Peanut Disease Management Reports

Late leaf spot pressure was moderate in the trial (approximately 95% defoliation in the untreated check and 8% defoliation in the Bravo WS program). All fungicide programs resulted in significantly less late leaf spot % defoliation than the untreated control. The grouping with the second highest amount of defoliation included Priaxor + Provost Opti + Bravo WS, Headline + Convoy + Bravo + Topsin, and Bravo + Tebuzol + Aprovia, whereas all remaining treatments not including the untreated control were in the lowest grouping for defoliation. Incidence of stem rot was very low (less than 3%) across the trial, and no significant differences were observed among treatments. Poor plant health and non-target diseases confounded stem rot rating in the untreated control and as such this was excluded from the analysis. All fungicide programs resulted in a significant increase in yield compared to the untreated control. No phytotoxicity was observed in the study. ...

Late leaf spot pressure in the trial was moderate (approximately 69% defoliation in the untreated check and 20% defoliation in the Bravo WS program). All fungicide programs resulted in significantly less late leaf spot defoliation than the untreated control. Three of the five plots for the Bravo WS + Proline + Provost Opti treatment were within one plot’s distance from an untreated plot, which plausibly contributed to the amount of defoliation observed in this treatment not being significantly different from the program with two Headline applications as reduced strobilurin (Headline) efficacy has been observed in South Carolina in recent years. Stem rot pressure was moderately low in the trial. Stem rot incidence in the untreated control was excluded from the analysis due to confounding diseases and poor plant health that interfered with stem rot rating. Incidence of stem rot was lowest on peanut receiving Bravo WS + 3 applications of Lucento + Folicur. All treatments resulted in a significant increase in yield compared to the untreated control. Yield was highest from peanuts treated with Bravo WS + Proline + Provost Opti + Folicur + Elatus. However, this treatment did not result in a significant increase in yield over those of the fungicide programs with Lucento applications. No phytotoxicity was observed in the study. ...

Late leaf spot pressure was low in the trial and defoliation did not exceed 6% in any treatment. Stem rot incidence was not observed to exceed 8% in all fungicide programs and did not significantly vary among treatments. Yields were relatively similar (between 5250 and 5890 lb/A) among all fungicide regimes and did not separate out statistically. No phytotoxicity was observed during the course of the study. ...

Characteristically, Thimet treatments had the most apparent phytotoxicity compared to other treatments. Thrips damage was significantly different among treatments 7 Jun (P < 0.0001) but were low overall. Tomato spotted wilt pressure was low overall and did not develop to substantial amounts in the trial (all treatments <5%). Stem rot was also low overall (<4%). Yield did not vary among treatments (P > 0.05). The replication outside of the irrigation area yielded substantially lower compared to irrigated replications due to considerable mid-season drought, but since the response was consistent across the replication, the data was not excluded from the analysis. Data from the trial does not support an obvious benefit to combined and concurrent in-furrow application of phorate (Thimet) and imidacloprid-based (Admire Pro or Velum Total) treatments. ...

Phytotoxicity responses were low (< 6%) and were characteristic of Thimet. Thrips pressure was low overall in the trial. All treatments exhibited significantly less spotted wilt stunting compared to the untreated check. The second highest grouping for spotted wilt stunting contained most remaining treatments, except for the half rate of Admire Pro + Thimet, Thimet + polymer, and Thimet (< 6% incidence). Stem rot incidence was moderately low and did not significantly vary among treatments (P > 0.05). Except for Thimet followed by Orthene at cracking, all treatments had significantly greater yield than the untreated check. More than half of the treatments were in the upper grouping for yield (>5170 lb/A). Data from the trial does not support a benefit to combined and concurrent in-furrow application of phorate (Thimet) and imidacloprid-based (Admire Pro or Velum Total) treatments. ...

Late leaf spot pressure was moderate in the trial (approximately 90% defoliation in the untreated check but numerically substantially less defoliation observed in the Equus check). While not statistically significant, all fungicide programs had lower defoliation compared to untreated check. Stem rot pressure was absent from the trial. All treatments exhibited significantly greater yield than the untreated check. Except for the treatment with Equus 16 fl oz (timing 1-5) + Equus 24 fl oz (timing 6) + Acropolis 17 fl oz (timing 1) + Orius 7.2 fl oz (timing 2-5) and untreated check, all remaining treatments yielded in the upper statistical grouping. No phytotoxicity was observed in the study. ...

