Effect Of Plant Population Research Articles

Plant population and row spacing effects on corn: Phenotypic traits of positive yield‐responsive hybrids

AbstractCorn (Zea mays L.) hybrids differ in their yield response to plant population and/or row spacing changes. The objective of this study was to identify the hybrid phenotypic traits underlying intensive plant population and row spacing yield responses to help breeders select for hybrids to be placed in these possible management systems. In 2017 and 2018, six commercial hybrids were planted at 94,000, 109,000, 124,000, and 139,000 plants ha−1 in a 76‐cm or 51‐cm row spacing at two locations in Illinois. In general, the more recently released hybrids and full‐season hybrids tended to have greater yields in response to both higher planting population and narrower row spacing. Of the 46 measured phenotypic traits, those related to shoot biomass had more plasticity than many of the leaf traits (i.e. total leaves, leaf length, leaf angle, etc.) in response to plant spatial arrangement, but root traits had even greater plasticity. While the hybrids had inherently distinct phenotypic traits, there was no difference between hybrids in the plasticity extent of their shoot or root traits in response to plant population and/or row spacing alterations. Stepwise multiple logistic regression was used to identify the key phenotypic traits (predictors) of hybrids with increased yield in response to greater planting populations and narrower row spacing. These key traits for increased yields were related to capturing more sunlight (leaf angle, width, length, and area per plant), plant size (stover biomass per hectare, shoot biomass per hectare, and plant width), and root weight per plant.

Narrow rows and high maize plant population improve water use and grain yield under conservation agriculture

AbstractThe relationship between maize (Zea mays L.) population density and grain yield is influenced by soil and crop management strategies, including Conservation Agriculture (CA). However, little is known about the response of maize grain yield to varying plant population and/or row spacing under CA. A 3‐yr study was conducted under CA to evaluate the effects of plant population and row spacing on maize grain yield, plant available soil water, and soil temperature. Plant populations ranging from 40,000 to 80,000 plants ha−1 were evaluated at three row spacings (0.5, 0.76, and 1.0 m). The response of maize grain yield to plant population was highly variable between seasons: it was not affected by plant population in the season with the highest early season rainfall but increased with increasing plant population in the driest season and in the season with well‐distributed, near average rainfall. Higher plant populations resulted in lower soil water levels, presumably due to greater water extraction. Plant population affected soil water availability in the 20‐ to 80‐cm soil layer in Season 2, while plant population affected soil water availability at all soil layers except the 10‐ to 20‐ and 60‐ to 80‐cm soil layers in Season 3. Rapid maize leaf‐canopy closure provided by increased plant population and narrower row spacing is critical to adequately utilize the benefits associated with CA.

Effect of Plant Population on Growth, Yields & Quality of Bread Wheat (Triticum Aestivum L.) Varieties at Kulumsa in Arsi Zone, South-Eastern Ethiopia

Effect of Plant Population on Growth, Yields & Quality of Bread Wheat (Triticum Aestivum L.) Varieties at Kulumsa in Arsi Zone, South-Eastern Ethiopia

Effects of plant population and row spacing on grain yield of aerial-sown and drill-sown rice

Objective guidelines about plant population are essential to ensure that yield potential of rice grain is not compromised. Drill-sowing of rice is increasing in popularity in many rice-growing regions of the world in response to a requirement for increased water productivity, but little information is available on row-spacing widths required to maximise grain yield potential. This research investigated the impacts of plant population on grain yield and yield components for aerial- and drill-sown rice, and the effects of row-spacing width for drill-sown rice grown in a temperate environment. Ten aerial-sown and five drill-sown experiments were conducted in south-eastern Australia over three seasons using four semi-dwarf rice varieties. Plant populations ranged from 7 to 396 plants m–2. Plant populations as low as 30 plants m–2 were able to achieve grain yields >12 t ha–1 but only when the plants were uniformly distributed. At a population of ~100 plants m–2, the impact of plant-stand distribution was negligible. Grain yield was maintained across a large range of plant populations, mainly through compensatory effects of more tillers per plant and more grains per panicle at lower plant populations. For aerial-sown rice, maximum grain yield (up to 14.9 t ha–1) was always achieved with a minimum plant population of 100 plants m–2, and likewise for drill-sown rice provided the row spacing was ≤27 cm. At equivalent plant populations, 36-cm row spacing produced lower grain yield than narrower row spacings. When large gaps existed between plants within the rows, neighbouring plants could not compensate for the gap at the wider 36-cm row spacing, and grain yield was reduced. A practical optimal plant population of 100–200 plants m–2 was found to be suitable for the semi-dwarf varieties used in this study for both aerial- and drill-sowing methods.

