Lower Vegetative Growth Research Articles

The Effects of Planting Density, Training System and Cultivar on Vegetative Growth and Fruit Production in Young Mango (Mangifera indica L.) Trees

Increasing the planting density of mango orchards appears promising for obtaining higher yields, particularly during the first productive years. However, the challenge is to maintain a good balance between vegetative growth and fruit production in the longer term. The objective of this study was to decipher the effects of planting density, training system and cultivar on young mango trees’ growth and production. The experiment, conducted in North Queensland, consisted of five combinations of planting density and training system applied to the cultivars Keitt, Calypso and NMBP-1243. The planting densities were low (208 tree ha−1), medium (416 tree ha−1) and high (1250 tree ha−1). The closed vase conventional training system was applied at each density. Single leader and espalier on trellis training systems were applied at medium and high densities, respectively. The tree canopy dimensions were measured every 6 months from planting, and tree production was recorded from the third to the fifth years after planting. Vegetative growth and fruit production were the results of complex interactions between planting density, training system, cultivar and/or time. The expected increase in orchard yield with higher planting density was observed from the first productive year, despite lower individual tree production at high planting density. Lower vegetative growth and fruit production at high planting density were probably caused by competition between trees. NMBP-1243 and Keitt showed more rapid vegetative growth. Keitt was the most productive cultivar during the first three productive years. The detailed results of this study provide avenues to further explore the behaviour of mango trees at high planting densities.

Innovative farming techniques for superior okra yield in Chitwan, Nepal: The benefits of plastic film mulch and pest exclusion net on soil properties, growth, quality and profitability

Okra (Abelmoschus esculentus) is a large-acreage cultivated, nutritious, commercial fruit vegetable crop in tropical and subtropical regions that plays a dominant role in Nepalese cuisine in the summer. Modified growing conditions through pest exclusion nets (PEN) and types of mulch on okra might be effective techniques to enhance yield and marketable production. Research is performed to investigate the effects of PEN and plastic film on the performance and yield of okra. An experiment laid out single factorial randomized complete block design with four replications and five treatments consists of: a) Control (No net + no mulch), b) Organic mulch (Rice straw mulch), c) Black plastic mulch, d) Silver plastic mulch, e) Pest exclusion net + black plastic mulch; on Swastik-2 F1 variety. The data were analyzed R software at the (p ≤ 0.05) level of significance and mean comparison is done using (Dunken Multiple Range Test) DMRT. This study revealed that silver plastic mulch and black plastic mulch treatment statistically resulted in pars & significantly higher yield (30.74 and 29.39 mt ha−1), leaf number/plant (27.98 and 26.73), branch number/plant (5 all), fruit number/plant (33 & 29) and the lowest days to flowering (39 & 40 days) compared to control; while PEN+black plastic mulching treatment resulted in higher plant height (212.93 cm), stem diameter (2.54 cm), fruit length (18.26 cm), fruit diameter (1.73 cm), fruit weight (32.80 g), longest days to flowering (43 days) and lowest leaf number per plant (15.58), branches/plant (4), yield (20.4 mt ha−1), light intensity (110.32 lx) which is undesirable yield perspectives but insect pest population is significantly lower in PEN results superior quality than other treatmets. Black plastic films and PEN+ black mulch raise soil temperature (max 34.89 °C) and increase soil moisture (18.15% vol) during germination. Plant inside PEN +black plastic mulching received low light intensity had higher vegetative growth but found with low yield. Plants in control and straw mulch treatments were found to have low vegetative growth and yield (22.7 and 24.4 tons/ha). Farmers can use silver and Black plastic plastics mulch, which are economically more viable and Productive as compared to other treatments for commercial cultivation of okra.

