Root Dry Mass Research Articles

The Effect of Scale Insects on Growth Parameters of cv. Chardonnay and cv. Sauvignon Blanc Grapevines Grown in a Greenhouse.

Plants can respond to insects that feed with stylet mouthparts using various processes that are initiated via the salicylic acid metabolic pathway. In Australia, scale insects of the genus Parthenolecanium can cause economic damage to grapevines as they feed on the vines and produce honeydew as a waste by-product, which supports the growth of black sooty mould on fruit and leaves, potentially affecting the plant growth and yield. Using rootlings of Sauvignon Blanc (SB, resistant) and Chardonnay (Char, susceptible), the growth and production of volatile organic compounds (VOCs) following exposure to scale insect infestations were measured under controlled greenhouse conditions. At harvest, the numbers of scale insects per five leaves were higher on plants infested at the start of the study compared with the control plants. Infested SB had increased dry root and shoot mass compared with the SB control, which was also the case with Char (control and infested). Leaf volatiles differed between cultivars in response to scale infestation. Benzyl alcohol decreased among infested SB plants compared with the other treatments. A change in the salicylic acid pathway as indicated by the change in benzyl alcohol may cause the increased growth in SB associated with the increased scale insect infestation.

CULTIVATION OF XARAÉS GRASS IRRIGATED WITH IRON MINING TAILINGS

The collapse of the Fundão dam in Brazil caused one of the biggest environmental disasters. One of the challenges was how to manage the tailings so that affected areas could be reused. This study aimed to verify whether applying different irrigation depths to Xaraés grass grown with iron mining tailings would affect grass shoot and root dry masses. The experiment was set up in a randomized design with five irrigation depths (40%, 60%, 80%, 100%, and 120% of crop evapotranspiration) and two additional treatments (grass grown in tailings with soil conditioner, and grass grown in natural soil), each with three repetitions. The grass was cut four times, and the shoot dry mass was evaluated after each cut, while the root dry mass was evaluated at the end of the experiment. Our results showed that irrigation depths had a positive linear effect on shoot dry mass and an exponentially increasing effect on root dry mass, with the highest averages in the treatment applying 120% of crop evapotranspiration. This study showed that even in adverse conditions, Xaraés grass was able to grow and develop well.

Produção de mudas de Pereskia aculeata combinando substratos e diâmetros de estaca

ABSTRACT Seedling production is one of the most important stages of plant cultivation, with quality mainly depending on the substrate and plant material used. This study aimed to evaluate the production of Pereskia aculeata seedlings combining substrates and cutting diameters. The experimental design was completely randomized, in a 5 × 3 factorial arrangement, corresponding to five substrate combinations (commercial, kapok, palm, commercial + kapok and commercial + palm) and three cutting diameter ranges (0.5-3.0, 3.1-5.5 and 5.6-8.0 mm). The following parameters were evaluated: plant height, leaf length and width, number of shoots and leaves, root length, shoot and root fresh mass, shoot and root dry mass, total fresh and dry mass and Dickson quality index. There was a significant interaction effect between substrates and cutting diameters on the seedlings formed, except for number of shoots, leaf length and root dry mass. Seedlings of higher quality can be achieved with larger cutting diameters combined with commercial substrate. The palm and kapok substrates can be used alternatively when combined with larger cutting diameters.

Effect of Brassinosteroids on the Ion-Exchange Properties of the Cell Walls of Barley Roots and Shoots under the Action of Heavy Metals

The effect of polymetallic contamination and concomitant treatment with brassinosteroids (homocastasterone or homobrassinolide) on barley plants and on the ion-exchange capacity of cell walls isolated from shoots and roots was studied. Under the influence of polymetals, a decrease in the dry mass of roots, water content, and the proportion of the cell wall in them was observed, but the addition of homocastasterone to the medium led to the restoration of these parameters almost to the control level. In the aerial part of plants, the influence of both polymetals and brassinosteroids on these parameters was weakly expressed. In the presence of homocastasterone, the content of demethylated carboxyl groups of polygalacturonic acid increased in the pectins of the cell walls of roots and leaves, which are the main binding sites for heavy metal ions in the apoplast. Thus, it can be assumed that treatment with brassinosteroids (homocastasterone) leads to a change in the composition and ion-exchange properties of the cell wall, which makes it possible to reduce the toxic effect of polymetals due to their immobilization in the apoplast.

