Banded Applications Research Articles

Evaluation of florpyrauxifen-benzyl for control of Old World climbing fern

Old World climbing fern [Lygodium microphyllum (Cav.) R. Br.; OWCF] is an invasive vine in many Florida wetlands. Management involves poodle cutting the climbing rachis at approximately 120 cm, with a subsequent foliar application of glyphosate to the remaining rooted vines. Recently, there has been increasing interest in synthetic auxin herbicides for OWCF control. Florpyrauxifen-benzyl is a new auxin mimic that was developed for weed control in aquatics and is selective at low use rates. There is limited information regarding its activity on OWCF. We conducted field studies at four wetland sites in south Florida from 2017 to 2020 to evaluate the effectiveness of florpyrauxifen-benzyl for OWCF control. In small-plot studies at two locations, florpyrauxifen-benzyl applied at 0.08 and 0.16 g L 1 reduced OWCFcover to 4%at 3 moafter treatment (MAT) and 21% at 6 MAT.However, florpyrauxifen-benzyl at these concentrations did not consistently control OWCF at 12 MAT. An additional study evaluated banded applications of florpyrauxifen-benzyl or glyphosate compared to poodle cutting for control of the climbing rachis. For both herbicides, banded applications did not control the climbing rachis, whereas poodle cutting provided complete control of all climbing rachis. Finally, an operational field study demonstrated florpyrauxifen-benzyl applied by professional applicators at 0.16 g L 1 reduced OWCF cover to 9% at 17 MAT and was not different from glyphosate applied at 14.4 g L 1. These studies indicate florpyrauxifen-benzyl is active on OWCF and future research should evaluate the effectiveness of repeat applications for longer-term control.

Evaluation of At-Plant Banded Applications of Verimark Versus Foliar Applications of Exirel for European Corn Borer Control on Green Bean in Wisconsin, 2021

Evaluation of At-Plant Banded Applications of Verimark Versus Foliar Applications of Exirel for European Corn Borer Control on Green Bean in Wisconsin, 2021

Nitrogen Management and Uptake by Corn on No‐Till and Ridge‐Till Claypan Soil

Core Ideas Seasonal corn N uptake was greater with ridge‐till than with no‐till. Increasing N fertilizer rate generally increased N uptake. Nitrogen uptake at R4 was greater with banded applications than broadcast in no‐till. Increasing N uptake increased yield, primarily by increasing kernels per ear. Information on N management is limited regarding N uptake and recovery by corn (Zea mays L.) grown on claypan soils in the eastern Great Plains, especially in conservation tillage systems. The objective of this study was to examine the effect of fertilizer N rate (0, 34, 67, 101, and 134 kg ha‐1) applied by surface broadcast, surface band (dribble), and subsurface band (knife) placement methods on N uptake by corn grown in no‐till and ridge‐till systems on a claypan soil. Ridge‐till consistently increased corn N uptake compared with no‐till by 53% early to 20% later during the growing season. Maximum N uptake rate was earlier in the season and greater with ridge‐till than with no‐till, perhaps helping to contribute to increased corn yields. Early in the season, corn N uptake was increased with low N fertilization rates, but not at higher rates. However, as the season progressed, N uptake increased with all rates. Even though the effect of N fertilizer placement on corn N uptake was not consistent during the entire season, by the R4 growth stage, placement did not affect N uptake in ridge‐till but was nearly 20% greater with banded (dribble and knife) applications than with broadcasting in no‐till. At low N rates, knife placement increased N uptake at R4, likely because of improved apparent N recovery, but was unaffected by placement at greater N rates. Improving total N uptake increased relative yield primarily by increasing kernels per ear, with lesser effects due to kernel weight and ears per plant.

