Gas exchanges and photosynthetic pigments of ‘Tommy Atkins’ mango as a function of fenpropimorph

ABSTRACT The objective of the present study was to evaluate the influence of the application of fenpropimorph and paclobutrazol on gas exchanges and photosynthetic pigments of ‘Tommy Atkins’ mango grown in the semi-arid region in different evaluation periods. Two experiments were carried out in ‘Tommy Atkins’ mango orchards in the first production cycle between September and December 2018 (first experiment) and between September and December 2019 (second experiment) in Petrolina, PE, Brazil. The experimental design adopted was randomized blocks in split plots in time, 4 × 4 + 1, with four replicates. The plots corresponded to the concentrations of fenpropimorph: 0, 0.7, 1.0, and 1.3 g per linear meter of plant canopy diameter plus the additional paclobutrazol treatment (1 g per linear meter of plant canopy diameter), and the subplots corresponded to the evaluation dates (0, 30, 60, and 90 days after the first application of treatments). The following traits were evaluated: CO2 assimilation rate, stomatal conductance, internal CO2 concentration, transpiration, water use efficiency, chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids. The fenpropimorph dose of 1.3 g per linear meter of plant canopy promotes a higher rate of CO2 assimilation; however, paclobutrazol was more effective in the accumulation of chlorophyll a and total chlorophyll, and the use of fenpropimorph did not interfere in the concentration of photosynthetic pigments.

Morphological and biochemical traits in chickpea resistance against Helicoverpa armigera Hubner (Lepidoptera: Noctuidae)

Investigation undertaken with eight chickpea genotypes (Vallabh Kallar Channa 1, Ankur (CSJ 140), JGK-2, Ganguar (GNG 1581), Jawahar Gram-1 (JGK 1), WCG-10 (Pant G-10), Avrodhi and ICC 506-EB as resistant check) for their morphological and biochemical traits of resistance to Helicoverpa armigera, indicated trichome number, length and density, and nitrogen, total chlorophyll and potassium content as influencing the resistance/ susceptibility levels in chick pea.

Separate and Combined Effects of Chlortetracycline and Oxytetracycline on Growth and Antioxidant Enzymes in Myriophyllum Aquaticum

As two typical tetracyclines, chlortetracycline (CTC) and oxytetracycline (OTC) coexist widely in water. In the experiment, Myriophyllum aquaticum (Vell.) Verdc was exposed to the orthogonal hydroponic environment with the concentrations of CTC and OTC at 1, 10, and 50 mg/L for 7 days (7 D) and 14 days (14 D). The results showed that the plant height, relative growth rates (RGR), and photosynthetic pigment contents of M. aquaticum decreased significantly after 14 D of CTC/ OTC, which was stronger than that after 7 D, and the toxicity of CTC was stronger than OTC. The combined toxicity of the two on the RGR and total chlorophyll content was mainly synergistic or additive after 7 D. After 14 D, the interaction changed to antagonism or addition, and the response of total chlorophyll content was more obvious than that of RGR. After 7 D of combined treatments, the malondialdehyde (MDA) content decreased significantly, superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activities responded to different combined concentrations, respectively, and CAT was the main protective enzyme of M. aquaticum. After 14 D of combined treatments, the hydrogen peroxide (H2O2) content increased significantly, the MDA content increased first and then decreased, and POD was the main protective enzyme among the three antioxidant enzymes. Overall, this study provided the first insight into the single and combined toxicity of CTC and OTC on the growth and physiology of M. aquaticum at different time periods, revealing the reversal of the combined toxicity with time of exposure.