Baccharis vulneraria (Asteraceae) cuttings in different substrates

Abstract The objective of the study was to identify the most suitable substrate and type of cutting to obtain seedlings from Baccharis vulneraria Baker cuttings. Apical and stem cuttings were collected from stock plants grown in a greenhouse. After collection, the cuttings were grown in the following substrates: commercial peat-based substrate (CPS); Vermiculite (VM); carbonized rice husk (CRH); Coconut fiber (CF); VM and CRH (1:1) (VM + CRH); VM and CF (1:1) (VM + CF); and CRH and CF (1:1) (CRH + CF) mixtures. The experiment used a completely randomized factorial design and, after 60 days, the percentage of survival and rooting (% SR), aerial part length (APL) and roots length (RSL), number of shoots (SN) and new leaves (LN), root volume (RSV), aerial part dry mass (APDM), and roots dry mass (RSDM) were evaluated. An interaction was found between the type of substrate and cutting for APL, RSL, LN, RSV, and RSM. On the other hand, %SR, SN and APDM differed only by cutting type. Apical cuttings showed higher APL, while internode cuttings showed higher SN, LN, RSV, and APDM. CPS promoted higher RSL in both types of cuttings, being a suitable option for the propagation of Baccharis vulneraria, particularly in internode cuttings.

Diferenças fisiológicas e anatômicas entre gramíneas subtropicais crescidas em solo alcalino-sódico alagado

Abstract The objective of this work was to evaluate the effects of 26 days of waterlogging, compared with field capacity, on different traits of the forage plants 'Finecut' Chloris gayana, 'Klein Verde' Panicum coloratum, and 'Shawnee' Panicum virgatum, grown in alkaline-sodic soil. Shoot and root dry mass, leaf greenness index, electrolyte leakage, and root histology were evaluated. The histological analysis was performed along the mid-portion of adventitious roots with a 2.0 mm diameter. Waterlogging inhibited the growth of P. coloratum, in addition to decreasing the leaf greenness index and causing injuries in the cell membrane of C. gayana and P. coloratum. At field capacity, only C. gayana and P. coloratum had aerenchyma; however, waterlogging induced the development and increased the area of the aerenchyma in P. virgatum and C. gayana, respectively. Waterlogging also thickened the exodermis and endodermis of all three genotypes, inducing a greater number of exodermis cell rows and a thicker internal tangential cell wall of the endodermis in C. gayana and P. virgatum. Although P. coloratum growth is more sensitive to waterlogging, there are radial oxygen loss barriers in the roots of the three evaluated genotypes.

Selected micronutrients effect on growth, development, and yield of black nightshade (Solanum nigrum)

AbstractBlack nightshade (Solanum nigrum) is an important indigenous leafy vegetable consumed in sub‐Saharan Africa. The species is an important source of micronutrients for medicinal purposes. A controlled experiment was conducted at the University of KwaZulu‐Natal, Pietermaritzburg, South Africa, to investigate the effect of zinc and boron applications on the growth, development, and yield of black nightshade. Each micronutrient (zinc and boron) was applied at five different concentrations, namely, 100 (T1), 200 (T2), 300 (T3), 400 (T4), and 500 (T5) ppm, including a control (T0) (distilled/high pressure liquid chromatography water spray), giving a total of six treatments. Treatments were arranged in a complete randomized design (CRD) with three replications, giving a total of 18 experimental units (pots). After 14 days of transplanting, the treatments were applied through foliar spraying three times over 24 h with an 8‐h interval between each spraying event. Data collection started 14 days after transplanting, and thereafter, measurements were taken fortnightly. At harvest (70 days after transplanting), fruit number, fresh shoot weight, dry shoot weight, root fresh mass, and root dry mass were determined. The results showed significant growth and yield differences with respect to the different concentrations of zinc and boron (p < 0.05). The application of 500 ppm of boron performed significantly better than all other treatments, viz., zinc, and control across the measured variables (p < 0.05). Therefore, it is concluded that the application of boron at 500 ppm was found to be effective in enhancing plant growth and higher fruit yield (45 fruits) of black nightshade.

