Influence Of Row Spacing Research Articles

Influence of row spacing on water use and yield of rain-fed wheat (Triticum aestivum L.) in a no-till system with stubble retention

A 3-year field study was undertaken to investigate the effect of row spacing on vegetative growth, grain yield and water-use efficiency of wheat. All 3 years of the study experienced 21–51% below-average rainfall for the growing season. Widening row spacing led to reduced biomass and tillers on per plant basis which could be related to the reduction in light interception by the wheat canopy in the wide rows which in turn could have reduced assimilate production. Reduction in vegetative growth in 54-cm rows translated into a significant reduction in grain yield which was strongly associated (r2 = 0.71) with the loss of spike density. The pattern of crop water use (evapotranspiration, ET) during the growing season was very similar for the three row-spacing treatments. However, there was some evidence for slightly lower ET (~5%) in 54-cm rows in two growing seasons. More importantly, there was no evidence for increased ET during the post-anthesis phase in wide rows as has been speculated by some researchers. Over the 3 years of the study, grain yield declined by 5–8% as row spacing increased from 18 to 36 cm and by a further 12–20% as row spacing increased from 36 to 54 cm. There was a consistent decline in water-use efficiency for grain (WUEG) with increasing row spacing over the 3 years. WUEG declined by 6–11% as crop spacing increased from 18 to 36 cm and declined further by 12–15% as row spacing increased to 54 cm. Lower light interception at wider row spacing could have reduced assimilate production by wheat as well as increased soil evaporation due to lower shading of the soil surface in more open canopies. Growers adopting wider row spacing on these relatively heavy textured soils are likely to experience some reduction in grain yield and WUEG. However, some growers may be prepared to accept a small yield penalty from intermediate row spacing as a trade-off for increased stubble retention and soil health.

Espaçamento, densidade populacional e adubação nitrogenada na cultura do milho

A distribuição espacial de plantas por área é um recurso para aumentar a produtividade. Para materiais de alta produtividade, são necessárias mais informações quanto à resposta à adubação nitrogenada. Assim, avaliou-se na cultura do milho a influência do espaçamento, da densidade populacional e de doses de nitrogênio no teor de nitrogênio nas folhas, estimativa do teor de clorofila, número de grãos por espiga, massa de 1.000 grãos, produtividade e teor de proteína nos grãos. O trabalho foi instalado no ano agrícola 2000/2001 e constou de tratamentos representados pela combinação de dois espaçamentos entre as linhas (0,80 e 0,60 m) com três densidades populacionais (40, 60 e 80.000 plantas ha-1) e quatro doses de nitrogênio em cobertura (0, 50, 100 e 150 kg ha-1 N). O aumento na doses de N em cobertura promoveram acréscimo no teor de N foliar, na estimativa do teor de clorofila, no número de grãos por espiga, na massa de 1.000 grãos, na produtividade e no teor de proteína nos grãos de milho. A maior produtividade de grãos foi obtida de acordo com as doses crescentes de N em cobertura juntamente com o espaçamento entre as linhas de 0,80 m e 80.000 plantas ha-1.

The Influence of Row Spacing and Seeding Rate on Seed Yield and Yield Components of Forage Turnip (Brassica rapa L.)

AbstractThe effects of four row spacings (17.5, 35.0, 52.5 and 70.0 cm) and five seeding rates (50, 100, 200, 400 and 800 viable seeds m−2) on seed yield and some yield components of forage turnip (Brassica rapa L.) were evaluated under rainfed conditions in Bursa, Turkey in the 1998–1999 and 1999–2000 growing seasons. Plant height, stem diameter, pods/terminal raceme, total pods/plant, seeds/pod and primary branches/plant were measured individually. The number of plants per unit area was counted and the lodging rate of the plots was scored. The seed yield and 1000‐seed weight were also determined. Row spacing and seeding rate significantly affected most yield components measured. The number of plants per unit area increased with increasing seeding rate and decreasing row spacing. Plant height was not greatly influenced by row spacing and seeding rate, but higher seeding rates reduced the number of primary branches and the stem diameter. The number of pods/main stem was affected by row spacing and but not by the seeding rate. Also, the number of seeds per pod was not affected by either the row spacing or the seeding rate. In contrast, the number of pods per plant clearly increased with increasing row spacing, but decreased with increasing seeding rate. The plots seeded at narrow row spacings and at high seeding rates were more sensitive to lodging. Seeding rate had no significant effect on seed yield in both years. Seed yield was similar at all seeding rates, averaging 1151 kg ha−1. However, row spacing was associated with seed yield. The highest seed yield (1409 kg ha−1) was obtained for the 35.0‐cm row spacing and 200 seeds m−2 seeding rate combination without serious lodging problems.

