Narrow-row Planting Research Articles

Reduced Surface Runoff Losses of Metolachlor in Narrow‐Row Compared to Wide‐Row Soybean

Cultural management practices that reduce the off-site transport of herbicides applied to row crops are needed to protect surface water quality. A soybean [Glycine max (L.) Merr.] field study was conducted near Stoneville, MS on Sharkey clay to evaluate row spacing (50 cm vs. 100 cm) effects on metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(methoxy-1-methylethyl) acetamide] transport. One day after the foliar application of metolachlor to 2.03 m wide by 2.43 m long plots, 60 mm h(-1) of simulated rainfall was applied until 25 min of runoff was generated per plot. The calculated mass of metolachlor intercepted by the soybean foliage was greater in narrow-row than wide-row soybean, 0.39 kg ha(-1) vs. 0.23 kg ha(-1), respectively. Field and laboratory studies indicated that less than 2% of the metolachlor intercepted by the soybean foliage was available for foliar wash-off 1 d after application. Antecedent soil water content at the start of the simulations was lower in narrow-row soybean. In turn, there was a 1.7-fold greater time to runoff on narrow-row plots. The greater time to runoff likely contributed to lower metolachlor concentration in runoff from narrow-row plots. Cumulative metolachlor losses were significantly greater in wide-row than narrow-row soybean, 3.7% vs. 2.2%, respectively. Findings indicate that narrow-row planting systems may reduce metolachlor runoff following a post-emergence application.

Radiation balance and evaporation partitioning in a narrow-row soybean canopy

Seeding rate and row spacing of agricultural crops are managed to maximize yield but also have significant implications for energy partitioning and canopy microclimate. The objective of this study was to measure radiation budget components in a narrow-row soybean [ Glycine max (L.) Merr.] canopy, determine soil water evaporation ( E) as the difference between measured evapotranspiration (ET) and plant transpiration ( T), and compare measured E and T with estimates from an energy balance approach. The study was completed in a production soybean field near Ames, IA, with 350,000 plants ha −1 in 0.38 m wide rows. The field was planted on 8 May 2004 and continuous measurements were made from 8 June to 27 September. Shortwave and longwave radiation components were measured above the canopy with hemispherical radiometers. Net all-wave and incoming and reflected shortwave radiation were measured beneath the canopy with line radiometers and downwelling longwave radiation was calculated from a radiation balance. ET was measured with an eddy covariance system and T was measured with sapflow stem gauges. On sunny days under full canopy conditions, nearly 90% of the shortwave and net radiation was attenuated by the canopy with over 80% of the available energy utilized by ET. E accounted for 8–12% of the ET under full canopy conditions although these percentages may be overestimates due to evaporation of dew present on the canopy. With such a large proportion of the available energy consumed by ET, fluxes of sensible heat ( H) were very low and vertical temperature gradients across the soil–canopy–atmosphere interface were only 2–3 °C. A Priestley–Taylor energy balance approach used to estimate E and T tended to underestimate E and overestimate T. The E underestimate may be due in part to E including evaporation of dew. Conversely, T was overestimated by 25 and 14% on sunny days under full canopy conditions even with direct measurement of R n interception by the canopy. Use of shortwave extinction coefficients to estimate R n interception failed to improve T estimates significantly. The high-population, narrow-row planting strategy resulted in a dense canopy that, under full canopy conditions, resulted in very little light penetration or E.

