In-furrow Application Research Articles

In-Furrow Application of Biologicals for Control of Rhizoctonia Diseases in Snap Bean

Florida ranks first in the production of fresh-market snap bean in the United States. Rhizoctonia diseases, including damping-off and root rot caused by Rhizoctonia solani, are important diseases in snap bean, particularly if there is heavy rainfall during the first month after seeding. Growers usually use seeds treated with fungicides to control soilborne pathogens including R. solani. However, there are concerns about resistance development in R. solani and the impacts of chemicals on the environment. In this study, three biological products (Howler, Theia, and Double Nickel LC) applied as an in-furrow spray at seeding and/or foliar sprays after emergence were evaluated in the field for their efficacy in controlling R. solani on snap bean. When nontreated seeds were used, Howler at 5 lb./acre and Double Nickel LC at 16 fl. oz./acre each applied as an in-furrow spray at seeding significantly ( P < 0.05) reduced disease incidence compared with the untreated control. However, weekly foliar sprays after emergence showed effectiveness in disease reduction only at a high inoculum level. The highest disease reduction of 95.4% was observed in the treatment with Howler at 5 lb./acre in the 2022 trial, and 32.8% for Double Nickel LC was observed at 16 fl. oz./acre in 2023. Both biologicals also significantly increased the pod yield, by 85.6% with Howler in 2022 and doubled by Double Nickel LC in 2023 when compared with the untreated control. Results from these field trials reveal the potential of these biologicals in the control of Rhizoctonia root rot in snap bean production.

Assessing Seed Treatments to Control Sudden Death Syndrome Caused by Fusarium virguliforme and Seedling and Root Disease Caused by Rhizoctonia sp. on Mungbean (Vigna radiata)

There is growing interest in producing mungbean ( Vigna radiata L. Wilczek) in the United States, which is driven by increased consumer demand. Strategies are needed for United States farmers to take advantage of this high-value crop and its environmental sustainability. Recommendations for the management of mungbean seedling and root diseases are lacking. Preliminary research in central Iowa mungbean fields from 2019 to 2023 has shown that mungbean is particularly vulnerable to Fusarium virguliforme, the cause of soybean sudden death syndrome (SDS), and Rhizoctonia sp., the cause of damping-off, root decay, premature defoliation, and pod abortion. The purpose of this study was to screen a variety of fungicides as a seed treatment or a soil band application to control root rot in mungbean. We performed three field studies over 2 years using mungbean cultivars Berken and OK2000. Seed treatments Evergol Energy + fluopyram and Evergol Energy + pydiflumetofen showed the highest performance ( P < 0.05), with approximately 30% more healthy roots than nontreated controls. Other treatments exhibited about 20% more healthy roots than the nontreated control. Biotam in-furrow application showed the highest plant population for ‘OK2000’, but we observed no treatment differences in plant stand for ‘Berken’.

Cyclobutrifluram (TYMIRIUM® technology): Low risks of a soil applied nematicide and fungicide to non-target soil invertebrates and bees

Cyclobutrifluram (TYMIRIUM® technology) is a seed- and soil-applied nematicide and fungicide which protects the plant root mass. Cyclobutrifluram acts by inhibiting mitochondrial complex II electron transport and succinate dehydrogenase inhibition (SDHI). Concerns over the potential adverse effects on non-target species were addressed by assessing whether recommended field application rates of cyclobutrifluram would result in adverse impacts on soil invertebrates or honeybees. Studies conducted under laboratory conditions with the active ingredient and two formulations provided No Observed Effect Concentrations for earthworm (Eisenia andreii) reproduction of 71–171 mg a.i./kg dry soil with no effects on soil mite (Hypoaspis aculifier) reproduction. There were no effects on honeybee (Apis mellifera) adults or larvae following chronic exposure to doses up to 400 and 160 mg/kg diet respectively. Using Brazil as a target market (soybean seed treatment and in-furrow application in fruiting vegetables), our laboratory studies indicate that the risk to two species of soil invertebrates and honeybees of the use of cyclobutrifluram either in-furrow or as a seed treatment was orders of magnitude below any levels of concern.