Effect of NPSB rates and plant population on growth parameters and yield of maize (Zea mays L.) in Ethiopia

Effect of NPSB rates and plant population on growth parameters and yield of maize (Zea mays L.) in Ethiopia

YIELD AND BIOMETRIC CHARACTERISTICS OF MAIZE SUBMITTED TO PLANT POPULATION AND TRINEXAPAC-ETHYL DOSES

ABSTRACT The use of plant growth regulators in agriculture can alter the morphology of corn plants, increasing crop yield due to the possibility of increasing the population. This study aimed to evaluate the effects of plant populations associated with trinexapac-ethyl (TE) doses on the biometric characteristics of shoot and grain yield of contrasting corn cultivars regarding plant architecture. Experiments were conducted in the field during two seasons with the hybrids 2B710 HX (flat leaf) and TL Status (erect leaf) in a randomized block design (four replications) and treatments in a 5 × 5 factorial scheme, with five plant populations (40, 60, 80, 100, and 120 thousand plants ha−1) and five TE doses (0, 100, 200, 300, and 400 g a.i. ha−1) applied by foliar spraying at the V6 stage. Plant height, ear insertion height, stem diameter, leaf area index, and grain yield were evaluated. An increment in population increases plant height, ear insertion height, and the leaf area index, but reduces stem diameter. The plant growth regulator TE reduces plant height and ear insertion height. The interaction between plant population and TE favors corn yield, with the highest values observed in combinations of 93.4 thousand plants ha−1 with a dose of 176 g ha−1 of TE for the hybrid 2B710 HX and 92.2 thousand plants ha−1 with a dose of 251 g ha−1 of TE for the hybrid Status TL.

Effect of soybean plant density on stem blight incidence

ABSTRACT No-till system and high plant density are common practices in soybean crops of the Brazilian southern region, which has increased the incidence of stem and pod diseases. The objective of this study was to evaluate the effect of plant populations on stem blight incidence. The experiments were conducted in Muitos Capões Municipality, Rio Grande do Sul State, during the seasons 2006/07 and 2007/08, using cultivars BRS 255 RR and CD 213 RR. The evaluated populations had 12, 18, 24, 30 and 36 plants m-2, spaced 0.45 m between rows. The experimental plot units consisted of 5m width and 10m length, arranged in randomized blocks with four replicates. Stem blight incidence was quantified at phenological stages R5.1, R5.5, R6 and R7 and the collected data underwent regression analysis. Higher soybean plant densities caused a positive and significant increase on stem blight incidence in all four phenological stages for both cultivars and seasons. There was no significant difference for soybean grain yield according to the increase in plant population. Results indicated that soybean management preventing high plant densities can contribute to reduce stem blight incidence.

Effect of different genotypes, tillage methods and plant populations on dry matter, grain yield, stover yield and harvest index of hybrid maize

Effect of different genotypes, tillage methods and plant populations on dry matter, grain yield, stover yield and harvest index of hybrid maize

The effect of rhizosphere microbes outweighs host plant genetics in reducing insect herbivory.

Rhizosphere microbes affect plant performance, including plant resistance against insect herbivores; yet, a direct comparison of the relative influence of rhizosphere microbes versus plant genetics on herbivory levels and on metabolites related to defence is lacking. In the crucifer Boechera stricta, we tested the effects of rhizosphere microbes and plant population on herbivore resistance, the primary metabolome, and select secondary metabolites. Plant populations differed significantly in the concentrations of six glucosinolates (GLS), secondary metabolites known to provide herbivore resistance in the Brassicaceae. The population with lower GLS levels experienced ~60% higher levels of aphid (Myzus persicae) attack; no association was observed between GLS and damage by a second herbivore, flea beetles (Phyllotreta cruciferae). Rhizosphere microbiome (disrupted vs. intact native microbiome) had no effect on plant GLS concentrations. However, aphid number and flea beetle damage were respectively about three- and seven-fold higher among plants grown in the disrupted versus intact native microbiome treatment. These differences may be attributable to shifts in primary metabolic pathways previously implicated in host defence against herbivores, including increases in pentose and glucoronate interconversion among plants grown with an intact microbiome. Furthermore, native microbiomes with distinct community composition (as estimated from 16s rRNA amplicon sequencing) differed two-fold in their effect on host plant susceptibility to aphids. The findings suggest that rhizosphere microbes, including distinct native microbiomes, can play a greater role than population in defence against insect herbivores, and act through metabolic mechanisms independent of population.

