Growing vegetables
Saeed Mohammadzade; Morteza Goldani; Fatemeh Yaghobi; Mohammad Bannayan Aval
Abstract
IntroductionIncreasing the tolerance to drought and nitrogen stress in tomato cultivars is essential for the sustainable and environmentally friendly production of this product. Also, knowing the morpho-physiological, biochemical and molecular responses to drought and nitrogen stress is important for ...
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IntroductionIncreasing the tolerance to drought and nitrogen stress in tomato cultivars is essential for the sustainable and environmentally friendly production of this product. Also, knowing the morpho-physiological, biochemical and molecular responses to drought and nitrogen stress is important for a comprehensive understanding of plant water tolerance mechanisms and nitrogen limitation conditions in higher plants. Therefore, the purpose of this study was to investigate the effect of different levels of irrigation and nitrogen fertilizer on the quantitative and qualitative characteristics of tomatoes in different Cluster rows under greenhouse conditions. Materials and MethodsThe experiment was conducted at the research greenhouse of the Faculty of Agriculture, Ferdowsi University of Mashhad, in two years, 2021-02 and 2022-03. The experiment was set up as split-plot layout based on randomized complete block design with three replications. Irrigation levels were considered as the main plot at three levels: 75% (I75), 100% (I100), and 125% (I125) of the crop water requirement. Nitrogen fertilizer was considered as the subplot at four levels: control (no nitrogen), 75 kg ha-1 (7.5 g m-²), 150 kg ha-1 (15 g m-²), and 225 kg ha-1 (22.5 g m-²) from urea as the nitrogen source. Tomato seeds (Newton cultivar) were sown in polyethylene seedling trays with a coco peat and perlite mixture as the substrate. The seedlings were transplanted to the main field at 15 cm height with 3-4 true leaves. In all stages of growth, consistent agricultural practices were applied, including weed control, pest and disease management. Fertilization for tomato plants was based on soil analysis. Initially, after transplanting the seedlings, a complete fertilizer with high phosphorus (NPK 10-52-10) was applied at a ratio of 1.5 kg per thousand plants. In the subsequent stages, complete fertilizers (NPK 20-20-20) and high-potassium fertilizers (NPK 20-20-36) were applied through irrigation. Throughout the plant's growth stages, to prevent potential deficiencies and harm to growth and fruit development, micronutrients were applied as foliar sprays. Results and Discussion The results for all three Clusters showed that although nitrate accumulation was higher in the first year compared to the second year, in both years, nitrate accumulation was higher at I75 and 225 kg ha-1 nitrogen compared to the other treatments. The highest nitrate accumulation in the sixth (6.12 mg.kg-1) and seventh (6.29 mg.kg-1) Clusters was observed in I75 and 225 kg ha-1 nitrogen treatment in the first year. In the eighth Cluster, contrary to the sixth and seventh Clusters, the highest nitrate accumulation was obtained in I100 and 225 kg/ha nitrogen (6.43 mg.kg-1) in the first year. Chlorophyll decreased with stress but increased with nitrogen levels. In all four Clusters, the highest chlorophyll a content was obtained in I100 and 225 kg ha-1 nitrogen, with values of 3.75, 3.70, 3.30, and 3.85 mg g-1 fresh weight, respectively. The highest fruit number per square meter was obtained in I125 and 225 kg ha-1 nitrogen treatment in the second year (260 fruits), although there was no significant difference compared to the first year. Furthermore, this treatment produced 11% more fruits than the highest fruit number at 100% moisture. The highest single fruit weight was obtained in I125 and 225 kg ha-1 nitrogen treatment in the first year of the experiment (254 g), although there was no significant difference compared to the second year. Additionally, this treatment showed no significant difference in fruit weight compared to the 225 kg ha-1 nitrogen and I100 treatment in the first year but was 11% higher in the second year. The highest yield (65.1 kg m-²) was obtained at I125 and 225 kg ha-1 nitrogen. However, in the control treatment without fertilizer, there was no significant difference in yield at I100 and I125. Furthermore, the highest water use efficiency was observed at I100, followed by I75. In all fertilizer treatments, I125 treatment had the lowest water use efficiency. The highest water use efficiency (285 kg m-³) was obtained at I100 and 225 kg ha-1 nitrogen. Conclusion In general, the results demonstrated that while excessive nitrogen fertilizer increased nitrate accumulation at different irrigation levels, the increased use of irrigation water reduced nitrate accumulation in tomato fruits while improved yield. Moreover, no significant difference in fruit yield was observed between I125 and I100, but optimum yield and favorable water use efficiency were obtained with less water consumption. Based on the results of this experiment, the recommended treatment under greenhouse conditions is irrigation at 100% of the FC and the use of 250 kg ha-1 nitrogen.