Comparison of Field Performance of Georgia-16HO and Florunner Cultivars in the Presence of Tomato Spotted Wilt

Field experiments were conducted at Tifton, Georgia from 2019 to 2020 to compare the effects of new peanut (Arachis hypogaea L.) cultivar ‘Georgia-16HO’ with the former industry standard cultivar ‘Florunner’, and in-furrow applications of phorate or imidacloprid insecticides on severity of tomato spotted wilt (TSW) caused by Tomato spotted wilt virus (TSWV), resultant yield, and crop value. Incidence of TSW was much lower for Georgia-16HO than for Florunner in both years, with differences more obvious in 2019 when the virus pressure was higher. Yield was greater for Georgia-16HO than Florunner in both years with greater differences when disease pressure was higher. Across all treatments, adjusted crop value for Georgia-16HO was ~$1450 /ha greater than for Florunner in 2019 and ~$839 /ha greater in 2020.

Evaluation of fluopyram for disease and root knot nematode control along with yield response on peanut

Efficacy of in-furrow application of fluopyram + imidacloprid alone or followed by fluopyram + prothioconazole at-pegging and aldicarb for managing peanut root-knot nematode populations, root and pod galling due to nematodes, and yield, along with non-target effects on leaf spot diseases and stem rot were compared on the root-knot susceptible cultivar Georgia-06G over seven years on an irrigated site with an established population of Meloidogyne arenaria race 1. In all years, fungicides were applied to all plots following a Peanut Rx application schedule. Root-knot nematode populations, nematode damage, and yield along with leaf spot severity and stem rot incidence significantly differed among years; except for nematode populations, these measured variables also differed by nematicide treatment. Averaged over years, galling and root damage was significantly reduced with aldicarb compared to the no-nematicide control but not with either of the fluopyram treatments. While similar late-season root-knot nematode populations were noted for all nematicide programs and the non-treated control, pooled over years, significant yield gains were obtained with aldicarb and fluopyram programs with the two-treatment program providing greater yields than the aldicarb treatment. Leaf spot severity, averaged over years, was similar in aldicarb and control treatments; however, both fluopyram treatments had significantly lower leaf spot severity than the aldicarb treatment. Stem rot incidence did not differ among nematicide treatments. In addition, pooled over years, there was a negative relationship between juvenile populations and yield, but this was relatively weak. Weather, particularly extreme rain conditions, impacted yield directly as well as indirectly by affecting leaf spot severity and nematode activity.

Burkholderia spp.-based biopesticide controls wireworms (Coleoptera: Elateridae) in potatoes.

Wireworms (Coleoptera: Elateridae) are economically significant pests of potatoes (Solanum tuberosum), damaging the marketable portion of the crop by feeding and tunneling into tubers. While conventional potato growers use the few registered synthetic insecticides to control wireworms, certified organic growers are left with less options due to the limited effectiveness of the available insecticides. Biologically derived pesticides provide an additional alternative for both systems. Certain gram-negative proteobacteria, such as Burkholderia spp., possess insecticidal compounds. However, very little is known about their efficacy on wireworms. From 2018 to 2021, we conducted experiments in Virginia to assess the efficacy of a Burkholderia spp.-based commercial pesticide, Majestene, as a wireworm control in potatoes. In a lab experiment, soil drench application of this insecticide at a rate of 66 g a.i. per 1 liter resulted in 30% wireworm mortality and significantly reduced wireworm feeding damage on potato tubers. In the field, in-furrow applications of Burkholderia spp. at a rate of 17.66 kg a.i. per ha significantly reduced wireworm damage to tubers in 2 of 7 field experiments conducted. By comparison, the commercial standard insecticide, bifenthrin, significantly reduced tuber damage in 3 of the 7 field experiments. Our study demonstrates the prospect for proteobacteria-derived insecticides for control of wireworms and potentially other soil-dwelling insects. In conclusion, findings present growers with another option to combat wireworm pressure, especially in organic systems.

Evaluation of fumigant and non-fumigant nematicides for management of Rotylenchulus reniformis on sweetpotato.

