Optimum Plant Population Density Research Articles

Respons Tanaman Padi pada Populasi Tinggi di Lahan Sawah Irigasi

Plant density is one of important technology in accordance with increasing rice productivity. Its in line with higher plant population up to optimum value, however increasing density above the optimum value will resulting decreasing yield. The optimum plant population density depends on many factors such as environment, management practices and specific varieties. This study aimed to obtain response of high population density on growth and yield in some rice varieties. The study was designed using split plot design with three replications. The main plot was plant population density, i.e. 213.333 plant population per ha (jajar legowo 2:1 planting method); 376.470 plant population per ha (jajar legowo ganda 1 planting method); 571.428 plant population per ha (jajar legowo ganda 2 planting method). Subplot was varieties i.e: Mekongga, Inpari-30 Ciherang Sub-1, and Inpari-32 HDB. The results showed that a high population density through jajar legowo ganda 2 planting method could increase the yield of Mekongga 16.31% and Inpari32 HDB 20.17% compared to jajar legowo 2:1 planting method, while Inpari-30 Ciherang Sub-1 had no significantly different between those two planting method. Therefore, the optimum irrigated rice yield could reach with plant density arragement and specific variety.

Review on Plant Population Density and Row Spacing Effects on Yield of Maize (Zea mays) in Ethiopia

In this review maize is highly sensitive cereal crop to most agronomic practices such as plant population density and plant spacing. Plant population density and row spacing is one of the best agronomic practice to increase maize crop productivities. Depending on the environmental yield potential of the land, improvements of intera and inter row spacing practices are important for land productivity to each maize varieties. The optimum plant population density that increases the yield and yield components of a single plant. As the review indicates most yield components of maize varieties are affected by plant population density and row spacing due to resource competition results yield reduction. As the plant population increase per cultivated land area, economic yield and above ground biomass yield was decreased. Similarly the narrowest intera and inter row plant spacing decreases economic yield and above ground biomass yield of maize crop. Keywords : population, maize, density, spacing, cob DOI: 10.7176/JBAH/10-21-02 Publication date: November 30 th 2020

English

A field experiment was conducted at Wondo Genet Agricultural Research Center in the production season of 2013/2014 and 2014/2015 with the objective of identifying the best combination of intra and inter-row spacing for optimum plant population density of rosemary. The treatments consisted of five intra-row spacing (50, 60, 70, 80, and 90 cm) and three inter-row spacing (60, 80 and 100 cm) with a total treatment combination of fifteen that were laid out in factorial randomized completely block design with three replications. Data on plant height, fresh leaf weight per plant, fresh aboveground biomass and dry leaf weight were collected and analyzed. The main effect of intra-row and inter-row spacing had a significant influence on the number of branch per plant, fresh leaf weight per plant, dry leaf weight per hectare and oil yield per hectare in each year and pooled mean. The interaction effect of intra-row and inter-row spacing caused significant variations in the number of branch per plant, fresh leaf weight per hectare and aboveground biomass per hectare in the pooled mean analysis. Plant height and oil content were not influenced by the main effect of intra-row and inter-row spacing and their interaction in each year and pooled mean. Significantly maximum fresh leaf yield (23777 kg ha-1) and fresh aboveground biomass (33746 kg ha-1) were obtained from the combined of 50 cm intra-row and 60 cm inter-row spacing. Significantly higher dry leaf yield (7081.1 kg ha-1) and (6333.4 mkg ha-1) and oil yield (174.6 kg ha-1) and (154.7 kg ha-1) were obtained from the main effect of 50 cm intra-row and 60 cm inter-row spacing respectively. It may, therefore, be concluded that spacing combination of 50 cm intra-row x 60 cm inter-row responded favorably in attaining higher leaf yield and oil yield of Rosemary in the area. Key words: Rosemary inter-row, intra- row, spacing, plant population.  