Effect of Row Width and Nitrogen on Cotton Morphology and Canopy Microclimate

Canopy structure is a function of cultural practices, genetics, and environment; specifically, practices affecting plant row width and soil fertility can change canopy structure. Canopy structure affects canopy microclimate. Canopy microclimate determines the rate of fruit development, pest pressure, and crop response to ambient conditions. The rank growth associated with excess N in cotton (Gossypium hirsutum L.) is associated with delay in fruit development and increased boll rot. This study was conducted to determine the effect of ultra narrow row (UNR) planting on canopy microclimate in cotton. Canopy microclimate in UNR cotton (18‐ to 25‐cm row width) and conventional (76‐ to 91‐cm row width) plantings with low N (16.8 kg ha−1 at planting only) or high N (16.8 kg ha−1 at planting and 202 kg ha−1 3 wk after bloom) fertilizer was quantified by monitoring the plant canopy temperature, relative humidity (RH), and vapor pressure deficit (VPD) every 15 min during the growing season. The study was conducted at Quincy, FL, on a Dothan sandy loam soil (fine loamy siliceous, thermic Plinthic Kandiudult) in 2000 and 2001. Plant height and nodes per plant were determined 60, 90, and 120 d after planting (DAP). A split‐plot design was used with row width as the main effect and N rate as subplot. During the hours from 0700 to 1900, temperature was 1 to 2°C higher and RH 3 to 7% lower in the conventional vs. the UNR plantings. In general, N and row width effects did not have as great an impact on canopy microclimate as did plant height. In 2001, when correlations were significant, as plant height increased to 1 m, canopy temperature during the hours of 0700 to 1900 on average decreased from 33 to 25°C, RH increased from 55 to 85%, and VPD decreased from 0.16 kPa to less than 0.08 kPa. In 2002, plants grew much faster and correlations of microclimate and plant height were not observed. Plant height under typical production conditions had more of an effect on canopy microclimate than did plant density or N treatment.

Influence of Roundup Ready Soybean Production Systems and Glyphosate Application on Pest and Beneficial Insects in Narrow-Row Soybean

Roundup Ready® soybeans, Glycine max (L.) Merrill, in narrow-row planting systems were investigated in 1998 in Mississippi to evaluate the effects of the transgenic crop and glyphosate herbicide on pest and beneficial insects. Insects found in sufficient numbers for meaningful analysis included adult bean leaf beetle, Cerotoma trifurcata (Forster); adult three-cornered alfalfa hopper, Spissistilus festinus (Say); adult big-eyed bug, Geocoris punctipes (Say), and; larvae of green cloverworm, Plathypena scabra (F.), and velvetbean caterpillar, Anticarsia gemmatalis (Hübner). Populations of C. trifurcata, S. festinus, P. scabra and A. gemmatalis were not reduced in genetically altered Roundup Ready soybean, or by recommended (by label) or delayed applications of glyphosate. Numbers of G. punctipes also were not reduced in Roundup Ready soybean, but were reduced by recommended applications of glyphosate during weeks three and four following the second recommended herbicide application. Geocoris punctipes densities also were reduced at 1 and 2 wks after the first glyphosate application in plots in which the second application of glyphosate was delayed. Numbers of G. punctipes may have been indirectly reduced by glyphosate within sample weeks two and three because of variations in weed densities after treatment with the herbicide.

Narrow-Row Planting Systems for Furrow-Irrigated Soybean

Narrow rows are often associated with soybean [Glycine max (L.) Merr.] yield improvements but results have varied depending on environment, cultivars, and management practices. The effect of narrow rows in conjunction with furrow irrigation and the response of soybean cultivars with different growth habits to narrow-row planting systems or furrow irrigation spacings have received limited attention in the midwestern USA. The objectives of this study were to: (i) determine if narrow- and twin-row planting systems offer yield advantages over the conventional wide-row planting system for furrow-irrigated soybeans; and (ii) determine the response of soybean cultivars with different growth habits to planting system and furrow spacing. During 1988, 1989, and 1990, we conducted experiments at South Central Research and Extension Center near Clay Center, NE, using three planting systems: wide, twin, and narrow; and two furrow-irrigation spacings: alternate- (or furrows spaced 60 in. apart) for the three planting systems and every-furrow irrigation (or furrows spaced 30 in. apart) for the wide- and the twin-row planting systems. Soybeans in narrow-and twin-row planting systems and determinate cultivars did not have yield advantages over the conventional wide-row planting system and indeterminate cultivars, respectively, in a year with yield-limiting conditions. However, in a year with no yield-limiting conditions and with a larger amount of total water available for soybean plants at early reproductive periods, narrow- and twin-row planting systems offered yield advantages over the wide-row planting system. Determinate cultivars yielded more than indeterminate cultivars only in the twin-row planting system and every-furrow irrigation. In a year with above average rainfall but unfavorable rainfall distribution pattern, there were no yield differences between either the narrow- and the wide-row planting systems or determinate and indeterminate cultivars. We recommend narrow and twin rows with determinate cultivars for south-central Nebraska only if the irrigation system has adequate capacity and is managed properly to provide adequate water early in the season.