Reniform nematode (Rotylenchulus reniformis) is a major pest of sweetpotato in many production regions in Southern United States. Applying soil fumigants and non-fumigant nematicides are the primary management strategies available to growers. This study compared the relative efficacy of nematicides (1,3-dichloropropene, fluopyram, oxamyl, fluazaindolizine, aldicarb, Majestene, and fluensulfone) for management of reniform nematode on sweetpotato. Fumigating soil with 1,3-dichloropropene consistently reduced soil population densities of reniform nematode at the time of planting in both trial years (31 - 36% reduction relative to the untreated control); however, the duration of suppression varied greatly by growing season. A similar trend was observed with fluopyram (56 - 67% reduction) and aldicarb (63 - 65% reduction), which provided season-long suppression of reniform nematode population development in 2021 but had no impact in 2022. In 2021, nematicide application had no impact on yield; however, in 2022, oxamyl and aldicarb increased the yield of U.S.#1 grade sweetpotato. Overall, soil fumigation with 1,3-dichloropropene and in-furrow application of fluopyram and aldicarb provided the most consistent suppression of reniform nematode on sweetpotato.

Management of Melanaphis sorghi (Hemiptera: Aphididae) in grain sorghum with early planting and in-furrow flupyradifurone application

Melanaphis sorghi is a key pest of sorghum production across the southern USA, where it causes serious damage that can lead to 100% grain yield loss in severe situations. Studies aiming to refine IPM strategies are crucial to improve management of this invasive pest. Here, the authors investigated the impact of planting date and insecticide application methods, including in-furrow vs. foliar applications, on M. sorghi infestation and grain sorghum yield. Field trials with four insecticide treatments (untreated, flupyradifurone in-furrow at 117 g/ha, flupyradifurone in-furrow at 146 g/ha, and flupyradifurone foliar at 73 g/ha) and two planting dates (mid-April to early May = early planting and late May to early June = late planting) were conducted on grain sorghum at Tifton, Georgia and Florence, South Carolina, in 2020 and 2021. Generally, early planted sorghum supported higher aphid density and severity of infestation as evident in the greater cumulative insect days in early planted sorghum in both Florence and Tifton. While a single foliar insecticide application immediately reduced infestations below the economic threshold, the lower rate in-furrow insecticide application significantly suppressed aphid density to near zero levels. These results suggest that foliar insecticide applications suppressed aphid densities, but were less consistent compared to in-furrow applications. Early planting dates and in-furrow insecticide treatments resulted in highest grain yield in both study locations. These data strongly suggest that planting early and using an in-furrow insecticide is the most consistent way to suppress M. sorghi infestations and improve grain yield in sorghum production in southern USA.

Impact of in-furrow fertilizers on winter wheat grain yield and mineral concentration

AbstractPlacement of fertilizer in the seed furrow to increase nutrient availability is a common practice in row-crop production. While in-furrow application of fertilizer is widely utilized in the production of winter wheat (Triticum aestivum L.), there is a lack of work evaluating new formulations and nutrient combinations that are available. The objective of this study was to quantify the effects of in-furrow fertilizer products and combinations of products on winter wheat grain yield, nitrogen and mineral concentrations. Trials were conducted across five site-years in central Oklahoma using 11 fertilizer formulations placed in-furrow at the time of planting. In locations that soil test phosphorus (STP) levels or potassium were above sufficiency, the use of in-furrow fertilizers did not improve yield over the control. Inconsistency of response was noted at locations where STP levels were below the critical threshold. While one location showed no response to the addition of P regardless of source, two other locations had significant yield responses from three or more P-containing fertilizers. The addition of both sulphur and zinc resulted in increased yield over the base product at one low STP location. Nutrient concentrations were also influenced in nutrient-limited soils; however, no trends in response were present. Based upon the results of this study, the application of in-furrow fertilizer has the potential to increase winter wheat grain yield and nutrient concentration, when soil nutrients are limiting. As expected the addition of fertilizer when soil test levels are at or above a sufficiency did not increase grain yield.

RESÍDUOS DE PLANTAS DE COBERTURA E Pochonia chlamydosporia NO CONTROLE DE Meloidogyne javanica EM SOJA

ABSTRACT Pochonia chlamydosporia (Pc) is a nematophagous fungus with saprotrophic activity. However, little is known about the interaction between Pc and green manure. This study aimed to investigate the interaction effects of different green manures and Pc on the control of Meloidogyne javanica in soybean. Two greenhouse experiments were conducted in different periods using a 6 × 2 factorial design, with six replicates. The first factor was green manure application (oat, brachiaria, crotalaria, millet, buckwheat, and untreated control) and the second factor was treatment with Pc (in-furrow application and untreated control). Cover crops were grown separately and applied to pots as green manure 15 days before soybean sowing. At 5 days after sowing, soybean was inoculated with 2 000 eggs and juveniles of M. javanica. At 60 days after inoculation, nematode and vegetative variables were determined. All green manures reduced nematode population levels, especially oat, crotalaria, and buckwheat. Pc treatment did not influence nematode population levels. Soybean plants treated with oat or crotalaria green manure had greater height than untreated plants in both experiments. The effects of factors on shoot fresh and dry weights differed between experiments, and green manure application did not affect root development. The findings confirmed the potential of plant residues to control M. javanica.

