Spring 2020 nematicide treatments (same treatments as in spring 2019) occurred during mid-April to late May. The timing was later than optimal due to the covid-19 lockdown. As done for the fall treatments, all liquid nematicides except oxamyl (which was sprayed by hand during the final third of the irrigation cycle) were injected for two hours, beginning 30 minutes after irrigation began and ending a half hour before the irrigation run ended. Nematicide effects on nematode populations were measured in July, as previously described. The average number of sting nematodes in aldicarb plots was 20% higher (NS) than that in untreated plots, whereas oxamyl plots had 68% fewer sting nematodes (P<0.05) than in untreated plots. Nematode numbers in the plots treated with the other nematicides ranged from 51%-82% of that in untreated plots, none of which were significant differences. The average cumulative numbers of sting nematodes measured 60 days following each of the three seasonal applications thus far during the project (areas under the curve) were 63%, 62%, 34%, 29%, and 6% lower than those in untreated plots for the Syngenta compound, oxamyl, Nimitz, Salibro, and Velum Prime, respectively. Sting nematodes in aldicarb treated plots were 18% more numerous than in untreated plots.Average fibrous root mass density for all nematicide treatments ranged between 10%-77% greater than for non-treated plots. Roots were significantly more abundant on trees treated with oxamyl, and both combinations of Salibro and the Syngenta material than those of untreated trees. The growth of the tree trunks during 1.5 years between February 2019 and July 2020 was 29% greater for trees treated with oxamyl than that of untreated trees (Dunnett, P<0.05). Growth rates of trees treated with other nematicides were between 1-13% greater than the untreated trees, but the differences were not significant. There was a strong inverse linear relationship (r= -0.35, n=56, P=0.01) between trunk growth during 1.5 years and the average sting nematode population density (log-transformed) during that time. In a second trial comparing untreated trees to trees treated with aldicarb in April 2019 and 2020, there were no differences in the trunk cross-sectional areas of either treatment at 15 months after the first treatment (untreated=1988 mm2 vs aldicarb=1973 mm2). Although young tree growth in this grove is very uneven, the cause(s) may be other than sting nematodes which were below detectable levels in most plots.In the perennial peanut trial, an incursion of weeds was noted in several peanut plots. Sting nematodes in those plots were significantly fewer in July 2020 (13.3 nematodes per 250 cm3 soil) than in the row middles with native vegetation (28.3 nematodes) but signifcantly more numerous than in pure stands of peanut (1.6 nematodes). Oxamyl reduced sting nematodes in the citrus rows by 55% compared to untreated plots (17 vs 37 nematodes per 250 cm3 soil; P=0.10). The tree girth was 15% greater in the oxamyl treatment, and 10% greater in the peanut treatment than in untreated plots, but the differences were not significant. There continued to be a strong inverse relationship between the size of the tree trunks and the (log) numbers of nematods in July 2020 (r= -0.63, P=0.01).