Reniform nematode (Rotylenchulus reniformis Linford and Oliveira) currently infests about 36% of the Mississippi G. hirsutum acres causing economic losses of $130 million annually. For more than 40 years nematodes, including R. reniformis, have been managed using an at-planting treatment of Temik 15G or with soil fumigants like Telone II. With the label loss of Temik 15G and expense of soil fumigants, there is a need to develop an integrated nematode management program centered around nematicide seed treatments (NST) with and without foliar applications of Vydate C-LV. In addition there is a need to better understand how new cotton cultivars provide improved growth, development and yield in nematode infested fields. Results from research at Auburn and Mississippi State Universities revealed tested varieties responded positively to NST and improved growth and yield without NST was variety specific especially early in G. hirsutum development (between nodes 1-9). Cutivars Phy 499, FM 1740 and Stv 5458 showed the greatest nematode tolerance while Phy 375 WRF had the least tolerance, benefitting greatly from NST. Trials involving NST with and without Vydate C-LV indicated yield of plants treated with Temik 15G was greater than plants treated with NST treatments. Aeris + Votivo with and without Vydate C-LV provided better plant growth and yield than Aeris alone or with Vydate C-LV. Relative to yield Vydate C-LV treatments increased pounds of lint cotton/acre across all treatments. There were no differences in fruit retention at fruiting site one during the square period with fruit loss primarily occurring between bloom and open boll. Vydate C-LV treatments increased overall fruit retention compared to all nematicide seed treatments making them comparable to Temik 15G.

Upland cotton (Gossypium hirsutum ) is an important fiber crop grown throughout the southern United States. Plant-pathogenic nematodes are worm-like animals that feed on the roots of most agronomic crops, including cotton. The southern root-knot nematode (Meloidogyne incognita, RKN) and the reniform nematode (Rotylenchulus reniformis, RN) cause significant yield losses in cotton every year. Current sources of resistance are effective but limited, therefore historical screenings of cotton accessions were revisited in search for novel resistance sources. None were identified but many of the screened accessions possessed markers of known root-knot nematode and reniform nematode resistance. The emerging guava root-knot nematode (Meloidogyne enterolobii, GRKN) is a risk for upland cotton production, and identifying host plant resistance would greatly reduce the yield losses for growers. Assays were conducted on the currently available RN and RKN resistance sources inoculated with GRKN. No known nematode resistance gene suppressed GRKN infection, indicating that work must be done to protect crops from the eventual discovery of GRKN in Mississippi fields. Using the same resistance sources, tests were conducted to determine if the currently available resistances to RKN and RN offer any suppression of secondary infection of non-target nematode species for resistance. This is referred to as systemic acquired resistance, which is the induction of non-specific plant defense. Assays found that early inoculation with the nematode targeted by resistance did not effect infection by a secondary nematode species.

Cotton ( Gossypium hirsutum ) growth, development, and yield can be limited due to reniform nematode and bacterial blight infestation. Studies were conducted in 2016 and 2017 to evaluate the profitability of a soil fumigant application, seed treatments, and in-furrow nematicides to protect cotton from nematode infestation as well as inoculation of bacterial blight at various growth stages in cotton to determine effects on yield. Research was conducted by applying various combinations of nematicides to cottonseed at planting and a fumigant prior to planting. Bacterial blight was conducted by inoculated on cotton at multiple growth stages throughout the year. Based on the results of these studies, a seed treatment plus in-furrow application should be applied at planting in nematode infested fields to increase yield and economic returns in cotton. Bacterial blight infestation was greatest when inoculated at pinhead square in cotton.