Growing vegetables
M. Amiri roudan; M.R. Hassandokht; D. Sadeghzadeh-Ahari; A. Mousavi
Abstract
Introduction
The use of natural and artificial mulches to reduce evaporation from the soil surface and retain moisture is one of the best measures to make optimal use of limited water resources and increase crop yields. Optimal production of plants in sandy soils has been challenged due to their ...
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Introduction
The use of natural and artificial mulches to reduce evaporation from the soil surface and retain moisture is one of the best measures to make optimal use of limited water resources and increase crop yields. Optimal production of plants in sandy soils has been challenged due to their low capacity in water retention and also production of plants in arid and semi-arid regions due to water shortage and drought stress. Water scarcity is increasing as a result of global warming, and attention is being paid to the methods that lead to water storage. Therefore, it is necessary to increase water consumption efficiency with new technologies. One of the new methods of water retention in the root zone is the use of a water retaining layer below the soil surface. By preserving water and elements in the root zone and creating a stable environmental state, it increases local production and economy by reducing soil erosion and groundwater pollution. Also, due to limited water resources, it is necessary to seek solutions to conserve water and increase water use efficiency. Mulch is considered as one of the best ways to retain water in the soil and reduce soil evaporation. Therefore, in this study, the application of impermeable soil layer on morphophysiological and biochemical traits of eggplant (Solanum melongena L.) was investigated using date leaf mulch under deficit irrigation stress.
Materials and Methods
This study was conducted in Roudan, Hormozgan, Iran. Main plot includes deficit irrigation stress in three levels (100, 70,40 % of plant water requirement), sub-plot includes mulch in two levels (date leaves and no mulch) and sub-sub-plot includes impermeable layer in three levels (0, 100, 120 cm). Eggplant seeds of the local variety Rudan were planted in the seedling tray and transplanted when the seedlings were about 15 cm long or 5-6 leaf stage. Shortly after transplanting the seedlings to the field, daily irrigation was performed. CROPWAT software was used to calculate 100 % of the water requirement. Stress was applied using drippers with lower flow rate or reduced irrigation hours and by installing water meters.
Results and Discussion
The results showed that the highest plant height (78 cm) belonged to date palm mulch, layer impermeable at depth of 120 cm and 100% water requirement. The use of date palm mulch and impermeable layer, especially the impermeable layer, has led to an increase in the number of leaves and fruits in the eggplant. The highest number of leaves (189) belonged to the treatment without mulch and with an impermeable layer of 120 cm soil depth in 100 % water requirement and the lowest (75.13) belonged to the treatment without mulch and impermeable layer in 40 % water requirement. The highest number of fruits belonged to the treatment without mulch and impermeable layer at depth of 120 cm and 100 % water requirement and the highest amount of dry matter (12.5%) belonged to the treatment of date palm mulch and impermeable layer at depth of 120 cm and 100 % water requirement and the lowest (1/9%) belonged to date palm mulch without impermeable layer and 70% water requirement. The results showed deficit irrigation stress reduced the amount of chlorophyll a, b and total in eggplant. The use of date palm mulch and impermeable layer in water requirement of 70 and 40 % has increased the amount of chlorophyll, which seems to be used in case of water shortage, reduce the adverse effects of dehydration and prevent the destruction of chlorophyll in eggplant. The highest amount of total chlorophyll belonged to the 100 % water requirement, without the use of date palm mulch and impermeable at depth of layer 120 cm. The highest amount of proline in this study belonged to treatment without date palm mulch, application of impermeable layer at depth of 0 cm and water requirement of 40 % and the lowest belonged to the treatment of date palm mulch, application of impermeable layer at depth of 120 cm and 100 % water requirement. The highest amount of eggplant water use efficiency was obtained in 40 % water requirement, use of date palm mulch and impermeable layer at depth of 120 cm. The results of this study also showed that deficit irrigation stress reduced fruit yield in eggplant and the use of date palm mulch and impermeable layer also increased eggplant yield. This increase in fruit yield is especially noticeable in the use of date palm mulch and impermeable layer at depth of 120 cm.
