Effect Of Different Plant Densities Research Articles

Planting Density Interferes with Strawberry Production Efficiency in Southern Brazil

In the search for more efficient production systems, many changes have occurred in the strawberry production sector. Planting density is one of the management techniques that most interferes with the quality of fruits and production aspects. This study aimed to evaluate the effect of different planting densities on the photosynthetic characteristics, fruit quality, and production of the strawberry cultivar Pircinque. The study was conducted in the 2018/2019 and 2019/2020 harvests in Lages, Santa Catarina, Brazil. The treatments consisted of plant spacing of 5, 10, 15, 20, 25, and 30 cm. The experimental design was in randomized blocks, with four blocks and plots of 20 plants. Plant spacing interfered with fruit quality, photosynthetic efficiency, production, productivity, and economic return. Due to the fruits of Pircinque having a higher quality than other cultivars, the planting spacing between 5 and 15 cm allows meeting the fruit’s main production and quality requirements. However, it is up to the producer to adapt the management if opting for higher planting densities, which allow for a greater economic viability of the business.

Effects of Different Planting Densities on Photosynthesis in Maize Determined via Prompt Fluorescence, Delayed Fluorescence and P700 Signals.

The mutual shading among individual field-grown maize plants resulting from high planting density inevitably reduces leaf photosynthesis, while regulating the photosynthetic transport chain has a strong impact on photosynthesis. However, the effect of high planting density on the photosynthetic electron transport chain in maize currently remains unclear. In this study, we simultaneously measured prompt chlorophyll a fluorescence (PF), modulated 820 nm reflection (MR) and delayed chlorophyll a fluorescence (DF) in order to investigate the effect of high planting density on the photosynthetic electron transport chain in two maize hybrids widely grown in China. PF transients demonstrated a gradual reduction in their signal amplitude with increasing planting density. In addition, high planting density induced positive J-step and G-bands of the PF transients, reduced the values of PF parameters PIABS, RC/CSO, TRO/ABS, ETO/TRO and REO/ETO, and enhanced ABS/RC and N. MR kinetics showed an increase of their lowest point with increasing high planting density, and thus the values of MR parameters VPSI and VPSII-PSI were reduced. The shapes of DF induction and decay curves were changed by high planting density. In addition, high planting density reduced the values of DF parameters I1, I2, L1 and L2, and enhanced I2/I1. These results suggested that high planting density caused harm on multiple components of maize photosynthetic electron transport chain, including an inactivation of PSII RCs, a blocked electron transfer between QA and QB, a reduction in PSI oxidation and re-reduction activities, and an impaired PSI acceptor side. Moreover, a comparison between PSII and PSI activities demonstrated the greater effect of plant density on the former.

Effects of planting density on diurnal variation of microenvironment in Huangguogan orchards

In this experiment, Huangguogan was used as the material. The effects of different planting densities on the diurnal variation of microenvironment in citrus orchard was studied, and thekey research findingsare as below. The orchard environmental factors, including light, daily average temperature and soil moisture, increased with the decrease of planting density. Compared with the density of 2×3m, thephotosynthetically active radiation(PAR in short), air temperature, soil temperature and soil moisture of density 4×5m on average increased by 423.7%, 5.5%, 2.18% and 4.9%. Air CO2 concentration and air humidity on average decreased by 1.8% and 4%. The daily range of PAR, air temperature, air humidity, soil temperature and soil humidity increased, and the daily range of air CO2 concentration decreased.

Experimental Study on Purification Effect of Biochemical Pool Model for Treatment of Pavement Runoff by Aquatic Plants

The road runoff after rainfall carries a lot of pollutants that could cause great harm to the water environment. A biochemical pool can be used as a treatment for the road runoff. In order to further improve the efficiency of road runoff treatment by biochemical pool and to evaluate the purification effect of the aquatic plants, two aquatic plants of Iris pseudacorus and Myriophyllum verticillatum were chosen in this research. The effect of different planting densities on the treatment of runoff pollutants and the planting mode by different aquatic plants were studied. The results show that both plants have the ability to remove the pollutants like chemical oxygen demand (COD), Zn, Cu, oil, and suspended solids (SS), and the ability is increased with the increase of planting density. The Iris pseudacorus is better than Myriophyllum verticillatum on the removal of Zn, while Myriophyllum verticillatum does better on the removal of Cu, oil, and SS. Combined planting mode can effectively improve the purification effect of COD and petroleum.

