Influence Of Plant Density Research Articles

Влияние густоты стояния растений на продуктивность подсолнечника

Влияние густоты стояния растений на продуктивность подсолнечника

RESEARCH ON THE OPTIMUM SHAPE AND SIZE OF POTATO RIDGES – PARTIAL RESULTS FROM TRIAL YEAR 2013

The partial results from the research carried out in 2013 at the Potato Research and Development Station TA¢rgu Secuiesc on the size and shape of the ridges and the influence of planting density in the case of two varieties and two types of ridges (ridges in one row and two rows) are presented. The pedoclimatic conditions characteristic of this trial year were favorable for potato cultivation. In the study of the optimal shape of potato ridges three different shapes have been studied: triangular shape, trapezoidal shape and double-trapezoidal shape. In the study of the optimal size of potato ridges three different ridge sizes were made: with cross-sectional areas of  800 cm 2 , 1200 cm 2 and 1600 cm 2 . The biological material used in these two experiments was the Bella Rosa variety, which is part of the class A biological category. The research on the influence of planting density was conducted on two potato varieties planted in ridges in a single row and in two rows: one that forms many but small tubers, the class A Gared variety and the second one that forms fewer but larger tubers, the class A Bella Rosa variety. Experiments with three different planting densities for each type of variety and each type of ridge (ridges in one row and two rows) were carried out: 40.000 plants/ha, 60.000 plants/ha and 80.000 plants/ha. For all variants four rows were planted and the process was repeated four times. The common technology of ridge ploughing was used and mechanically performed phytosanitary treatments were executed with the usual products. To achieve the objectives the following elements were taken into consideration: - yield and production (kg/ha) - average weight of a tuber (g) - average number of tubers per nest - average number and weight of tubers under and over 40 mm per nest An analysis of variance was carried out for completely randomized plots and the data processing was accomplished by using average values, the “t-test” at 5%, 1%, 0,1% significant difference levels and the Duncan Multiple Range Test.

Effect of planting density and sowing date on the essential oil content and composition of lemon verbena (Lippia citriodora)

Lemon verbena leaves are used as the plant for injection, aromatic, digestive and antispasmodic properties. Lemon verbena leaves has a mild sedative and reputation for relieving abdominal discomfort. In order to examine the influence of planting density and sowing date on the essential oil Neral, Geranial and Limonene in Lippia citriodora , an experiment was performed in Rasht experimental farm, Gilan province, 2011. The experiment was done as a factori al on the basis of randomized complete blocks design in three replications. Density treatments at three levels: 2, 4, 6 plants /m 2 and sowing treatment of March 24 th , April 8 th and April 24 th . The chemical composition was analyzed by Gas chromatography (GC ) and Gas chromatography/mass spectrometry (GC/MS) . 37 compounds were identified in the Essential oil of Lippia citriodora . The most important compounds in plant lemon verbena were Neral, Geranial and Limonene. Regarding the obtained results, planting dens ity and sowing date treatments had a significant effect on the rate of essential oil and the highest amounts of Neral, Geranial and Limonene were measured as 23.25, 33.68 and 5.84 in the 4 plant/m2 and planting on March 24 th .

Yield and fruit quality of okra (Abelmoschus esculentus L. Moench) in response to plant density

A greenhouse study was conducted from February - May 2013 at Kent Estate, Harare, Zimbabwe, to determine the influence of plant density on growth and yield of okra cv. ‘Clemson Spineless’. The trial was laid out in a Randomised Complete Block design (RCBD) using 4 replications. Five levels of plant density viz. 20 800 plants ha -1 , 31 200 plants ha -1 , 41 600 plants ha -1 , 52 000 plants ha -1 , and 62 400 plants ha -1 were used as treatments. Data collected was statistically analyzed using Analysis of variance (ANOVA). The Least Significant Difference (LSD) was used for mean separation (P < 0.05). Tallest plants were recorded from plant density of 62 400 plants ha -1 whilst shortest plants were recorded at plant density of 20 800 plants ha -1 . Plant density of 31 200 plants ha 1 produced the highest number of branches whilst plant density of 62 400 plants ha-1 recorded the lowest number of branches. The highest number of pods was recorded at plant density of 31 200 plants ha-1 whilst the lowest pod number was recorded at plant density of 62 400 plants ha -1 . Pod length generally decreased as plant density increased with longest and lowest pods recorded at 20 800 and 62 400 plants ha-1 respectively. The highest fruit fresh yield was recorded from plant density of 31 200 plants ha -1 whilst the lowest was recorded from 62 400 plants ha-1. Results of the study showed that plant density of 31 200 plants ha -1 gives the highest