Agronomic Response of Corn (Zea maysL.) Hybrids to Plant Populations

Field studies were conducted in 2016 and 2017 under rain-fed conditions in south-central Louisiana, (a) to determine the effects of plant density levels on plant height, ear height, stalk diameter, lodging, corn grain yield, test weight, and photosynthetically active radiation with modern corn hybrids in central Louisiana and (b) to test the hypothesis that the response of grain yield to plant population density would depend on the reproductive plasticity (flex, semiflex, or fixed ear) of the hybrids evaluated. Rainfall was above average while air temperatures were below average during the growing season in both years. Grain yield showed a hybrid response in one of two years (fixed ear greater than semiflex ear) while yields increased as plant populations increased. Test weights were less with the fixed ear hybrid and the effect of plant populations was inconsistent with increased populations resulting in greater test weight in one of two years. Lodging increased as plant populations increased with the fixed ear hybrid resulting in greater lodging in one of two years. There was a hybrid by plant population interaction for ear height and seed weight. The effect of plant populations is an important factor for corn yield; however, yield gains associated with higher plant populations may be dependent on the genetic predisposition of corn hybrids (regardless of the reproductive plasticity) to tolerate various environmental conditions and stresses associated with higher populations.

Effect of organic manure and plant population on growth and yield of Vicia faba L.

A field experiment was conducted at Alwardea farms in Babylon governorate during winter season i. e. 2014–15. The experiments were conducted in silty clay soil to investigate the effect of population density and organic manure on growth and yield of broad bean-Spanish cultivar (Barcelona). Three poultry residue levels (0, 2 and 4 t/ha) and three levels of plant population (180.000, 240.000 and 300.000 plants/ha) were used. RCBD factorial experiment method was followed with three replicates. The results showed that there was a significant difference in organic residue levels. From the results, it was inferred that addition with 4 t/ha was the best choice for optimum plant height, number of branches, chlorophyll content, weight of 100 grains, and total yield when compared to control samples which resulted in low means of the studied parameters. On the other hand, the results revealed a significant difference between the planting density in all growth and yield indicators. The optimum planting density was 180.000 plants/ha in which the number of branches, chlorophyll content in leaves, weight of 100 seeds and total yield (2710 kg/ha) were achieved. The interaction treatment (4 t/ha and 180.000 plants/ha) was significant in all the interactions.

Plant Population and Maize Grain Yield: A Global Systematic Review of Rainfed Trials

Maize (Zea mays L.) productivity has increased globally as a result of improved genetics and agronomic practices. Plant population and row spacing are two key agronomic factors known to have a strong influence on maize grain yield. A systematic review was conducted to investigate the effects of plant population on maize grain yield, differentiating between rainfall regions, N input, and soil tillage system (conventional tillage [CT] and no‐tillage [NT]). Data were extracted from 64 peer‐reviewed articles reporting on rainfed field trials, representing 13 countries and 127 trial locations. In arid environments, maize grain yield was low (mean maize grain yield = 2448 kg ha−1) across all plant populations with no clear response to plant population. Variation in maize grain yield was high in semiarid environments where the polynomial regression (p < 0.001, n = 951) had a maximum point at ∼140,000 plants ha−1, which reflected a maize grain yield of 9000 kg ha−1. In subhumid environments, maize grain yield had a positive response to plant population (p < 0.001). Maize grain yield increased for both CT and NT systems as plant population increased. In high‐N‐input (r2 = 0.19, p < 0.001, n = 2 018) production systems, the response of plant population to applied N was weaker than in medium‐N‐input (r2 = 0.49, p < 0.001, n = 680) systems. There exists a need for more metadata to be analyzed to provide improved recommendations for optimizing plant populations across different climatic conditions and rainfed maize production systems. Overall, the importance of optimizing plant population to local environmental conditions and farming systems is illustrated.