Seaweed extract effect on arbuscular mycorrhizae spore in soil engineered by earthworm, and the soil effect on upland rice growth

Seaweed extract is known to contain nutrients and growth-regulating substances that affect soil biota, and a source of protection against pests and diseases. Earthworm, which is an example of a soil biota and playing the role of ecosystem engineer, has the ability to produce suitable land biostructures, for the inhabitation of arbuscular mycorrhizal fungi (AMF), which has an impact on upland rice growth. Therefore, this study aims to determine, (i) the effect of seaweed extract on the population of earthworms and spores of arbuscular mycorrhizal fungi, and (ii) the impact of the engineered soil on the growth of local upland rice varieties. Furthermore, the extract of seaweed, such as Kappapychus alvarezii, was divided into five concentration levels, namely 0%, 20%, 40%, 60%, and 80%. Each treatment was drenched into the soil from the cogongrass vegetated area, mixed with 20 Pheretima sp., and maintained for 49 days in the greenhouse. The result showed that the total difference in the earthworms’ concentration treatments was not significant. It also showed that the total AMF spores in the engineered soil products of 20% concentration was the highest. Based on treatment with the earthworm engineered soil products, the highest and lowest vegetative growth and yield components of upland rice were observed at the concentrations of 80% and 0%, respectively. In conclusion, the application of seaweed extract to the soil did not significantly reduce the earthworm population. The extract concentration of 20% also increased the total AMF spore in the engineered soil. Moreover, highly treated engineered soil products increased the growth and yield components of upland Kambowa rice on cogongrass soils.

Drought-Adaptive Mechanisms of Young Sweet Cherry Trees in Response to Withholding and Resuming Irrigation Cycles

The present work evaluates the main adaptive mechanisms developed by young sweet cherry trees (Prunus avium L.) to cope with drought. For this purpose, the young trees were subjected to two drought cycles with different water stress intensities followed by a recovery period. Three irrigation treatments were applied: control treatment (CTL) irrigated to ensure non-limiting soil water conditions; moderate water stress (MS) subjected to two drying cycles whose duration was dependent on the time elapsed until the trees reached values of midday stem water potential (Ψstem) of −1.3 and −1.7 MPa for the first and second cycle, respectively; and severe water stress (SS) similar to MS, but with reference values of −1.6 and −2.5 MPa. In-between drought cycles, MS and SS trees were irrigated daily as the CTL trees until reaching Ψstem values similar to those of CTL trees. The MS and SS trees showed an important stomatal regulation and lower vegetative growth. The decreasing leaf turgor potential (Ψturgor) during the drought periods accounted for 40–100% of the reduction in leaf water potential at midday (Ψmd). The minimum osmotic potential for mature leaves was about 0.35 MPa lower than in well-irrigated trees. The occasional osmotic adjustment observed in MS and SS trees was not sufficient to maintain Ψturgor values similar to the CTL trees or to increase the specific leaf weight (SLW). The leaf insertion angle increased as the water stress level increased. Severe water stress (Ψstem < −2.0 MPa) resulted in clear early defoliation as a further step in water conservation.

Canopy Index Evaluation for Precision Management in an Intensive Olive Orchard

The evaluation of the canopy in orchard cultivation is a key aspect for the main cultivation techniques, such as pruning, thinning, harvesting, production and improved fruit quality. The possibility of having a periodic screening of the state of development of the vegetation can be of practical support to growers. Research on the application of precision agriculture has provided tools for reading and interpreting crops, and the resulting information is potentially useful. Many of the systems under study provide after monitoring information processing systems that reduce the timeliness of intervention. Especially in intensive systems such as olive groves, knowing the precise intervention points is often essential. In the present work, a multi-parameter instrument was used for field monitoring on the agricultural tractor to analyse the canopy. The system allows measuring various indicators such as height and density of the canopy and the temperature and humidity of the ambient air and at the leaf level. The first evaluation of the data made it possible to identify areas with greater vegetative concentration and greater or lesser development. The system made it possible to identify with good approximation the homogeneous areas, based on the Canopy Index (CI) evaluation to be subjected to subsequent and specific management efforts, dividing them into low, ordinary, and high vegetative growth. The results highlight the possibility of directly combining operators able to intervene with the same passage, selecting based on differences in growth, typical varietal specificities, and areas of deficient development or that are affected by plant diseases, confirming the objective of defining the areas of the orchard that require different management and workload techniques.