Influence of Planting Date and Row Width on Abundance of Velvetbean Caterpillars (Lepidoptera: Noctuidae) and Southern Green Stink Bugs (Heteroptera: Pentatomidae) in Soybean

The influence of soybean planting date and row width on seasonal abundance of velvetbean caterpillars, Anticarsia gemmatalts Hubner, and southern green stink bugs, Nezara viridula (L.), was examined in large field plots during 1987-1988. Late-season populations of velvet bean caterpillars were more abundant in ‘Braxton’ soybeans planted in early June than in early May. They also were more numerous in narrow rows (45 cm) than in wide rows (90 cm), regardless of velvet bean caterpillar population density or sampling date. Southern green stink bugs were more numerous from July to mid-August in soybeans planted in early May than in soybeans planted in mid-Mayor early June. In late September to mid-October, when peak numbers were observed, there were more stink bugs in the narrow-row plantings than in the wide-row plantings. Several planting date, row spacing, and sampling date interactions were noted and are discussed. The canopy closure index (space left open between rows) was higher in the later plantings and wide rows, whereas plant height was higher in the earlier plantings and about the same for both row widths. Plot yields varied among planting dates between years but were higher in narrow rows both years.

Growth dynamics of determinate soybean in narrow and wide rows at late planting dates

Abstract Previous studies indicated that the increased light interception available in narrow-row plantings generated greater total (dry-weight) biomass at growth-stage R5 (BR5) in soybean [Glycine max (L.) Merr.]. This increased biomass accumulation resulting from narrow rows is especially important in increasing seed yields at late planting dates compared with optimal. The first objective of this study was to determine the relative importance of crop growth rate ( CGR ) and relative growth rate ( RGR ) in causing greater BR5 in narrow rows, compared with wide, at late planting dates. Since CGR is determined by net assimilation rate (Pn) × L) (leaf area index) and GGR is determined by Lr (leaf area ratio), another objective was to determine which of these secondary factor(s) were responsible for changes in CGR and RGR in narrow rows compared with wide. Field-studies were conducted at late planting dates (in July) during 1987 and 1988 with two commercial soybean cultivars, at 100-cm (wide) rows at normal plant density, 50-cm (narrow) rows at normal plant density, and 50-cm rows at high plant density (50H). The test was conducted at Baton Rouge, Louisiana on a Mhoon silty clay (fine-silty, mixed, nonacid, thermic, Typic Fluvaquents) soil. Relative growth rate made no contribution to greater biomass accumulation in narrow rows. Increased CGR in narrow rows resulted more from increased L than changes in Pn. This increased L resulted in greater light interception (Q) and hence greater CGR . Duration of L (Ld) in narrow rows compared with wide was related to increased leaf number rather than area per leaf (Al). Genetic/cultural manipulations which increase light interception during emergence-to-R5 would be expected to enhance CGR , increase BR5, and hence increase seed yield at late plantings.

Double-row Spacing Results in Higher Yields of Bush Green Beans

Abstract Increased plant population and a decrease in rectangularity (arrangement of plants in a more uniform or square pattern) have resulted in increased yield of bush beans (Phaseolus vulgaris L.) (Atkin, 1961; Goulden, 1976; Jones, 1969; Mack and Hatch, 1968). Mack and Hatch (1968) reported an average yield increase of 17% for two bush green bean cultivars in a 15-cm-square arrangement (rectangularity of 1:1), as compared with plants in 91-cm rows (rectangularity of 1:36). Double rows were not evaluated. Kueneman et al. (1979) found that narrow-row planting of dry beans produced higher yields than wider rows, but there was no difference in yield between double rows 10 cm apart as compared with single rows of 38 and 76 cm. It may be impractical to plant accurately in a square arrangement of 15 × 15 cm, for example, compared to wider rows, and this type of planting may result in higher incidence of white mold (Sclerotinia sclerotiorum) disease (Steadman et al., 1973).