Impact of Different Nitrogen Levels to the Grain Yield and Yield Components of Some Corn (Zea mays L.) Hybrids

Aims: The study was designed to elucidate the effect of different nitrogen (N) fertilizer levels on five different maize cultivars. Study Design: A split plot experimental design in randomized complete blocks (RCBD) with three replicates. Arrangement of seven nitrogen levels and five single cross hybrids were compared. Main plots were nitrogen levels and subplots were varieties. Place and Duration of Study: College of Agricultural Engineering Sciences at the University of Duhok, Iraq. The study was undertaken fromMarch– August 2021. Methodology: At the present research, five single cross-hybrid corn varieties were used, which were: CADZ, DKC6050, DRACHMA, MYIMY and ZP6468D. Arrangement of seven nitrogen fertilizer levels were 0, 50, 100, 150, 200, 250 and 300 kg N ha−1. The following features were studied: plant height, leaf area index, thousand kernel weight, total grain yield, total chlorophyll, protein% and oil %.The collected data were projected to SAS software program for analysis. The significant differences between treatment means were calculated using Duncan’s multiple ranges. Results: It was reveal that there were significant effect of different nitrogen fertilizer levels, maize genotypes as well as the interaction of nitrogen and genotype of maize (P<.01) for plant height, leaf area index, 1000 kernel weight, total grain yield, total chlorophyll and protein %. However, There were no significant differences between different maize genotypes as well as different nitrogen fertilizer levels (P>.05) with oil %, but the interaction of nitrogen and genotype of maize was significant (P<.01). Conclusion: Increasing the amount of nitrogen had better effect on studied characteristics of different maize varieties, in which adding 300 kg nitrogen had optimum results. In considering the response of maize varieties to nitrogen, the best variety was DRACHMA genotype while the worst variety was CADZ genotype, however this hybrids was superior in some traits.

Heteroblastic Foliage Affects the Accumulation of Non-Structural Carbohydrates and Biomass in Pinus massoniana (Lamb.) Seedlings

Pines have heteroblastic foliage (primary and secondary needles) during seedling stage, but how heteroblastic foliage affects carbon storage and biomass accumulation, contributing to seedling quality, is unclear. We investigated the influences of heteroblastic foliage on photosynthetic physiological characteristics, non-structural carbohydrate (NSC) and biomass accumulation in current-year seedlings; the key factors determining biomass accumulation were mainly determined by principal component screening, Spearman correlation, and path analysis. The results indicated that (1) primary needles have high photosynthetic pigments (chlorophyll a and total chlorophyll), net photosynthetic rates (Pn), the potential maximum photochemical efficiency (Fv/Fm), and leaf instantaneous water use efficiency (WUEi), whereas higher non-photochemical quenching (NPQ) suggested that sudden light increases induce the initiation of quenching mechanism in primary needles; additionally, secondary needles had a lower transpiration rate (Tr), limiting stomata (Ls), and light saturation point. (2) Secondary needles promoted soluble sugar (fructose and glucose) increases in leaves compared to that of primary needles and increased the leaf biomass accumulation (from 47.06% to 54.30%), enhancing the overall ability of photosynthetic organs; additionally, secondary needles can enhance the proportion of starch storage in the roots, and NSC accumulation was significantly increasing in the seedling leaves and roots. (3) Photosynthetic pigments (carotenoids, chlorophyll a, and total chlorophyll) had direct positive effects on primary needle seedling (PNS) biomass and promoted biomass by indirectly increasing soluble sugar synthesis in the stems. The Pn was the main physiological factor determining PNS biomass accumulation. In addition, the WUEi, Ls, and NPQ had direct negative effects on PNS biomass accumulation, inhibiting photosynthesis to limit seedling growth. Considering the functional traits in heteroblastic foliage is necessary when assessing different leaf types of Pinus massoniana (Lamb.) seedlings, in particular those threats implicated in light, water, and temperature relations. Our results can be beneficial to guide the establishment of seedling management and afforestation measures.

Salinity stress affects growth and physiology of mulberry (Morus sp.)

Mulberry (Morus sp.) plant is used to feed silkworms, and the leaves contain compounds with medicinal properties of secondary metabolites. However, the content of these compounds tends to increase under stress conditions, for instance, salt stress. This study, therefore, aimed to determine the accessions of mulberry with tolerance for salt stress. The stem cuttings of seven accessions from 5 regions, Bogor, Pati, Situbondo, Bali, and Gowa, were planted following a factorial randomized block design with 3 replications. Subsequently, the first factor using the accessions, and the second factor using NaCl solution (0.0%, 0.2%, 0.3%, and 0.4% concentrations) were performed. The variables observed were growth (leaves number, plant height, and shoots number), photosynthesis rate, total chlorophyll, and proline content. The results showed that the M6 accession exhibited tolerance under high salt stress, based on the leaves number, plant height, shoot number, photosynthesis rate, and proline content. Furthermore, an increase in salt concentration was discovered to cause a decrease in growth, photosynthesis rate, and total chlorophyll content. Also, proline accumulation stimulated by high salt stress possibly plays an important role in salinity tolerance.