Plant and soil microbial community responses to different water management strategies in an almond crop.

Climate change is one of the main challenges facing the agricultural sector as it strives to meet global food needs. In arid and semiarid areas, the scarcity of water imposes the use of alternative sources - such as reclaimed water (RW) or desalinated water (DW) - and of deficit irrigation strategies, such as regulated deficit irrigation (RDI), in order to maintain productivity. The impact of both alternative water sources and RDI strategies on soil microbial communities in conjunction with the crop response has been little studied, and far less in fruit trees. Here, we evaluated the effects of the irrigation water quantity (RDI or the optimal water amount) and quality (DW or saline RW) on: i) the biomass, composition, and activity of the soil microbial community, and ii) the plant agro-physiological response at the level of the water status, nutrients, vegetative growth, and yield of almond trees. The DW-RDI treatment had a lower vegetative growth than the rest, reducing the nutrient requirements and increasing the contents of organic carbon and nitrogen in soil. This coincided with a significant increase in the bacterial biomass and enzyme activities in soil, as well as with a decrease in plant nutrient use efficiencies and yield. Irrigation with RW increased the fungal biomass. When there were no water restrictions (RW-FI), none of the plant agro-physiological parameters were affected; when RDI was applied (RW-RDI), the highest soil sodicity was reached and vegetative growth and yield were negatively affected, although the plant nutrient use efficiencies did not decrease as much as with DW-RDI. In addition, the plant nutrient use efficiencies were negatively correlated with the soil enzyme activities. These results improve our knowledge of the functioning of plant-soil interactions in Mediterranean crops subjected to different irrigation strategies.

Influence of Meloidogyne javanica parasitism on soybean development and chemical composition

BackgroundSoybean is a major economic crop worldwide, but its yield and quality are greatly affected by root-knot nematode infection. This study aimed to assess the effects of Meloidogyne javanica parasitism on soybean growth, yield, and quality. Soybean plants were inoculated with 0, 1000, 2000, or 4000 eggs + second-stage juveniles (J2) of M. javanica and evaluated for vegetative and nematode parameters. Grains from each treatment were analyzed for yield, proximate composition, total phenolic content, total flavonoid content, isoflavone profile, and antioxidant capacity.ResultsPlants free of nematodes had lower vegetative growth and higher yield than nematode-infected plants. The maximum estimated reproduction factor was 34.85, achieved by inoculation of 2433 eggs + J2. Moisture, fiber, and protein contents decreased with increasing inoculum levels. Lipid content increased with inoculum level until reaching 22.59 g 100 g−1 of sample. Total phenolic and flavonoid contents decreased with increasing inoculum level up to about 2000 eggs + J2 and then increased until reaching 219.20 mg gallic acid equivalents 100 g−1 of sample and 121.67 mg quercetin equivalent 100 g−1 of sample, respectively, at 4000 eggs + J2. A similar behavior was observed for antioxidant capacity determined by the 2,2-diphenyl-1-picrylhydrazyl radical scavenging, superoxide radical scavenging, and ferric reducing antioxidant power assays. The highest contents of malonylgenistin (539 mmol g−1), acetylglycitin (106 mmol g−1), and genistin (87 mmol g−1) were found in grains from plants inoculated with 4000 eggs + J2.ConclusionsM. javanica inoculum level affected soybean development, grain production, yield, composition, and antioxidant capacity.

Expression of a Chloroplast-Targeted Cyanobacterial Flavodoxin in Tomato Plants Increases Harvest Index by Altering Plant Size and Productivity.