The sexual neighborhood through time: competition and facilitation for pollination in Lobelia cardinalis.

Reproductive success in flowering plants is influenced by the morphology and timing of reproductive structures as well as the density of surrounding conspecifics. In species with separate male and female flower phases, successful pollen transfer is also expected to vary with the density and ratio of surrounding male and female flowers. Increased density of surrounding flowers may increase pollinator visitation rates, but the densities of male and female flowers will determine the availability of pollen and the strength of competition for pollen receipt. Here we (1) quantify the influence of surrounding plant density on total seasonal fruit and seed production, (2) quantify the influence of sexual neighborhood (surrounding sex ratio and densities of male- and female-phase flowers) on fruit and seed production for individual flowers presented within the season, and (3) compare the influence of plant density on fitness to that of focal plant phenotype, specifically stigma-nectary distance and plant height, in a natural population of the pollen-limited, hummingbird-pollinated hermaphrodite Lobelia cardinalis. These relationships were examined at four spatial scales (10, 20, 50, and 100 cm). By examining temporal and spatial scales we found that (1) total seed production per plant decreased with increasing plant density at the smallest scale but increased with increasing density at all larger scales; (2) at any given time, a female-phase flower benefited from a higher density of surrounding male-phase flowers and a lower density of surrounding female-phase flowers; (3) when sex ratio was explicitly analyzed, a female-phase flower benefited from a lower proportion of surrounding female flowers as well as a lower total flower density; and (4) at the whole-plant level, taller plants were more likely to produce fruit (even when accounting for total number of flowers produced), consistent with pollinator preference for taller floral displays. Our results suggest that the local density of male and female flowers (and surrounding sex ratio) influences successful pollen transfer, implying that the local floral environment may shape how attraction traits like plant height are related to fitness.

Effect of plant density and seed position on mother plant on physiological characteristic of cocklebur (Xanthium strumarium) seeds

Experiments were conducted in 2010 to determine the influence of plant density and seed position on the mother plant on seed physiological characteristics of cocklebur (Xanthium strumarium). Cocklebur burs were collected in fall of 2010 from Research Farm of University of Agricultural Sciences and Natural Resources of Gorgan, Iran. The experiment was established as factorial arrangement using a completely randomized design with three replications. The factors included different densities of cocklebur (0, 2, 4, 6 and 8 plant m-2) and the top and bottom parts of the canopy. Non dormant seeds were used for determining cardinal temperatures and tolerance to salinity and drought stresses. Base, optimum and ceiling germination temperatures were estimated between 7.09 to 12.33, 32 to 35 and 44 to 45 respectively in different treatments. Salinity stress up to 300 Mm and osmotic potential 8 bar inhibited the germination completely. Comparison of base temperatures and sigmoid equation coefficients showed that seeds produced in the top had higher germination than those that produced at the bottom of the mother plant. It seems plant densities through seed position on the mother plant affect seed quality. Likewise changes of light quality and quantity in shade environment increased seed dormancy in matured seeds. Shade environment affect seed germination on mother plant that increased dormancy of seeds maturing under shade be an adaptive response that reduces the probability of germination of offspring under unfavorable (shade, competitive) conditions.