Carapaça de mexilhão-dourado pode ser uma alternativa ao calcário na correção de solo?

ABSTRACT Golden mussel is an invasive species in South America that causes environmental and economic damage due to the formation of large colonies without natural predators. This study aimed to test the agricultural use of golden mussel shell as a limestone substitute, as the shell is rich in calcium carbonate. The experiment was carried out in pots, with eight treatments (sandy soil; clay soil; sandy soil + 1.0 Mg ha−1 of limestone; clay soil + 1.0 Mg ha−1 of limestone; sandy soil + 1.0 Mg ha−1 of fresh shell; clay soil + 1.0 Mg ha−1 of fresh shell; sandy soil + 1.0 Mg ha−1 of calcined shell; clay soil + 1.0 Mg ha−1 of calcined shell), in addition to the application of the following fresh and calcined shell doses: 0, 1.0, 1.5 and 2.0 Mg ha−1. Rice was cultivated in all treatments, and the soil fertility and rice shoot and root dry masses were evaluated. The shell provided good chemical conditions to the soils and raised their pH and phosphorus and calcium contents. The agricultural use of golden mussel shell showed to be efficient for soil correction and can be considered an alternative to limestone.

Proportions of sewage sludge in the production and quality of Malpighia emarginata DC. seedlings.

Sewage sludge (SS) has nutritional contents and has been implemented in the cultivation of seedlings. This study aimed to evaluate the quality of Malpighia emarginata DC. seedlings produced in different substrates with SS. Treatments were implemented with the addition of SS, and after 180 days seedling the characteristics were measured: aerial part and root system length, stem base diameter, number of leaves, fresh and dry mass of aerial part and root, and total biomass. The Dickson Quality Index (DQI) was calculated and the macro and micronutrient content of the aerial part and root. The accumulation of macronutrients in the root system followed the order of N>K>P>Ca>Mg>S, and aerial part of N>Ca>K>P>Mg>S, in the two vegetative structures N and S were in lower concentration. For micronutrients, the accumulation in the root system occurred with Fe>Zn>Mn>Cu>B, and aerial part with Fe>Mn>Zn>B>Cu. It was noted that in the two vegetative structures the Fe content was more concentrated. The use of SS in the substrate formulation proved effective in obtaining viable seedlings for field planting, being recommended the treatment with 60% SS + 40% organic compost.

Fruit biometrics and maturity on the quality of Diospyros inconstans Jacq. Seeds

Abstract: This study aimed to evaluate the biometric characteristics of fruits and seeds of Diospyros inconstans Jacq., germination and formation of seedlings obtained from fruits at three maturity stages, subjected to different temperatures. Biometric data were obtained from 100 fruits and 100 seeds. The determining parameters in the biometry of the fruits were: length, width, mass and number of seeds/fruit and for the seeds: length, width, thickness and mass. In the germination test, a factorial scheme (3x4), three maturity stages (green, intermediate and reddish), and four temperatures (20, 25, 30 and 35 °C) were used. The analyzed variables were: germination, germination speed index (GSI), mean germination time (MGT), time to obtain 50% germination (t50), percentage of seedlings, length and dry mass of shoots and roots, and collar diameter. Fruits and seeds showed greater variation in the parameters fresh mass and number of seeds per fruit. The germination speed index was higher in seeds from reddish fruits, and seeds from green fruits originated better-developed seedlings. Temperatures of 25 and 30 °C are recommended for conducting the seed germination test at the three maturity stages.