Evaluation of the Effects of Intra and Inter Row Spacing on the Growth and Yield of Ground Nut (Arachis Hypogaea L.) at Haro Sabu, Western Ethiopia

Ground nut (hypogaea L.) is one of most important food crop grown in Oromia Regional State, Ethiopia. However, its productivity is very low due to inappropriate intra and inter spacing practice. Thus,the study was conducted in 2016 and 2017 during the main cropping season at Haro Sabu Agricultural Research Center and Kombo subsite of Kelem Wollega zone of Western Ethiopia to identify the effects of different spacing on growth parameters, yield and yield components of ground nut varieties. The experiment was laid out in Randomized complete Block design with three replications in factorial arrangement. The experiments was consist of two factors. Nine levels of spacing were 50cmx5cm, 50cmx10cm, 50cmx15cm, 60cmx5cm, 60cmx10cm, 60cmx15cm 75cmx5cm, 75cm x10cm, 75cm x15cm and two varieties (Manipinter and Sartu). The highest total number of pods per plant (21.36) was obtained from variety manipinter. Regarding to spacing, the highest number of pods per plant (25.00) was obtained from 75cmx10cm and followed by 75cmx15cm(22.45) . The highest hundred seed (66.85g) weight and grain yield (2105 kg ha -1 ) was recorded from manipinter variety. Regarding to spacing, the highest grain yield (2474 and 2433 kg ha -1 ) was obtained from 50cmx5cm and 60cm x5cm respectively. The highest net benefit (50269.00 and 50245.00 ETB ha -1 ) was recorded from 50cmx5cm and 60cmx5cm spacing respectively. However the highest marginal rate return (288.46%) was recorded from spacing 60cm x 5cm followed by 50cm x 5cm (2.66%). Therefor spacing of 50cmx5cm and 60cmx5cm was optimum plant population density for production of ground nut in Kelem Wollega zone of western Ethiopia. Keywords : Arachis hypogaea L., grin yield, interaction effect, spacing DOI : 10.7176/ALST/70-04

Influence of Plant Population Density on Growth and Yield of Chamomile (Matricaria chamomilla L.) at Wondo Genet, South Ethiopia

An experiment was conducted at Wondo Genet Agricultural Research Center in the production season of 2016 and 2017 with the objective of identifying the best combination of intra and inter-row spacing for optimum plant population density of chamomile. The experiment was conducted using four intra-row spacing (40 cm, 50 cm, 60 cm and 70 cm) and three inter-row spacing (40 cm, 60 cm and 80 cm) with a total treatment combination of twelve that were laid out in factorial RCBD design with three replications. The main effect of intra-row and inter-row spacing had a significant influence on a number of flowers per plant, the weight of fresh flower per plant in both cropping seasons. In 2016 cropping season significantly higher number of flowers per plant was obtained from the interaction spacing of 60 cm × 60 cm and In 2017 cropping season weight of fresh flower per plant was affected by the interaction spacing of 60 cm × 80 cm. Significantly maximum fresh flower weight per hectare and dry flower weight per hectare was obtained from the main effect of 40 cm intra-row and 40 cm inter-row spacing in both cropping seasons and in 2017 cropping season their interaction was significantly influenced by the weight of fresh flower per hectare. The pooled mean analysis showed that the maximum fresh flower weight per hectare (3779 kg ha-1), dry flower weight per hectare (517.2 kg ha-1) and (586.7 kg ha-1) were obtained from the treatment combination of 40 cm intrarow with 40 cm inter-row spacing. In 2016 cropping season maximum oil yield (5.6 kg ha-1) was obtained from the treatments combination of 40 cm intra-row with 40 cm inter-row spacing. Therefore we suggest that the bestcombined intra-row and inter-row spacing for chamomile is 40 cm × 40 cm to attain maximum yield under appropriate management conditions at Wondo genet and similar agroecology zones.

Effect of Some Agronomic Practices to Increase Maize Yield in Ghana

Low plant densities of maize are often observed in fields of farmers practising no-till agriculture which causes low grain yield in Ghana. With the increasing population and consumption of maize in the country, research must be directed to solve this problem to enhance maize production. In this paper, a 2x3 factorial experiment in randomized complete block design with 4 replications was carried out at Wioso in the Atwima-Nwabiagya District in the Ashanti Region of Ghana during the major season of 2007 in order to come out with the best practices in maize production. The objectives of the study were to determine the right period of refilling maize field and the comparative effect of refilling with seed and seedling on the growth, optimum population density, and yield of maize. The factors were material for refill, which was either seeds or seedlings, and time of refilling either at 5, 10, and 15 days after planting. The results showed that refilling with seedlings produced the greatest positive effect in the number of leaves per plant, leaf length, leaf diameter, plant height and stem girth. Furthermore, refilling with seedlings contributed more to the optimum plant population density. Total grain yield when seedlings were used as refill was 967kg per hectare more than when seeds were used as refill material. On the other hand, plants from seeds refill were weak, lodged more and allowed much solar radiation penetration to the ground. Grain yield from seed refill plants was 6%, whilst seedling refill plants contributed 34% to the total grain yield. Refilling at 5 days after planting induced greater growth than 10 or 15 days after planting. The results indicate that it is possible to do refilling in maize field by using seedling as this contributes more than the traditional method of using seeds.