Effects of plant population and soil amendment on growth and grain yield of grain amaranth (<i>Amaranthus cruentus</i> L.)

Experiments were conducted at the National Horticultural Research Institute (NIHORT), Ibadan, Nigeria in 2012 and 2013 cropping seasons to determine the effects of plant population and soil amendments on the growth and yield of two varieties of amaranth. The treatments consisted of two varieties of grain amaranth (TE81/28 and CEN18/97), three plant populations (100,000; 60,000 and 40,000 plants ha-1). Six levels of soil amendment (0, 25, 50, 75, 100kgN ha-1 of organic fertilizer and 100kgN ha-1 of inorganic fertilizer. The trials were designed as 2 x 3 x 6 factorial and laid out in split-split plots arrangement and repeated three times. Two varieties of grain amaranth (TE81/28 and CEN 18/97) as main plots, three plant population (100,000; 60,000 and 40,000 plants ha-1) as sub plots while six levels of soil amendments as sub-sub plots. Data collected on plant height, number of branches and grain yield were analyzed using the analysis of variance and treatment means separated by the least significant difference at 5% probability level. The results showed that though the organic soil amendment gave a progressive increase in the parameters measured with an increase in application levels, the in-organic soil amendment (100 kg N ha-1) significantly increased both the growth and yield parameters at 60,000 plants ha-1 with CEN18/97 amaranth variety.Keywords: Soil amendment, Growth and Yield

Foraging responses of sheep to plant spatial micro-patterns can cause diverse associational effects of focal plant at individual and population levels.

Multiple-scale foraging decisions by large herbivores can cause associational effects of focal plant individuals neighboured with different species. Spatial micro-patterns between the focal plant and its neighbouring species within patches can affect herbivore foraging selectivity at within- and between-patch scales, which may consequently lead to associational plant effects occurring at both plant individual and population levels. However, these associational effects have not been explored together in the plant-herbivore interaction studies. We aim to evaluate how plant spatial micro-pattern within different quality patches mediate herbivore foraging selectivity, thereby affecting the associational effects of focal plant individuals and population. Using sheep as the model herbivore and a medium preferred species as the focal plant, we conducted a manipulative experiment by allowing sheep grazing freely among three different quality patches, each of which consisted of preferred, unpreferred and focal plant species with different abundances forming spatially aggregated or dispersed micro-patterns. Results showed that, compared with the aggregated plant micro-pattern, dispersed plant micro-patterns within different quality patches increased sheep within-patch selectivity, and caused diverse associational effects of focal plant individuals. Focal plant individuals experienced neighbour contrast defence (i.e. got protection in the high quality patch) and associational defence (i.e. got protection in the low quality patch), respectively, when plants distributed dispersedly in the low and high quality patch. Focal plant individuals simultaneously experienced associational susceptibility (i.e. got damage in the high quality patch) and neighbour contrast susceptibility (i.e. got damage in the low quality patch) when plants distributed dispersedly in the medium quality patch. Furthermore, dispersed plant micro-patterns reduced sheep foraging selectivity between patches, and led to a lower consumption of focal plant population compared with the aggregated plant micro-pattern. Herbivores adopt different within- and between-patch foraging decisions to maintain a high intake of the preferred species in response to various plant micro-patterns, and consequently cause diverse associational effects of both focal plant individuals and population. These associational effects have important implications for understanding the species coexistence and plant community assembly in the grazing ecosystems.

Corn (Zea mays L.) Response to Hybrid, Row Spacing, and Plant Populations in the Blacklands of Central Texas