The pest control and pollinator protection dilemma: The case of thiamethoxam prophylactic applications in squash crops

A major challenge in sustainable agriculture is finding solutions to manage crop-damaging pests such as herbivores while protecting beneficial organisms such as pollinators. Squash is a highly pollinator-dependent crop that is also attractive to herbivores like the striped cucumber beetle. While synthetic insecticides can provide control of insect pests, they can also affect non-target organisms such as pollinators. Thus, growers need to balance pest management with pollinator protection to ensure optimal yield. Thiamethoxam is a commonly used systemic insecticide that translocates throughout plants, leaving residues in nectar and pollen. The aim of this study was to evaluate whether there are uses of this insecticide that provides efficient pest control while minimizing pesticide pollinator exposure. Specifically, we tested how different prophylactic application methods (seed treatments, in-furrow applications, and early foliar sprays) of commercially available thiamethoxam products impact pest control, bee visitation, yield, and pesticide residues in flowers of squash crops. We found that among the different methods of thiamethoxam application, in-furrow application best prevented defoliation and resulted in the highest fruit weight and number. However, it also produced the most frequent and highest concentrations of thiamethoxam in nectar and pollen, reaching lethal levels for squash bees. Our study provides evidence that under current application methods, thiamethoxam does not provide a sustainable solution for squash growers and further research is required on more efficient pesticide delivery methods, as well as non-pesticide pest control measurements.

In-furrow application of arbuscular mycorrhizal fungi propagules enhanced yields, plant vigor, and biomass accumulation of soybeans (Glycine max) and maize (Zea mays)

Highly weathered soils are commonly found in most crops cultivation sites of Brazil, such as maize and soybean. They impose many challenges for plant growth, such as reduced nutrient availability. Hyphal networks, resulting from mutualistic symbiotic associations between plants and arbuscular mycorrhizal fungi (AMF), could be a viable alternative to improve plant growth and nutrition by enhancing root access to a significantly larger soil surface area, increasing nutrient availability and uptake. Thus, we aimed at evaluating in-furrow applications of propagules from four AMF species to enhance soybeans and maize yields, plant vigor, plant height, and biomass accumulation. Thereby, four soybeans and six maize field trials were conducted in the 2018/2019 growing season in Brazil in different environments. Two EndoMaxx SC rates (150 or 300 ml ha-1) were tested, with or without P fertilization during sowing. Results indicated that both rates positively impacted all variables analyzed, regardless of crop species and P fertilization. Even in the absence of P fertilization, AMF-colonized soybeans and maize treatments were either significantly higher or similar to the untreated control. Moreover, crop yield was 2.6-9.1% more when the highest rate of AMF was applied in combination with P fertilization compared to the P-fertilized untreated control. In-furrow EndoMaxx SC applications are an alternative to increase the sustainability of soybean and maize production, especially in a scenario, in which yield must be maximized in the coming decades to supply food for the exponentially growing population without expanding cultivations to new sites.

Effect of In-Furrow Application of Fluopyram on Leaf Spot Diseases of Peanut.

In peanut (Arachis hypogaea) production, in-furrow applications of the premix combination of the succinate-dehydrogenase-inhibitor (SDHI) fungicide and nematicide fluopyram and the insecticide imidacloprid are used primarily for management of nematode pests and for preventing feeding damage on foliage caused by tobacco thrips (Frankliniella fusca). Fluopyram is also active against many fungal pathogens. However, the effect of in-furrow applications of fluopyram on early leaf spot (Passalora arachidicola) or late leaf spot (Nothopassalora personata) has not been characterized. The purpose of this study was to determine the effects of in-furrow applications of fluopyram + imidacloprid or fluopyram alone on leaf spot epidemics. Field experiments were conducted in Tifton, GA in 2015, 2016, and 2018 to 2020. In all experiments, in-furrow applications of fluopyram + imidacloprid provided extended suppression of early leaf spot and late leaf spot epidemics compared with the nontreated control. In 2020, there was no difference between the effects of fluopyram + imidacloprid and fluopyram alone on leaf spot epidemics. Results indicated that fluopyram could complement early-season leaf spot management programs. Use of in-furrow applications of fluopyram should be considered as an SDHI fungicide application for resistance management purposes.