Research on the Optimum Shape and Size of Potato Ridges

The partial results from the research carried out in 2012 at the Potato Research and Development Station Tg. Secuiesc on the size and shape of the ridges and the influence of planting density in the case of two varieties and two types of ridges (ridges in one row and two rows) are presented. The results were heavily influenced by the unfavorable weather conditions in 2012 when there was a smaller amount of precipitation compared to the multiannual average rainfall during the growing season: -115.4 mm. The insufficient moisture resulted in the inhibition of potato tuberization, reabsorption of stolons and young tubers and in this period some of the water content in tubers passed into the leaves. In the study of the optimal shape of potato ridges three different shapes have been studied: triangular shape, trapezoidal shape and double-trapezoidal shape. In the study of the optimal size of potato ridges three different ridge sizes were made: with cross-sectional areas of 800 cm2 , 1200 cm2 and 1600 cm2. The biological material used in these two experiments was the Bella Rosa variety, which is part of the class A biological category. The research on the influence of planting density was conducted on two potato varieties planted in ridges in a single row and in two rows: one that forms many but small tubers, the class A Gared variety and the second one that forms fewer but larger tubers, the class A Bella Rosa variety. Experiments with three different planting densities for each type of variety and each type of ridge (ridges in one row and two rows) were carried out: 40.000 plants/ha, 60.000 plants/ha and 80,000 plants/ha. For all variants four rows were planted and the process was repeated four times. The common technology of ridge ploughing was used and mechanically performed phytosanitary treatments were executed with the usual products. To achieve the objectives the following elements were taken into consideration: yield and production (kg/ha), average weight of a tuber (g), average number of tubers in the nest. An analysis of variance was carried out for completely randomized plots and the data processing was accomplished by using average values, the “t-test” at 5%, 1%, 0.1% significant difference levels and the Duncan Multiple Range Test.

Physiological Dynamics of Maize Nitrogen Uptake and Partitioning in Response to Plant Density and N Stress Factors: I. Vegetative Phase

ABSTRACTFrom a physiological perspective, field studies that quantify the influence of plant density (PD) and N rate on biomass (BM) and N uptake are needed to build more functional partitioning models for maize (Zea mays L.). The overall goal was to quantify the effects of maize hybrid (two genotypes), PD (low = 54,000; medium = 79,000 and high = 104,000 pl ha‐1), and N rate (low = 0, medium = 112 and high = 224 kg N ha‐1) on the organ‐specific dry mass and N allocation, and on the resource capture (ratio of leaf area index [LAI] to BM), and resource use efficiency (ratio of N uptake to LAI) parameters, during the vegetative phase at four site‐years. Allometric analyses revealed that the resource capture was primarily affected by the PD, and the resource use efficiency by the N rate. The stoichiometry between leaf and stem dry mass was unaffected by the treatment factors, but no isometry was documented (greater BM to the stem than leaf). The N rate primarily modified the leaf and stem N concentrations (0N vs. 112–224N). With respect to resource use efficiency, modifications in the leaf N content per unit of LAI were joint outcomes of changes in leaf mass and %N (N concentration). In contrast, physiological changes in the stem N content per unit of LAI were more dependent on changes in the stem %N (greater N storage capacity) rather than in the stem mass. Intensifying competition with neighboring plants reduced per‐plant mass similarly in both leaf and stem structures, and improving N supply was proportionately more beneficial in maintaining plant mass and stem %N at high PD during vegetative growth.

Plant species composition alters the sign and strength of an emergent multi-predator effect by modifying predator foraging behaviour.

The prediction of pest-control functioning by multi-predator communities is hindered by the non-additive nature of species functioning. Such non-additivity, commonly termed an emergent multi-predator effect, is known to be affected by elements of the ecological context, such as the structure and composition of vegetation, in addition to the traits of the predators themselves. Here we report mesocosm experiments designed to test the influence of plant density and species composition (wheat monoculture or wheat and faba bean polyculture) on the emergence of multi-predator effects between Adalia bipunctata and Chrysoperla carnea, in their suppression of populations of the aphid Metopolophium dirhodum. The mesocosm experiments were followed by a series of behavioural observations designed to identify how interactions among predators are modified by plant species composition and whether these effects are consistent with the observed influence of plant species composition on aphid population suppression. Although plant density was shown to have no influence on the multi-predator effect on aphid population growth, plant composition had a marked effect. In wheat monoculture, Adalia and Chrysoperla mixed treatments caused greater suppression of M. dirhodum populations than expected. However this positive emergent effect was reversed to a negative multi-predator effect in wheat and faba bean polyculture. The behavioural observations revealed that although dominant individuals did not respond to the presence of faba bean plants, the behaviour of sub-dominants was affected markedly, consistent with their foraging for extra-floral nectar produced by the faba bean. This interaction between plant composition and predator community composition on the foraging behaviour of sub-dominants is thought to underlie the observed effect of plant composition on the multi-predator effect. Thus, the emergence of multi-predator effects is shown to be strongly influenced by plant species composition, mediated, in this case, by the provision of extra-floral nectar by one of the plant species.