Impact of Mustard Seed Meal Applications on Direct-Seeded Cucurbits and Weed Control

Weed control in organic production systems can be a labor intensive and expensive process. Mustard seed meal (MSM) is phytotoxic and a potential pre-emergent and preplant-incorporated organic herbicide for controlling germinating and emerging weed seedlings: unfortunately, MSM may also adversely impact seedling survival of certain direct-seeded vegetable crops. Field research was conducted in southeast Oklahoma (Lane, OK) to determine the phytotoxic impact of MSM on indigenous weeds and seedling establishment of cantaloupe (Cucumis melo L.) var. ‘PMR-45’, cucumber (Cucumis sativus L.) var. ‘Marketmore 76’, yellow squash (Cucurbita pepo L.) var. ‘Crookneck’, and watermelon (Citrullus lanatus L.) var. ‘Dixie’. The factorial experiment included 2 MSM incorporation levels (no incorporation and incorporation), 2 MSM application rates (2.25 and 4.5 mt/ha), 2 application patterns (banded and solid), 2 experimental control treatments (1 for each incorporation method) and four replications. The soil [Bernow fine sandy loam, 0-3% slope (fine-loamy, siliceous, thermic Glossic Paleudalf)] was prepared for planting by plowing, fertilizing, and forming raised beds. MSM was applied to raised beds 3 m-long on 0.76 m-centers. The banded application produced a 10.2 cm-wide MSM-free area in the bed center where the crop would later be direct-seeded. The MSM was then either left on the surface or incorporated into the top 2.5-5.0 cm and then direct-seeded with cantaloupe, cucumber, yellow squash, and watermelon. Plant stands and weed control ratings were collected during the experimental period. Twenty-eight days after planting, the entire plot was harvested and the fresh and dry plant weights determined. Although applications of MSM provided sufficient broadleaf, grass, and total weed control, cucurbit establishment and development, the application of MSM at 2.25 and 4.5 mt/ha severely reduced crop establishment of direct-seeded cucurbits. Further research should address banded applications of MSM with either established direct-seeded or transplanted cucurbits and other vegetable crops in the same manner as others have done with corn gluten meal.

Effect of In-Furrow and Early-Season Banded Applications of Fungicides on Incidence of Early Leaf Spot of Peanut

Field experiments were conducted in Tifton, GA, in 2012-2014 to determine the effect of in-furrow applications of prothioconazole and early-season banded applications of prothioconazole or pyraclostrobin on incidence of early leaf spot (Cercospora arachidicola) of peanut (Arachis hypogaea). In each year, border rows were planted in May as a source of inoculum for plants in the treatment plots. Plots were planted in August or September after epidemics of early leaf spot were severe in the border plots. Fungicide application regimes included two rates (100 and 200 g a.i./ha) of prothioconazole applied in-furrow at planting, and 200 g a.i./ha of prothioconazole or 164 g a.i./ha of pyraclostrobin applied concentrated in a 30-cm band 21 days after planting (DAP). Incidence (percent of leaflets with one or more leaf spot) of early leaf spot was monitored until 54 to 57 days after planting in each year. In all years, disease incidence was below 10% at 28 DAP in plots treated with 200 g a.i./ha of prothioconazole in-furrow compared to over 40% in nontreated plots at the same time. In-furrow applications of 100 g a.i./ha of prothioconazole were less effective, but suppressed leaf spot incidence compared to the control. Banded applications of either fungicide at 21 DAP resulted in a decrease in leaf spot incidence, and prevented increase in leaf spot incidence for 19 days or longer. Accepted for publication 30 November 2015. Published 3 December 2015.

