Year: 2005
Type: dissertation
Abstract: Pesticides comprise a large portion of production inputs in cotton. Reducing or\nenhancing their efficacy presents an avenue to increase profit. Pesticides containing\nboth insecticidal and growth enhancing properties may be a viable option to increased\nprofitability. In cotton (Gossypium hirsutum L.), early season applications of some\ninsecticides have shown effects similar to those of plant growth regulators (PGRs).\nTRIMAX?? (imidacloprid) is one of these purported PGR insecticides. TRIMAX?? and\nCentric?? 40WG (thiamethoxam), both nitroguanidine insecticides, have properties that\nmay exhibit PGR activity.\nA two - year field study was conducted at the Texas A&M Agricultural\nExperiment Station in Burleson County, Texas to assess the physiological effects of\nCentric?? 40WG and TRIMAX?? on cotton. The statistical design consisted of a\nrandomized complete block with four replications. Treatments consisted of each\ninsecticide being applied one, two, and three times at the 5- leaf stage, 5- leaf stage plus\n10 days after initial treatment (DAIT), and 5-leaf stage plus 10 DAIT plus 20 DAIT.\nRates consisted of TRIMAX?? and Centric?? 40WG being applied at 0.020 and 0.017\nL/ha, respectively. Data was collected for plant height, total number of nodes, biomass\npartitioning, photosynthetic rate, midseason plant mapping, end of season box- mapping,\nyield, and fiber quality analysis.\nNo significant differences in lint yield were observed among any of the\ninsecticide PGR treatments. There was a general trend for numeric decreases in lint\nyield with each additional insecticide application for both chemistries, with the\nexception of TRIMAX?? at three applications in 2004. No significant differences were\ndetected in any of the growth parameters that were measured (height, total nodes,\nbiomass partitioning, and leaf area). Numerical differences resulted in trends, but rate\nresponses did not follow any logical pattern. Numerous trends and rate responses were\nalso observed in the Absolute and Relative Growth Rates, and photosynthetic rates, but\nno significant differences were evident. In general, as more insecticide was applied, the\nphotosynthetic rates decreased along with lint yield.\nBased on the parameters investigated during the course of this two-year study,\nthere is no conclusive evidence that supports TRIMAX?? or Centric?? 40WG as being\ngrowth and or yield enhancers in cotton.
Author: Cy Christopher McGuire
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: green
OpenAlex ID: W2754906020