Heat-tolerant pepper cultivar exhibits high rates of chlorophyll, photosynthesis, stomatal conductance and transpiration in heat stress regime at fruit developing stage

Relevance. Abiotic stress, as heat, significantly affect plant and floral organs growth and development, fruit set, productivity, the quality, and survival of crops. Heat injury occurs when plants are exposed to these temperatures for a long period of time. Depending on the intensity and duration of exposure to the high temperatures, photosynthesis, respiration, membrane integrity, water relations and the hormone balance of the plants may affected.Material and methods. In this study used the commercial pepper cultivar “NW Bigarim” (HT37) released in South Korea and accessions “Kobra” (HT1) and “Samchukjaere” (HT7) selected as heat tolerant and susceptible, respectively. Total chlorophyll index and photosynthetic activities measured using a SPAD meter (Konica, Japan) and portable photosynthesis measurement system (LI-6400, LI-COR Bioscience, Lincoln, NE, USA), respectively.Results. To evaluate the positive effects of high temperature regime (40/28°C day/night, 14/10-h light/dark cycle) on the response of photosynthetic parameters in pepper plants with different heat susceptibility, we measured the total chlorophyll content (CHL) and photosynthetic activities such as photosynthesis (Pn), stomatal conductance to H2O (Gs) and transpiration rate (Tr) in a heat-tolerant (HT1) and -susceptible cultivars (HT7) in comparison with released cultivar (HT37) at fruit development stage. Heat-tolerant cultivars showed higher and more stable index of the CHL, Pn, Gs and Tr than those in heat-sensitive cultivars for 14 days of heat treatment (HT) period. However, the initial index of Pn, Gs and Tr showed significant alteration among pepper plants regardless of thermotolerance rate before HT on day 0 and day 7 after recovery at normal treatment condition (NT) except for CHL, meaning that plants response to high temperature regime is different from that in normal condition. These results suggest that constant high rates of Pn, Gs and Tr as well as of CHL in heat stress condition periods confer to avoid from heat injury during reproductive growth stages.

Antioxidant properties of pepper (Capsicum annuum L.) depending on its cultivar and fruit colouration

Due to its nutritional, health-promoting and taste-related values, new cultivars are introduced every year. The aim of the study was to assess the biological value of Polish and Bulgarian cultivars of pepper grown in moderate climate conditions and collected at different degrees of maturity. Ascorbic acid, carotenoids, polyphenols, chlorophyll a, chlorophyll b, total chlorophyll and antioxidant activity (DPPH) were determined in air-dried fruit. The investigation included five Polish cultivars: Roberta, Marta Polka, Etiuda, Trapez, and Cyklon and five Bulgarian cultivars: Bulgarski Ratung, Sivriya, Kurtovska Kapiya, Delikates, and Dzuliunska Shipka. Its design involved randomised sub-blocks, with three replications comprising nine plants each. The area of a single plot was 1.44 m²(1.2 m × 1.2 m). The study confirmed the strong antioxidant properties of pepper grown in the field, without cover, and under temperate climate conditions. The vegetable is rich in vitamin C, polyphenols, carotenoids, chlorophyll pigments, and shows high antioxidant activity. However, the biological value of pepper is cultivar-dependent and is also determined by the fruit colouration degree. The coloured fruits are richer in vitamin C and carotenoids than the green ones, and when matured, they have greater antioxidant capacity. Green fruits contain more chlorophyll a, chlorophyll b and total chlorophyll than the coloured ones. The fruits of cv. Etiuda were the richest in vitamin C, of cv. Sivriya in polyphenols, of cv. Dzuliunska Shipka in carotenoids, and of cv. Trapez in total chlorophyll. Cv. Sivriya showed the strongest antioxidant properties.

