Cotton variety evaluation with and without Velum Total for root-knot nematode management in south Alabama, 2018

摘要

Ten cotton varieties were evaluated with and without the addition of Velum Total for management of the root-knot nematode Meloidogyne incognita (race 3) at Auburn University's Gulf Coast Research and Extension Center, Fairhope, AL. A control field that was not infested with the root-knot nematode had the same ten varieties planted with and without the addition of Velum Total. Both fields were a Malbis sandy loam soil type (59% sand, 31% silt, and 10% clay). The fields were arranged in a randomized complete block design with five replications. The plots were planted on 9 Jun, and seeds planted at a depth of 2.5 centimeters. Test plots consisted of 4 rows, two treated with Velum Total and two untreated, that were 6.1 meters long with a 1-meter row spacing and a 1.8-meter alley between replications. Velum Total was applied at planting as an in-furrow spray at a rate of 1.02 L/ha to the right two rows of each variety leaving the left two rows untreated. All plots were maintained throughout the season with standard insecticide, herbicide, and fertilizer practices as recommended by the Alabama Cooperative Extension System, and watered as needed with an overhead irrigation system. Nematode population density (eggs/gram of root) and plant biomass were taken 40 days after planting by digging four plants at random for each plot. Extraction of nematode eggs from roots was accomplished by shaking the roots in 6% NaOCl for 4 minutes and collecting the eggs on a 25-um sieve. The test was harvested and yield data were collected on the 30 Nov. Data were analyzed with SAS 9.4 using PROC GLIMMIX and LS-means were compared using Tukey-Kramer's method (P < 0.05).