Most fungicide programs resulted in low late leaf spot incidence corresponding to < 11% incidence (lowest statistical grouping). While some S2399 treatments (Bravo WS + 2 applications of S2399 4 fl oz and Bravo WS + 3 applications of S2399 2.65 fl oz at timing 1, 3, and 5) had statistically greater late leaf spot incidence than this lowest grouping, the treatment observed with the highest late leaf spot incidence included four applications of Convoy. Late leaf spot defoliation on 26 Sep was not significantly different among treatments. However, the general trend as seen with the previous disease incidence rating can be seen with the defoliation rating, in which the Convoy treatment had the numerically highest % defoliation. While numerically lower, the Bravo WS + Tebuconazole and Bravo WS + Convoy treatments were not significantly different from the Bravo-only control, in which each had > 32% stem rot incidence. Except for the Bravo WS + 2 applications of Elatus program, all remaining treatments were in the lower statistical grouping. The numerically lowest treatment was Bravo WS + 4 applications of S2399 2 fl oz, followed by Bravo WS + 3 applications of Elatus and several S2399 treatments, notably the Bravo WS + 2 applications of S2399 4 fl oz, and two programs of Bravo WS + 3 applications of S2399 2.65 fl oz (at timings 1, 3, 5 and 3, 4, 5) (stem rot incidence < 18%). The program with Fontelis was at the upper end of the lower statistical grouping and was comparable to the Bravo WS + Provost + Convoy program. As overall late leaf spot defoliation levels were managed to a fairly low level, treatment yields closely followed corresponding stem rot incidences. All treatments had significantly greater yield compared to the Bravo check. While not statistically different, the Convoy program had numerically less yield than the Bravo WS + Tebuconazole program. All S2399 programs were in the upper grouping for yield (yield > 4000 lb/A) with the numerically highest yield noted from the Bravo WS + 4 applications of S2399. Results from this trial support S2399 being a competitive stem rot product compare to Elatus applied at 7.3 oz/A and a more effective product compared to Fontelis or Convoy applied at 16 fl oz/A or tebuconazole. ...

On 17 May, the untreated control had the most thrips damage, whereas the AgLogic treatment had the least thrips damage. The same general trend was observed in the latter two thrips damage ratings, with Admire Pro + Radiant and Thimet + Orthene having the lowest damage ratings during the final assessment. Radiant, Orthene and Exirel performed fairly similar with regards to thrips damage. For TSW stunting, there was some drought stress during the 7 Sep rating which confounded ratings during that time; thus the second rating would generally be regarded as more representative. During the second TSW rating, the statistically lowest TSW stunting was observed in the Thimet treatments, as well as with AgLogic. The grouping with the most stunting was made up of the imidacloprid-based treatments (Admire Pro and Velum Total), as well as the two-broadcast-application Exirel treatment. The inclusion of the Aquasorb marginally increased stunting with Admire Pro and marginally decreased stunting with Thimet, though these differences were not significant. There was a fair amount of variability in the yield data from this study. The numerically highest yielding treatment was Thimet + post-emergence Orthene, followed by Thimet + Exirel at crack and then AgLogic. Also in the upper grouping were the repeat treatments of Radiant and Exirel, Admire Pro + Aquasorb (which was not statistically different from Admire Pro alone) and Admire Pro + Orthene. The untreated control also fell into the upper statistical grouping for yield. The lowest yielding grouping was comprised of Velum Total, Admire Pro, two applications of Orthene, Thimet + Aquasorb (which was not statistically different from Thimet alone), and Admire Pro paired with either Exirel or Radiant approximately 21 days after planting. ...