Yield and Fruit Quality of Watermelon in Response to Plant Population

There is an increase in demand for watermelon (Citrullus lanatus L.) in Nigeria. Information is needed on how to maximize yield. Field trials were conducted in 2006 and 2007 to evaluate the performance of watermelon cvs. Sugarbaby and Kaolack at four planting densities in Ilesha, Ibadan, and Dogondawa representing the forest, derived Savanna (transitional zone between the forest and Guinea savanna), and the Guinea Savanna ecological zones of Nigeria, respectively. Cultivars responded differently to planting density with respect to fruit yield, with ‘Sugarbaby’ producing higher yields, 6.35 and 12.93 Mt·ha−1 in Ilesha and Ibadan, respectively, whereas ‘Kaolack’ produced higher yields (23.85 Mt·ha−1) in Dogondawa. Generally, the forest ecology had the lowest fruit yield when compared with Savanna ecologies. Differences in fruit yield existed among the ecologies due to planting density, with llesha having the highest yield at 11,111 plants·ha−1. Highest yield was at 14,815 plants·ha−1 in Ibadan and Dogondawa. Average fruit weight decreased with increased planting density. Density response appears to be location dependent and producers should plant watermelon at optimum plant population density as determined by experimental results in each ecological zone of Nigeria.

Response of a Leafy and Non‐Leafy Maize Hybrid to Population Densities and Fertilizer Nitrogen Levels

Optimum plant population density (PPD) of maize (Zea mays L.) for grain and/or silage production depends on hybrid type, soil fertility and agronomic management. Limited information exists on the yield response of Leafy maize hybrids to different PPD under varying N application rates. A field study was conducted during 2003 and 2004 in Ottawa, Canada to evaluate grain and silage yields of a Leafy hybrid (‘Maizex LF850 RR’) with a conventional hybrid (‘Pioneer 3893’), under three PPD (60 000, 75 000, and 90 000 plants ha−1) and four N fertilizer (0, 75, 150, and 225 kg N ha−1) regimes. Canopy light interception, plant dry matter (DM), silage, and grain yield were measured. The Leafy hybrid had 20 to 25% more leaf area, on an individual plant basis, and produced significantly greater silage DM (21.1 vs. 20.0 Mg ha−1), but had a significantly smaller grain yield (9.4 Mg ha−1) than the conventional hybrid (9.7 Mg ha−1). The Leafy hybrid was more sensitive to high density and low N stresses, resulting in more barren plants (up to 15%), lower harvest index (HI), thus significantly lower grain yield than the conventional hybrid in 2003. Grain yield reached to a maximum with 225 kg N ha−1 followed by 75 and 150 kg N ha−1, but silage DM was not different between 150 and 225 kg N ha−1 Plant population density had no effect on grain yield but silage yield increased linearly as PPD increased from 60 000 to 90 000 plants ha−1 Within the tested range of PPD, no differential response of hybrids was observed in terms of grain yield or silage DM, and N treatments had no effect on response of hybrids to PPD. We conclude that the Leafy hybrid was more sensitive to high PPD and low N stresses than the conventional hybrid especially for grain production. The optimum PPD for silage production may be beyond 90 000 plants ha−1 for both types of hybrids.

