Vegetative Growth Parameters Research Articles

Effect of some regulating substances on the vegetative parameters of flame seedless grapes cleft grafted on three nematode resistant rootstocks.

Grapes, the second next to Citrus, are one of Egypt's most popular fruits. Egypt is the world's 14th largest grape producers. The Flame seedless grape is a popular and early-season cultivar and one of the most prevalent grape kinds. Because the grape is nematode-sensitive, grafting on nematode-resistant rootstocks could be an effective way to minimize worm infection. The purpose of this study is to investigate the effect of IBA, Kinetin in graft union, and some grapevine rootstocks, such as Harmony, Freedom, and Salt Creek, on the percentage of Flame seedless grapevine survival and vegetative growth parameters when grafted using the cleft grafting method on the 15th February grafting date. When the Flame seedless grapes were treated at the graft union of the Freedom rootstock with a high level of indole-3-butyric acid (IBA, 1000 ppm) and a low level of Kinetin (250 ppm), they had a significantly higher survival percentage, shoot length, shoot diameter, L/D ratio, number of leaves per shoot, leaf area, fresh weight of leaves, fresh weight root system, dry weight of leaves and shoots, and dry weight root system in both seasons. It can be concluded that grafting on Freedom rootstock and using a low amount of Kinetin (250 ppm) are the most effective treatments for getting the highest percentage of survival and vegetative development parameters in Flame seedless grapevine.

Potential of Bioagents and Botanicals on Vegetative Growth Parameter of Betelvine (Piper betle) against Leaf Spot (Colletotrichum capsici Syd.)

The betelvine (Piper betle L.) is a perennial climbing evergreen shrub belonging to the Piperaceae, also known as the pepper family. As leaves has economic part of betelvine crop and consumed freshly harvested leaves. The present study were carried out at farmer’s field in collaboration with Department of Plant Pathology, Sam Higginbottom University of Agriculture Technology and Sciences Prayagraj to find out the ecological, environmentally and biological safe treatment to manage the disease as well increases the plant height and leaves length. Among all the treatment Trichoderma harzianum found to increase maximum plant height at different days after planting. While, Trichoderma viride increases the maximum leaves length and breadth during both the year.

The potential of some ameliorative substances in improving growth, yield and quality of carrot under heat stress conditions

A field experiment was carried out in two successive seasons of 2019 and 2020 on the late planting of carrot cv. Shantiny in El-Badrasheen, Giza, Egypt to study the effect of sowing dates and foliar spray applications by using some growth natural and chemical stimulants to increase the plants' ability to withstand heat stress. The experiment was established in a split-plot design with two sowing dates during 15 February and 15 March as the main factors and six treatments of exogenous foliar spray applications as submain factors as follows: untreated plants (control); potassium silicate K-Si at 2g/L; salicylic acid at 2mM; glycine betaine at 100 mM; moringa leaf extract (MLE) at 3.3% and date palm pollen grain extract (DPPGE) at 2g/L. Results revealed that sowing carrots in February significantly increased vegetative growth characteristics, i.e., plant height in both seasons and fresh and dry weight in the second season. Also, the fresh weight of roots in the second season and total marketable yield in both seasons were significantly increased with February sowing. All chemical parameters, either quality or heat indicators, were enhanced considerably with March sowing as a reaction to heat stress. Moreover, all foliar spray treatments gained the higher significant values of vegetative growth, yield, quality characteristics, and chemical parameters [N, P, K, Ca, Mg, proline, antioxidant activity DPPH, total carbohydrates, total carotenoids, total chlorophyll, and total phenols] as compared with untreated plants. In conclusion, foliar spray treatments with MLE and DPPGE are promising materials for heat stress-tolerant applications.