Influence of Row Spacing and Residual Herbicides on Weed Control in Glufosinate-Resistant Soybean (Glycine max)1

Field experiments were conducted in 1998 and 1999 at two locations in Mississippi to determine weed control efficacy of postemergence soybean herbicides alone or following pendimethalin + imazaquin preemergence in glufosinate-tolerant soybean planted in 38- or 76-cm rows. Glufosinate applications controlled pitted morningglory better than conventional herbicide treatments, regardless of row spacing. Pendimethalin + imazaquin did not increase the efficacy of glufosinate on pitted morningglory. Pitted morningglory control was increased in narrow rows when compared to wide rows with all treatments. Sicklepod control ranged from 90 to 100% in narrow rows with glufosinate, regardless of rate. Residual herbicides alone controlled sicklepod 54%, regardless of row spacing. With grass species, two applications of 420 g ai/ha glufosinate controlled weeds 82 to 100%. Residual herbicides followed by 420 g/ha glufosinate controlled grass species 80% or more, regardless of row spacing. Hemp sesbania control ranged from...

Influence of row spacing on growth, light and water use by sorghum

SUMMARYGrain sorghum (Sorghum bicolor L. Moench) was grown in Texas in 1985 at a constant population density of c. 6·6 plants/m2 in rows 0·5, 1·0 and 1·5 m apart and with the soil profile at field capacity at planting time. Dry matter production and yield were least at the widest spacing, principally because of a reduction in number of tillers. Dry matter accumulation was in direct proportion to the amount of light intercepted and largely independent of spacing between rows, with a conversion coefficient of 1·71 g dry matter/MJ energy intercepted. The most widely spaced crop used less water but not in proportion to the extent that ground cover was reduced. Water use efficiency was also less in the most widely spaced crop, probably because of heat advection from the bare soil between rows.

Influence of Row Spacing, Seeding Rates and Herbicide Systems on the Competitiveness and Yield of Peanuts1

Abstract Peanuts (Arachis hypogaea L. ‘Florunner’), infested with sicklepod (Cassia obtusifolia L.) were grown during 1977 and 1978 in 20.3-, 40.6- and 81.2-cm row widths (on Dothan sandy loam and on Greenville sandy clay loam). The crop was maintained weed-free for 0, 2, or 5 weeks or for the entire growing season. Three herbicidal systems with various intensities were utilized. In 1978, reduced and regular rates of in-row crop seeding were compared. Weed-free maintenance for 5 weeks generally produced yields of peanuts equivalent to those obtained with continuous weeding. Sicklepod green weights were reduced by 28 and 53% in peanuts with row spacings of 40.6 and 20.3 cm, respectively, as compared to standard 81.2 cm spaced rows. Peanuts in close-row patterns yielded about 14% higher than the conventional 81.2 cm row spacing when averaged for all studies. Adjustments of the in-row seeding rate to produce a more normal seed-drop per hectare reduced the yield of peanuts only 1 to 3% and, therefore, did not negate the increased yields produced with close-row spacings.

Influence of Row Spacing on Competitiveness and Yield of Peanuts (Arachis hypogaea)

Peanuts [Arachis hypogaea(L.) ‘Florunner’], infested with sicklepod (Cassia obtusifoliaL.) and Florida beggarweed [Desmodium tortuosum(Sw.) DC.] were grown in 20.3-, 40.6-, and 81.2-cm rows on Dothan sandy loam at Headland, Alabama, and on Greenville sandy clay loam at Plains, Georgia. In-row seeding rates were equal, regardless of row width. Peanuts were maintained free of sicklepod and Florida beggarweed for 0, 2, and 5 weeks after emergence or throughout the season. In either the absence or presence of weeds, peanut yields generally increased with decreasing row width. Quality of peanuts was not adversely affected; in fact, desirable attributes such as percent sound mature kernels (SMK's) were sometimes increased as the row width decreased. Weed growth with close rows was much less than with standard 81.2-cm rows. Although yields of peanuts were lower with increasing time of weed competition, the influence of row spacing on competitiveness of the peanut canopy remained relatively constant on both soil types. Generally, weeds from either seeded or natural stands produced equivalent competitive results.

Influence of Row Spacing on Weed Competition by Cotton

When planted with narrow (53 cm) row spacing, cotton (Gossypium hirsutumL.) ‘McNair 210’ produced maximum yields with as little as 6 weeks of weed-free maintenance. With wider row spacing (79 and 106 cm), however, 10 and 14 weeks of weed-free maintenance were required for maximum yield. When weeds were allowed to grow in cotton for more than 2 to 4 weeks after planting, yield reductions occurred. This tolerance period did not differ with row widths of 53, 79, or 106 cm.