The trial was exposed to moderate thrips and tomato spotted wilt pressure. Emergence of Thimet and AgLogic treatments were not significantly different from the untreated check, whereas Admire Pro and Velum Total exhibited significantly less emergence than this previous group. The untreated control had the most thrips damage, whereas the AgLogic, Velum Total, and Admire Pro treatments had the least. There was some drought stress during the 7 Sep tomato spotted wilt rating which confounded ratings and resulted in lower levels of infection than observed during the 5 Jul rating; thus, the earlier rating would be regarded as somewhat more representative. During the first rating, the statistical grouping with the most TSW stunting included Admire Pro and Velum Total. Thimet was associated with the least stunting, though this was not statistically different than the untreated check. AgLogic exhibited significantly more stunting than Thimet but was not statistically different compared to the check. During the second rating, the imidacloprid (Admire Pro and Velum Total) treatments were not significantly different from the untreated check or AgLogic. Overall yields were low in this field, despite having a strong fungal disease management program and irrigation. It is not clear why yields were low, though they were also low in an adjacent separate test. ...

Thrips and TSW pressure was moderate in the trial. All treatments had significantly higher yield and significantly less thrips damage than the untreated check. Phytotoxicity was observed as leaflet chlorosis characteristic of Thimet. The untreated control had the highest TSW stunting, which was statistically similar to Thimet + Exirel banded at 4.26 fl oz/A. The lowest TSW stunting was within the grouping containing Thimet + one broadcast application of Exirel, Thimet alone, and Thimet + one banded Exirel application at 13.5 fl oz/A. Plants were noticeably drought stressed during the 7 Sep TSW stunting assessment, thus, the previous assessment is likely more representative. It is uncertain why yield overall was low across treatments in this irrigated trial. Another separate trial in the same field, however, similarly had relatively low yields. The only treatment sharing the lowest statistical grouping with the untreated control was Thimet + two Exirel 13.5 fl oz/A banded applications. Within this 2-replication trial, there did not appear to be a marked benefit to using the concentrated band application of Exirel. Similarly, within this study the different application methods of Exirel did not statistically surpass the Orthene treatment (current industry standard post-emergence insecticide). ...

Leaf spot pressure was fairly high and stem rot pressure was moderate in the trial. The treatments with Miravis had the least leaf spot defoliation (< 6%). The only treatment with a statistically similar reduction in defoliation was the Propulse + Aquasorb + Bravo + Provost Opti program. Inclusion of Aquasorb in a program did not significantly affect defoliation levels. The Bravo-only standard treatment had the highest percent defoliation, which was statistically similar to the Bravo + Elatus program. Overall, Propulse in-furrow contributed to reductions in defoliation due to late leaf spot, as did Provost Opti, though Miravis was clearly the most effective treatment against late leaf spot in the trial. The more effective fungicide programs for reducing stem rot incidence included either Provost Opti or Elatus. Propulse in-furrow or Miravis were not associated with improved stem rot control. The numerically greatest yielding treatment was Propulse + Bravo + Elatus, followed by Propulse + Bravo + Provost Opti. Yield results were influenced by the combination of leaf spot defoliation and stem rot control efficacies of individual programs. For example, the lowest ranking programs were either not effective against stem rot alone or were not effective against stem rot and only moderately effective against late leaf spot; moderate yielding programs either were not effective against late leaf spot but effective against stem rot (Bravo + Elatus), were highly effective against late leaf spot but not against stem rot (Bravo + Miravis) or were moderately effective against both diseases (Bravo + Provost Opti). ...

Leaf spot pressure was negligible in the trial. Under high disease pressure, Elatus (2 applications) and Provost Opti + Convoy (2 applications each) were effective treatments in managing stem rot and yield. Proline at 45 or 60 DAP numerically reduced stem rot incidence compared to the Bravo + Tebuzol standard but had significantly lower yield. The Bunchabugs + Biovate + Calbore treatment was no different from Bravo-only (e.g., did not decrease disease or increase yield), with yield not exceeding 1000 lb/A. ...

The AgLogic treatment was generally associated with the least thrips damage, which was closely followed by imidacloprid-based treatments (Admire Pro and Velum Total). Phytotoxicity, observed as leaflet chlorosis, was highest in the Thimet treatment. The treatments with the statistically lowest TSW stunting were Thimet, AgLogic, or Admire Pro followed by Orthene. Thimet and AgLogic provided the greatest reductions in TSW incidence. The untreated control had the lowest yield, which was not significantly different from imidacloprid-based treatments (Admire Pro and Velum Total) that were not followed by Orthene. Overall with regards to yield and TSW stunting, the phorate- and aldicarb-based treatments (Thimet and AgLogic, respectively) appeared to have a slight performance advantage over imidacloprid-based treatments, though these differences were not always statistically significant. The absence of nematode pressure did not allow for the nematicidal properties of Velum Total and AgLogic to be evaluated within this trial. ...

