Recoverability of Upland Cotton Following Terminal Removal At Various Growth Stages

Many natural occurrences have the potential to reduce crop productivity by causing damage to cotton terminals at various stages of growth and development.  Mechanical damage to terminals from crusting, sandblasting, insect damage, deer feeding, and severe weather events can cause damage to stems and foliage at various stages of crop development.  More specifically, hail damage is the most common cause of terminal damage and is capable of causing light to severe damage to many crops including cotton.  The objective of this study was to determine the response of cotton to terminal removal at different stages of cotton growth and development.  A replicated field trial was conducted at the Pee Dee Research & Education Center located in Florence, SC in 2011 and 2012.  Treatments consisted of 16 different growth stages of terminal removal based on nodal development.  Terminals were removed at various stages at node 2, 4, 6, 8, 12, 16, and 20.  An untreated check was also included, and treatments were imposed on dryland and irrigated cotton.  Plots consisted of 4 rows, spaced 38 inches apart and were 40 feet long. PHY 499WRF was planted with a John Deere 1700 Vacuum planter at a rate of 4 seed per row foot. Plots were arranged as split plots in a randomized complete block design with four replications. Irrigation or dryland were main plots, and the 16 terminal removal treatments were sub-plots.   Data collected included above-ground plant dry matter at peak bloom, and a final plant map at the end of the season. At season’s end, the middle two rows of each four row plots was machine-harvested.