Can the botanical azadirachtin replace phased-out soil insecticides in suppressing the soil insect pest Diabrotica virgifera virgifera?

BackgroundDue to recent bans on the use of several soil insecticides and insecticidal seed coatings, soil-dwelling insect pests are increasingly difficult to manage. One example is the western corn rootworm (Diabrotica virgifera virgifera, Coleoptera: Chrysomelidae), a serious root-feeder of maize (Zea mays). We investigated whether the less problematic botanical azadirachtin, widely used against above-ground insects, could become an option for the control of this soil insect pest.MethodsArtificial diet-based bioassays were implemented under standard laboratory conditions to establish dose response curves for the pest larvae. Then, potted-plant experiments were implemented in greenhouse to assess feasibility and efficacy of a novel granular formulation of azadirachtin under more natural conditions and in relation to standard insecticides.ResultsBioassays in three repetitions revealed a 3-day LD50 of 22.3 µg azadirachtin/ml which corresponded to 0.45 µg/neonate of D. v. virgifera and a 5-day LD50 of 19.3 µg/ml or 0.39 µg/first to second instar larva. No sublethal effects were observed. The three greenhouse experiments revealed that the currently proposed standard dose of a granular formulation of 38 g azadirachtin/hectare for in-furrow application at sowing is not enough to control D. v. virgifera or to prevent root damage. At 10× standard-dose total pest control was achieved as well as the prevention of most root damage. This was better than the efficacy achieved by cypermethrin-based granules and comparable to tefluthrin-granules, or thiamethoxam seed coatings. The ED50 for suppressing larval populations were estimated at 92 g azadirachtin/ha, for preventing heavy root damage 52 g/ha and for preventing general root damage 220 g/ha.ConclusionsThere seems clear potential for the development of neem-based botanical soil insecticides for arable crops such as maize. They might become, if doses are increased and more soil insecticides phased out, a promising, safer solution as part of the integrated pest management toolkit against soil insects.

Insecticidal Application Methods against Melanaphis sacchari (Hemiptera: Aphididae) on Sorghum in Northeastern Mexico

