Nitrate Contents in Petioles of Standard and Narrow Row Planted Cotton Under the Low Desert Ecosystem.

Cotton is still an important crop in California’s low desert, particularly Palo Verdi valley, Blythe, Riverside, CA. and the Mexicali valley in Mexico. Growers typically utilize a standard planting system that involve wide beds and hence low cropping densities. There is an increasing interest in a narrow row planting that utilizes narrower bed sizes or planting in two lines over the same standard beds, resulting in high plant densities per cropping area. Research is being conducted at the UC Desert Research and Extension Center (DREC) to evaluate nutrition and yield of three different varieties of cotton having variable growth architecture under both cropping systems. For this particular presentation, we shall only deal with NO3 concentrations in petioles of the different cotton varieties. Cotton plants were sampled for petiole NO? concentrations at 60, 77, 106, and 121 days after planting (DAP), representing square formation, peak bloom, cutout and open boll stages of crop growth, respectively. Our preliminary findings showed that petiole NO? concentration in cotton is affected by plant architectural characteristics and planting systems. All varieties had higher NO? concentrations when planted under standard cropping system than under the narrow row spacing, but some are affected more than other varieties. Key words: cotton, narrow row cotton, standard plating, cotton architecture, petiole nitrate ______________________1Agronomy Advisor, UC Cooperative Extension imperial county. 2PhD student at UABC and visiting Scholar at UC Cooperative Extension imperial county 1Abstract of a presentation. Agronomic Society of America (ASA), November 6-9, 2016. Phoenix, AZ