Natural extracts elevated drought resistance in Iris tingitana plant

A study was carried out for two seasons (2020/21 and 2021/22) to examine the effect of various natural extracts individually or in combination on the drought resistance of Iris tingitana cv. Wedgewood. A mixture of sand and clay (1:1 v/v) was prepared as a growth media. The treatments were (0, 25, and 50 % water drought) with liquid active biostimulants (garlic and seaweed) five times intervals after two weeks from bulb germination. The results revealed that plants at different soil moisture with various biostimulants succeeded in producing flowers of the best quality. Water drought at 25% also increased chlorophyll (a & b) and carotenoids in leaves, while drought at 0% recorded the highest increase in gibberellic acid. At 25% drought, vegetative growth and flower parameters were at their highest levels. Moreover, water drought at 50 % increased abscisic acid (ABA), proline, and catalase. Additionally, increases in vegetative growth, the number of leaves, flower parameters, chlorophyll (a & b), and carotenoids in leaves were noted as a result of applying seaweed extract at a concentration of 10 mL L-1; however, the best results for gibberellic acid were obtained using the highest concentration of garlic extract (500 mL L-1). The interactions between treatments indicated the superiority of growing bulbs at 25 % water drought with applying seaweed extracted at 10 mL L-1 that improved vegetative growth and most of the flower parameters. Meanwhile, treating plants at 25 % water drought with either seaweed at 5 mL L-1 or garlic extract at 500 mL L-1 realized the higher chlorophyll (a & b), carotenoids, and gibberellic acid (GA3) content.

Negative relationship between topsoil root production and grain yield in oat and barley

Production and maintenance of vegetative organs is costly for cereal crops, and thus it should be advantageous for crop production to produce no more roots and shoots than necessary to ensure maximum output. Excessive growth of vegetative organs may be genetically determined or triggered by resource deficiency or competition. While aboveground structures have received much attention from breeders, the same is not true of roots, which are not so readily observable. The purpose of this study was to examine the relationship between collective crop yield and vegetative growth parameters under favourable abiotic conditions in densely sown monocultures of oat and barley, with specific focus on root traits in the topsoil. A diverse set of existing varieties, as well as original crosses within both species were sown as monoculture patches in the field. Significant negative relationships were found between several root length-related traits and grain or protein yield in both species. Among oat crosses, we found a significant negative relationship between topsoil root length density and both grain and protein yield. In barley, the negative relationship between root length and yield was tied to shoot biomass - plants that grew longer roots per unit shoot biomass (root length ratio) produced lower grain yields. The results indicate that plants produced longer roots in the topsoil than necessary for maximum yield. While we cannot state with certainty the cause of the observed negative relationships between root growth and yield parameters, the results still suggest that root growth redundancy exists in cereals.

Studies on Effect of Different Cutting and Varieties on Growth Parameter of Spinach Beet (Beta vulgaris var. bengalensis L.)

During the Rabi season, the Department of Horticulture at Babasaheb Bhimrao Ambedkar University Lucknow (U.P.) conducted research on the effect of different cuttings and varieties on the Horticulture Research Farm. The experiment was conducted in a RBD design with 16 treatments and two factor varieties (V1 Chandrika, V2 Pusa Jyoti, V3 All Green, and V4 Palak Katadar) and treatment (C0 no cutting, C1 cutting 1, C2 cutting 2, and C3 cutting 3). We found that the effect of cutting on vegetative growth parameters, viz., plant height, number of leaves, leaf length, leaf width, leaf petiole length, and germination percentage, is significant. We found that cutting C0 had a significant influence on the growth parameters (plant height, number of leaves, leaf length, leaf width, and petiole length), with the minimum observed at C3, the maximum germination observed at C1 as compared to C2 treatment, and the least germination recorded at C0 treatment. While plant height, number of leaves, leaf length, leaf width, petiole length, and germination percentage have a greater influence on Pusa jyoti (V2) than on All Green (V3), minimums are reported for Chandrika (V1).Find that combination V2C3 getting maximum green yield per unit area and per unit time.