Integrated Management of Bermudagrass (Cynodon dactylon) in Sugarcane

Bermudagrass is a difficult perennial weed to manage in Louisiana sugarcane. Research was conducted to compare interrow tillage practice, postharvest residue management, and herbicide placement on bermudagrass proliferation and sugarcane yield. Tillage frequencies included conventional (four tillage operations per season), reduced (two tillage operations), and no-till. Residue management practices included removal by burning, sweeping from row top into the wheel furrow, and not removed. Spring herbicide placement treatments included broadcast, banded, or no herbicide application. With conventional tillage, broadcast and banded herbicide applications resulted in similar bermudagrass cover in the first and second ratoon crops, but bermudagrass cover was greater when using banded applications (22%) compared with broadcast application (15%) in the third-ratoon crop. Bermudagrass cover was greatest with no-till. When herbicides were banded, bermudagrass cover was greater in reduced tillage than conventional tillage in all three ratoon crops. Postharvest residue management did not affect bermudagrass ground cover. In plant cane, sugarcane yields were lowest when herbicide was not applied. In ratoon crops, sugarcane and sugar yield were reduced when herbicide was not applied regardless of tillage practice. Cane and sugar yield were generally equal when comparing reduced and conventional tillage. Total sugarcane yield (4 crop yr) for the no-till program was reduced 11, 15, and 25%, respectively, when herbicides were broadcast, banded, and when herbicide was not applied, compared with conventional tillage. Failure to remove residue reduced sugarcane yield by 5, 7, and 10% in first, second, and third ratoons, respectively, compared with burning. Eliminating unnecessary tillage practices can increase profitability of sugarcane through reduced costs, but it will be imperative that herbicide programs be included to provide adequate bermudagrass control and that postharvest residue is removed to promote maximum sugarpostane yield.

E12

The objective of this study was to evaluate the efficacy of several soil systemic insecticides applied as bed-top banded spray applications against sweetpotato whitefly. Broccoli ‘Emerald Crown’ was direct seeded into double row beds on 42 inch centers on 25 Aug, 2011. Plots were one bed wide by 35 ft long and bordered by one untreated bed. Stand establishment was achieved using overhead sprinkler irrigation, and irrigated with furrow irrigation thereafter. Four replications of each treatment were arranged in a RCB design. Product formulations and rates for each spray program are provided in the table. The soil insecticides were applied as a surface-band treatment using a single-row boom equipped with 1 flat fan nozzle (8004VS) oriented parallel with the seed line and calibrated to deliver 25 gallons of spray per acre at 40 psi. A 2-3 inch spray band was placed directly over each seed line immediately following planting. The insecticides were incorporated into the soil using sprinkler irrigation that is commonly employed for seed germination during stand establishment. Evaluations of SWF control was estimated by counting the number of total nymphs on two, 2-cm disk sections taken from 2 consecutive basal leaves collected from each of 5 plants per replicate at various days after plant emergence (DAPE). SWF nymph densities on each leaf disk were estimated under magnification in the laboratory. Because of heterogeneity of mean variances, data were log transform (mean+0.5) and subjected to ANOVA; means were separated using Fprotected LSD (P ≤ 0.05). Actual non-transformed means are presented in the table.

Successional trajectory of loblolly pine ( Pinus taeda) plantations established using intensive management in Southern Mississippi, USA

Although secondary succession in commercial pine plantations offers opportunities to manage for biodiversity, questions remain regarding effects of stand establishment intensity on biodiversity. Therefore, we examined 9 years of post-harvest plant succession in loblolly pine plantations established under a range of intensive management regimes in Mississippi, USA, including combinations of mechanical site preparation, chemical site preparation, and herbaceous weed control. We evaluated plant community structure using coverage of eight growth forms, and community composition using species-level coverage. Stands established without chemical site preparation retained more post-harvest woody and vine species and had less variable species turnover than chemically prepared stands. Chemically prepared stands provided opportunity for greater expression of early succession herbaceous and subshrub communities. Broadcast herbaceous weed control reduced expression of the early succession community relative to banded applications, but a single broadcast application did not prevent strong re-emergence of that community the following year. Conversely, multiple broadcast applications of herbaceous weed control reduced expression of early succession species beyond the year of final treatment, possibly through inhibiting establishment until favorable conditions were past, rather than by directly favoring woody dominance. Plant community structure converged as crown closure approached, and structural differences were largely insignificant by year 5. However, small differences in composition that may affect biodiversity were retained and may last until midrotation harvest and subsequent treatment. Greater diversity of plant communities in stands with chemical site preparation may benefit biodiversity in establishing plantations if not inhibited by broadcast herbaceous weed control. Resources committed to broadcast weed control may be more usefully diverted to midrotation management that improves biodiversity after thinning. These results can be used to target management of early succession species at stand and landscape scales. Given the known effects of this limited array of treatments on biodiversity, additional establishment regimes should be monitored to provide information critical to meeting stand- and landscape-level biodiversity goals.