Conclusion
It seems that the impermeable layer and date palm mulch have reduced the negative effects of water stress on the plant, increased fruit yield and water use efficiency and reduced the effects of stress.
Reyhane Setayesh; Mohammad Kafi; Jafar Nabati
Abstract
Introduction: The population growth and water requirement for domestic consumption, industry, agriculture and urban development in Mashhad megacity, increase pressures on freshwater resources. Therefore, planning for water use optimization is necessary. The new allocation of water resources for landscape ...
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Introduction: The population growth and water requirement for domestic consumption, industry, agriculture and urban development in Mashhad megacity, increase pressures on freshwater resources. Therefore, planning for water use optimization is necessary. The new allocation of water resources for landscape greenish, especially in arid and semi-arid is difficult. Therefore, water allocation to landscape is valuable and should be used efficiently. According to water resource limitation, using drought-tolerant plant species and determine threshold of drought tolerance in landscape can improve water use management. Plants that naturally survive in your area are the ones best adapted to your soil, climate and rainfall. By selecting plants that either avoid or tolerate dry conditions, a beautiful, thriving landscape can be made possible. Drought-tolerant plants survive long periods of drought by storing water internally or by developing extensive root systems that sink deep into the soil. Many drought-tolerant plants have additional protection through a waxy coating that reduces evaporation or hairs on the leaf surface that reflect some of the light, insulating the plant. Most drought-tolerant plants use several of these features to survive on low amounts of precipitation. Japanese barberry is a compact woody deciduous shrub with arching branches. Leaf colours include green, bluish-green to dark red and purple. B. thunbergii's progress in the United States has, to date, been held in check to the south by, probably, its need for cold winter temperatures for stratification of the seeds, and to the west by, probably, drought conditions. Although very drought tolerant once established, a very dry terrain would tend to discourage its incursion. Rugged, adaptable, no serious problems or pests, easy to maintain, transplants readily, shade and drought tolerant, deer resistant is typical ad copy found at any site offering this shrub of colourful fall foliage. In this regard, drought stress tolerance thresholds of ornamental barberry plant in Mashhad landscape were evaluated.
Materials and Methods: In order to determine the qualitative and quantitative drought stress tolerance thresholds of ornamental barberry (Berberis thunbergii) plant an experiment was conducted basis on randomized complete block design with three replications in Plant Production Complex of Mashhad Municipality. Treatments included; 100, 80, 60, 40, and 20% of culculated water requirements based on evaporation pan data. Two years old plants with similar size were transplanted from pots to field in 16 March 2012. Treatments were applied after establishment in 28 April and sampling was arranged in 6 August, 23 August, 6 September, and 7 October. During the growing season, the evaporation level was daily measured from pan Class A. In each sampling two plants sampled randomly from each plot for measuring the plant height, highest branches, number of branches, fresh and dry weight, dry mater percentage, irrigation water use index and freshness index.
Results and Discussion: Results showed that with increasing severity of drought stress plant height of barberry reduced significantly, but there were no significant difference between 100 and 80% of water requirement treatments. The highest branches reduced by diminishing water application volume but there were no significant difference among 100, 80 and 60% of water requirement application. The maximum of branch number was observed at 60 percent water requirement, however, there were no significant difference between 100 and 60% of water requirement treatments. The number of branches in 60% was 26% lower than 80% of water requirement. Therefore, application of 60% water requirement with 23 branches per plant produced highest branch number. The highest and lowest plant fresh weight was measured in 100% and 20% water requirement application, respectively. Application of 60% of water requirement produced statistically on the same biomass production of 100% of water requirement application. The lowest freshness index was observed in 20 and 40% of water requirement, but there were no significant difference among 60, 80 and 100% of water requirement applications.
Conclusion: Generally, results showed that ornamental barberry plant is a drought resistant plant and it can be alive by only 20% of its water requirement application, but for having freshness ornamental barberry in urban landscape, at least 60% of its water requirement should be applied. Based on the present results, water application of ornamental barberry could be reduced to 60% of calculated water requirement. It could be saved water application of barberry up to 4400 m-3.ha-1 in a growing season in Mashhad condition.
yahya selahvarzi; zabihollah zamani; A.R. Talaie; mohammadreza fattahi
Abstract
Introduction: Pomegranate (Punica granatum L.) belonging to the family Punicaceae, native to subtropical regions of Iran and adapted to arid or semi arid climates with mild winters. Pomegranate is fairly drought tolerant but requires regular irrigation to produce high yield and fruit weight. Large ...