Effects of planting density on potato growth, yield, and water use efficiency during years with variable rainfall on the Loess Plateau, China

A 3-yr field study was conducted in semiarid areas of the Loess Plateau to investigate the effects of different planting densities on the soil water, potato growth, yield, and WUE during the normal year (2015), relatively dry year (2016), and relatively wet year (2017). The five potato planting densities were 3.75 × 104 (A, traditional local planting density as a control), 4.50 × 104 (B), 5.25 × 104 (C), 6.00 × 104 (D), and 6.75 × 104 plants ha–1 (E). During the three years, the differences in soil water storage among the five planting densities were significant in the early and middle potato growth stages, when the soil water storage levels in treatments B and C were 8.8 % and 10.8 % higher (P < 0.05) than those in A. Treatments B and C significantly (P < 0.05) increased the potato emergence rate by 12.5 % and 7.5 % to promote growth in the early and middle stages. The planting density had a decreasing parabolic relationship with the potato yield. After fitting a function to the three years of data, the highest tuber potato yield varied with the amount of rainfall and the optimum level was 5.12–5.58 × 104 plants ha−1. The WUE and rainwater use efficiency (RWUE) were significantly higher under B and C compared with A in the normal and relatively dry years. WUE and RWUE were significantly higher in B, C, and D compared with A in the relatively wet year. The optimum planting density with treatments B and C obtained higher net profits. Thus, the recommended optimum planting density should be 4.50–5.12 × 104 plants ha−1 in relatively dry years and 5.13–5.58 × 104 plants ha−1 in normal and relatively wet years to increase dryland potato production and water use efficiency in the semiarid regions of the Loess Plateau, China.

Effects of Different Planting Densities on Cultivating Quality of Padus maackii Seedlings

Effects of Different Planting Densities on Cultivating Quality of Padus maackii Seedlings

PENAMPILAN ALFALFA (Medicago sativa) DEFOLIASI PERTAMA PADA JARAK TANAM DAN UMUR DEFOLIASI YANG BERBEDA

Forage, the main feedstuff for ruminants, includes grasses and legumes, browses, and side products of food crops. However, legumes generally have greater crude protein content relative to other species of forage plants. One of the species of legumes is alfalfa (Medicago sativa), a perennial crop that can grow from the tropics up to sub tropics. In spite of its excellent nutrient content, In Indonesia alfalfa is still not widely explored and used for feedstuff. A study was conducted to explore and evaluate of alfalfa performances in terms of the height, number of tillers, dry matter (DM) and crude protein (CP) productions under the effects of different plant densities and ages of defoliation”. The height of the location of study was 200 m above sea level with an average temperature of 270 C. The results showed that the ranges of the height of alfalfa, the numbers of tillers, DM and CP productions were 33.31-56.32 cm, 36.38-82.36 tillers/bunch, 556.9-1018.9 kg/ha/defoliation, and 149.75 – 291.79 kg/ha/defoliation, respectively. In general, the ages of plant at the time of defoliation and plant distances affected (P&lt;0.05) the variables being studied. The older plants resulted in greater DM and CP yields, and more densely plantation resulted in greater DM and CP yields.Keywords: alfalfa, plant density, defoliation age.

Rubber and plantain intercropping: Effects of different planting densities on soil characteristics.