Influence of Corn Gluten Meal on Squash Plant Survival and Yields

Corn gluten meal (CGM) is a non-selective preemergence or preplant-incorporated herbicide that inhibits root development, decreases shoot length, and reduces plant survival. The development of a mechanized application system for the banded placement of CGM between crop rows (seed row not treated) has increased its potential use in organic vegetable production, especially in direct-seeded vegetables. The objective of this research was to determine the impact of CGM applications (formulations, rates, incorporation, and banded applications) on direct-seeded squash (Cucurbita pepo) plant survival and yields. Neither CGM formulation (powdered or granulated) nor incorporation method (incorporated or non-incorporated) resulted in significant differences in plant survival or squash yields. When averaged across all other factors (formulations, incorporation method, and banding), CGM rates of 250 to 750 g·m−2 reduced squash survival from 70% to 44%, and squash yields from 6402 to 4472 kg·ha−1. However, the banded application (CGM placed between rows) resulted in significantly greater crop safety (75% survival) and yield (6402 kg·ha−1) than the broadcast (non-banded) applications (35% survival and 4119 kg·ha−1 yield). It was demonstrated that banded applications of CGM can be useful in direct-seeded squash production and other organic direct-seeded vegetables.

SQUASH PRODUCTION AND ORGANIC WEED CONTROL

Although CGM has been identified as an organic herbicide for weed control in turf and established vegetable plants, direct contact with vegetable seeds can decrease crop seedling development and plant survival by inhibiting root and shoot development. The objective of this research was to determine the impact of banded corn gluten meal applications on squash plant survival and yields. This factorial field study was conducted during Summer 2005 on 81-cm-wide raised beds at Lane, Okla., with two application configurations (banded and solid), two CGM formulations (powdered and granulated), two incorporation treatments (incorporated and nonincorporated), and three application rates (250, 500, and 750 g·m–2). The two CGM formulations at three application rates were uniformly applied in both banded and solid patterns on 19 Aug. The banded application created a 7.6-cm wide CGM-free planting zone in the middle of the raised bed. The CGM applications were then either incorporated into the top 2.5 to 5.0 cm of the soil surface with a rolling cultivator or left undisturbed on the soil surface. `Lemondrop' summer squash (Cucurbita pepo L.) was then direct-seeded into the center of the raised beds. When averaged across the other factors, there was no significant difference between powdered and granulated CGM formulations or incorporating and nonincorporating the CGM for either squash plant survival or yields. As the CGM application rates increased the plant survival and yields decreased. Banded application resulted in significantly greater crop safety (90% plant survival) and yields (445 cartons/ha) than the broadcast (solid) applications (45% plant survival and 314 cartons/ha). The research demonstrated the potential usefulness of CGM in direct-seeded squash production, if used in banded application configuration.