Optimum plant population density for chickpea and dry pea in a semiarid environment

Chickpea (Cicer arietinum L.), an annual grain legume, is being broadly included in cereal-based cropping systems throughout the semiarid Canadian prairies, but information on optimum plant population density (PPD) has not been developed for this region. This study, which was conducted from 1998 to 2000 in southwestern Saskatchewan, determined the effect of PPD on field emergence, seed yield and quality, and harvestability of kabuli and desi chickpea compared with dry pea (Pisum sativum L.). Seed yields of all legumes increased with increasing PPD when the crops were grown on conventional summerfallow. The PPD that produced the highest seed yields ranged from 40 to 45 plants m-2 for kabuli chickpea, from 45 to 50 plants m-2 for desi chickpea, and from 75 to 80 plants m-2 for dry pea. When the legumes were grown on wheat stubble, the PPD that gained optimum seed yield ranged from 35 to 40 plants m-2 for kabuli chickpea, from 40 to 45 plants m-2 for desi chickpea, and from 65 to 70 plants m-2 for dry pea. The proportion of large-sized (>9-mm diameter) seed in the harvested seed was >70% when the kabuli chickpea was grown on summerfallow regardless of PPD, whereas the large-seed proportion decreased with increasing PPD when the crop was grown on wheat stubble. Increases in PPD advanced plant maturity by 1.5 to 3.0 d and increased the height of the lowest pods from the soil surface by 1.4 to 2.0 cm (or 5 to 10%), with desi chickpea receiving the greatest benefits from increased PPD. The percentage of plants established from viable seeds per unit area decreased substantially as PPD increased, with kabuli chickpea emergence decreasing from 90% at PPD = 20 plants m-2 to 72% at PPD = 50 plants m-2, from 81 to 69% for desi type, and from 83 to 59% for dry pea . The reason for the low field emergence with increased PPD is unknown, but methods which lead to improved field emergence represent a great opportunity to increase seed yield and reduce production costs for both chickpea and dry pea in this semiarid region. Key words: seed size, Cicer arietinum, Pisum sativum, seeding rate, summerfallow

Optimum plant populations for okra (Abelmoschus esculentus) in a mixture with cassava (Manihot esculenta) and its relevance to rainy season-based cropping systems in south-western Nigeria

Experiments were conducted in Nigeria to evaluate the optimum plant population density for okra (Abelmoschus esculentus) sown in monoculture or intercropped with cassava (Manihot esculenta). The crops were sown as late and early season crops in 1997 and 1998. Okra was sown at varied spacings to achieve final plant densities of 25000, 35000 and 50000 plants/ha in both monoculture and mixed stands. Intercropping had no significant effect on okra phenology (time to vegetative growth, flowering and fruiting). However, it significantly reduced weed growth by 25–45% and nematode infection in okra by 36%, and kept the canopy environment of cassava cooler by 3·0–4·4°C and more moist by 5–10g/kg, compared with monoculture. The durations of vegetative and reproductive growth and the weed-control ability of okra in both cropping systems were influenced by population density. Okra sown at 50000 plants/ha took the longest time to reach specific phenological stages, controlled weeds best and gave the highest fresh pod yields in both seasons. There was little increase in pod yields between 35000 and 50000 plants/ha in mixed stands in late season sown crops. The growth and tuber yield of cassava were not significantly affected by intercropping and okra population density.The growth of okra and cassava were better with early than late season sowing, irrespective of okra population density or cropping system. This appears to have been due mainly to the effect of temperature and rainfall differences between the seasons. The substantial variation in the weather during the two seasons also had greater effect in monoculture than mixed stands. It is concluded that when rainfall is limiting, okra could be intercropped with cassava using population density up to 35000 plants/ha to allow the vegetable to develop and to maximize pod yield under the relatively dry conditions. The optimum target suggested is 50000–60000 plants/ha during the wet periods.

Intercropping maize with cassava or cowpea in Ghana

Maize/cassava and maize/cowpea intercrops were evaluated in southern Ghana, over a 5-year period to determine the optimum combination of component crop varieties and component plant population densities to optimize productivity of maize-based intercropping systems. Results indicated that some cowpea varieties which perform well under sole cropping tend to climb under intercropping and may not be adapted for intercropping. Selection of improved cowpea lines under intercropping might, therefore, be necessary. Full-season maize intercropped with short-duration cassava (LER=1.5), and medium-maturing cowpea intercropped with early-maturing or full-season maize (LER=1.4-1.53) resulted in high productivity of the intercrops. The optimum plant population density of the intercropped maize (50,000 to 58,000 plants ha-1) was similar to the recommended optimum sole crop maize plant population density. It is recommended that intercropped cassava population density should not exceed 15,000 plants ha-1 to obtain marketable sizes of cassava roots. Planting double rows of cowpea between two rows of maize was a better alternative (LER=1.60-1.62) to sole cropping. Ghana Jnl agric Sci. Vol.32(2) 1999: 129-136

Effects of plant population density and cultivar on growth, yield and yield components in groundnut (Arachis hypogaea 1.)