NEURO-FUZZY MODELING AS SUPPORT FOR DECISION-MAKING IN THE PRODUCTION OF IRRIGATED CORIANDER UNDER MULCH IN THE SEMI-ARID REGION

Reducing water consumption by crops in semi-arid regions is an important factor for the sustainability of agriculture in these locations. In this sense, this study aims to evaluate the neuro-fuzzy inference method as a support for decision-making in irrigated coriander cultivation. The experiment was performed in two cultivation cycles in Pentecoste-CE, Brazil. The experiment was conducted in randomized blocks arranged in a split-plot design with five primary treatments, consisting of irrigation depths (50, 75, 100, 125, and 150% of the localized evapotranspiration, ETcloc), and five secondary treatments, consisting of different levels of bagana mulch (0, 25, 50, 75, and 100%, equivalent to 16 t ha−1). Neuro-fuzzy models with two input variables and eight output biometric variables were developed to evaluate growth (plant height, number of roots, and root length) and yield variables (productivity and shoot and root fresh and dry mass). In the first cycle, the best results occurred close to 55% ETcloc and between 40 and 50% of mulch; in the second cycle, water consumption returned results between 50 and 80% ETcloc. The fuzzy and multiple regression models showed MAE, MSE, and RMSE errors of 9, 22, and 10% lower, respectively. The neuro-fuzzy model might be a viable option for decision-making in irrigated crops, being able to optimize the use of natural resources and available water in semi-arid regions. The use of 55% of irrigation depth and a range of 40 to 50% of mulch can be a strategy for a higher water use efficiency.

Paclobutrazol como estratégia para a indução da precocidade reprodutiva de maracujazeiro azedo

Abstract The adoption of growth regulators can be an alternative method to modulate the quality of the propagation material and obtain reproductive precocity. The objective was to evaluate if a gibberellin biosynthesis inhibitor affects the morphophysiological, biochemical and anatomical parameters of sour passion fruit seedlings and if such alterations affect the reproductive period. Two trials were conducted. In trial I, 40 days after emergence, the seedlings were immersed up to the substrate level in paclobutrazol (PBZ) solutions at concentrations of: 0, 40, 80, 120 and 160 mg L-1. At 45 days after the application of PBZ - DAA, the morphophysiology, biochemistry and anatomy were evaluated. Trail II was conducted in pots, using seedlings from trail I with 45 DAA of PBZ. At 200 days after transplanting, accumulation of shoots and roots fresh and dry mass (g), flowering speed index, total number of reproductive organs and SPAD index were evaluated. In seedlings, restriction of shoot growth induced by PBZ was associated with root increment, seedling quality, photosynthetic pigments and optimization of gas exchange. A shorter period of transition from the juvenile – vegetative phase to reproductive is observed when the seedlings were submitted to PBZ concentrations.

Produtividade e atividade antioxidante de brotos de feijão (Vigna radiata L.) mediada por alguns elicitores

ABSTRACT: The production of bioactive food is one of the goals of agriculture. Sprouts used for human consumption are an efficient way to increase the intake of essential nutrients, such as minerals, vitamins, and other bioactive compounds. The use of elicitors can increase the nutritional value of these products. Biomass production, phenolic compound content, and antioxidant activity of mung bean sprouts (Vigna radiata L.) after elicitation were examined in this study. Mung bean sprouts were treated with salicylic acid (SA), ascorbic acid (AA), and tocopherol (TOC) at different concentrations and numbers of applications. Shoot and root lengths and dry mass were measured on five-day-old sprouts. Total phenol content and antioxidant activity were determined using the DPPH assay on dried ethanolic extracts. Total soluble protein content and superoxide dismutase activity were measured in frozen hypocotyls. All elicitors stimulated the antioxidant functions of sprouts and, at the highest concentrations, reduced the biometric parameters; therefore, lower concentrations were better. For the first time, a balance between elicitor concentration and application in instalments was achieved to maintain the production of sprouts with enhanced nutritional characteristics.

Desempenho fisiológico de sementes de Tabebuia aurea submetidas a estresses abióticos

ABSTRACT Seeds subjected to abiotic stresses may have their physiological performance compromised, impairing the multiplication of species. Thus, the objective was to evaluate the germination and initial development of Tabebuia aurea seedlings subjected to water and salt stresses. Water stress was simulated with two osmotic agents (PEG 6000 and mannitol) at five osmotic potentials (0.0, -0.2, -0.4, -0.6 and -0.8 MPa). For salt stress, three osmotic agents (NaCl, KCl and CaCl2) were used at five concentrations (0, 6, 12, 18 and 24 dS m-1). The experiments were conducted under a completely randomized experimental design, with four replicates of 25 seeds, in a factorial scheme (osmotic agents × potentials), and the data were subjected to analysis of variance and regression. The variables analyzed were germination, first germination count, germination speed index, root and shoot length, and seedling root and shoot dry mass. The results showed that water and salt stresses reduced the germination and vigor of T. aurea seeds, with water stress being more harmful to the species, especially when induced by PEG 6000. Of the salts used, the one that most harmed the species was CaCl2, followed by NaCl and KCl.

