher yield from the earlier planting than from the later planting that was incongruent with the weekly insect monitoring data alone.