Nutrient imbalance and yield limiting factors of low input East African highland banana (Musa spp. AAA-EA) cropping systems

Low yields of East African highland bananas (Musa spp. AAA-EA) are often attributed to poor and declining soil fertility, which outweighs other biophysical factors and management practices. We investigated the influence of planting density on nutrient mass fractions and nutrient imbalance indices in bananas under small-scale, low-input systems using the compositional nutrient diagnosis (CND) approach. Boundary line functions were developed to identify yield limiting factors and quantify their contribution to the yield gap. Soil, plant, yield and water data were collected in plant density experiments conducted in three contrasting agro-ecological sites of Rwanda (i.e. Kibungo low rainfall with medium soil fertility, Rubona high rainfall but low soil fertility and Ruhengeri high rainfall with high soil fertility). Effects of site×cultivar and site×density on bunch yield were significant (p<0.05). Annual yields (tha−1yr−1) ranged from 6.1 to 9.2 at Kibungo, 9.5 to 21.5 at Rubona and 7.0 to 25.0 at Ruhengeri. Similar trends were registered for the above ground dry matter yield. CND indices showed that K, Mg and P were the most deficient elements in areas with low inherent soil fertility (Kibungo and Rubona). The yield gap analysis also confirmed that K was the most limiting factor, contributing to a predicted yield gap of 55.3% at Kibungo while P and Mg collectively contributed to a 35% yield gap at Rubona. An increase in plant density resulted in an increase in average yield gap from 45.6 to 70.2% at Kibungo, whilst the average yield gap decreased significantly with increases in plant density from 47.5 to 30.2% at Rubona and 76.6 to 53.7% at Ruhengeri. The study confirmed that soil fertility is a more limiting factor than water, but both CND norms and boundary line analysis showed that predicted yield gaps seem to be higher for plant density than soil fertility. Therefore, plant density management is an entry point to optimize yield of East African highland bananas.

Influência da densidade de plantio da cultura da melancia sobre suas características de produção na Chapada do Apodi, CE

The aim of this work was to study the influence of plant density on physical characteristics and productivity of watermelon fruits in the Chapada of Apodi, Limoeiro do Norte, Ceará, Brazil. The experiment was carried out in field condition where two plantation densities were evaluated: A1 = 10.000 plants ha-1 and A2 = 5.000 plants ha-1, with ten replications, in plots of 6.0 m² (2.0 x 3.0 m), at spacings of 2.0 x 0.5 m and 2.0 x 1.0 m, in completely randomized design. No significant difference among the plantation densities was observed as to number of fruits per plant, equatorial diameter of fruit, fresh weight of fruit and yield fruits per plant. The total yield of fruit per hectare was higher in A1 density (66.7 t) compared to A2 density (33.57 t). The planting density influenced the total yield of watermelon fruits.