Competition and Canopy Architecture as Affected by Soybean (Glycine max) Row Width and Density of Redroot Pigweed (Amaranthus retroflexus)

The effects of soybean row width and redroot pigweed density on growth of crop and weed were studied in field trials in 1983, 1984, and Structural relationships within the canopies of soybean and redroot pigweed in relation to row width and weed density were studied in 1984 and 1985 to assess canopy geometry in relation to intra- and interspecific competition. Early in the growing season, soybean biomass was reduced in the presence of both high and low densities of pigweed. Pigweed biomass was also reduced in the presence of soybeans, especially when grown in narrow rows (25 cm). By midseason, pigweed's contribution to total biomass had reached 43% in wide-row (76-cm) stands and 24% in narrow rows. Soybean produced two to four times more leaf area than pigweed during the first half of the growth season. Narrow-row planting favored soybean leaf area production. Soybean LAI values from weedy stands were reduced compared to those from weed-free stands. Pigweed's contribution to total leaf area averaged 29% in wide-row spacing and 15% in narrow rows. Pigweed leaf area was concentrated in the upper strata of the canopy and thus reduced light available to soybean leaves lower in the canopy. Leaf area distribution patterns suggested that soybean and pigweed were competing for light even though soybean had produced more leaf area than pigweed. These relations were consistent from year to year in spite of variable water conditions.

Soybean Row Spacing: Effects on Insecticide Efficacy Against Three Common Lepidopteran Defoliators of Different Size Classes

Field studies were conducted in wide- and narrow-row soybean plantings during 1981 (central Mississippi)and 1982 (south Mississippi)to investigate the differential effect of commonly used insecticides in three common species of lepidopteran larvae of three size classes (small, medium, and large). Percentage of larva reduction was calculated based on populations in the untreated control on the same sample date, and data were analyzed separately for each of three species. Results demonstrated clear differences between row-spacing types for each of three pest species (soybean looper, Pseudoplusia includens (Walker); velvetbean caterpillar, Anticarsia gemmatalis Hubner; and green cloverworm, Plathypena scabra (F.) when all size classes are combined. When row-spacing data were combined in a single analysis, differences among size classes were noted; large larvae generally, but not always, were more difficult to control than small or medium larvae. Analyses to segregate differences between row spacings within size classes are presented for each species. Significant differences were recorded in many instances. The differences observed 2 days after application often were not observed at later intervals. Data from these experiments may prove helpful in the development of pest management programs that consider agronomic (row-spacing) and biological (size-class)effects on insecticide effectiveness.

Critical Evaporative Demands for Differential Stomatal Action in Peanut Grown in Narrow and Wide Row Spacings1

AbstractInduced stomatal closure behavior of irrigated peanut (Arachis hypogeaeL. cv. Comet, a bunch type) as related to row spacing and evaporative demand has been previously demonstrated as real and repeatable. The objective of this research was to determine the magnitude of evaporative demand that induced stomatal closure in narrow‐row plantings. Stomates in wide rows tended to show far less closure on the same days. The differences were not noted on days with low evaporative demand. Concurrent measurements of net radiation, dry‐ and wet‐bulb temperature, and horizontal wind velocity were made every 15 min. Estimates of environmental evaporative demand were made. No distinct peak or cumulative evaporative demand levels were found that separated stomatal differential action days from nonaction days. However, analysis of the cumulative advective energy component of cumulative evaporative demand showed a threshold above which stomatal closure responses were noted. This threshold was 8.5 MJ m−2. Further detailed analysis of the factors involved in the cumulative advective energy component indicated stomatal closure was dominated by neither horizontal wind velocity, integrated over time, nor integrated vapor pressure deficit.