CORN GLUTEN MEAL: ALTERNATIVE WEED CONTROL FOR SQUASH

Corn gluten meal (CGM) has been identified as a potential organic preemergence and preplant-incorporated herbicide. It is an environmentally friendly material that has demonstrated ability to decrease seedling development and plant survival by inhibiting root and shoot development. Unfortunately, CGM can also decrease the development and plant survival of direct-seeded vegetable crops. As a result, the use of CGM is not recommended in conjunction with direct-seeded vegetables. The development of equipment to apply CGM in banded configurations has created an opportunity to investigate whether banded CGM applications will provide significant crop safety for direct-seeded vegetables. The objective of this research was to determine the impact of banded CGM applications on squash plant survival and yields. A factorial field study was conducted during the summer of 2004 on 81-cm-wide raised beds at Lane, Okla., with two application configurations (banded and solid), two CGM formulations (powdered and granulated), two incorporation treatments (incorporated and non-incorporated), and three application rates (250, 500, and 750 g·m–2). The two CGM formulations at three application rates were uniformly applied in both banded and solid patterns on 18 Aug. The banded application created a 7.6-cm-wide CGM-free planting zone in the middle of the raised bed. The CGM applications were then either incorporated into the top 2.5 to 5.0 cm of the soil surface with a rolling cultivator or left undisturbed on the soil surface. `Lemondrop' summer squash (Cucurbita pepo L.) was then direct-seeded into the center of the raised beds. When averaged across the other factors, there was not a significant difference between powdered and granulated CGM formulations or incorporating and non-incorporating the CGM for either squash plant survival or yields. CGM application rates made a significant difference for both squash survival and yields, when averaged across all other factors. As the CGM application rate increased, the plant survival and yields decreased. When averaged across all other factors, the banded application resulted in significantly greater crop safety (59% plant survival) and yields (228 cartons/ha) than the solid applications (25% plant survival and 118 cartons/ha). The research demonstrated the potential usefulness of CGM in direct-seeded squash production, if used in a banded application configuration. Additional research should further investigate the interaction of CGM application rates and the width of the CGM-free zone on crop safety for various vegetables.

CORN GLUTEN MEAL APPLICATION OPTIONS FOR WEED CONTROL

Producers of organic vegetables often report that weeds are a troublesome production problem. It has been documented that corn gluten meal (CGM), a by-product of the wet-milling process of corn, is phytotoxic. As a preemergence or preplant-incorporated herbicide, CGM inhibits root development, decreases shoot length, and reduces plant survival of weed or crop seedlings. The development of a mechanized application method for CGM and the ability to apply the material in a banded pattern would increase its potential use in organic vegetable production, especially in direct-seeded vegetables. Therefore, the objective of this research was to develop a mechanized method to uniformly apply CGM to the soil surface in either a broadcast or banded pattern. An applicator was assembled using various machinery components (fertilizer box, rotating agitator blades, 12-volt motor, and fan shaped gravity-fed row banding applicators). The equipment was evaluated for the application of two CGM formulations (powdered and granulated), three application rates (250, 500, and 750 g·m–2), and two application configurations (solid and banded). Field evaluations were conducted during Summer 2004 on 81-cm-wide raised beds at Lane, Okla. Differences between CGM formulations affected the flow rate within and between application configurations. The granulated formulation flowed at a faster rate, without clumping, compared to the powdered formulation. While the CGM in the banded configuration flowed faster than the solid application. It was determined that the CGM powder used with the solid application configuration was inconsistent, unreliable, and thus not feasible for use with this equipment without further modifications. These evaluations demonstrated the feasibility of using equipment, rather than manual applications, to apply CGM to raised beds for organic weed control purposes. Several design alterations may increase the efficiency and potential usefulness of this equipment. If research determines equivalent weed control efficacy between the two CGM formulations, the granulated formulation would be the preferred formulation for use in this equipment. This equipment would be useful for evaluating the benefits of banded applications of CGM for weed control efficacy and crop safety for direct seeded vegetables.

Soil fertility distributions in long-term no-till, chisel/disk and moldboard plow/disk systems