Invasion of the sugarcane aphid, Melanaphis sacchari (Zehntner), into all sorghum (Sorghum bicolor (L.) Moench)–producing areas in Mexico in 2013 prompted a series of studies on assessing and developing integrated pest management strategies for the pest. To avoid economic yield losses, studies were first focused on identifying effective insecticides against this new insect pest. Several trials identified the best insecticides, and their use was soon popular among sorghum growers (Rodríguez-del-Bosque and Terán 2015, Southwest. Entomol. 40: 433–434). However, there was a need to explore economic and effective application methods against this invasive aphid; thus, the objective of this investigation was to determine the effectiveness of four application methods and timing of those applications for controlling M. sacchari in northeastern Mexico.This study was conducted at the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias Experiment Station near Río Bravo, in northern Tamaulipas, Mexico (N25°57′, W98°01′), during the fall growing season of 2014, spring and fall of 2015 and 2016, and spring of 2017. The sorghum hybrid DK-54 was planted in February and in July during the spring and fall seasons, respectively, using a randomized complete block design with four replications. Plots were 4 rows (0.8 m) wide × 10 m long. Imidacloprid (Velfidor 350 SC®, Velsimex, Cd. México, México) was applied with a 20-l manually operated backpack sprayer in the following treatments: (1) in-furrow application at planting at 210 g active ingredient (a.i.)/ha; (2) banded application of 210 g a.i./ha 7 cm to the side of the row and 7 cm deep when plants were in the boot stage; (3) application of 105 g a.i./ha at the base of the plants during the boot stage; (4) application of 105 g a.i./ha over the plants during the boot stage; and (5) no treatment (control). Insecticide was applied in Treatments 2–4 when M. sacchari density averaged 100 aphids/leaf at the boot stage of plant growth. For these treatments, aphid (adults + nymphs) density was determined on two leaves (bottom and middle) of 10 randomly selected plants in the two central rows of the plots 7 and 14 d after application. Percentage control obtained in each treatment was calculated as % control = ([No. aphids in control – No. aphids in treatmentn)/(No. aphids in control)] × 100. Percentage data were transformed by square root to normalize distribution. These transformed data were subjected to analysis of variance with treatment means compared using the LSD test (P < 0.05) (SAS Institute 2012, SAS release 9.3 ed., Cary, NC).At 7–14 d after application, mean aphid density in the control treatment varied from 2,170 aphids/leaf during fall 2014 to 180 aphids/leaf during spring 2017 (Table 1), showing a progressive decline of M. sacchari population after first detected in 2013. Based on these results, the two most efficacious treatments were application of 105 g a.i./ha at the base of the plants during the boot stage (Treatment 3) and application of 105 g a.i./ha over the plants during the boot stage (Treatment 4) with a mean % control > 93%. These two methods were intended to simulate ground and aerial applications. Both were consistently effective in reducing aphid density, with the exception of the spring 2017 application over the plants that yielded only 75% control. Any differences in effectiveness of application over the plants versus application to the base of the plants might be explained by a longer time for translocation of the imidacloprid to reach the basal leaves where aphids are highly concentrated on the sorghum plant (Simon-Delso et al. 2015, Environ. Sci. Pollut. Res. 22: 5–34).On the other hand, the prophylactic in-furrow application of imidacloprid at planting (Treatment 1) resulted in an observed 82% (range 41–96%) control, and the banded application at the boot stage (Treatment 2) resulted in 76% control (range 25–99%). Treatments 1 and 2 were inconsistent and costly (double insecticide dose) as compared with Treatments 2 and 3. In summary, the best application and timing methods for controlling M. sacchari in northeastern Mexico were either the application at the base or over the top during the boot stage.

Efficacy of select insecticide seed treatments and in-furrow applications for managing the brown stink bug, Euschistus servus (Say) (Hemiptera: Pentatomidae), in seedling maize

The brown stink bug, Euschitus servus, is an important early season pest of field corn. It feeds directly on the growth point of developing plants leading to delays in growth, stunting, and a reduction in yield when injury is severe. Injury from stink bug feeding is often observed days to weeks after it occurred at which point management provides no benefit. This study, conducted in Suffolk, VA in 2018 and 2019, examined prophylactic insecticide options, including seed treatments and in-furrow applications, for their efficacy against brown stink bug. Seed treatments are applied by manufacturers to many commercially available corn seed at different rates for below ground pests. In 2018 and 2019, brown stink bugs were artificially infested in seedling corn plots treated with clothianidin applied to the seed, bifenthrin applied in-furrow, or terbufos applied in-furrow. In 2019, an early and late planting date were used. The impact of stink bug feeding in the presence of each of these treatments, as well as the impact of the treatments on stink bug feeding behavior and mortality, were assessed. We found that clothianidin seed treatments have the potential to mitigate early season feeding from brown stink bugs and prevent yield reduction. We also observed reduced feeding activity and plant injury in early planted corn, suggesting later planted corn is more susceptible to stink bug injury. These results suggest that no additional management may needed for brown stink bugs in seedling corn when planting seed treated with insecticides.

AGRONOMIC PERFORMANCE OF SUGARCANE INOCULATED WITH Nitrospirillum amazonense (BR11145)

ABSTRACT Sugarcane cultivation areas are usually characterized by low soil fertility and high nutrient demand, especially for nitrogen. Technologies that can raise crop yield and lower the use of pesticides and fertilizers are among the main needs of this crop. The objective of this study was to evaluate the agronomic performance of sugarcane after in-furrow application of the diazotrophic bacterium Nitrospirillum amazonense (BR11145). The treatments consisted of applying five doses of N. amazonense-based product to the planting furrow, 0.25, 0.5, 1.0, 1.5, and 2.0 L commercial product (c.p.) ha-1; a treatment consisting of the combination of Bacillus subtilis and Bacillus licheniformis; one control without fertilization; and one control with fertilization. Based on the results obtained from the pooled analysis of two field experiments, the N. amazonense-based product improved the growth parameters of sugarcane plants, and at doses of 1.0 and 1.5 L c.p. ha-1, these benefits resulted in a significant increase in yield and in the amount of sugar per hectare. Inoculation with diazotrophic bacteria can benefit sugarcane, especially because it promotes the growth and yield of the crop similarly to fertilizers.