Influence of plant density on variability of soil fertility and nutrient budgets in low input East African highland banana (Musa spp. AAA-EA) cropping systems

The productivity of East African highland (EAH) banana cropping systems is declining, particularly in areas with low inherent soil fertility. Soil fertility management requires knowledge of nutrient flows at the interface between the soil surface and the soil system. The magnitude of soil fertility dynamics and nutrient depletion was studied for a short-term banana plant density trial in three contrasting agro-ecological sites of Rwanda (Kibungo low rainfall with medium soil fertility, Rubona high rainfall with low soil fertility and Ruhengeri high rainfall with high soil fertility) using nutrient stock and partial nutrient balance calculations. Plant density did not influence significantly nutrient mass fractions in plant parts (fruit, leaves and pseudostems) but nutrients contained through shredded leaves and pseudostems and those removed through bunch dry matter increased with plant density. Plant density responses to variation in soil fertility and partial nutrient balances seemed to depend on diversity in climate and soil type. Partial N and K balances (kg ha−1 year−1) were estimated to be strongly negative at Rubona and Ruhengeri while Ca and Mg were positive at Kibungo and Ruhengeri but negative at Rubona. This study showed that partial nutrient balances associated with soil nutrient stocks can provide the first order of magnitude of nutrient depletion in low input EAH banana cropping systems. This brings attention from agricultural researchers and farmers to develop options that can improve the productivity of these systems, where resource availability for improved nutrient management is scarce.

Influence of planting density and rotation age on the profitability of timber production for Norway spruce in Central Europe

When forest stands are established by planting, the initial density is often chosen based on recommendations of specific plant numbers. Since forest owners typically face different alternatives for the employment of their opportunities and since market situations often change more rapidly and on a smaller scale than the characteristics of forest sites, the question arises whether these factors are reflected in one or within a small range of planting densities. Even though some advised densities might be profitable for some forest owners and market situations, the shift of profitable timber production as a result of changes in the circumstances surrounding the investment is unclear. In this paper, the influence of the planting density on the profitable production of timber is analysed with the explicit inclusion of price differentials as these offer incentives for the choice of the planting density in Central Europe. Since numerical calculations based on empirical data are required for an analysis of the complex facets of price differentials, the specific statements are restricted to the tree species Norway spruce (Picea abies Karst.). By means of typical calculation examples, the effects of changes in investment parameters are exemplified and discussed against the background of a sensitivity analysis. The results reveal the boundaries for the profitable production of high-quality timber and show that forest owners might compensate changes in the investment situation by adjustments of either or both the rotation age and the planting density.

Tillering Characteristics of Multi-tiller Maize and Influence of Plant Density and Sowing Date

Different maize varieties were used to study the tillering characteristics and regulations of multi-tiller maize under dif-ferent plant densities and sowing dates.The results showed that tillers were co-elongated with leaves of main stem,the number of primary tiller(n) and leaf age of main stem(N) had the relationship of n = N-3,the secondary tillering had the same relationship as the primary one.Tillering ability showed significant differences among different maize varieties,Mexican's tillering ability was the strongest,the maximum tiller number was about 25-40,and Keduo 4 was about 2-4 and then Wuyue 97-1 was about 1-2,however,Zhengdan 958 had no tiller in general.The tillering ability of maize could be affected by sowing date and plant density.Higher temperature and sunlight and lower plant density were favorable to tiller's development.With the postponement of sowing date,the interval from seeding to tillering became shorter,the growth of tiller's leaves became quicker,and the maximum tiller number was increased.When sowed on 25 April and 25 June at 45 000 plant ha-1 population,the maximum tiller number of the Keduo 4 was 3.50 and 4.00 while the ultimately tiller number was 2.33 and 2.00,respectively,so the eliminating rate of tiller was 33.4% and 50.0% respectively.The similar changes were observed in 30 000 and 60 000 plant ha-1 populations.With the incre-ment of plant density,tiller's occurrence was postponed,and the leaf ages decreased on same day after emergence of seedling,tiller number of main stem with the same leaf age and the maximum and ultimately numbers reduced,the tillers' eliminating rate increased.When sowed on 25 April,taken the 30 000,45 000,and 60 000 plant ha-1 populations,the maximum tiller number was 3.80,3.50,and 3.22,and ultimately tiller number was 3.00,2.33,and 1.67,so the eliminating rate was 21.05%,33.43%,and 48.14%,respectively.The changes were similar when sowed at 25 June.