An experiment was conducted at the University of Queensland Redland bay Farm (27°37′ S, 153°17′ E) in southeast Queensland, Australia to study response of groundnut cultivars [Improved Virginia Bunch, NC-7, Q18801 (Virginia types), TMV-2, McCubbin and Red Spanish (Spanish types)] to different plant population densities (6.3, 11.1, 25.0 and 100.0) arranged in square spacings. The objective was to study plant physiological and morphological characteristics associated with the optimum plant population density among groundnut cul- tivars. Leaf area index (LAI), interception of photosynthetically active radiation (PAR), total dry mass (TDM), dry mass (DM) partitioning, economic yield and yield components were measured. The results show that TDM and economic yield were both maximized at 25 plants m−2 in all cultivars and so were the radiation use efficiency (Ec), crop growth rate (CGR) and DM partitioning'toTeproductive components (pods and kernels). Overall, variation in economic yield (kernel DM) was determined by pod harvest index (HI), kernel HI, ratio of pod to peg plus pod number, kernel number per pod and kernel size. Most of these components were maximized at the optimum plant population density.

Optimum sowing dates and plant populations for winter peas (Pisum sativum)

Experiments to evaluate the optimum plant population density and sowing date for winter peas, semi-leafless cv. Rafale, were sited on free draining sandy loam soils at Thornhaugh, Cambridgeshire in 1993/94 (Expt 1), 1994/95 (Expt 2) and 1995/96 (Expt 3). Peas were sown at the end of October, in mid-November and early December, at seed rates to achieve final plant densities in spring of 50, 70 or 90 plants/m2. Seed rates were calculated allowing for 20% seedbed loss and plant loss due to winter kill in Expt 1, and 15% in the other two years.Peas sown in warmer seedbeds in October emerged in early December or before, November-sown peas did not emerge until mid-January and December-sown peas from late February to mid-March. The growth stage of October-sown peas was thus more advanced than the later sowings over the winter and spring period. Winters were mild for Expts 1 and 2, but there were more frost periods during Expt 3.The yield of winter peas was dependent on sowing date. Yields of Rafale sown in October were highest in Expt 1, but lower than November-sown peas in 1995 (Expt 2), as a result of damage from late frosts during flower initiation in April, and in 1996 (Expt 3) due to plant losses after a more severe winter, frost periods and very cold winds in March. In Expts 1 and 2, yields of December-sown peas were significantly lower than November-sown peas, probably because they were adversely affected by drought stress during the sensitive flowering period. Therefore the optimum time for sowing winter pea cv. Rafale to achieve reliable yields appears to be mid-November. In some years, however, conditions may be too wet for late drilling, particularly on heavier soils.The highest plant population densities of 90 plants/m2 gave the highest yields in Expts 2 and 3, but there was little increase between 75 and 90 plants/m2. Bearing in mind financial return and seed costs, the optimum target suggested is 75–80 plants/m2.

Plant Population Density x Sowing Date Interaction in Wheat

Wheat yield response to sowing date is very well known in Northwest of Mexico; however, sowing date x plant population density has not been studied before. The objective of this work is to set wheat performance at early sowing date when using low plant population density. Six experiments were carried out during two years (1994-96) planting in three different sowing dates (November 15, December first and January 10). Each of these experiments contained five plant population densities treatments (13.5, 24.1, 54 and 217 thousand plants/ha plus a check with 120 kg seed/ha) with three cv: Bacanora T88, Oasis F86 and Tepoca T67. Plant population densities x sowing date interaction was significant. This was due to a higher yield with 117 thousand plants/ha than the check in early dates (end of November) and the opposite in later dates. Plant population density x sowing date x variety interaction was also significant. This was due to the fact that Tepoca T87 response to any increment in seed dosage even in early sowing date. The optimum plant population density was 200 thousand plants/ha for November 15 and 260 for December first. Plant population density response was explained mainly by the tillering capacity of wheat, and sowing date response was mainly due to kernel weight.