Inoculation Methods and Doses and Relationship with the Vegetative and Reproductive Development of Soybeans

This study aimed to evaluate and compare the method of in-furrow inoculant application with the other existing methods, as well as, in different doses in the development of soybean culture. The experimental design was randomized blocks in a two-factorial scheme (4 x 3), with four inoculation methods, without inoculation (control), by seed, in-furrow and leaf spray, with three doses, 100, 200 and 400%. Leaf and root dry mass, number of nodules, pods per plant, number of seeds per vegetables, height, knots per plant, productivity, root resistance and average chlorophyll content were measured. The combination of factors did not affect plant height, leaf dry matter, root resistance, grains and pods per plant, plant per knot and weight of 100 seeds, affecting only other parameters, in which the largest root dry matter occurred in in-furrow inoculation in the dose of 400%, with 3.82 g plant-1, against 3.43 g plant-1 in the by seed method in the same dose. In the in-furrow application at the 100% dose, the highest number of grains pod-1 occurred, with 3.42 grains pod-1, combined with an increase in pods plants-1, and a 19% increase in productivity relative to the control, and 9.5% at the third increase, in the spray. Co-inoculation methods affect the development of soybeans, and the method that provided the greatest of soybean development was by in-furrow.

Combining penthiopyrad with azoxystrobin is an effective alternative to control seedling damping-off caused by Rhizoctonia solani on sugar beet

The soil-borne fungus Rhizoctonia solani causes damping-off on sugar beet seedlings. Growers rely on fungicides to protect sugar beet in fields affected by R. solani. Quinone outside inhibitor (QoI) fungicides, such as azoxystrobin, have been applied as in-furrow and foliar sprays to manage R. solani, but repeated use of QoI fungicides pose risks in fungicide resistance. Penthiopyrad is a novel fungicide with the succinate dehydrogenase inhibitor (SDHI) mode of action. The objectives of this study were to compare the efficacy of penthiopyrad used as a sole seed treatment versus azoxystrobin as an in-furrow or a post-planting application for controlling R. solani; to determine if a penthiopyrad seed treatment combined with azoxystrobin as a post-planting application can improve control of R. solani over sole penthiopyrad seed treatment, azoxystrobin in-furrow or post-planting spray application. Seedling survival rate and area under disease progress curve (AUDPC) for seedling loss rate were used to measure the efficacy of each treatment. A sole penthiopyrad seed treatment at 14 g a. i. kg−1 of seeds, and penthiopyrad seed treatments at 7 and 14 g a. i. kg−1 of seeds combined with one azoxystrobin in-furrow application 14 days after planting resulted in similar seedling survival rate and AUDPC as achieved with the standard azoxystrobin in-furrow application. However, post-planting foliar spray of azoxystrobin alone failed to control seedling damping-off. Our research suggests that penthiopyrad can be used as a seed treatment to provide early protection to vulnerable seedlings while azoxystrobin can be used as a post-planting application to protect the ensuing adult plants.

Inoculation of Wheat With Azospirillum spp.: A Comparison Between Foliar and In-furrow Applications

The present work aimed to evaluate the agronomic performance of wheat grown under no-tillage system and submitted to different doses and methods of inoculation with Azospirillum spp. Eight treatments were tested: 1) control; 2) half N dose; 3) full dose of N; 4) half N dose + standarded inoculation by seeds (200 mL ha-1); 5) half N dose + in-furrow inoculation (200 mL ha-1); 6) half N dose + in furrow inoculation (300 mL ha-1); 7) half N dose + inoculation by foliar spraying (200 m ha-1) and 8) half N dose + inoculation by foliar spraying (300 mL ha-1). The following parameters were evaluated: number of tillers per plant, number of grains per spike, shoot dry biomass, weight of thousand seed mass, hectoliter weight, nitrogen content in grains, nitrogen content in shoot dry matter as well as crop yield. Our results showed that the supply of the half dose of mineral N associated to foliar inoculation with Azospirillum at the dose of 300 mL ha-1 provided positive results on wheat yield, confirming the bacterial ability to fix N. However, only the full mineral N fertilization stood out as the best N fertilization management.