Two field experiments were conducted at Ellembelle and Jomoro districts in the Western region of Ghana where rubber cultivation is a predominant farming activity. The objective of the study was to assess the effect of rubber and plantain intercropping systems on selected soil properties. The experiment was arranged in a randomized complete block design (RCBD) with 3 replications. The treatments were the sole crop rubber (R), sole crop plantain (P) and three intercrop systems comprising an additive series of plantain: one row of plantain to one row of rubber (PR), two rows of plantain to one row of rubber (PPR) and three rows of plantain to one row of rubber (PPPR). Generally, agroforestry systems improved the soil hydraulic properties considerably, with the highest cumulative infiltration rates of 5.16 and 8.68 cm/min observed under the PPPR systems at the Ellembelle and Jomoro sites, respectively. Microbial biomass C (Cmic), N (Nmic) and P (Pmic) was significantly improved (P < 0.05) under the agroforestry than the monocrop systems. The Cmic, Nmic and Pmic values were highest under the PPPR system at both Ellembelle (Cmic, = 139.9 mg/kg; Nmic = 36.26 mg/kg and Pmic = 87.6 mg/kg) and Jomoro (Cmic = 78.7 mg/kg; Nmic = 80.3 mg/kg and Pmic = 3.45 mg/kg) sites.

The effects of different plant densities and nitrogen levels on certain macro and micro element contents of okra

Farkli bitki yogunlugu ve azot seviyelerinin bamyada bazi makro ve mikro element icerikleri uzerine etkileri OZET Farkli bitki yogunlugu ve azot seviyelerinin bamyada (Abelmoschus esculentus L.) mikro ve makro element iceriklerine etkilerinin arastirildigi calisma, Ege Universitesi Odemis Meslek Yuksekokulu ile Ege Universitesi Menemen Arastirma, Uygulama ve Uretim Ciftligi uygulama arazilerinde gerceklestirilmistir. Split-plot deneme desenine gore uc tekerrurlu olarak kurulmus, ana parselleri azot uygulamalari ve alt parselleri bitki yogunluklari olusturmustur. Azotlu gubreler ure ve amonyum nitrat formunda uygulanmistir. Bes farkli azot seviyesi (0, 40, 80, 120 ve 160 kg N ha -1 ) ve iki farkli dikim mesafesi (15*70cm ve 25*70 cm) test edilmistir. Meyve ve yapraklarda makro ve mikro besin belirlenmistir. Yapraklarin N icerigi Odemis lokasyonunda yuksek azot seviyeleri ile artmis, yapraklardaki maksimum azot icerigi 80 kg N ha -1 uygulamasinda kaydedilmistir. Ayrica, Odemis lokasyonunda, yapraklardaki Mg, Zn, ve Mn icerigi, meyvelerde P, Ca, Mg, Fe ve Zn icerikleri azot dozlarindan onemli olcude etkilenmistir. Menemende, kontrol karsilastirildiginda yapraklardaki Mg, Cu ve Zn,alinimi ve meyvedeki Zn alimini azot dozlarindan onemli olcude etkilenmistir. ABSTRACT Field trials were conducted in two locations: the training fields of the Ege University Odemis Vocational High School and Ege University, Menemen Research, Application and Production Farm, where the effects of different plant densities and nitrogen levels on macro and micro element contents of okra ( Abelmoschus esculentus L.) were investigated. The field layout was a split-plot design with three replicates, where the main plots consisted of nitrogen applications and sub-plots of plant densities. Nitrogen fertilizers were applied in the form of urea and ammonium nitrate. Five different nitrogen levels (0, 40, 80, 120 and 160 kg N ha -1 ) and two different distances between rows (15 cm * 70 cm and 25 cm * 70 cm) were tested. Macro and micro nutrients in fruits and leaves were determined. The N content of the leaves increased with higher nitrogen levels in the Odemis location. The maximum nitrogen content in leaves was determined at the 80 kg N ha -1 application in this location. Additionally, t he content of Mg, Zn, and Mn in the leaves and P, Ca, Mg, Fe, and Zn in fruits significantly affected nitrogen doses at the Odemis location. The Mg, Cu and Zn uptake of leaves and Zn uptake in fruit when compared to the control significantly affected nitrogen doses at Menemen.