Tomato is the most important horticultural crop worldwide. Domestication has led to the selection of highly fruited genotypes, and the harvest index (HI), defined as the ratio of fruit yield over total plant biomass, is usually employed as a biomarker of agronomic value. Improvement of HI might then result from increased fruit production and/or lower vegetative growth. Reduction in vegetative biomass has been accomplished in various plant species by expression of flavodoxin, an electron shuttle flavoprotein that interacts with redox-based pathways of chloroplasts including photosynthesis. However, the effect of this genetic intervention on the development of reproductive organs has not been investigated. We show herein that expression of a plastid-targeted cyanobacterial flavodoxin in tomato resulted in significant reduction of plant size affecting stems, leaves, and fruit. Decreased size correlated with smaller cells and was accompanied by higher pigment contents and photosynthetic activities per leaf cross-section. Flavodoxin accumulated in green fruit but declined with ripening. Significant increases in HI were observed in flavodoxin-expressing lines due to the production of higher fruit number per plant in smaller plants. Therefore, overall yields can be enhanced by increasing plant density in the field. Metabolic profiling of ripe red fruit showed that levels of sugars, organic acids, and amino acids were similar or higher in transgenic plants, indicating that there was no trade-off between increased HI and fruit metabolite contents in flavodoxin-expressing plants. Taken together, our results show that flavodoxin has the potential to improve major agronomic traits when introduced in tomato.

Conversion to organic and biodynamic viticultural practices: impact on soil, grapevine development and grape quality

Aim: The effects of integrated, organic and biodynamic management on soil quality and the growth and morphological development of Riesling grapevines were assessed during the first 4 years of a long-term field trial in Geisenheim, Germany. The overall aim was to understand the effects of these different viticultural practices on soil quality and plant morphology as the basis for product quality.Methods and results: As indicators of soil quality, earthworm abundance and the activity of selected enzymes were assessed. The vegetative and reproductive development of the grapevines, as well as their susceptibility to fungal diseases in the field, wood and grape composition, and grape yield, were investigated. Individual variables were subjected to analysis of variance. Additionally, all variables were subjected to multivariate principal component analysis. Compared with plots under integrated management, plots under the two biological treatments were characterized by higher soil quality and lower vegetative growth and grape yield, and therefore higher exposure of grapes and lower grape cluster compactness, and, probably as a result of these morphological differences, lower incidence of acetic acid rot. Principal component analysis clearly differentiated the three treatments, and showed that biodynamic management had more pronounced effects than organic management in terms of enhanced soil fertility and reduction of vegetative growth.Conclusions: In the present study, organic and especially biodynamic management resulted in a morphology favouring production of high-quality grapes. The treatments differed in terms of fertilization and plant protection methods as well as choice of cover crops. Therefore, further research is necessary with respect to root growth and the nitrogen and water uptake dynamics of vines and cover crops. The differences between grapes produced under organic and biodynamic management emphasize the need for more research on the mode of action of biodynamic preparations.Significance and impact of the study: In recent years, both winegrowers and consumers have expressed steadily growing interest in organic and especially biodynamic wine production. The present study contributes to a better understanding of the effects on grapevine growth and morphological development of shifting to these methods as a way to increase product quality.

Characterization of coffee cultivars leaf rust-resistant subjected to framework pruning

The goal of our work was to evaluate physiological and agronomic traits, as well as the relationship between these traits in coffee cultivars coming from a germplasm supposedly resistant to leaf rust, and their response to framework pruning. The experiment was conducted at the Federal University of Lavras in randomized blocks with three replicates, with spacing of 3.5 x 0.7 m and plots of 12 plants. An amount of 25 coffee cultivars was evaluated, from which 23 were considered resistant and two susceptible to leaf rust. Traits analyzed were the plagiotropic branch length and number of nodes, net photosynthetic rate, transpiration rate, water use efficiency, fluorescence and chlorophyll index, leaf area index, leaf rust incidence and yield. Catucaí Amarelo 20/15 cv 479, Araponga MG1 and Tupi IAC 1669-33 cultivars show highly responsive to framework pruning. These cultivars have high yield associated to high net photosynthetic rate, water use efficiency and low transpiration rate. Moreover, the last two cultivars show a low incidence of leaf rust. The Acauã cultivar has a good response to framework pruning, showing high yield associated to lower incidence of leaf rust. Catucaí Vermelho 785/15 cultivar is not responsive to framework pruning because show lower yield, high incidence of leaf rust, low vegetative growth and low water use efficiency.