Integrating Application Methods and Concentrations of Salicylic Acid as an Avenue to Enhance Growth, Production, and Water Use Efficiency of Wheat under Full and Deficit Irrigation in Arid Countries

As water deficit in arid countries has already become the norm rather than the exception, water conservation in crop production processes has become very critical. Therefore, it is urgent to develop feasible strategies to achieve this goal. Exogenous application of salicylic acid (SA) has been proposed as one of the effective and economical strategies for mitigating water deficit in plants. However, the recommendations concerning the proper application methods (AMs) and the optimal concentrations (Cons) of SA under field conditions seem contradictory. Here, a two-year field study was conducted to compare the effects of twelve combinations of AMs and Cons on the vegetative growth, physiological parameters, yield, and irrigation water use efficiency (IWUE) of wheat under full (FL) and limited (LM) irrigation regimes. These combinations included seed soaking in purified water (S0), 0.5 mM SA (S1), and 1.0 mM SA (S2); foliar spray of SA at concentrations of 1.0 mM (F1), 2.0 mM (F2), and 3.0 mM (F3); and combinations of S1 and S2 with F1 (S1F1 and S2F1), F2 (S1F2 and S2F2), and F3 (S1F3 and S2F3). The results showed that the LM regime caused a significant reduction in all vegetative growth, physiological, and yield parameters, while it led to an increase in IWUE. The application of SA through seed soaking, foliar application, and a combination of both methods increased all of the studied parameters in all the evaluated times, resulting in higher values for all parameters than the treatment without SA (S0). The multivariate analyses, including principal component analysis and heatmapping, identified the foliar application method with 1-3 mM SA alone or in combination with seed soaking with 0.5 mM SA as the best treatments for the optimal performance of wheat under both irrigation regimes. Overall, our results indicated that exogenous application of SA has the potential to greatly improve growth, yield, and IWUE under limited water application, while optimal coupling combinations of AMs and Cons were required for positive effects in field conditions.

Cow dung putrefaction via vermicomposting using Eisenia fetida and its influence on seed sprouting and vegetative growth of Viola wittrockiana (pansy).

The current research was conducted at Vermi-tech Unit, Muzaffarabad in 2018 to evaluate the efficacy of cow dung and vermicompost on seed sprouting, seedlings, and vegetative developmental parameters of Viola x wittrokiana (pansy). In the current study, vermicompost was produced using Eisenia fetida. Physicochemical parameters of vermicompost and organic manure were recorded before each experimentation. The potting experiment was designed and comprised of eight germination mediums containing different combinations of soil, sand, cow dung, and various concentrations of vermicompost such as 10% VC, 15% VC, 20% VC, 25% VC, 30% VC, and 35% VC. Seed sprouting and seedling developmental parameters were observed for 28 days while vegetative plant growth parameters were recorded after 10 weeks of transplantation in various vermicompost amended germination media. Pre and post-physicochemical analysis of germination media were also recorded to check their quality and permanency. The current findings showed that 30% VC germination media was an effective dose for early seed germination initiation and all seed germination parameters. However, the significant vegetative plant growth and flowering parameters of pansy occurred at 35% VC. Findings revealed that vermicompost not only enhanced the seed germination and growth of pansy but also improved soil health. These results indicate that vermicompost can be exploited as a potent bio-fertilizer for ornamental plant production.

Performance of chrysanthemum varieties under the agro-climatic subzone of Bundelkhand

An experiment was conducted to evaluate twelve varieties of chrysanthemum for vegetative and flowering attributes at the Rani Lakshmi Bai Central Agricultural University, Jhansi under the Agro-climatic subzone of Bundelkhand during the years 2019–20 and 2020-21 in Randomized block design with three replications. A wide range of variation was observed in the performance of the twelve varieties evaluated for vegetative growth and flowering parameters. The variety Flirt recorded maximum plant height (49.90 cm) whereas maximum plant spread (40.27 cm) was recorded in variety Pusa Shwet. Minimum days (46.33 days) taken to 50% flowering were recorded in variety Sadbhawana. Maximum average flower weight (3.86 g) was recorded in variety Flirt whereas, the highest number of flowers per plant ((38.78) was observed in Pusa Sona. However, the maximum flowering duration (52 days) was recorded in variety Kundan.

Effect of varieties and pinching days on growth and yield attributes of African marigold (Tagetes erecta L.)