Influence of Plant Density and Integrated Nutrient Management on N, P and K Contents and Uptake of Quality Protein Maize

A field experiment was carried out at G.B. Pant University of Agriculture &amp; Technology, Pantnagar, Uttarakhand to find out the effect of different plant densities and integrated nutrient management on N, P and K content and uptake of quality protein maize (QPM) during spring 2010 in factorial randomized block design replicated thrice with three plant densities viz., 66,666, 83,333 and 100,000 plants ha-1 and five modes of nutrition viz., 100% recommended dose of fertilizer (RDF) inorganic, 125 % RDF inorganic, 100 % recommended dose of nitrogen (RDN) through inorganic + 25 % RDN through organic, 75 % RDN through inorganic + 25 % RDN through organic and 50 % RDN through inorganic + 50 % RDN through organic The results revealed that high plant density resulted in reduction of N, P and K content in source as well as sink while fertilizer application either through inorganic alone or in variable combinations with organic did not influence nutrient content neither in source nor in sink.

Planting density affects vigour and production of ‘Arbequina’ olive

The hedgerow orchard type is being increasingly used with the olive although not much information is still available about its suitability to this species. The objective of this study was to assess the influence of planting density (312, 416, 625 and 1,250 trees ha-1) on vigour and productive characteristics of ‘Arbequina’ olive trees planted in 2003. Significant linear regressions have been observed between planting density and tree width, trunk cross section area and canopy volume. Increasing planting density showed positive linear correlation (R2=0.63) with canopy volume per hectare. There was a negative correlation between planting density and production per tree in the five first crops, but it was positive with production per hectare both in olive and olive oil production with coefficients of determination ranging from 0.16 to 0.43 and from 0.28 to 0.46, respectively. A significant linear regression (R2= 0.31 and 0.48) was found between planting density and fruit size on two of the studied cropping years. Our results have not allowed establishing any relationship between planting density and fruit oil content. Finally, the studied densities did not affect the oil fatty acid composition. The production increase observed at the highest tried density is linked to the increase in canopy volume per hectare, but these results should be checked at later stages of tree development, as this study covers only until the fifth harvested crop.

Forage yield and nutritive value of Tanzania grass under nitrogen supplies and plant densities

The objective of this experiment was to evaluate the nitrogen and plant density influence on the yield, forage dissection and nutritive value of Tanzania grass (Panicum maximum Jacq.). The design was of completely randomized blocks with three replications in a factorial arrangement with four nitrogen levels (0, 80, 160 or 320 kg/ha N) and three plant densities (9, 25 or 49 plants/m2). The plots were cut at 25 cm from soil level when the canopy reached 95% of light interception. The total dry matter forage yield and dry matter forage yield per harvest increased linearly with the nitrogen fertilization. The leaf and stem yield had the same response. The senesced forage yield was quadratically influenced by the nitrogen. The stems ratio in the morphologic composition was high in the high nitrogen levels and in the low plant densities. The leaf:stem ratio showed high values in this trial, but it was increased in plots without nitrogen and high plant density. The pre-grazing height was reduced with the increase in plant density. The nutritive value was favored by the nitrogen fertilization, which increased the crude protein level and reduced neutral detergent fiber and lignin. These factors increased the leaf and stem in vitro digestibility of organic matter. Nitrogen fertilization increases the forage yield of Tanzania grass under rotational grazing. After the establishment, plant density has little influence on the Tanzania grass yield and its forage dissection. The harvest with 95% light interception improves the structure and nutritive value of Tanzania grass pastures.

Scale-dependent determinants of plant species richness in a semi-arid fragmented agro-ecosystem