Effect of planting density on growth, yield and fruit quality of apple cv. Jeromine

A field experiment was conducted to study the effect of different planting densities on growth, yield and fruit quality of three-years-old apple trees during 2017–2018. The experiment was laid out in a Randomized Block Design consisting of four treatments of planting densities viz., 5333 trees/ha (2.5 m × 0.75 m), 4000 trees/ha (2.5 m × 1.0 m), 3200 trees/ha (2.5 m × 1.25 m) and 2666 trees/ha (2.5 m × 1.5 m) and each treatment was replicated six times. The maximum annual shoot growth (44.58 cm) and increase in tree height (42.55 cm) was recorded in planting density of 2666 trees/ha (2.5 m × 1.5 m) which was significantly higher than all other planting densities. Highest fruit yield per tree (4.93 kg/tree) was observed in high density 2666 trees/ha (2.5 m x (17.50 tonne/ha) was recorded in planting density of 5333 trees/ha (2.5 m x 0.75 m). Maximum fruit length (65.90 mm), fruit diameter (76.07 mm), fruit weight (177.45 g), sugars content and anthocyanin content was found in planting density of 2666 trees/ha (2.5 m x 1.5 m). On the basis of two-years study, it can be concluded that the planting densities of 3200 trees/ha (2.5 m x 1.25 m) and 2666 trees/ha (2.5 m x 1.5 m) could be the optimum density for higher production of quality fruits.

Cultivation of “Roxo de Valinhos” Fig Tree in Different Plant Densities for Production of Green Figs for Industry in the Region of Campo Das Vertentes-MG

The objective of this work was to study the effect of different planting densities on the development and production of “Roxo de Valinhos” green figs for industry, in the Campo das Vertentes-MG region. The experiment was installed at the Risoleta Neves Experimental Field—CERN/EPAMIG. The plants used were three years old and were arranged in three randomized blocks, subject to three different planting densities, with spacings ranging from 1 m (4000 plants·ha-1), 1.5 m (2666 plants·ha-1), and 2 m (2000 plants·ha-1) between plants in the planting line and 2.5 m between row for all planting densities. The average length of the branches (m), average number of fruits per branch, average number of fruits per plant, average weight of fruits, average yield per plant and the average yield per hectare (kg) were evaluated. It was verified that, there were no significant differences in the length of branch and in the average weight of fruit, in the three densities of fig tree planting. (4000 plants·ha-1), the average number of fruits per branch (7.5), per plant (55.87) and yield per plant (878.93 kg) were lower, however. The average yield per hectare (3515.73 kg) was higher than in other growing densities. It is concluded that, the higher density of plants (4000 plants·ha-1), provides the highest productivity per area, without damages to the quality of the fruits.

Responses of Grain Maize to Plant Density at Different Irrigation Regimes

In order to examine the effects of different plant densities, plant patterns and irrigation regimes on yield, yield components and harvest index of grain maize, a field experiment was conducted at Miyandoab Agricultural Research Station, Iran. A strip split plot experiment was conducted based on randomized complete block design with three replications. The results showed that the effect of plant density was significant on kernel yield, harvest index, 1,000 kernel weight. The highest kernel yield was obtained from 90,000 plants ha-1 density. Maximum grain yield (18.530 t ha-1) was obtained from furrow irrigation. However, there was no significant difference between moisture levels of 100% and 120% of field capacity. The lowest kernel yield was obtained at 80% field capacity. This study also showed that mean kernel weight and the number of kernels per row were the most determinant factors in grain yield formation. The highest and the lowest harvest indices were obtained at 120% and 80% treatments of field capacity treatment, respectively.

