Leaf Tissue Nutrient Research Articles

Leaf Pigment, Phenolic Content, and Production of Green Shallot of Five Different Shallot Varieties

Five shallot varieties namely ‘Bauji’, ‘Bantaeng’, ‘Tuk Tuk’, ‘Rubaru’, and ‘Palasa’ were examined for their leaf pigment, total phenolic content, leaf tissue nutrient analysis, and green shallot production. The experiment was conducted in in Cikabayan greenhouse, IPB University, Dermaga, Bogor, arranged in a randomized complete block design with single factor (variety) and three replications. The observations were carried out three times in the maximum vegetative period, consisting of 20, 30, and 40 days after planting. The result showed that ‘Palasa’ had the highest leaf pigment content, such as chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid, while the anthocyanin content fluctuated between the varieties and observation times. ‘Palasa’ also had the highest sulfur content in the leaf tissues. On the contrary, ‘Palasa’ had the lowest production compared to other the varieties. Meanwhile, ‘Bantaeng’ had the highest green shallot production, total nitrogen, and total phosphorus content in the leaf tissues. Total phenolic content fluctuated in the five varieties and observation times. The highest total phenolic content was in ‘Tuk Tuk’, observed 20 days after planting. The principal component analysis (PCA) showed that the five shallot varieties formed three clusters. The first was ‘Palasa’, the second cluster was ‘Bauji’, ‘Tuk Tuk’, and ‘Rubaru’, while the third cluster was ‘Bantaeng’. ‘Palasa’ had the highest content of leaf pigment, while Bantaeng had the highest leaf production. Leaf pigment and total phenolic content changed along with the increasing plant age in all varieties.

Effects of varying levels of nitrogen on plant growth, anti-Fusarium oxysporum activity and 3,5-dicaffeoylquinic acid concentration of extracts from hydroponically cultivated Helichrysum cymosum (L.)

Experiments were conducted to assess the effects of varied nitrogen (N) concentrations on plant growth, tissue nutrient content, and antimicrobial activity of acetone extract of aerial parts of Helichrysum cymosum. Six weeks old rooted cuttings were treated with 52.5, 105.0, 210.0, and 420.0 mg N/L by varying the nutrient N level in plant growth medium. Plant growth parameters, leaf tissue nutrient content, anti-Fusarium oxysporum activity, and a well-known bioactive secondary metabolite (3,5-dicaffeoylquinic acid) concentration in the plant extracts were analysed. Leaf number increased with increasing N level, while height increase was highest at the lowest N treatment. Tissue analysis of N content and LC-MS analysis of the acetone extracts of aerial parts indicated that lower N treatment corresponded to lower tissue N and higher accumulation of 3,5dicaffeoylquinic acid in the extracts, respectively. In conclusion, lower nutrient N level significantly correlated with increased antimicrobial activity and yield of the targeted compound of the crude acetone extract of H. cymosum. This study suggests that nitrogen fertilization may be manipulated to optimize bioactivities of crude extracts of medicinal plants.

Establishment of Leaf Tissue Nutrient Sufficiency Ranges of Two Perovskia Selections by Chronological Age

The objective of this study was to determine optimum fertilizer concentrations, identify leaf tissue nutrient sufficiency ranges by chronological age, and establish leaf tissue nutrient standards of containerized Russian sage (Perovskia sp.). Common Russian sage (P. atriplicifolia Benth.) and ‘Crazy Blue’ Russian sage were greenhouse-grown in a soilless substrate under one of six constant liquid fertilizer concentrations [50, 75, 100, 200, 300, or 400 mg·L−1 nitrogen (N)] with a constant level of a water-soluble micronutrient blend. Fertilizer concentrations sufficient for optimal plant growth and development were determined by analyzing plant height, diameter, growth index, primary shoot caliper, axillary shoot number, and total dry mass; they were found to be 100 to 200 mg·L−1 N after a 6-week crop cycle. Recently, mature leaf tissue samples were collected from plants fertilized with 100 to 200 mg·L−1 N and analyzed for elemental contents of 11 nutrients at 2, 4, and 6 weeks after transplant (WAT). An overall trend of increasing foliar nutrient concentrations over time was observed for all elemental nutrients. For instance, at 2 WAT, the total N concentrations of common Russian sage and ‘Crazy Blue’ Russian sage ranged between 3.68% and 5.10% and between 3.92% and 5.12%, respectively, and increased to ranges of 5.94% to 5.98% and 5.20% to 5.86% at 6 WAT, respectively. Before this study, no leaf tissue concentration standards have been reported; therefore, this study established leaf tissue concentration sufficiency ranges for the trialed Perovskia selections.