From June to August 2021, a field experiment was carried out at the College of Natural Resource Management, Puranchaur-19, Kaski to examine the effects of pinching on the vegetative growth and yield characteristics of African marigold (Tagetes erecta L.). Two major varieties, Karma-666 and Karma-555, were evaluated in the experiment with three different dates of pinching (Control, 20 DAT, and 40 DAT), which were set up in a Randomized Complete Block Design (RCBD) with four replications. According to the findings, at 5% level of significance, no significant difference was found in the interaction effect between growth and floral characters. Karma-555 showed greater plant spread (34.77 cm) and more branches per plant (13.73) than Karma-666. Additionally, Karma-555 was found to have a higher number of flowers plant-1 (39.10) and flower yield plant-1 (335.77 g). However, Karma-666 had significantly (P <0.001) high fresh flower weight (10.51 g) and flower diameter (7.18 cm). Plants pinched at 20DAT were found to be the most effective for enhancing vegetative growth parameters and flower yield.

Organo Mineral Fertilizers Increases Vegetative Growth and Yield and Quality Parameters of Pomegranate cv. Wonderful Fruits

In recent years, to improve sustainable production in horticultural crops, many new types of strategies have been developed, including organo-mineral fertilization to complement chemical fertilizers in order to enhance the nutritional status of plants and sustainability of the agroecosystems. This study was performed on a young pomegranate orchard of the “Wonderful” cultivar during the 2018 and 2019 seasons. The purpose was to evaluate the effects of three foliar applications (at the red ball, fruit setting, and fruit development stages) of four commercial organo-mineral fertilizers (Hendophyt®, Ergostim XL®, Siapton® 10L, and Allibio Rad®) on vegetative growth, yield, and several other physico-chemical parameters of the fruits, throughout each season. The results obtained showed several differences between the two years. The annual trunk growth of trees under all compared treatments showed significantly lower values in 2018 (average 9.7 mm) than in 2019 (average 11.8 mm). At the end of the two-year period, the biostimulant treatments resulted in significantly larger trunk diameters (average 43.6 mm) than the control (39.6 mm). Only in 2018, significantly higher number of fruits per tree, number of arils per fruit, edible part, and juice yield were obtained under biostimulant treatments compared with the control. No differences among treatments were observed for any color parameters or physico-chemical traits in the fruits for either year. In 2019, fruit morpho-pomological properties tended to be lower than in 2018, while in contrast, total phenol content and antioxidant activity were higher. The warmer and windier weather conditions of 2019 probably led to greater plant stress conditions, with a reduction in fruit size and an increase in the bioactive compounds of juice. In conclusion, due to the various positive results, foliar organo-mineral fertilizers could be recommended to improve the performance of pomegranate Wondeful cv. under similar conditions.

Foliar Fertilization of Potassium Silicon Improved Postharvest Fruit Quality of Peach and Nectarine [Prunus persica (L.) Batsch] Cultivars

Peach fruit quality is dependent on preharvest treatments and orchard practices. The aim of this study is to evaluate the effects of preharvest potassium silicon fertilization on fruit postharvest quality. Two peach cultivars (“Early Bomba” and “Plagold 17”) were sprayed with three concentrations of potassium silicon (K-Si) at fruit set, stone hardening, and physiological maturity stages. The applied treatments corresponded to control (T0 = 0% K-Si) pulverized with distilled water and two K-Si treatments (T1 = 3% K-Si and T2 = 4.5% K-Si). The blooming and harvesting dates, vegetative growth and agronomical parameters were analyzed over two growing seasons (2021–2022). Peach fruits were stored at 5 °C and 95% RH during two cold storage periods (2 and 4 weeks) followed by 2 days at room temperatures. The fruit weights (FW), color, firmness, soluble solids content (SSC), titratable acidity (TA), pulp stone ratio (P/S) and fruit weight loss (FWL) were evaluated. The anthocyanins, flavonoids, total phenolics, carotenoids and antioxidant capacity (DPPH) were determined. Vitamin B5 and vitamin C were analyzed by HPLC. The ethylene rate and the chilling injury symptoms (CI) were analyzed after two cold storage periods (2 and 4 weeks). Results showed that the applied potassium silicon treatments (3% K-Si and 4.5% K-Si) enhanced the FW, SSC, TA, FWL, fruit composition and CI. Anthocyanins and total phenolics increased after cold storage period under K-Si treatments. The nectarine cultivar (cv) Early Bomba showed low sensibility to chilling injury symptoms as compared to the cv Plagold 17.