Acclimatization of Sweet Potatoes Under in vitro Application of Diatomaceous Earth.

Diatomaceous earth is an organic naturally occurring material rich in silicon. This silicon source can be used in organic agriculture, it also has a great potential of use in the acclimatization of crops. However, there are no reports of the effects of diatomaceous earth supplementation on the micropropagation of sweet potato. Thus, the objective of this study was to evaluate the effects of different concentrations of diatomaceous earth applied in vitro on the growth, physiology and anatomy of sweet potato cv. 'Brazlândia Branca' after acclimatization. Four concentrations of diatomaceous earth. After 30 days of in vitro growth, the plants were transferred to a greenhouse for acclimatization. After 45 days, leaf number, shoot and root length, fresh and dry shoot and root mass, gas exchange, chlorophyll content, root and leaf anatomy. The experimental design was completely randomized. The supplementation of diatomaceous earth in the in vitro cultivation had beneficial effects, increasing the accumulation of mass, improving the photosynthetic apparatus and promoting favorable anatomical characteristics during the acclimatization of the sweet potato plants. In addition, the use of diatomaceous earth achieved adequate seedling development, with higher seedling quality and resistance to biotic and abiotic effects than attained with control treatment.

Produção hidropônica de girassol ornamental, com refrigeração da solução nutritiva, e adensamento de plantio

Abstract The temperature of the nutrient solution is one of the main obstacles of hydroponic production in hot climates and can affect the nutrient absorption of plants. Additionally, the hydroponic cultivation of cut flowers is rarely done, and hence, there is a lack of studies on this topic. The objective of this experiment was to determine the ideal temperature of the nutrient solution as well as the influence of the plant density factor for hydroponic cultivation in NFT (Nutrient Film Technique) of the cultivar Girassol de Jardim Amarelo Alto, ISLA ® . The experiment was installed in a greenhouse, with 50% shading. The experiment adopted a completely randomized design in a factorial scheme with plots subdivided in space, with the main plots composed of two densities (15 and 30 plants m-2) and the subplots of four temperatures of the nutrient solution (20, 25, 30 °C and uncontrolled temperature) with three replications each. The variables analyzed were plant height, stem diameter, internal and external diameter of the flower, number of leaves, number of buds and flowers, dry and fresh root mass, dry and fresh shoot mass, and cultivation cycle. The data were submitted to an analysis of variance using the statistical software SISVAR. The density of 15 plants m-2 proved to be more efficient, presenting plants of commercialization standard. Cooling the nutrient solution did not improve the production and quality of sunflower flowers.

Maturation and harvest time of Ateleia glazioveana Baill. seeds.

Ateleia glazioveana Baill. is a pioneer, rustic and can be used for forest recovery. This work aimed to study the process of physiological maturation of this species. The research was carried out in the city of Alegre - ES, the trees were identified in the floral anthesis and accompanied during the filling of the fruits and development of the seeds until the complete maturation. The fruits were harvested at the following stages 7, 14, 21, 28, 35 and 42 days after anthesis, and characterized according to: morphometry, moisture, fresh and dry mass of fruits and seeds, germination, germination speed index, shoot and root length and dry mass of seedlings. The regression equations were adjusted for the main characteristics analyzed as a function of the harvest period. The point of physiological maturity of timbó occurred at 42 days after anthesis.

Salicylic acid does not relieve salt stress on gas exchange, chlorophyll fluorescence, and hydroponic melon growth.