The amount of thrips damage on 18 May was fairly low; all treatments displayed statistically less damage than the untreated control. By 27 May, thrips damage increased noticeably. The untreated control had the most damage, and the treatments in the lowest statistical grouping that did not overlap with the mid grouping consisted of Admire Pro and Thimet + Orthene. The presence of Thimet was generally associated with increased levels of characteristic phytotoxicity, though the untreated control interestingly was in the upper statistical grouping at 12.3% (this was not observed during the 7 Jun rating). During both tomato spotted wilt stunting ratings, the untreated control was in the upper statistical grouping but was surpassed by greater stunting in the Velum Total treatment. Aside from the untreated control, treatments including imidacloprid (Admire Pro and Velum Total) had the highest levels of stunting, and treatments containing phorate (Thimet) had the least stunting. Acephate (Orthene) improved tomato spotted wilt control in combination with imidacloprid treatments but did not improve control provided by phorate. Similarly, Vydate + Thimet did not reduce tomato spotted wilt stunting beyond that of Thimet alone. The lowest yield was associated with the untreated control. The grouping with yield significantly greater than the lowest ranking grouping consisted of Admire Pro + Orthene, Thimet + Orthene and Velum Total. Thimet and Velum Total + Orthene were also in the upper most grouping, but their values were not significantly different from those of the lowest grouping. ...

Late leaf spot pressure was moderate in the trial, and the presence of one fungicide application allowed for high levels of defoliation to develop. The most effective treatment observed in this study 26 days after application was Priaxor 8 fl oz/A. White mold disease pressure was low in this trial. Treatment yields did not separate out statistically. ...

Late leaf spot pressure was moderate in the trial. Both varieties benefited from the application of premium fungicides (beyond the industry standard Bravo). White mold disease pressure was low in this trial. While statistical differences were observed between the treatments, the low level of white mold pressure did not provide the most optimal conditions to compare treatment efficacy. Bailey treated with Priaxor at 30 DAP yielded the highest among the treatments. This was statistically similar to programs including Elatus, Provost Opti and Topsin (Sullivan only), Priaxor and Provost Opti (Bailey only). Overall, the programs including premium products were associated with yield increases ranging from approximately 50 to 550 lb/A compared to a basic Bravo + Tebuzol program. The exception to this was how Bailey treated with Proline at 30 DAP yielded approximately the same as the basic Bravo + tebuconazole programs. ...

For both varieties, thrips damage was consistently greatest in the untreated check, with all treatments having significantly less damage. Stunting from TSW was consistently lowest in Thimet-containing treatments and greatest in imidacloprid-containing treatments. Further details focus on the 16 Sep TSW rating. In Georgia 06G plots, the only treatments with significantly less stunting than the untreated check were Thimet + Propulse and Thimet alone treatments. In TUFRunner 511 plots, TSW stunting was 11.4% in the untreated check, which was statistically similar to all other treatments, with the exception of Velum Total, Admire Pro + Propulse, and Admire Pro which had significantly greater stunting. These three treatments, as well as Wrangler, all had significantly more stunting than the Thimet + Propulse and Thimet alone treatments. Phytotoxicity was either 0.0% (TUFRunner 511) or nearly 0.0% (Georgia 06G) for all treatments excluding Thimet. The most phytotoxicity (leaflet chlorosis) was seen in the Thimet followed by Propulse and Thimet alone treatments, which were both statistically more than all other treatments excluding Thimet. For Georgia 06G, yield was significantly greatest in the Thimet + Propulse treatment and least in the untreated control. Admire Pro alone and Wrangler were the only treatments with yields not significantly greater than the untreated control. For TUFRunner 511, yield was also greatest in the Thimet + Propulse treatment and least in the untreated check, though this was not statistically significant. Nematodes were not present to a meaningful degree in any of the fields used for this study. ...