Ratios for Predicting Field Populationis of Soybean Insects and Spiders from Sweep-net Samples1

Calibration ratios were computed to predict field populations of 40 arthropod groups per m2 from sweep-net samples in soybean. First, absolute populations were estimated by a combination of cage-aerosol and D-Vac techniques. These counts were then related to numbers in 50-sweep samples. The tests were conducted at the beginning of flowering, late pod set, and mid-pod fill in wide-row (76-cm) and narrow-row (38-cm) plantings. A statistical comparison of 11 of these groups demonstrated that the sweep-net collected some groups more effectively than others. Immatures of Hemiptera, Homoptera, and Thysanoptera required especially high ratios to convert to populations per m2 Soybean growth stage also influenced effectiveness of the sweep net for some groups, with a smaller percentage of the total population being collected during pod development than at the beginning of flowering or during pod fill. Row spacing had little effect on the calibration ratios, with one exception; i.e., adults of the soybean thrips, Sericothrips variabilis (Beach), were most effectively sampled in the narrow-row (38-cm) planting. Procedures are outlined for converting economic thresholds from number per row-m (or m2) to number per 50 sweeps. Relative variation of the sweep data is also discussed, and methods are presented for determining the optimum number of samples for experimental analysis.

Soybean Cultural Practices: Effects on Populations of Green Cloverworm, Velvetbean Caterpillar, Loopers and Heliothis Complex 12

Insects were monitored in soybean of early-, medium-, and late-maturity groups planted April through July in several row spacings at four locations in Mississippi for 1 to 3 years. Nondamaging populations of the green c1overworm, Plathypena scabra (F.), were present from June through September, and damaging populations were observed at one location after a drought. Green cloverworm populations were generally higher in late plantings, in late-maturing cultivars, and in narrow-row plantings. Damaging populations of the velvetbean caterpillar, Anticarsia gemmatalis Hubner, occurred in August or September. In 1976 and 1978 only the June and July plantings were seriously defoliated, but in 1977 all but the early-maturing April and May plantings were seriously defoliated. Velvetbean caterpillar populations were highest in late plantings, late-maturing cultivars, and in narrow-row plantings. Populations of loopers, Pseudoplusia includens (Walker) and Trichoplusia ni (Hubner), were generally less than 1/m2, but populations up to 3.2/m2 occurred at one location after insecticide treatment. Effects of planting date, cultivar, and row spacing were not consistent. Populations of the Heliothis complex larvae were generally less than 0.05/m2, but populations as high as 3.74/m2 were observed in blooming soybean. Populations of the Heliothis larvae were about equal in narrow- and wide-row plantings. In wide-row plantings, populations of Heliothis larvae averaged 0.98/m2 in closed canopy and 0.24/m2 in open canopy soybean.

Date of Planting and Row Spacing Effects on Four Soybean Cultivars1

AbstractSoil moisture conditions favor April planting of soybeans [Glycine may (L.) Merr.] in the southern USA, but reports have indicated that soybean cultivars were not adapted to April planting. Data are not available on the response of newer cultivars to early and late plantings. Also, reports from the north central USA have indicated that soybeans yield more when planted in narrow (46 cm or less) than in wide (92 cm or greater) rows, but there are conflicting data regarding row width from the southern USA.A 3‐year study was conducted on a Tifton silt loam (fine‐loamy, siliceous, thermic, Plinthic Paleudult) at Tifton, Georgia (31° 28‘ N). ‘Essex’, ‘Davis’, ‘Bragg’, and ‘Hutton’, maturity groups V through VIII, respectively, were planted in narrow (46 cm) and wide (92 cm) rows at 15day intervals from early April to early July.The interval from planting to flowering decreased for Essex and Davis as the planting date was delayed from early April through early July. This relationship occurred for Bragg and Hutton after early May planting. Essex was the earliest flowering and produced the shortest plants among all cultivars within each planting date. Essex was too short for efficient combining.The overall effect of narrow rows vs. wide rows was a yield inuease of 1.2 quintals/ha or 4.2%, but yield response to narrow row planting was not affected by cultivars or planting dates.Highest yields of Essex were obtained from early May planting. The other three cultivars yielded equally well when planted from late April through early June. Yields of all cultivars were lower for early April and early July plantings than for May and early June plantings.May to early June was the optimum planting period for Davis, Bragg, and Hutton for the combined factors of yield, plant height, and seed quality, and none of the cultivars performed well in April planting. However, the late flowering characteristics of Davis, which apparently is responsible for relatively tall plants in April plantings, offers possibilities for use in breeding programs to develop desirable cultivars for April plantings but improved seed quality needs to be combined with other desirable traits.