In permanent no-till (NT), soil nutrients are no longer mixed into the topsoil as with moldboard plow/disking (MD), whereas chisel/disking (CD) does limited mixing. Surface broadcast and/or banded nutrient applications may result in high and low fertility zones in permanent NT, with possible implications for soil sampling and nutrient placement. We investigated effects of 25 years of continuous NT, CD and MD with corn planted in the same row locations on organic matter (SOM), pH-H 2O and Mehlich-3 extractable phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg). Vertical distribution at 0–5, 5–10 and 10–15 cm depths was measured as well as horizontal distributions across corn rows. We observed higher SOM and P in NT and CD than in MD in the 0–15 cm layer. SOM content was greatest in the top 5 cm in NT, but declined sharply with depth. SOM content in CD was not as high at the surface as in NT, but did not decline as fast as in NT. SOM was uniform but low throughout the 0–15 cm depth of MD. In all tillage systems, SOM did not vary across rows. Soil pH was higher in the 0–5 cm layer of NT than the deeper layers but the reverse was true in the CD or MD treatments. Concentrations of P, K and Ca were higher in the surface 0–5 cm than 10–15 cm depth of all tillage systems, but most strikingly in NT and CD. Starter fertilizer injection resulted in higher P and lower pH in the injection zone of all tillage treatments, but most notably in NT. The pH was depressed under the band of side-dressed nitrogen with all tillage systems. Potassium accumulated in the rows of the previous crop, probably because it leached from crop residue that accumulated there. Tillage did not affect Mg distribution. Optimal nutrient management in NT should take account of horizontal and vertical nutrient and pH distributions. Samples in long-term NT could potentially be taken to a shallower depth if calibration curves are available. To avoid underestimating P and K availability or overestimate lime needs, high P or decreased pH bands should be avoided, as well as crop rows. Possibilities to reduce P and K applications with banding need more investigation. Results show the importance of regular liming in NT to maintain surface pH in the optimum range, but also show that lime does not have to be incorporated.

Water Quality in Walnut Creek Watershed: Herbicides in Soils, Subsurface Drainage, and Groundwater

AbstractHerbicide transport in subsurface drainage can result in unacceptable levels of contamination in surface waters. This study assessed the extent of atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3‐,5‐triazine‐2,4‐diamine] and metribuzin [4‐amino‐6‐(1,1‐dimethyethyl)‐3‐(methylthio)‐1,2,4‐triazin‐5(4H)‐one] transport to subsurface drainage and shallow groundwater. A corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] rotation was used with corn receiving banded atrazine applications of 459 g ha−1 in 1992 and 561 g ha−1 in 1994. Soybean were treated with metribuzin at 420 g ha−1 in 1993 and 1995. Monthly flow‐weighted average concentrations of atrazine in drainage water did not exceed 3 µg L−1 and annual losses ranged from 0.02 to 2.16 g ha−1 during the 4‐yr study. Less than 3% of the groundwater samples contained atrazine concentrations exceeding the 3 µg L−1 maximum contaminant level for drinking water (MCL). Atrazine was detected more frequently in groundwater beneath the lowest parts of the field, despite greater than average sorption to soils in that area. Metribuzin was also found in groundwater, but only half as frequently as atrazine. The patterns observed in subsurface drainage and groundwater reflected the persistence of atrazine and metribuzin in soil. Atrazine was detected in >90% of surface soil samples up to 23 mo after application, whereas metribuzin was rarely detected during the second year following application. Atrazine was found far more commonly than metribuzin in soil below 30 cm depth.

Spatial Variability Patterns of Phosphorus and Potassium in No‐Tilled Soils for Two Sampling Scales

AbstractThe increasing use of grid soil sampling methods and variable‐rate fertilization requires better understanding of patterns and causes of lateral variability of nutrients. This study assessed patterns of spatial variability of P and K for two scales of sampling on eight no‐tilled corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] fields. The fields had received no P or K fertilization since the last harvest but had varied histories of fertilization. Fifty 10‐core (0‐ to 15.2‐cm depth) composite samples were collected from 2.2‐m2 areas separated 3.05 m from each other along each of two 150‐m intersecting transects laid out across and along old crop rows. Sixty‐seven single‐core samples spaced 7.6 or 15.2 cm were collected from 7.85‐m segments of the transects across rows. Variography revealed high random and spatially structured variability for most fields. The structure of the variability differed among fields and directions within a field. Plots of soil‐test P and soil‐test K values, fast Fourier transform analyses, and semivariograms showed clusters and periodic patterns of variable regularity and size across fields. The cyclic patterns were more defined across crop rows. Small‐scale cyclic patterns with a period of ≈ 1 m revealed for some fields probably resulted from repeated banded fertilizer applications. Large‐scale cyclic trends with periods of 15 to 18 m or a multiple of this distance were probably the result of broadcast fertilization with commercial bulk spreaders. Sampling methods should be developed for fields with high spatial variability of cyclic structure at various scales. Producers should pay more attention to uniform application of fertilizers and manure.