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Introduction: Pomegranate (Punica granatum L.) belonging to the family Punicaceae, native to subtropical regions of Iran and adapted to arid or semi arid climates with mild winters. Pomegranate is fairly drought tolerant but requires regular irrigation to produce high yield and fruit weight. Large parts of Iran within the boundaries of central deserts (Dasht-e-kavir and Kavir-e-Loot) have arid or semi-arid conditions which make them suitable for pomegranate production. However drought crisis and water resources restriction are very serious in these areas.
Materials and Methods: This experiment was conducted on 7-year old pomegranate cv. Shahvar trees from 2013 to 2014 in Torbat-e-Heydarieh, Razavi Khorasan, Iran. Irrigation treatments and Gibberellic acid application were used in Completely Randomized Split-Plot Design with four replications. Irrigation treatments included [1-control: 100% of estimated crop evapotranspiration (Etc) 2-Sustained deficit irrigation (SDI): watering was constantly used at 50%Etc, and 3-Regulated deficit irrigation (RDI): not watering was imposed until fruit set and then irrigation was applied same as control]. Foliar application of Gibberellic acid was done with two concentrations (0 and 150 ppm) at early May and September. Precipitation and pan evaporation (Ep) was recorded by weather station that located at 15 km distance from the studied orchard. Daily crop reference evapotranspiration (ETo) was estimated by penman-monteith equation. Trees were drip-irrigated by two lateral lines parallel to the tree row and four emitters that each one delivers 4 liters per hour. Fruit weight and numbers, tree production (yield), peel, arils and juice percent and finally fruit cracking of each treatment were determined at ordinary harvest time in late of October. Some uniform and intact fruits per treatment transferred to cold storage (T= 5 ◦C, RH= 85-90%). After storage period the fruits transfered to shelf life condition (7 days at 20 ◦C and RH= 65-70%) to evaluate physiochemical traits at 2 different storage periods (9 and 18 weeks). Weight loss and chilling index were determined during 3 weeks intervals of storage. Weight loss was evaluated by a gravimetric method and results were expressed as percent of initial fresh weight. Chilling index was quantified by 5 point scale of fruit husk injury: (1: without disorder, 2: slight disorder signs 3: moderate signs 4: severe signs and 5: unmarketable).
Results and Discussion: In present research the effects of deficit irrigation treatments on all the measured attributes was significant at harvest time (p≤ 0.01). But Gibberellic acid spray had significant effect only on Fruit weight, juice percent and fruit cracking disorder. Likewise, deficit irrigation and Gibberellic acid interaction showed significant difference for fruit weight and cracking disorder. The results indicated that fruit weight, total yield and fruit juice in regulated deficit irrigation increased by 39.6, 17.1 and 16.6 percent in compare with control, respectively. Fruit numbers in control trees (108.3) was more than sustained (93.6) and regulated (87) deficit irrigation. It is possible that sustained (SDI) and regulated (RDI) deficit irrigation have decreased sprouting growth and consequently second or third waves of pomegranate flowers that forming on these shoots was lower by water restricting. Pomegranate peel percent in studied deficit irrigation strategies were less than control and naturally aril percent was more in these treatments. In other hand, the highest fruit cracking (9.1%) and lowest fruit weight (205.8 g) occurred in sustained deficit irrigation. However Gibberellic acid application could increase fruit weight and alleviate cracking disorder. The results of cold storage experiment showed that maturity index, antioxidant activity, total anthocyanin and chilling index improved by Sustained deficit irrigation. Variations of ripening index during cold storage occurred because of sugar conversion, not the changes of organic acids content. Indeed, rate of starch degradation to simple carbohydrates in fruits increase under drought condition. Probability drought in deficit irrigation treatments as an oxidative stress motivates antioxidant system and consequently increases chilling resistance in pomegranate fruits. Preharvest Gibberellic acid application amended weight loss and increased total anthocyanin and antioxidant activity during cold storage.
Conclusions: On the base of this study it seems that using of some deficit irrigation strategies have acceptable consequences on pomegranate fruit production at conditions of water resources restriction. Likewise Gibberellic acid application on trees that were subjected by deficit irrigations ameliorates the adverse effects of drought stress.