Weed Control, Growth, and Yield of Tomato After Application of Metribuzin and Different Pendimethalin Products in Upper Egypt

Weeds are very problematic for tomato production worldwide. Differences in formulations of the same herbicide have different effects on weeds and crops. There are no published studies on the effect of the capsule suspension of pendimethalin (Pend) products on tomato in Egypt. The present study aims at evaluating three pre-plant Pend products compared with a post-plant metribuzin (Met) and hand hoeing on their efficiency on weed control and on the growth, yield, yield attributes, stand loss rate of tomato plants, and their economic benefit implications in tomato production. During the fall-winter seasons of 2019/2020 and 2020/2021, six weed control treatments were studied including three pre-plant Pend products, a post-plant Met, hand hoeing, and un-weeded control in tomato field experiments. Weed density, fresh weight [FW], and FW reduction% were measured. Tomato measurements included stand loss rate, vegetative growth parameters, leaf chlorophyll concentration, fruit diameter and length, marketable and total yields, fruit total soluble solids, and pH. All herbicides and hand hoeing treatments significantly reduced weeds FW. Stand loss rates of tomato were 0% in hand hoeing followed by Sencor (~ 9.3–11.1%). Vegetative growth and leaf chlorophyll concentration were improved in all treated plots as compared to the control. The highest significant increases in tomato branch number, plant height, stem diameter, and shoot FW were observed in Sencor and Mostmicro treatments. The highest marketable and total fruit yields were observed with Sencor. Met had the highest benefit–cost ratio in the study. All herbicides were effective against various noxious weeds, but tomato “hybrid 65,010” was more tolerant to Met which resulted in better yields than those obtained with Pend products. The most cost-effective method of weed control was Met.

Biological Nanofertilizers to Enhance Growth Potential of Strawberry Seedlings by Boosting Photosynthetic Pigments, Plant Enzymatic Antioxidants, and Nutritional Status

Strawberry production presents special challenges due the plants' shallow roots. The rooting stage of strawberry is a crucial period in the production of this important crop. Several amendments have been applied to support the growth and production of strawberry, particularly fertilizers, to overcome rooting problems. Therefore, the current investigation was carried out to evaluate the application of biological nanofertilizers in promoting strawberry rooting. The treatments included applying two different nanofertilizers produced biologically, nano-selenium (i.e., 25, 50, 75, and 100 mg L-1) and nano-copper (i.e., 50 and 100 mg L-1), plus a control (untreated seedlings). The rooting of strawberry seedlings was investigated by measuring the vegetative growth parameters (root weight, seedling weight, seedling length, and number of leaves), plant enzymatic antioxidants (catalase, peroxidase, and polyphenol oxidase activity), and chlorophyll content and its fluorescence and by evaluating the nutritional status (content of nutrients in the fruit and their uptake). The results showed that the applied nanofertilizers improved the growth, photosynthetic pigments, antioxidant content, and nutritional status of the seedlings compared to the control. A high significant increase in nutrient contents reached to more than 14-fold, 6-fold, 5-folf, and 4-fold for Cu, Mn, N, and Se contents, respectively, due to the applied nanofertilizers compared with the control. The result was related to the biological roles of both Se and CuO in activating the many plant enzymes. Comparing the Se with the CuO nanofertilizer, Cu had the strongest effect, which was shown in the higher values in all studied properties. This study showed that nanofertilizers are useful to stimulate strawberry seedling growth and most likely would also be beneficial for other horticultural crops. In general, the applied 100 ppm of biological nano-Se or nano-CuO might achieve the best growth of strawberry seedlings under growth conditions in greenhouses compared to the control. Along with the economic dimension, the ecological dimension of biological nanofertilizers still needs more investigation.