Field studies were conducted during the 2013 and 2014 growing seasons in central Texas near Taylor (30.5326o N; 97.4548o W) to determine the effect of hybrid, row spacing, and plant populations on corn growth and yield. Two corn hybrids (BH 8844 and BH 8900) were compared at 53,000, 62,000, and 71,000 plants ha-1 planted one row on a single bed or twin rows (spaced approximately 20 cm apart) on a single bed. Plant counts were taken 4 to 6 wk after planting while ear height measurements were taken approximately four wk prior to corn harvest. Crop yield was determined by harvesting all eight rows of each plot with a combine. Weights were adjusted to 12% moisture. Experimental design was a factorial arrangement using a randomized complete block design with corn hybrid (2), row spacing (2), and seeding rates (3) as factors. Data were analyzed using PROC GLM with SAS (SAS Institute, Inc., Cary, NC) and treatment means separated by Fisher's protected least significant difference test at P = 0.05. Plant height was not affected by plant populations or row spacing as only hybrid response was significant with BH 8900 being taller in both years. Row spacing affected ear height in one of two years with the twin row spacing having a taller ear placement in the dryer year. No differences were seen with ear placement with respect to plant populations. In the dry year, yield of BH 8844 decreased as plant populations increased; however, no differences were noted with BH 8900. In the wet year, the inverse was seen with increased yield with higher populations with both hybrids. The twin row system increased BH 8900 yield in 2013. In 2014, with BH 8844, the single row system outyielded twin row and no differences noted with BH 8900. The results were quite variable and this was due in part to rainfall events in the two years. Plant and ear height was influenced by hybrid while yield response was somewhat affected by population and row spacing. A hybrid x row width response was noted indicating that certain hybrids will respond to row spacing more than others.

Effect of Male Planting Date and Female Plant Population on Hybrid Maize Yield and Evaluation of Use of Hybrid-Maize Simulation Model for Grain Yield Estimation in Hybrid Maize Seed Production

The study was carried out to determine the effect of male planting date (MPD) and female plant population (FPP) on the grain yield (GY) performance of a three-way hybrid and to evaluate Hybrid-Maize simulation model for grain yield estimation in hybrid seed maize production. Fifteen treatment combinations of five MPD as a deviation from the female planting date and three FPP replicated three times were used. The Hybrid-Maize simulation model programme was used to forecast the possible GY outcomes for the fifteen treatments of the experiment using estimated parameters and weather data for the 2006/7 season. The field experiment produced significant (P < 0.005) main effects but non-significant interaction effects for GY, yield components and antheis-silking interval (ASI). Female seed yield was affected by time of male pollen shed relative to female silking: ASI, with highest yields associated with close synchrony (ASI= +/-3 days). ASI had a significant effect on the number of kernels per ear (KPE), with the greatest KPE (318) associated with an ASI of +/-3 days. FPP effects on yield are typical for maize, showing a curvilinear response from low to high density. The optimum population density for GY was 5.4 plants m-2. Simulation output from the Hybrid-Maize simulation model showed an overestimation of GY compare to the observed yield. Furthermore, the model was unable to predict yields for the low FPP of 2.7 plants m-2. We found that Hybrid-Maize simulation model has limited potential for simulating hybrid maize seed production, as it does not accommodate limitations that may occur during the growing season: difference in male and female planting dates, pollen density and dispersion. Hence, the fixed parameters for the Hybrid-Maize simulation model can only be used in maize commercial production.

Influence of Plant Population and Weed Control Treatments on Associated Weeds, Growth, Yield and Quality of Faba Bean

To investigate the effect of faba bean plant populations (80000, 96000 and 120000 plants/feddan) resulted from the difference between hill spacing (30, 25 and 20 cm) and the efficiency of eight weed control treatments (butralin, metribuzin, oxadiargyl, each previous herbicides followed by one hand hoeing, two hand hoeing and unweeded check) on associated weeds, growth, yield and its attributes as well as chemical analysis. Two field experiments were conducted at the Experimental farm of El-Serw Research Station, Agricultural Research Center, Damietta Governorate, Egypt during winter seasons of 2015/2016 and 2016/2017. Main findings showed that increasing plant population from 80000 to 120000 plants/fedsignificantly decreased the broadleaved, grassy and total weeds dry weight by 46.32, 33.44 and 43.77% in the first season and by 45.99, 38.10 and 44.32% in the second season, respectively after 70 days from sowing. Plant population of 120000 plants/fed produced the highest values of plant height, dry weight/plant and LAI in both seasons. Moreover, sowing faba bean at 120000 plants/fedincreased seed yield/fed by 15.46 and 5.03% in the first season and 16.33 and 7.84% in the second season compared with 80000 and 96000 plants/fed, respectively. Two hand hoeing method significantly decreased the broadleaved, grassy and total weeds dry weight by 93.58, 99.24 and 95.68% in the first season and 92.62, 98.95 and 94.89% in the second season, respectively compared with the unweeded check. The results indicated that two hand hoeing method was the most superior treatment in increasing plant height, dry weight/plant and leaf area index at 70 and 90 days from sowing as well as yield, yield attributes and chemical composition of faba bean seeds followed by applying oxadiargyl herbicide with one hand hoeing treatment. It could be recommended that growing faba bean at plant population 120000 plants/fed integrated with two hand hoeing or oxadiargyl herbicide with one hand hoeing maximized seed yield per unit area.