Interactive Impact of Biochar and Arbuscular Mycorrhizal on Root Morphology, Physiological Properties of Fenugreek (Trigonella foenum-graecum L.) and Soil Enzymatic Activities

Arbuscular mycorrhizal fungi (AMF) inoculation and biochar amendment has been reported to improve the growth of several crop plant; however, their role in stress amelioration individually as well as in combination has not been worked out. Limited information is available about the synergistic use of biochar and Arbuscular Mycorrhizal Fungi (AMF). Here, we investigated the synergistic effect of biochar and AMF on plant development, root architecture, the physiological performance of fenugreek (Trigonella foenum-graecum), and soil enzymatic activities. Biochar and AMF were shown to have a considerable effect on plant height, according to the data (53.3 and 66.6%, respectively), leaf number (22.5 and 45.1%), total root length (19.8 and 40.1%), root volume (32.1 and 71.4%), chlorophyll a content (26.0 and 17.8%), chlorophyll b content (50.0 and 28.9%), total chlorophyll content (30.0 and 18.1%), and carotenoid content (60.0 and 48.0%) over the control treatment. There was a considerable increase in plant height when biochar and AMF were combined together by 80.9%, total root length by 68.9%, projected area by 48.7%, root surface area by 34.4%, root volume by 78.5%, chlorophyll a content by 34.2%, chlorophyll b content by 68.4%, total chlorophyll content by 44.5%, and carotenoid content by 84.0% compared to the control. Our results recommend that the combination of biochar and AMF is advantageous in fenugreek growth, microbial biomass, and soil enzyme activities.

Effect of Spraying With Bread Yeast Suspension and The Addition of NPK+(TE) on The Chemical Content of The Leaves of Tamarind Young Plants (Tamarindus indica L.)

The experiment was carried out during the spring season from 1/3/2019 to 1/9/2019, to study the effect of foliar spraying with a suspension of bread yeast at concentrations 0.0, 2.5, 5.0 and 7.5 g.L-1, and the addition of the compound chemical fertilizer NPK+Trace Elements(TE)20-20-20 for soil with three levels (0.0, 0.5 and 1.0 g.plant-1 ) and their interactions in the chemical content of the leaves of two years old tamarind young plants. The research was carried out as a factorial experiment (4*3) according to the randomized complete block design (RCBD) with three replications. The indicators of the study showed that the foliar spraying with bread yeast suspension led to an improvement in most of the studied traits of tamarind young plants and the foliar spraying treatment with a concentration of 7.5 g.L-1 excelled in achieving the best results in comparison with the control treatment of nitrogen, phosphorous, potassium and protein content in the tamarind young plants leaves. Total chlorophyll and carotene, yeast did not have any significant effect in any of the concentrations in the experiment. The compound chemical fertilizer NPK+Trace Elements improved all the studied characteristics of tamarind young plants, and the treatment at the level 0.5 g.plant-1. While the concentration of one g.plant-1was superior in recording a significant increase of potassium concentration in the leaves. Whereas, the interaction between foliar spraying with bread yeast suspension and the addition of the neutral chemical fertilizer NPK+Trace Elements showed a significant effect in most of the studied traits, where the treatment was superior to 7.5 g.L-1 yeast and 0.5 g.plant-1 neutral fertilizer in recording the highest content in leaves of element N andprotein in the leaves, while the treatment recorded 7.5 g.L-' yeast and 0g.plant-1 neutral fertilizer was superior in the percentage of phosphorous, while the concentrations7.5 g.L-1 yeast and lg.plant-1. Neutral fertilizer were superior in percentage of Potassium in the leaves of tamarind young plants achieved a concentration of 0.0 g.L-1 yeast and 0.5g.plant-1 neutral fertilizer an outperformance in the leaf content of total chlorophyllwhile the treatment recorded 5 g.L-1 yeast and 0 g.plant-1 neutral fertilizer was superior in the percentage of carotene.