Influence of Row Spacing and Straw Mulch on First Stage Drying

AbstractEvaporation during first stage drying was measured with evaporation plates on the soil surface in grain sorghum plots with 25‐, 50‐, and 100‐cm row spacings, during several stages of grain sorghum [Sorghum bicolor (L.) Moench] development in 1972 and 1973. Evaporation during first stage drying was affected by row spacing, leaf area index (LAI), and soil shading. Both LAI and soil shading were related to row spacing and plant population. The more complete plant canopy of grain sorghum with narrow‐row spacing decreased penetration of radiant energy to the soil surface and reduced the evaporation rate of soil water during first stage drying. Evaporation was greatest during the early part of the season when shading was least and lowest during boot stage and pollination, when all leaves were fully expanded and provided maximum plant canopy and soil shading. Narrow‐row spacing established an earlier, and more complete plant canopy than conventional 100‐cm row spacing and shaded more of the soil surface from early vegetative growth to maturity. Soil surface shaded near solar noon was a better indicator of first stage evaporation beneath a canopy than LAI.The combined effect of a mulched surface and a plant canopy on reducing evaporation was the product of the fractional reduction in potential evaporation resulting from the plant canopy and the evaporation resulting from the mulched surface with no canopy cover. An empirical equation was developed from the evaporation data for use in calculating first stage evaporation as related to potential evaporation, fraction of the soil surface shaded, and mulch rate.

The influence of row spacing and plant population on the effect of weed competition in soybeans

An experiment was done to determine the reduction in yield attributable to weed competition when soybeans were grown in 25,50,75 and 100 cm rows and within-row densities of 10, 20 and 40 plants m-1. There was no effect of weeds on yield when soybeans were grown in 25 cm rows but a 20 per cent decrease with 50 cm rows, 26 per cent with 75 cm rows and 37 per cent with 100 cm rows. Within-row density had no effect but there was a trend towards an interaction between within-row density and the presence or absence of weeds. Narrow rows and higher within-row densities increased the height of the bottom pod, lodging and the number of pods m-2 but decreased stem diameter, number of pods per plant and the yield per plant. Narrow rows decreased yield per pod and seeds per pod. There was a trend, which was not significant (P < 0.05), towards reduced yield per pod and seeds per pod with higher within-row densities. Weed competition reduced stem diameter, pods per plant, pods m-2 and yield per plant. Weeds had no effect on the height of the bottom pod, yield per pod and seeds per pod. Soybean grain weight was not changed by row spacing, row density or weed competition.

Influence of Row Spacing, Irrigation, and Weeds on Dryland Flax Yield, Quality, and Water Use1

AbstractField experiments were conducted during 1966 and 1967 at Mandan, N. D. to evaluate the effects of row spacing (7.5, 15, and 30 cm), irrigation water at fruiting, and weed competition (primarily from Setaria virilis) on water use by flax (Linum usitatissinum L.). An irrigation of 50 mm at the fruiting stage increased flaxseed yields only when weeds were controlled, particularly in the dry year of 1967. Flaxseed yields increased at row spacing narrowed from 30 to 7.5 cm only on unweeded plots. Weed growth reduced flaxseed yields for the 2‐year period from 26 to 53%, with the least reduction from 7.5‐cm row spacing. Midsummer rains or supplemental water at fruiting was less effective in increasing flaxseed production when weeds were present, but some degree of weed control was achieved with narrower row spacing. Oil content of flaxseed was not affected by treatments, but iodine number was slightly higher for the wider spacing (30 cm) in 1966. Total water use was not affected by row spacing or weed treatment, but water use efficiency was increased by narrow row spacing and by weed control. Water use patterns indicated deeper root penetration during the drier year.

Influence of Row Spacing and Plant Density on Single Harvest Tomato Yields1

Abstract Ripe fruit yields of ‘Campbell 17’ tomatoes at the 50% ripe fruit stage increased from 6.0 to 13.1 tons per acre in the population range of 1,815 to 7,260 plants per acre. Constant yield was obtained in the population range from 7,260 to 29,040 plants per acre in single rows and from 4,840 to 58,080 plants per acre in the twin rows. Single harvest at the 85% ripe fruit stage resulted in a yield increase from 7.5 to 20.8 tons per acre in the population range from 1,815 to 9,680 plants per acre in single rows. A significant decrease in yield was obtained at the population of 29,040 plants per acre. The ripe fruit yield from twin rows at this harvest stage reached a nearly constant yield plateau of 19.3 to 22.8 tons per acre in the population range of 7,260 thru 29,040 plants per acre. Plant spacing of 3 inches in the row in both single and twin rows resulted in a significant yield reduction at the later harvest date. A power form curve expressed the yield per plant—plants per acre relationship at plant spacings of 6 to 12 inches in the single rows and from 6 to 24 inches in the twin rows.

Influence of Row Spacings on Yield and Quality of Sugarcane in Georgia

AbstractSugarcane (Saccharum officinarum L.) was grown in row spacings of 107, 122, 137, 152, and 168 cm in the field experiments in 1957, 1958, and 1959. Plant cane, 1st‐ and 2nd‐year stubble crops were harvested from each experiment. Yield of cane per hectare, percent juice extracted from stalks and degrees Brix of the juice were obtained. The mean cane/ha yields of the three varieties of cane per hectare were significantly higher from rows spaced 107, 122, and 137 cm than from those spread 152 or 168 cm. Row spacings had no significant influence on percentage of juice extracted or Brix of the juice. These data indicate that increased yields could be expected from narrow row spacings but the added cost of seedcane, cultural practices, and harvesting would need to be balanced against the increased yield.