Effect of fertilizer placement on yield of established alfalfa stands

Alfalfa yield response to P and K fertilization management has been documented elsewhere, but little work has been done in western Canada. Field studies conducted on two Manitoba soils for 4 yr evaluated the effects of four levels of monoammonium phosphate and three levels of potassium chloride fertilizers, applied as a surface broadcast or as an in-soil band application, on the yield of established alfalfa (Medicago sativa L.) stands. Applied P increased total annual forage yield on the clay loam soil by 1.53 t h−1 (47%), when averaged over the 4 yr of the study, but did not increase yields on the fine sandy loam. Yield response to P application on the clay loam soil increased over the 4 yr of the study. Potassium application resulted in minor or no increases in forage yield on both soils. On the clay loam soil, there was no yield difference between banded and broadcast fertilizer applications. On the fine sandy loam soil, band application reduced yields slightly compared with broadcast application, particularly at the first harvest following fertilizer application. Grass ingress into the plots was reduced by K application but was not affected by P fertilization, which may indicate a beneficial effect of K fertilization on alfalfa vigor and persistence. Key words: Potassium, phosphorus, banding, broadcast, persistence

A New Method of Soil Application of Aldicarb

Only 5 to 20% of in-furrow, soil-applied aldicarb (2-methyl -2-(methylthio)propionaldehyde 0(methylcarbamoy1) oxime) is absorbed by crop plants, with up to 80% degrading in the soil. The objective of this research was to determine if aldicarb could be applied directly to potato (Solanum tuberosum L.) seedpieces at planting using in-furrow rates without a reduction of potato beetle (Leptinotarsa decemlineata Say) control, thus reducing the amount of aldicarb that falls between the seedpieces. Field tests were conducted for 2 yr to determine the effectiveness of two methods of soil applications of aldicarb for control of Colorado potato beetle on white potato. Aldicarb applied at planting time as in-furrow seedpiece treatments, or as in-furrow banded applications, at rates of 1.0, 2.0, 3.0 lb a.i./acre were effective for early season reduction of Colorado potato beetle larvae. Rates of 1.0 and 2.0 lb a.i./acre of aldicarb with either application method effectively reduced plant defoliation caused by Colorado potato beetle until early June, while the 3.0 lb a.i./acre rate reduced plant defoliation through July. Research Question The Colorado potato beetle is the most important pest of white potatoes throughout the eastern coast of the USA. Aldicarb was used on potatoes from 1969 through the 1970s as a banded in-furrow application at a rate of 3.0 lb a.i./acre. Because of concerns of groundwater contamination, the rate was reduced to 2.0 lb a.i./acre in 1985, then changed to a topdress postemergence application at 2.0 lb a.i./acre in 1988, and finally the label was suspended after 1989. Would aldicarb application directly to the seedpiece at planting time effectively control Colorado potato beetle and reduce environmental concerns? Literature Summary Residues of aldicarb persist longest in the more acidic, sandy soils. These soils are found throughout the potato-production areas of the eastern USA. Aldicarb behavior is influenced by pH, soil moisture, soil temperature, clay content, and organic matter. Only 5 to 20% of soil applied aldicarb is absorbed by crop plants. Study Description A field test was conducted over 2 yr to compare the standard in-furrow application method of aldicarb on white potatoes with an experimental seedpiece application. Rates of 1.0, 2.0, and 3.0 lb a.i./acre were applied either in the furrow or with the seedpiece at planting time. Percentage of plant defoliation over time, numbers of Colorado potato beetle larvae, and tuber yields at harvest were compared to evaluate the effectiveness of the treatments. Applied Question Is there an alternative application method of aldicarb granules to the standard in-furrow method that can potentially decrease the amount of aldicarb placed between the seedpieces? Aldicarb applied as an in-furrow seedpiece treatment, using a modified Bio-Serv seedpiece applicator, was as effective as the standard in-furrow application method for early season reduction of Colorado potato beetle. Rates of 1.0, 2.0, 3.0 lb a.i./acre, significantly reduced the number of early season beetle larvae, compared with larval number in untreated plots. Application rate did not significantly influence larval number. Rates of 1.0 and 2.0 lb a.i./acre with either application method effectively reduced the defoliation caused by beetle feeding until early June, while the high rate reduced plant defoliation through July. Aldicarb application rate, within application method, did not influence tuber yield. The seedpiece application method of aldicarb is as effective as in-furrow application for Colorado potato beetle control. The seedpiece application method concentrates aldicarb granules directly over and around the seedpieces and may improve absorption by the plant and reduce environmental concerns.