Performance of Vegetative Growth and Artificial Fruit Body Formation of Hypsizygus marmoreus in Bangladesh

Hypsizygus marmoreus is an edible and medicinal mushroom belongs to Basidiomycetes. The optimal culture conditions for the vegetative growth of brown and white strains of H. marmoreus were investigated to obtain suitable farming condition. Temperature suitable and unsuitable for vegetative growth was obtained at 20 and 35oC, respectively. The both strains of H. mermoreus love medium temperature and the mycelial growth was well developed at 20-25oC. This mushroom prefer pH ranging 6-8 for mycelial growth. The highest and lowest mycelial growth was found at pH 7 and 5 of both strains, respectively. Among 5 different carbon sources, sucrose was the best, whereas, maltose and lactose were the worst. The most suitable nitrogen sources were CaNO3 (in brown strain 65.6 mm and in white strain 56.3 mm) and the most unsuitable was NH_4H_2PO_4 (in brown strain 44.02 mm and in white strain 40.2 mm). Five different culture media were used to screen the optimal mycelial growth of H. marmoreus. PDA and YM (yeast-malt extract) were the most suitable and Czapek dox and Hennerberg were the most unfavorable for vegetative growth, whereas, glucose peptone was moderately suitable. The highest and lowest vegetative growth was observed in media prepared with mango (Mangifera indica) and koroi (Albizia procera) sawdust, respectively. However, for both strains, 3 weeks were required to complete mycelium running in mango sawdust, whereas, 4 weeks were spent to get 100% mycelium running in mahagoni (Swietenia mahagoni) and koroi sawdust. The premordia and fruiting bodies of H. marmoreus were formed in the mango sawdust medium sooner. The fruiting bodies of brown strain were formed earlier than white strain after occurrence of primordia. In case of limiting ventilation, the stem development was found to be good but no cap was seen to be formed. Ventilation influenced the growth and development of fruit body of H. marmoreus. Therefore, it could be said that physiochemical requirement for the vegetative growth is strictly considerable and results focused in this paper could be followed by farmers to scale up farming of H. marmoreus in Bangladesh.

Vegetative growth of grasslands based on hyper-temporal NDVI data from the Modis sensor

Abstract: The objective of this work was to analyze the development of grasslands in Zona da Mata, in the state of Minas Gerais, Brazil, between 2000 and 2013, using a parameter based on the growth index of the normalized difference vegetation index (NDVI) from the moderate resolution imaging spectroradiometer (Modis) data series. Based on temporal NDVI profiles, which were used as indicators of edaphoclimatic conditions, the growth index (GI) was estimated for 16-day periods throughout the spring season of 2012 to early 2013, being compared with the average GI from 2000 to 2011, used as the reference period. Currently, the grassland areas in Zona da Mata occupy approximately 1.2 million hectares. According to the used methods, 177,322 ha (14.61%) of these grassland areas have very low vegetative growth; 577,698 ha (45.96%) have low growth; 433,475 ha (35.72%) have balanced growth; 39,980 ha (3.29%) have high growth; and 5,032 ha (0.41%) have very high vegetative growth. The grasslands had predominantly low vegetative growth during the studied period, and the NDVI/Modis series is a useful source of data for regional assessments.

Conocarpus Biochar Induces Changes in Soil Nutrient Availability and Tomato Growth Under Saline Irrigation