Effects of Narrow Row, Plant Population, and Nitrogen Application on Cotton Fiber Characteristics1

AbstractNarrow row cotton (Gossypium hirsutum L.) has shown the potential for earlier maturity. This is especially significant in areas where season length is marginal. The effect of narrow row plantings has been similar to a reduced N application rate.Studies were conducted on a Teller fine sandy loam (fine‐loamy, mixed, thermic, Udic Argiustolls) to relate the effects of N rates (0, 45, and 90 kg/ha), row spacing (25, 51, and 76 cm), and plant population (123,550 and 173,000 plants/ha) on cotton fiber characteristics. The effects of N‐row spacing and N‐population interactions were apparent. Finer fiber (decreased micronaire) resulted from high N with 25‐cm row width or high N and high population. But where no N as is applied, the 25‐cm row width produced coarser fibers. There were significant positive correlations between micronaire readings and lint and seed yields in both years.N effects on uniformity index varied from year to year. Uniformity index tended to decrease for 25‐cm row width as plant population increased and at the low plant population as row spacing increased from 25 to 76 cm. In both years there were significant correlations between uniformity index and percent pulled lint, and between uniformity index and fiber fineness.Increasing row spacing without increasing plant population, and vice versa, led to significantly lower fiber strength by 0‐inch gauge measurements in 1973. However, increasing row spacing from 25 to 76 cm produced a significant increase in fiber strength in 1974 by the 1/8‐in. gauge measurement. Fiber strength was negatively correlated with yield in 1974.The major fiber properties of length, strength, and fineness were not consistently affected by the variables of N, row spacing, and population. Some of the interacting effects are of special interest and deserve further evaluation so that the influence of climatic differences can be placed in perspective in relation to the treatment variables.

Narrow Row Planting of Cotton Genotypes and Boll Weevil Damage123

Studies of the relationship of Anthonomus grandis Boheman to short season cottons cultured in different planting arrangements were carried out in Texas for 3 seasons; a single experiment was conducted in each season. Effective blooming periods of ca. 30 days before buildup of 2nd generation boll weevil populations resulted in yields of 600–800 lb lint/acre from certain genotypes. This increased production was associated with the ability of a genotype to retain a high percent of its flowers during the blooming period. Maximum earliness and yields were recorded with genotypes planted 2 drills on 40-in. beds or single drills on 26⅔-in. beds.

Response of Cotton to Row Patterns and Plant Populations1

AbstractTheoretically, cotton planted in narrow rows at high plant populations has a potential of reducing production cost by promoting earlier maturity. The cost of controlling insects, weeds, and harvest due to a once‐over harvest would all be reduced.Studies were conducted to determine how a cultivar developed for conventional production methods would respond to a narrow row system. Coker 310 was planted in conventional 91.4 cm rows at a population of 107,489 plants/ha, in four 40.6 cm rows on a 182.9 cm bed and in twin 25.4 cm rows on a 91.4 cm bed at populations of 214,977; 286,636; and 358,295 plants/ha for 3 years.There were no differences in yield, earliness, lint percent, fiber length or strength between narrow row and the conventional check. The conventional check produced larger bolls, fewer blooms, a lower potential yield and set a higher percent of early blooms.Narrow rows gave no differences in total yield, earliness, lint percent, fiber length, or strength resulting from row patterns or plant populations. The highest plant population gave more blooms in twin 25.4 cm rows, but not in 40.6 cm rows. Potential yield was not influenced by population within row patterns, but there was a row pattern response at the same plant population.Boll size tended to be inversely related to plant population. The highest plant population in the 40.6 cm rows produced a finer fiber than other treatments.This study indicates the potential of high population — narrow row planting is lost mainly through excessive shedding of young bolls during the first 3 weeks of blooming.