Quality characteristics and nutrient yield of fodder maize (Zea mays) as influenced by seeding density and nutrient levels in Indo-Gangetic Plains

Productivity and quality traits of forage crops are largely affected by agronomic management at field conditions in different climatic strata. Therefore, the present field investigation was carried out during kharif season of 2014 and 2015 at ICAR-NDRI, Karnal to evaluate the effect of different planting densities and fertility levels on nutritive yields and quality of fodder maize (Zea mays L.). An experiment was laid out in split plot arrangement with three treatments in main-plot of planting densities of 60, 75 and 90 kg seed/ha and six treatments in subplot of nutrient levels, i.e. 0, 50, 75, 100, 125 and 150% recommended dose of fertilizer (RDF), i.e. 120 kg N/ha and 60 kg P2O5/ha. All the seed rates were found statistically at par for all the parameters except fiber fractions, i.e. neutral detergent fiber (NDF), acid detergent fiber (ADF) and acid detergent lignin (ADL) content, in which 60 kg/ha seed rate accumulated significantly lower fiber contents. However, numerically higher values of fodder yields and quality parameters were observed at lower planting density. Nutrient levels showed significant increase in fodder yields with increase in dose of fertility up to 125% RDF. The combined use of 60 kg/ha seed rate and 125% RDF obtained significant maximum green (61.7 t/ha) and dry fodder yield (14.1 t/ha). The results showed that use of 150% RDF improved CP content by 20.2%, ether extract by 20.1% and ash content by 23.3% over control. Further, the maize fodder supplied with 150% RDF attributed minimum level of fiber fractions and magnitude of reduction in NDF was 3.49%, ADF was 3.54% and that of ADL was 7.65% in comparison to 0% RDF. The combination of 60 kg/ha seed rate and 125% RDF obtained significant maximum CP (1542.1 kg/ha), EE (367.4 kg/ha) and ash yield (1280.0 kg/ha). The use of 150% RDF also resulted into improvement in the nutrient content to the tune of 20.2% in N and 12.5% in P and enhanced nutrient uptake by 50.5% of N and 41.9% that of P over control. It can be concluded that to realize higher productivity with enhanced quality of fodder maize with optimum density (60 kg/ha) and use of 125% of RDF are quite helpful, which will further strengthen and sustain the performance of livestock in terms of health and milk production.

Growth and yield of okra (Abelmoschus esculentus (L.) Moench) grown in the marginal upland area of Sta. Rita, Samar as influenced by different planting densities and mulching materials

Okra or Lady’s finger, botanically known as Abelmoschus esculentus (L.) Moench, is a tropical and sub-tropical indigenous vegetable crop commonly grown for its fibrous, slimy, and nutritious fruits and consumed by all classes of population. It has also several medicinal and economic values. Despite its many uses and potential value, its importance is under estimated, under-utilized, and considered a minor crop and little attention was paid to its improvement. The study was conducted to evaluate the effects of different planting densities and mulching materials on the growth and yield of okra grown in slightly sloping area in the marginal uplands in Sta. Rita, Samar, Philippines. A split-plot experiment was set up with planting density as main plot and the different mulching materials as the sub-plot which were: unmulched or bare soil, rice straw, rice hull, hagonoy and plastic mulch. Planting density did not significantly affect the growth and yield of okra. Regardless ofthe mulching materials used, mulched plants were taller and yielded higher compared to unmulched plants. Moreover, the use of plastic mulch resulted to the highest total fruit yield. The results indicate the potential of mulching in increasing yield and thus profitability of okra production under marginal upland conditions.

The effects of different plant densities and silage corn varieties on silage yield and some yield parameters in no-till seeding

In this study, the possibility of growing silage corn, which is used as an important nutrient in livestock and whose production is increasing in recent years, by no-till seeding method under Erzurum conditions was investigated. For this purpose, three silage corn varieties (DKC-5783, Prestige, and ADA-9510) suitable for Erzurum's climatic conditions in terms of vegetation period were selected from a large number of silage corn seeds widely grown throughout Turkey and their development conditions under no-till seeding conditions were investigated. A precision vacuum no-till seeder with double disk type furrow opener was used for silage corn seeding. Based on three different intrarow seed spacings (10, 15, and 20 cm), physical properties of soil, plant emergence, yield, and yield parameters as well as the planting performance of the machine were examined. According to the results obtained from the study, it was determined that mean emergence time decreased and seedling emergence increased as intrarow seed spacing increased. Furthermore, it was also found that DKC-5783 had the best emergence time, the best seedling emergence percentage, and the highest emergence rate index. Where yield decreased as intrarow spacing increased, ADA-9510 had the highest yield among varieties. Generally, intrarow seed spacing of 20 cm and DKC-5783 and ADA-9510 gave the best results.