Thermally modified organic materials commonly known as biochar have gained popularity of being used as a soil amendment. Little information, however, is available on the role of biochar in alleviating the negative impacts of saline water on soil productivity and plant growth. This study, therefore, was conducted to investigate the effects of Conocarpus biochar (BC) and organic farm residues (FR) at different application rates of 0.0% (control), 4.0% and 8.0% (weight/weight) on yield and quality of tomatoes grown on a sandy soil under drip irrigation with saline or non-saline water. The availability of P, K, Fe, Mn, Zn and Cu to plants was also investigated. The results demonstrated clearly that addition of BC or FR increased the vegetative growth, yield and quality parameters in all irrigation treatments. It was found that salt stress adversely affected soil productivity, as indicated by the lower vegetative growth and yield components of tomato plants. However, this suppressing effect on the vegetative growth and yield tended to decline with application of FR or BC, especially at the high application rate and in the presence of biochar. Under saline irrigation system, for instance, the total tomato yield increased over the control by 14.0%–43.3% with BC and by 3.9%–35.6% with FR. These could be attributed to enhancement effects of FR or BC on soil properties, as indicated by increases in soil organic matter content and nutrient availability. Therefore, biochar may be effectively used as a soil amendment for enhancing the productivity of salt-affected sandy soils under arid conditions.

EFFECT OF POLLINATION ON FRUIT SET AND EVALUATION OF PHENOLOGICAL, POMOLOGICAL AND MORPHOLOGICAL CHARACTERISTICS OF SOME INTRODUCED SWEET CHERRY CULTIVARS UNDER KHORASAN RAZAVI PROVINCE

Self and cross-incompatibility is one of the limiting factors in sweet cherry production. Scince some self-compatible exotic sweet cherry cultivars have been recently introduced to Iran, this study was conducted to investigate adabtibility of six introduced cultivars Summit, Red Dorfi clone 3, Sunburst, Samba, Blamarka and a local cultivar Siah Mashhad in Khorasan Razavi, Mashhad, Iran during 2010-2013. In most cultivars, flower buds were formed and developed on spurs, however flower formation in annual shoots was also observed. There were significant differences among cultivars for vegetative characters (height, width, crown volume and current season vegetative growth). Cultivars Summit and Sunburst had the highest and the lowest vegetative growth, respectively. There was 10 days variation in start of flowering time. Blamarka and Summit were early (27 March) and late (6 April) blooming cultivars, respectively. The results showed that fruit weight of cultivars was significantly different and Blamarka (3.14 g) and Sunburst (9.83 g) had the lowest and the highest fruit weight, respectively. Summit, Samba, Blamarka, and Siah-Mashhad were self-incompatible and cultivars Stella, Red Dorfi clone 3 clone and Sunburst were self-compatible under Khorasan Razavi province conditions.

Integrated analysis of climate, soil, topography and vegetative growth in Iberian viticultural regions.

The Iberian viticultural regions are convened according to the Denomination of Origin (DO) and present different climates, soils, topography and management practices. All these elements influence the vegetative growth of different varieties throughout the peninsula, and are tied to grape quality and wine type. In the current study, an integrated analysis of climate, soil, topography and vegetative growth was performed for the Iberian DO regions, using state-of-the-art datasets. For climatic assessment, a categorized index, accounting for phenological/thermal development, water availability and grape ripening conditions was computed. Soil textural classes were established to distinguish soil types. Elevation and aspect (orientation) were also taken into account, as the leading topographic elements. A spectral vegetation index was used to assess grapevine vegetative growth and an integrated analysis of all variables was performed. The results showed that the integrated climate-soil-topography influence on vine performance is evident. Most Iberian vineyards are grown in temperate dry climates with loamy soils, presenting low vegetative growth. Vineyards in temperate humid conditions tend to show higher vegetative growth. Conversely, in cooler/warmer climates, lower vigour vineyards prevail and other factors, such as soil type and precipitation acquire more important roles in driving vigour. Vines in prevailing loamy soils are grown over a wide climatic diversity, suggesting that precipitation is the primary factor influencing vigour. The present assessment of terroir characteristics allows direct comparison among wine regions and may have great value to viticulturists, particularly under a changing climate.