Thrips damage was consistently greatest in the untreated check, with all treatments having significantly less damage. The most phytotoxicity (chlorosis near edge of leaflet) was seen with Thimet followed by Propulse (16.0%), which was statistically more than Thimet alone, Velum Total 18 fl oz/A, and Velum Total 14 fl oz/A followed by Propulse (5.0%, 6.0%, and 8.0%, respectively). Neither did Velum Total nor one of its active ingredient component-related Propulse consistently produce phytotoxicity. Velum Total at 14 fl oz/A had significantly more stunting than the untreated check, and all Velum Total containing treatments had significantly more stunting than the Thimet only treatment, which also had the least stunting. Under the trial conditions, yield was greatest in the Thimet only treatment and least in the untreated control. Treatments with Velum Total had increased yield compared to the check, but this was not significant. ...

The trial site was exposed to moderately high levels of late leaf spot disease pressure. All treatments controlled defoliation to less than 6%. Stem rot pressure moderately high in the test. Approximately 3.4% of the row of the untreated check had other diseases (e.g., Cylindrocladium black rot and Rhizoctonia) that were not further differentiated. All treatments had significantly higher yield than the untreated check. ...

The trial site was exposed to high levels of late leaf spot disease pressure. Late leaf spot disease incidence was 100% on all treatments during both rating dates and as such was not included in the analysis. Stem rot disease pressure was essentially absent from half of the trial site. As such, over interpretation of efficacy of stem rot control is cautioned. The only treatments with significantly less stem rot compared to the untreated check were Bravo 24 fl oz/A + Elatus 7.14 fl oz/A + Induce 0.25% and Bravo 24 fl oz/A + Elatus 9.5 oz/A + Induce 0.25%. Highly variable and low irrigated yields were the result of nearly a month of weathering and deer damage after peanuts were inverted. The most severely deer damaged plots were excluded from the yield analysis (1 plot was severely affected for the following treatments: untreated check, Bravo 24 fl oz/A, Bravo 24 fl oz/A + Convoy 13 fl oz/A, Bravo 24 fl oz/A + Priaxor 6 fl oz/A, Bravo 24 fl oz/A + Orius 7.2 fl oz/A, and Bravo 24 fl oz/A + Elatus 7.14 oz/A + Induce 0.25% v/v 1 plot; 2 plots were severely affected for the following treatments: Bravo 24 oz/A + Provost 10.7 fl oz/A, and Bravo 24 fl oz/A + Abound 12 fl oz/A + Orius 7.2 fl oz/A; and 3 plots were severely affected for Bravo 24 fl oz/A + Elatus 9.5 oz/A + Induce 0.25% v/v). All treatments had significantly greater yield than the untreated check. ...

The trial site was exposed to moderately high levels of late leaf spot disease pressure. All treatments had > 92% late leaf spot disease incidence. All fungicide programs reduced late leaf spot defoliation compared to the untreated check. All treatments with exception of Headline 9 fl oz/A significantly reduced stem rot incidence. Yield was significantly increased compared to the untreated check by all fungicide treatments. In this test, disease management nor yield were not significantly different among Priaxor produced for 2014 and Priaxor produced for 2015. ...

Cylindrocladium black rot (CBR) can cause serious losses of peanuts when severe. This disease is caused by a soil fungus (Cylindrocladium parasiticum) and typically occurs in the same field areas year after year. Crop rotation and variety resistance are two of the best ways to manage this disease (see the Peanut Production Guide for additional details). In greater disease pressure situations, particularly with susceptible varieties, fungicide applications can be very helpful. The below data comparing the effectiveness and cost-returns of different treatments for CBR were shared from work conducted by Mark Crosby, Wade Parker, Bob Kemerait, and Amanda Smith in a nearby site in Midville, Georgia in 2014. While disease pressure was overall relatively light, the choice of which product to use still became important. In this trial, the Priaxor-Bravo-Muscle-Priaxor treatment came out on top providing the most overall benefit. It will be good to compare these results to future trials that have greater amounts of disease pressure. ...

When thinking about trying a new variety, it helps to see how it performed in different trials and situations. The data below is from a collaborative trial between Mr. Wade Parker, UGA Extension Agent, and Clemson University – EREC. These trials were conducted under irrigation in Jenkins County and Midville, Georgia. ...