Effects of density of planting and time of nitrogen application on maize varieties in different ecological zones of West Africa

Field experiments were conducted in 1992 on soils which have been classified as Alfisols ranging from Paleustalf to Oxic Paleustalf which represent three different ecological zones of West Africa. This research was conducted to determine the effect of density of planting on yield and yield components at 53,333, 66,666, and 79,999 plants‐ha‐1 and time of nitrogen (N) fertilizer application [50% at planting and 50% at four weeks after planting (4WAP), entire N application at two weeks after planting (2WAP), and 50% at planting and 50% at anthesis]. The experiment was a factorial arrangement fitted to randomized complete block design and replicated three times. The maize (Zea mays L.) varieties used in this study gave increased yields at population density up to 53,333 plants‐ha‐1 in Ikenne and Mokwa, while a response of 79,999 plants‐ha‐1 was obtained at Kaduna. The results also showed that a split application of N at planting and 4 WAP appeared to be the best for Ikenne, while the entire application at 2WAP appeared to be the best in savanna ecologies. The results indicate increase yield with increasing latitude suggesting that the higher solar radiation in the savanna ecologies increase the photosynthetic capacity of the maize plants used in the study. Maize genotypes used in this study did not respond to density beyond 53,333 plants‐ha‐1 at Ikenne and Mokwa, though a response was obtained up to 79,999 plants‐ha‐1 at Kaduna. Thus, it can be concluded that density response is location dependent and that farmers should plant maize at highest optimum plant population density as determined by experimental results in each ecological zone of West Africa. The results also showed that a split application of N at planting and 4WAP appeared to be the best for Ikenne, while the entire N application at 2WAP appeared to be the best for the savanna ecologies.

Cucumber Yield Response to Plant Density and Spatial Arrangement

The effects of plant population density and spatial arrangement of plants on yield of gynoecious pickling cucumber (Cucumis sativus L.) have not been clearly defined for the south central region of the USA. This research was conducted to identify adapted cultivars, the optimum plant population density (PPD), and plant spatial arrangement (PSA) of cucumber intended for once-over mechanical harvest. Cucumber cultivars Calypso, Discover, Flurry, Lucky Strike, Napoleon, Peto Triplemech, Regal, and Tamor were grown at PPDs ranging from 26 000 to 130 000 plants/acre. Calypso and Discover were grown with PSAs of 15 by 4-in., 22 by 3-in., and 32 by 2-in. row and plant spacings on beds 76 in. wide and a constant population density of approximately 82 000 plants/acre [...]

Factors affecting growth and yield of short-duration pigeonpea and its potential for multiple harvests

SummaryEnvironmental and cultural factors that may limit the yield of short-duration pigeonpea were investigated over three seasons. Plants in the peninsular Indian environment at Patancheru grew less and produced less dry matter by first-flush maturity than at Hisar, a location in northern India where the environment is considered favourable for the growth of short-duration pigeonpea. However, with a similar sowing date in June, the mean seed yields of three genotypes, ICPL 4, ICPL 81 and ICPL 87, were very similar, at about 2·3 t/ha, in both environments. This was mainly due to the higher ratio of grain to above-ground dry matter at Patancheru. In addition to the first harvest, all genotypes showed a potential for two more harvests owing to the warm winters at Patancheru. The potential for multiple harvests was particularly high in ICPL 87, which yielded 5·2 t/ha from three harvests in 1982–3, 3·6 t/ha from two harvests in 1983–4, and 4·l t/ha from three harvests in 1984–5. The optimum plant population density at Patancheru was 25–35 plants/m2 for ICPL 87, but was higher for the other two genotypes.At Patancheru, the total dry-matter and seed yield of first and subsequent harvests were significantly reduced by delaying sowing beyond June. Generally, the second- and the third-harvest yields were lower on vertisol than on alfisol under both irrigated and unirrigated conditions.The total yield of ICPL 87 from two harvests was far higher than that of a well-adapted medium-duration genotype BDN 1, grown over a similar period. The yield advantage was greater on the alfisol because of the better multiple harvest potential of this soil. The results of this study demonstrate that properly managed short-duration genotypes of pigeonpea may have considerable potential for increased yield from multiple harvests in environments where winters are warm enough to permit continued growth.