Sustainable Urban Horticulture of Sweet Pepper via Vermicomposting in Summer Season

The need for extend the urban horticulture to cover the food security demands, to mitigate CO2 emissions and avoid the extreme heat waves drive this study to investigate the ability of using soilless culture systems, vermicomposting technology and net cover in producing vegetables in urban area in summer season. The aim of this study was to determine the effect of different vermicompost rates mixed with the standard substrate peat moss: perlite (perlite: peat moss: vermicompost (45:45:10) (Mix.10%), perlite: peat moss: vermicompost (40:40:20) (Mix.20%), perlite: peat moss: vermicompost (35:35:30) (Mix.30%) and perlite: peat moss (50:50 V/V) (Control) under three microclimate conditions (plants covered with black net, white net and without cover) on vegetative growth and yield of sweet pepper (Capsicum annuum L. cv. Reda) grown in pots culture during summer seasons of 2012 and 2013 at the Central Laboratory for Agricultural Climate, Agricultural Research Center, Dokki, Giza Governorate.
 Physical and chemical properties of substrates, vegetative growth and yield characteristics, agrometerological data and mineral contents were determined. The obtained data indicated that vermicomposting could contribute in mitigate CO2 emission, save the essential nutrients and energy via recycling the urban organic wastes to vermicompost. The physical and chemical properties were affected by vermicompost. The best vegetative growth and yield of sweet pepper were given by (Mix.20%) vermicompost mixture followed by (Mix.10%) and (Mix.30%) vermicompost mixture. There were also significant differences between cover net treatments in affecting vegetative growth and yield of pepper, the white net was superior for producing pepper during the summer season; while the black net gave the lowest plant growth and yield. The best treatment was (Mix.20%) vermicompost mixture with white net cover, while the lowest vegetative growth and yield were obtained by (Control) vermicompost mixture with black cover net during the two tested seasons. These results suggested that vermicomposting and green roof can be used in urban area for producing food instead of incineration the urban organic wastes or imported food from rural area and using white cover net to improve the pepper growth and productivity during summer season.

Differential responses to short-term salinity stress of heat-tolerant cherry tomato cultivars grown at high temperatures

Although many new tomato cultivars with various degrees of heat-tolerance have been released, year-round tomato production in subtropical lowlands is still challenged by summer heat and an increasing risk from salinity stress. Little information about the simultaneous effects of heat and salinity on growth and fruiting in tomatoes is available. It was hypothesized that cultivars which perform better in high temperatures are also more tolerant to salinity stress. Two highly heat-tolerant cultivars, ‘Tainan ASVEG No. 19’ (TA19) and ‘Taiwan Seed ASVEG No. 22’ (TSA22), and one moderately heat-tolerant cultivar, ‘Hualien ASVEG No. 21’ (HA21), were grown under high temperature conditions and were irrigated with a 0, 50, 150, or 200 mM NaCl solution for 20 days. Vegetative growth, fruiting behavior, and fruit quality were monitored. Number of leaves, leaf area, shoot fresh and dry weights, and root fresh weight were generally decreased with increasing level of salinity stress, but root dry weight was not affected, resulting in an increase in root to shoot ratio in all three cultivars. Yield was also decreased by salinity treatments in all three cultivars due to reduced number of flowers, fruit set, and fruit size. The highly heat-tolerant ‘TA19’ had the lowest vegetative growth and the highest yield under the high temperature condition, but the yield was strongly suppressed by the short-term mild salinity treatment. On the other hand, vegetative growth was little affected and the degree of yield reduction was less intense with the short-term mild salinity treatment in the moderately heat-tolerant ‘HA21’. The result indicated that effects of heat stress and salinity stress are not additive and differential responses to salinity under high temperatures exist among cultivars with various degrees of heat-tolerance.