Forage nutritive value of sweet basil cultivars affectedby different plant density with corn

In order to assessment of the effects of different plant density (20, 30, 40 S.B M + 8 C; 20, 30, 40 S.B I + 8 C plants m-2 and sloe cropping of S.B. M40 and S.B. I 40) on forage nutritive value of sweet basil cultivars (Mubarake and Italian large leaf) a randomized complete block design with three replications was conducted in University of Tabriz, Iran. Results showed that the effect of different plant density of sweet basil cultivars was significant (p is less than 0.05) on dry matter (DM), acid detergent fiber (ADF), ash, crude protein (CP) and oil yield of sweet basil cultivars. However, oil percentage of both sweet basil cultivars was not affected by different plant density with corn plants. DM, ADF, CP percentage and yield and also oil yield of both sweet basil cultivars were significantly decreased as result of different plant density with corn plants, in contrast, ash of both cultivars increased in those treatments. ash, CP%, CP and oil yield of Mubarake cultivars were greater than that of Italian large leaf cultivar in sole plant density. It was concluded that different plant density between sweet basil+ corn had positive effect on forage nutritive value of both sweet basil cultivars.

EFFECT OF SOME PRE AND POSTHARVEST TREATMENTS ON QUALITY AND STORABILITY OF GREEN ONION

This experiment was carried out during the winter seasons of 2014/2015 and 2015/2016 at the Agriculture Research Farm, El-Kassasien Hort. Res. Station, Ismalia Governorate, Egypt, to clarify the effects of different plant densities, 5 cm on one side (33 plant /m2), 2.5 cm on one side (66 plant /m2), 5 cm on both sides (66 plant /m2), and 2.5 cm on both sides (133 plant /m2) on quality parameters and yield of green onion plants (Allium cepa L.), cv. Giza 6 grown under sandy soil conditions, and also to study the impact of hydro-cooling and packaging green onion plants in polypropylene pouches on the quality parameters of green onion during storage at 3°C ±1and 95% RH for 15 days. The obtained data indicated that sowing green onion seeds at low density 5cm on one side (33 plant /m2) significantly increased plant weight, bulb diameter, neck diameter, bulb length, and total dry weight per plant in both seasons of study as compared to other treatments. Meanwhile, higher plant density 2.5cm on both sides (133 plant /m2) significantly increased total yield per fed., Regarding, storage experiment, the obtained results showed, that there were a considerable and a continuous increase in weight loss %, leave extension, root development, and curvature of green onion stem as the storage period was extended. On the other hand, a significant decline happened in general appearance, chlorophyll content, and TSS% as the storage period increased. The combination between hydro-cooling and packaging, effectively maintained green onion plants with fresh appearance and acceptable sensory quality for 10 days at 3°C ±1 and 95% RH.

Yield and quality of Moringa oleifera under different planting densities and cutting heights in southwest China