The objective of this study was to evaluate the salicylic acid applications in attenuating the harmful effects of saline nutrient solution on the physiology and growth of 'Gaúcho' melon cultivated in the NFT hydroponic system. The experiment was conducted in a greenhouse, in Pombal-PB, Brazil. The cultivation system used was the Nutrient Film Technique - NFT hydroponics. A completely randomized split-plot design was used, with the plot referring to four levels of salinity in the nutrient solution - ECns (2.1 control, 3.2, 4.3, and 5.4 dS m-1) and the sub-plot four concentrations of salicylic acid (SA) (0, 1.5, 3.0, and 4.5 mM), applied via foliar spray, with six replications. Nutrient solution of 4.3 and 5.4 dS m-1 electrical conductivity promotes higher maximum and variable fluorescence, respectively. The stomatal conductance, transpiration, stem diameter, main branch length, leaf dry mass, and stem dry mass of 'Gaúcho' melon plants decrease with the increase in salinity of the nutrient solution. Salicylic acid increases the initial fluorescence and the main branch length of 'Gaúcho' melon plants in hydroponic cultivation. Salicylic acid at a concentration of 1.5 to 4.5 mM did not attenuate the effects of salt stress on the internal CO2 concentration, CO2 assimilation rate, and root dry mass of 'Gaúcho' melon plants.

Changes in the Physiological and Morphometric Characteristics and Biomass Distribution of Forage Grasses Growing under Conditions of Drought and Silicon Application.

Research on mitigating the effects of water scarcity by applying silicon to perennial grasses is still insufficient. This study was conducted to investigate the effect of spring and summer droughts and silicon applications on gas exchange parameters; the morphometric characteristics of root systems; and the biomass distribution of Festulolium braunii, Festuca arundinacea, and Lolium perenne cultivars. Plants were treated with a drought during the tillering phase once a year (during spring or summer regrowth) for 21 days. Foliar nutrition with silicon was applied twice under the drought conditions. Grasses in a pot experiment were cut three times during vegetation. The plants that were exposed to the drought had lower values of the gas exchange parameters than those that were well watered. The beneficial effect of silicon was related to the reduction of excessive water loss through transpiration during the spring drought. Under the drought and silicon applications, the water use efficiency, root dry mass, and length increased compared to the control. Moreover, silicon increased the proportion of both the finer and thicker roots in F. braunii and L. perenne, while the distribution of the root diameter changed least in the more resistant F. arundinacea. Silicon also reduced the carbon content in the roots and increased root carbon accumulation. Our results indicated that Si may help perennial forage grasses cope better with drought stress. This was due to the allocation of carbon to the roots to develop the fine root network, increasing the length and root biomass and improving the water use efficiency.

Co-Inoculation of Trichoderma asperellum with Bacillus subtilis to Promote Growth and Nutrient Absorption in Marandu Grass

The authors have investigated the effects of different doses of mineral fertilizers combined with co-inoculation of Bacillus subtilis and Trichoderma asperellum to promote plant growth and use efficient nutrients in a plant Urochloa (Syn. Brachiaria) brizantha cv. Marandu. Individual experiments with doses of the nutrients nitrogen (N), phosphorus (P), and potassium (K) were carried out. The experiment was conducted in a completely randomized design, factorial 3 × 5. With the treatments: control noninoculation, inoculation with Bacillus subtilisUFRA-92, and coinoculation (MIX) with T. asperellum (UFRA-06, UFRA-09, UFRA-12, and UFRA-52) + B. subtilis x nutrient omissions (0%, 25%, 50%, 75%, and 100%). Each treatment had five replications. Biometric parameters, nutrient content, and nutrient use efficiency were evaluated. The results showed that the inoculants promoted growth in Marandu grass. The use of inoculants promoted growth and increased N, P, and K uptake by Marandu grass. Co-inoculation changed leaf area, shoot length, elongation rate, and leaf appearance for N and K and root dry mass for P. In addition, the co-inoculation combined with doses of 75% of N, 50% of P, and 50% of K increased the nutritional content of the leaves by 256% of N, 280% of P, and 29% of K and provided greater agronomic efficiency, with increments of 462% of N, 544% of P, and 177% of K, compared to the control treatment. We present the potential of co-inoculation of B. subtilis and T. asperellum to promote the growth of Urochloa under reduced fertilizer application. There was an improvement in plant growth and nutrient use efficiency.