The effect of tillage and KCl addition on pH, conductance, NO3-N, P, K and Cl distribution in the soil profile

Distribution of NO3, P, K, Cl, pH and conductance through the soil profile were measured on two soil types after 4 yr of crop production using zero tillage (ZT) or conventional tillage (CT), with or without addition of KCl. All plots received N and P fertilizer each year as banded applications. Surface concentrations of NO3-N were higher under ZT than CT, particularly on the fine sandy loam soil. Accumulation of NO3-N also occurred in the 60- to 120-cm zone, under both tillage systems in both soils. Carryover of NO3-N was substantially greater on the silty clay than the fine sandy loam soil. Phosphate accumulated at the depth of band application in both soils under both tillage systems. Potassium concentration was generally higher under ZT than CT in the surface 15 cm of both soils, presumably due to surface retention of K from fertilizer applications and crop residues. Chloride was higher under ZT than CT in the surface 5 cm of both soils, but was higher under CT than ZT in the 30- to 60-cm and 60- to 120-cm depths in the silty clay soil, if KCl had been applied. The pH on both soils under both tillage systems was reduced in the 10- to 12.5-cm soil depth, corresponding to the zone of fertilizer application. On the silty clay soil, pH was higher under ZT than CT in the 10- to 15-cm depth and tended to be higher under ZT than CT at all depths below 15 cm. Conductance was not influenced by tillage in either soil. Application of KCl increased K and Cl concentrations in the surface 15 cm on both soils. Concentration of Cl was increased to 120 cm in both soils, indicating the mobility and leaching potential of this anion. Conductance and pH were increased in the 2.5- to 5.0-cm and 10- to 12.5-cm depths by KCl application in the fine sandy loam soil, but on the silty clay soil, only conductance was increased. Key words: Zero tillage, nutrient stratification, pH stratification

Leaching Characteristics of Banded and Broadcast Inorganic Tracers

A field study was conducted on an Ocilla loamy coarse sand to determine the leaching characteristics of banded and broadcast applications of bromide and chloride. Bromide and chloride were applied in two treatments to eight plots absent of any crop. One treatment consisted of banding one tracer while broadcasting the other. For the second treatment, the banded and broadcast chemicals were reversed. Lateral and vertical movement was observed and comparisons were made between banded and broadcast tracer applications. Results indicate soil variability, dispersion, and diffusion negated potential banding effects on the solute plume below the root zone.

Soil sampling fields that have received banded fertilizer applications

Abstract Banding of fertilizers below the seed at planting under reduced tillage conditions is becoming more commonplace. This technique however, can lead to difficulties in obtaining a representative soil sample for determining the status of mobile (N,S) and nonmobile (P,K) nutrients. This study was designed to evaluate three different soil sampling techniques. These techniques included: systematic (taking a series of soil cores perpendicular to band rows), controlled (random soil sampling avoiding the band row), and random soil sampling. All three sampling techniques adequately estimated the mobile nutrient status of soils; however, differences as a consequence of soil sampling techniques were observed for non‐mobile nutrients. The systematic sampling technique provided the highest non‐mobile nutrient values, while the controlled sampling procedure the lowest. Considering time, labor costs and the lack of availability of skilled labor the random sampling technique was the best for sampling fertilizer ba...