Effects of agronomic factors on yield and quality of whole corn plants and the impact of feeding high concentrations of corn silage in diets containing distillers grains to finishing cattle.

Corn plants were sampled over 2 consecutive years to assess the effects of corn hybrid maturity class, plant population, and harvest time on whole corn plant quality and yield in Nebraska. A finishing experiment evaluated the substitution of corn with corn silage in diets with corn modified distillers grains with solubles (MDGS). The first 2 harvest dates were at the mid- and late-silage harvest times whereas the final harvest was at the grain harvest stage of plant maturity. Whole plant yields increased as harvest time progressed (yr 1 quadratic P < 0.01; yr 2 linear P < 0.01). However, differences in TDN concentration in both years were quite minimal across harvest time, because grain percentage increased but residue NDF in-situ disappearance decreased as harvest time was delayed. In the finishing experiment, as corn silage inclusion increased from 15 to 55% (DM basis) by replacing dry rolled and high moisture corn grain with corn silage in diets containing 40% MDGS, DMI, ADG, and G:F linearly decreased (P ≤ 0.01), with the steers on the 15% corn silage treatment being 1.5%, 5.0%, and 7.7% more efficient than steers on treatments containing 30, 45, and 55% corn silage, respectively. Calculated dietary NEm and NEg decreased linearly as corn silage inclusion increased indicating that net energy values were greater for corn grain than for corn silage. In addition, dressing percentage decreased linearly (P < 0.01) as silage inclusion increased suggesting more fill as silage inclusion increases in diets. Cattle fed greater than 15% corn silage in finishing diets based on corn grain will gain slower and be slightly less efficient and likely require increased days to market at similar carcass fatness and size. When 30% silage was fed with 65% MDGS, DMI, and ADG were decreased (P < 0.01) compared to feeding 30% silage with 40% MDGS suggesting some benefit to including a proportion of corn in the diet. Conversely, when 45% silage was fed with 40% MDGS, ADG, and G:F were greater (P < 0.04) than when 45% silage was fed with just grain implying a greater energy value for MDGS than for corn grain. Substituting corn silage for corn grain in finishing diets decreased ADG and G:F which would increase days to finish to an equal carcass weight; however, in this experiment, increasing corn silage levels with MDGS present reduced carcass fat thickness without significantly decreasing marbling score.

Effect of Plant Population on the Growth of Hybrid-Maize (Zea Mays L.) in The Northern Guinea Savanna of Nigeria

Effect of Plant Population on the Growth of Hybrid-Maize (Zea Mays L.) in The Northern Guinea Savanna of Nigeria

Effect of plant population on yield and yield components of safflower cultivars in rainfed condition of Vidarbha region

This study was carried out to develop best suitable plant population of two safflower cultivars in rainfed condition. The experiment was conducted at Oilseeds Research Unit Dr. P. D. K. V, Akola, during 2015-16 using a FactorialRandomized BlockDesign with three replications. Plant population were 1.66, 1.11, 0.83, 0.66 and 0.55 lakh plants/ha and cultivars included were Annigeri-1 and NARI 38. Branches per plant, effective capsules per plant, 100 seed weight and harvest index were significantly decreased as plant population increased. With increasing plant population, seed yield and biological yield were increased. The highest seed yield was obtained from plant population 1.66 lakh/ha (1150 kg/ha) which was at par with 1.11 lakh/ha plant population (1121 kg/ha) and lowest seed yield was recorded in 0.55 lakh/ha plant population (916 kg/ha). National check Annigeri-1 yielded higher seed yield than NARI-38 mainly due to higher number of effective capsules per plant. Similar trend was noticed in gross return, net return and B:C.