Respostas morfológicas e fisiológicas de Calliandra haematocephala ao estresse de salinidade da água e vermicomposto

Abstract Salinity is one of abiotic stress that affects plant growth and production. The objective of this study was to investigate the effect of salinity and vermicompost on morphology and physiology parameters of Calliandra haematocephala. The experiment was carried out with salinity treatments at 1000, 2000 3000 ppm in addition to the control (tap water, 280 ppm), vermicompost treatments at 5%, 10%, 15%, and 20% in addition to the control. The results indicated that increasing level of salinity resulted in reduction in vegetative growth and flowering parameters (plant height, number of branches/plant, stem diameter, root length, fresh and dry weights of leaves and roots/plant, number of flowers /plant, as well as fresh and dry weights of flowers /plant), total chlorophylls, total carbohydrates, K+%, Ca2+%, and K+/Na+ ratio, while increased proline, Na+ and Cl−% in the plants. Catalase (CAT), superoxide dismutase (SOD), Ascorbate peroxidase (APX) enzyme activities significantly increased with elevating salinity level from 0 to 3000 ppm. Application of vermicompost with any concentration had a positive effect on vegetative growth and flowering parameters, total chlorophylls, total carbohydrates, nutrient uptake, K+/Na+ ratio, proline content, enzyme activities and reducing accumulation of Na+ and Cl−% toxic ions in leaves. Based on the results, application of vermicompost at 20% recommended for alleviating the harmful efects of salinity on Calliandra haematocephala plants irrigated with saline water at concentration up to 3000 ppm.

Plant Growth-Promoting Bacterial Consoprtia as a Strategy Towards Crop Growth and Fitness of Little Millet (Panicum sumatranse L.)

Little millet, a minor cereal cultivated in semi-arid regions of India, is renowned for its nutraceutical properties. The endophytic plant growth-promoting bacterial (PGPB) communities help crop plants increase growth and health, endure stress tolerance, and enhance nutrient availability. Seed biotiztion with these endophytic PGPBs can facilitate the host plant to develop a defense against pathogens and challenging environments. Thus the present study aimed to biotize the little millet seeds (var. ATL1) with PGPBs, viz., Bacillus albus LRS2, Alcaligenes faecalis LSB6, Bacillus amyloliquefaciens LAS10 and Bacillus velezensis LLB10 and to evaluate their efficiency by developing as a consortia of these isolates for improved plant growth and development. The seeds were biotized with all the strains individually and as consortia to evaluate their plant growth attributes in vitro and in vivo. The results showed significant differences in vegetative growth parameters and yield attributes compared with the control over consortia biotized seeds. During the panicle initiation stage (27 DAS), the shoot length (59.2, cm), root length (13.9 cm), total plant biomass (1.46 g), number of productive tillers plant-1 (5), panicle length (13.2 cm) and 1000 grain weight (5.12 g), grain yield plant-1 (28.45 g), straw yield (36.21 g) registered more in consortia biotized plants compared to non-biotized plant maintained as control. Thus, the present study confirmed that the inoculation of little millet seeds with the Consortia of indigenous strains could promote plant growth and productivity. Further, the Vol 110|10-12 inoculant can be recommended as a novel bio-inoculant for enhancing crop health and sustainable production in little millet.

Priming Apoplast-Associated Bacillus Amyloliquefaciens LAS10 Enhances Growth and Yield Attributes of Little Millet Under Drought Stress