Aims: (1) Understanding how the relationship between species richness and its determinants depends on the interaction between scales at which the response and explanatory variables are measured. (2) Quantifying the relative contributions of local, intermediate and large-scale determinants of species richness in a fragmented agro-ecosystem. (3) Testing the hypothesis that the relative contribution of these determinants varies with the grain size at which species richness is measured. Location: A fragmented agro-ecosystem in the Southern Judea Lowland, Israel, within a desert–Mediterranean transition zone. Methods: Plant species richness was estimated using hierarchical nested sampling in 81 plots, positioned in 38 natural vegetation patches within an agricultural matrix (mainly wheat fields) among three land units along a sharp precipitation gradient. Explanatory variables included position along that gradient, patch area, patch isolation, habitat heterogeneity and overall plant density. We used general linear models and hierarchical partitioning of variance to test and quantify the effect of each explanatory variable on species richness at four grain sizes (0.0625, 1, 25 and 225 m2). Results: Species richness was mainly affected by position along a precipitation gradient and overall plant density, and to a lesser extent by habitat heterogeneity. It was also significantly affected by patch area and patch isolation, but only for small grain sizes. The contribution of each explanatory variable to explained variance in species richness varied with grain size, i.e. scale-dependent. The influence of geographic position and habitat heterogeneity on species richness increased with grain size, while the influence of plant density decreased with grain size. Main conclusions: Species richness is determined by the combined effect of several scale-dependent determinants. Ability to detect an effect and effect size of each determinant varies with the scale (grain size) at which it is measured. The combination of a multi-factorial approach and multi-scale sampling reveals that conclusions drawn from studies that ignore these dimensions are restricted and potentially misleading.

Plant Density Influence on Yield and Nutritional Quality of Soybean Seed

Plant density is an important factor affecting soybean seed yield and but information regarding plant density effects on seed quality is highly scarce. The present study examines the relationship of seed yield and quality of two soybean varieties viz., PB-1 and G-2 with plant densities. The experiments were conducted in three consecutive seasons viz., Rabi 2004-05, Kharif 2005 and Rabi 2005-06 at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh, Bangladesh. Six plant densities viz., 20, 40, 60, 80, 100 and 120 plants m -2 were established using an equidistant planting pattern having spacings of 22.4×22.4 cm, 15.8×15.8 cm, 12.9×12.9 cm, 10.0×10.0 cm and 9.1×9.1 cm, respectively. A split-plot design was used having variety as main plot and density as sub-plot with three replicates. The results revealed that soybean seed yield increased with increase of plant density and the highest yield was obtained at 80 to 100 plants m -2 depending on variety and season. The further increase in plant density reduced the seed yield. The seed yield, seed protein and mineral contents such as phosphorus, calcium, potassium, sulphur and zinc showed a quadratic relation with plant density. Seed protein content decreased with increase in plant density up to 80 or 100 plants m -2 and then increased with further increase in plant density while reverse occurred for seed yield and different minerals. The results also showed that seed protein content was inversely related with seed yield and mineral contents in seed.

Variety and Plant Density Influence upon the Yield of Autumn White Headed Cabbage

SUMMARY White headed cabbage (Brassica oleracea L., Alef. var. capitata f. alba D.C. – Brassicaceae family) is one of the most important vegetable from our country, this fact being proved by the large area where this vegetable is cultivated, which represents 20 – 27% from the total surface cultivated with different vegetables (Berar, 2006; Ciofu et al.,2003; Glaman and Popa, 2005; Indrea et al., 2007; Stan and Munteanu, 2001). The bifactorial experience regarding the influence of variety and plants density upon headed cabbage yield was organized in 2010, in Apahida, from Cluj County. The two factors of the research were: the variety, with four graduations: Saratoga F1, Ramada F1, Gumma F1, Bajonet F1 and plants density, with two graduations: 47,600 plants/ha (0.7m x 0.3m) and 35,700 plants/ha (0.7m x 0.4 m). The main purpose of this research was the observation of variety and plants density influence upon the obtained production, but also finding the suitable hybrid which can ensure a higher plant density, in the same time with a high yield of a best quality. The objectives of the experience were: the observation of the four varieties which were taken in culture, measurements regarding: plants high, rosette diameter, number of leaves, plants weight, and the influence of the studied factors upon the harvesting dynamics, the obtained yield quantity and quality. By results analyzing it can be concluded that by using a lower plant density in a white headed cabbage culture (in this case using only 35,700 plants/ha in place of 47,600 plants/ha) a higher yield can be obtained, while the variety with best results was Ramada F1 (107.67 t/ha-47,600 pl/ha and 126.53 t/ha - 35,700 pl/ha).