Moringa oleifera is a multipurpose plant that is now being promoted as a fodder crop. The aim of this study was to evaluate the effect of different planting densities (0.2m×0.2m, 0.4m×0.4m and 0.8m×0.8m) and cutting heights (15, 30 and 60cm) on the biomass yield and quality of Moringa oleifera in valley areas of southwest China during the period 2010–2012. The results indicated that the highest planting density of 0.2m×0.2m in combination with the intermediate cutting height of 30cm produced the highest fresh matter (FM) and dry matter (DM) yield throughout the whole evaluation period. The 0.2m×0.2m planting density not only produced the highest FM (8.43–76.41Mgha−1) and DM (1.66–12.85Mgha−1) yield, but also the highest fine and coarse fractions of the plant over two consecutive evaluation years irrespective of season, i.e., rainy or dry. The 30cm cutting height resulted in the highest FM (25.18–41.53Mgha−1) and DM (5.28–8.27Mgha−1) yield in the rainy season, whereas the 15cm cutting height resulted in the greatest yield in the dry season (4.38–13.16Mgha−1 FM and 0.82–2.26Mgha−1 DM). These findings suggest that the lower cutting height could be recommended in the low rainfall area to produce the highest moringa yield. Additionally, the crude protein (CP) content was higher in the rainy season (235.3–257.6gkg−1 DM) than in the dry season (224.1–232.8gkg−1 DM) and was significantly affected by planting density in the rainy season. However, the crude fibre (CF) (up to 192.7gkg−1 DM), neutral detergent fibre (NDF) (up to 293.1gkg−1 DM), acid detergent fibre (ADF) (up to 208.4gkg−1 DM), DM (up to 173.7gkg−1) and ash (up to 94.5gkg−1 DM) contents were higher in the dry than in the rainy season. Planting density only significantly affected the DM and ash contents in the rainy season, and the CF content in the rainy and dry season. The crude lipid (EE) content (22.9–26.1gkg−1 DM)did not differ significantly between the different planting densities, whereas in vitro DM digestibility (IVDMD) (766.3–853.6gkg−1 DM) was significantly affected by planting density in the rainy season. The cutting height had no significant effect on the CP, IVDMD, EE, NDF, DM and ash contents in either the rainy or dry season, but the CF content in the dry season and the ADF content in the rainy season were significantly affected by cutting height. These data suggest that as a forage crop, moringa is not only a good source of protein but has a balanced fibre component with a high digestion rate for livestock, especially ruminants.

Agromorphological Variations and Essential Oil Production of Satureja khuzestanica Jamzad Under Different Planting Densities

Plant density is an important factor in determining the microenvironment in the agricultural and plant production systems. This study examined the effects of different planting densities (25×60 cm, 25×70 cm, 25×80 cm, 35×60 cm, 35×70 cm, 35×80 cm, 45×60 cm, 45×70 cm, and 45×80 cm) on agromorphological parameters and essential oil production of Satureja khuzestanica Jamzad, in 2 growing years. The essential oils were isolated from aerial flowering parts of the plants by hydrodistillation method and subjected to GC and GC-MS analyses to determine the constituents. The mean total two years of growth results indicated that the plant dry weight increased with decreasing density. The highest and the lowest leaf + inflorescence yield per unit area were obtained in the highest and the lowest planting density, respectively. Also, results showed that the 18 compositions were identified in essential oil of S. khuzestanica plants under all employed treatments. In general, essential oil percentage was increased with decreasing of planting density. In contrast, the maximum (25.37 g.m-2) and the minimum (10.06 g.m-2) essential oil yield were recorded in the highest and the lowest planting density, respectively. Interestingly, carvacrol was the major component of oils, which is also showed more variability (ranging from 90.32% to 94%) than that of other components under employed treatments. It is concluded that the S. khuzestanica should be cultivated at high plant densities for getting high essential oil yield and the maximum amount of carvacrol.

Influence of Nitrogen Levels and Planting Geometry on Sweet Sorghum (Sorghum bicolor) Juice Sugar Quality Traits Under Semi-arid Tropical Environment

Sweet sorghum (Sorghum bicolor (L.) Moench) is a potential bioenergy crop that produces both food (from grain) and biofuel (from stalk juice). The present investigation undertaken to assess the effect of different plant density and nitrogen levels on juice extraction and sugar quality traits of sweet sorghum grown in postrainy season of 2008–2009. Three planting geometries as main treatments (30 × 15, 45 × 15 and 60 × 15 cm) and four levels of nitrogen (0, 30, 60 and 90 kg ha−1) application levels as sub-plot treatments were assessed in split-plot design. It is found that the combination of relatively lower nitrogen application level (60 kg ha−1) with maximum population density (spacing 45 × 15 cm) are needed for higher sugar and ethanol yields in the farmer fields.