Little millet plant, in general, withstands various climatic changes and environmental stresses. The endophytic bacterial communities associated with these plants help the plant to develop enduring harsh conditions. Priming seeds with endophytic bacteria helps the host plant grow under adverse environments. The present study aimed to prime the seeds with apoplastic endophytic bacteria, Bacillus amyloliquefaciens LAS10 from little millet (var. ATL1) and to evaluate the efficiency to tolerate an osmotic potential of -10 bars (-1MPa). The seeds were primed with B. amyloliquefaciens LAS10 to investigate the plant growth attributes in vitro and in vivo. Induced drought stress was imposed using different concentrations of PEG6000 in vitro and by withholding the irrigation for ten days during panicle initiation in vivo. Biometric observations were recorded. The results showed significant differences both in vegetative growth parameters as well as yield attributes compared with the control under moisture stress. During the panicle initiation stage (20 DAS), the shoot length (32.26, and 28.36 cm), root length (19.1, and 17.7 cm), total plant biomass (4.61, and 2.47 g), number of productive tillers plant-1 (5, and 3), the total number of panicles plant1 (15.63, and 13.69), panicle length (9.9 cm, and 9.1 cm) and 1000 grain weight (12.91, and 11.92 g), grain yield plant-1 (16.92, and 12.24g), straw yield (21.65, and 19.31) registered more in B. amyloliquefaciens LAS10 primed plants compared to uninoculated control under both irrigated and drought stressed conditions, respectively. Thus, the present study confirmed that the inoculation of little millet with the apoplastic bacterium B. amyloliquefaciens LAS10 could promote plant growth and productivity under moisture stress. Further, the apoplastic bacterium B. amyloliquefaciens LAS10 can be recommended as a bio-inoculant for alleviating drought stress in little millet and enhancing crop fitness and sustainable little millet production.

Effect of some Nano fertilizers on vegetative growth parameters of some new maize hybrids under water stress conditions

Effect of some Nano fertilizers on vegetative growth parameters of some new maize hybrids under water stress conditions

Aphids and Citrus responses to excessive nitrogen fertilization

The aim of this study was to assess the effect of an excessive nitrogen mineral fertilizer on the vegetative growth of Citrus as well as on the densities and population dynamics of the main aphid species Aphis spiraecola Patch (Hemiptera, Aphididae). Two trials were conducted on clementine trees, Citrus clementine Hort. ex Tan. in 2016 and 2017. The quantities of nitrogen delivered varied from no nitrogen (control) to the triple recommended dose of nitrogen (3ARD) in a complete randomized block design. Results showed that all vegetative growth parameters evaluated for the clementine trees responded positively to the amount of nitrogen supplied. The highest values were obtained with the highest N doses in both years. A positive response also was observed for aphids for all doses of N even the lowest, with densities increasing proportionally to N inputs. The highest dose (3ARD) increased aphid populations by 3 times compared to the control. The aphid dynamics differed between the two years, probably under the influence of other factors such as rainfall. Thus, too much nitrogen should be avoided in Citrus orchards. Aphid management cannot be separated from the management of fertilization, as this agronomic practice would maintain aphid densities at acceptable levels without the need for repeated insecticide applications.

Nematicidal activity of sweet annie and garden cress nano-formulations and their impact on the vegetative growth and fruit quality of tomato plants

Root-knot nematode is one of the major problems that face the agricultural production of several vegetable crops. Chemical nematicides have been banned because of their healthy and environmental undesirable attributes. So, this study aimed to evaluate the potential use of sweet annie (Artimisia annua) and garden cress (Lepidium sativum) as green routes for the development of effective and eco-friendly alternative nematicides. Nematicidal activity of sweet annie and garden cress aqueous extracts (500 g/L) in the original and nano-forms were evaluated against Meloidogyne incognita in tomato planted in infected soil under greenhouse conditions. Nineteen phenolic compounds were identified in A. annua extract, which was dominated by chlorogenic acid (5059 µg/100 mL), while 11 compounds were identified in L. sativum extract, that dominated by p-hydroxybenzoic acid (3206 μg/100 mL). Nano-particles were characterized with smooth surface, spherical shape and small size (50–100 nm). Under laboratory, the nano-formulations showed mortality percentage of M. incognita J2 greater than the original extract from. Vegetative growth parameters of tomato plants treated with A. annua and L. sativum extracts significantly improved compared to the control plants. Also, biochemical analysis revealed that the extracts were able to induce tomato plants towards the accumulation of phenolic compounds and increasing the activity of defensive enzymes (protease, polyphenol oxidase and chitinase) resulting in systemic resistance. Regarding tomato fruits yield and quality, the studied treatments significantly improved the yield and physicochemical parameters of tomato fruits in terms of fruit weight, diameter, TSS, pH, lycopene content and color attributes gaining higher sensorial acceptance by the panelist. Generally, both extracts represent promising nematicide alternatives and have potential use in crop management. The nano-form of A. annua extract outperformed the nematicidal activity of other studied treatments.