THE EFFECT OF BIO-FERTILIZERS AND AMINO ACIDS ON TOMATO PRODUCTION AND WATER PRODUCTIVITY UNDER NET-HOUSE CONDITIONS

The present study was carried out during two successive seasons, 2011/2012 and 2012/2013, at the Agricultural Research Station; El-Otouria, Sheehaniya, Doha, Qatar; to investigate the response of two tomato cultivars (Isabella and Milas) to biofertilizers and amino acids. Two biofertilizer treatments, rizobacterien at a rate of 2 and 4 liter per feddan and one of amino acid (Delfan) at a rate of 200 ppm, were used. Chicken manure, at a rate of 10 tons/ feddan, was the control treatment. Results showed the superiority of Isabella compared to Milas in terms of vegetative growth and fruit yield. Using Rizobacterien at a rate of 4 liter/feddan plus Delfan (amino acids) at a rate of 200 ppm increased growth and fruit chemical characters, earliness and total yield. The average fruit weight per plant was significantly high under Rizobacteria at a rate of 4 liter/feddan plus Delfan (amino acids) at a rate of 200 ppm. The lowest vegetative growth, fruit and yield characters were obtained from Rizobacteria at a rate of 2 liter/feddan. The water productivity results showed that all treatments led to the increase of fruit yield. Isabella cultivar had higher water productivity than Milas cultivar. Using of Rizobacterien at a rate of four liter/feddan also increased the water productivity. The same trend was obtained by using Delfan at a rate of 200 ppm. Concerning water productivity, Isabella cultivar had higher water productivity 16.7 and 17.2 kg of tomato fruits per cubic meter of irrigation water (m3) compared with Milas cultivar which produced15.9 and 16.5 kg tomato fruits per cubic meter of irrigation water for first and second seasons, respectively. Isabella cultivar plus amino acid (Delfan) gave the highest water productivity 19.1 and 19.7 kg of tomato fruits per m3 water for first and second seasons, respectively compared the other treatments.

The effect of plants density and population on yield and yield components and forage in dual purpose cultivation of barley cultivars (Hordeum vulgare L.)

In order to study the effect of plant population and Density on the yield components and forage in dual cultivation of barley cultivars, a split plot experiment in the form of randomized complete block design with for replications was carried out in Khuzestan agricultural and natural resources research farm in 2011-2012. The main factor consisted of two barley cultivars (midday, 10th global) and the sub factor consisted of four levels of planting density (250, 350, 450, 550 seed per square meter). The results of the experiment showed that the effect of cultivar and planting density on grain yield was significant at 1% level. The interactive effect of cultivar and density on 1000-grain weight, biomass yield of final harvest time, forage, and harvest index was not significant. However, the difference between various cultivars in terms of total biomass yield was significant at 5% level. The highest rate of grain yield, biological yield, number of grains per area unit, and 1000-grain weight belonged to 10th global cultivar with density of 550 seeds per square meter. The interactive effect of cultivar and planting density on the yield of forage was not significant while the effect of planting density on forage was significant at 1% level. The highest forage yield belonged to 10th global cultivar with density of 550 seeds per square meter and the lowest yield belonged to midday cultivar with density of 250 seeds per square meter. The results of the experiment indicated that 10th global cultivar with high yield potential produced more vegetative organs and its early season vegetative growth was more than midday cultivar and consequently it had higher yield of forage, and also had produced more fertile tillers and foliages than the midday cultivar; moreover, it had higher forage and grain production potential than the midday cultivar while the midday cultivar had the lowest vegetative growth and its grain and forage production potential was less than 10th global cultivar. * Corresponding Author: Roya Dashti Nejad  dashti1287@.yahoo.com

Crescimento e Rendimento Produtivo do Feijoeiro Submetido à Restrição Hídrica

The bean crop is affected by climate conditions, where plant development is influenced by water stress. One of the ways to meet the needs of the plant is through irrigation. Thus, in this work we sought to investigate the vegetative growth and production yield of the bean subjected to water stress during its cycle. For this purpose, beans of the cultivar Manteiga were cultivated in 5 dm3 pots and subjected to treatments of 50 and 100% field capacity. The parameters analyzed were: plant height, leaf area, number of root nodules, dry weight of the shoots, roots and total, dry mass of the grains and grain number and grain yield. According to the data obtained the following growth indexes were determined: increase of total dry matter and that of the stem, leaf and root. The experiment was conducted in a greenhouse at the Federal University of Vicosa, arranged in a randomized complete block design in a split-plot in time, with four replications. The results showed that there was lower vegetative growth and lower production yield in plants subjected to water restriction, imposed by the treatment of 50% field capacity, indicating the need for adequate control of soil water management as a suitable strategy for production.