Intraspecific competition reduces plant size and quality and damage severity increases defense responses in the herbaceous perennial, Asclepias syriaca

Competition among plants within populations affects plant size, nutrient status and allocation to defenses. Herbivory places additional stress on plant allocation of resources. When resources are limited due to intraspecific competition, induced defenses may reduce costs of defense responses and trade-offs between allocation to growth or defense. We hypothesized that increased intraspecific competition would result in a decrease in plant size and leaf tissue nutrient quality, and that both intraspecific competition and leaf damage severity would affect inducibility of leaf defensive traits. We tested these hypotheses in common milkweed (Asclepias syriaca) using greenhouse experiments that manipulated plant density and damage severity treatments. We measured a suite of leaf traits generally related with herbivore performance, including size; nitrogen, carbon, lignin, and fiber concentrations; and latex production. Increased density decreased plant size and leaf nutrient quality, but increased lignin levels. Damage severity increased leaf lignin levels and latex production. There were no density–damage severity interactions. We additionally addressed the question of whether plants respond differently to simulated or natural herbivory and hypothesized that insect herbivores and mechanical plant tissue removal would similarly affect induced defensive responses. Leaf fiber and lignin increased in response to damage, but the response was greater on plants subjected to simulated, compared with caterpillar herbivory. Other plant traits responded similarly to either damage type. Our findings suggest that intraspecific competition has the potential to generate feedbacks among plants and herbivores as plants respond to herbivory.

Response of Calceolaria ×herbeohybrida Cultivars to Substrate pH and Corresponding Leaf Tissue Nutrient Concentration Effects

Calceolaria (Calceolaria ×herbeohybrida) is a flowering potted greenhouse crop that often develops upper-leaf chlorosis, interveinal chlorosis, and marginal and leaf-tip necrosis (death) caused by cultural practices. The objectives of this research were to 1) determine the optimal incorporation rate of dolomitic and/or hydrated lime to increase substrate pH; 2) determine the influence of the liming material on substrate pH, plant growth, and leaf tissue nutrient concentrations; and 3) determine the optimal substrate pH to grow and maintain during calceolaria production. Sphagnum peatmoss was amended with 20% (by volume) perlite and incorporated with pulverized dolomitic carbonate limestone (DL) and/or hydrated limestone (HL) at the following concentrations: 48.1 kg·m−3 or 144.2 kg·m−3 DL, 17.6 kg·m−3 DL + 5.3 kg·m−3 HL, or 17.6 kg·m−3 DL + 10.6 kg·m−3 HL to achieve a target substrate pH of 4.5, 5.5, 6.5, and 7.5, respectively. Calceolaria ‘Orange’, ‘Orange Red Eye’, ‘Yellow’, and ‘Yellow Red Eye’ were grown in each of the prepared substrates. For all cultivars, substrate solution pH increased as limestone incorporation concentration and weeks after transplant (WAT) increased, although to different magnitudes. For example, as limestone incorporation increased from 48.1 kg·m−3 DL to 17.6 kg·m−3 DL + 10.6 kg·m−3 HL, substrate solution pH for ‘Orange’ calceolaria increased from 4.1 to 6.9 to 4.8 to 7.2 at 2 and 6 WAT, respectively. Substrate solution electrical conductivity (EC) and growth indices were not influenced by limestone incorporation, but total plant dry mass increased. Few macronutrients and most micronutrients were influenced by limestone incorporation. Leaf tissue iron concentrations for ‘Orange’, ‘Orange Red Eye’, ‘Yellow’, and ‘Yellow Red Eye’ calceolaria decreased by 146%, 91%, 71%, and 84%, respectively, when plants were grown in substrates incorporated with increasing limestone concentrations from 144.2 kg·m−3 DL to 17.6 kg·m−3 DL + 10.6 kg·m−3 HL (pH 6.5–6.9). Therefore, incorporating 144.2 kg·m−3 DL into peat-based substrates and maintaining a pH <6.5 will avoid high pH–induced Fe deficiency and prevent upper-leaf and interveinal chlorosis.

Expanding leaf tissue nutrient survey standards for 74 floriculture species

Expanding leaf tissue nutrient survey standards for 74 floriculture species

Incorporating slow release coated polymer aluminum sulfate into the substrate to produce blue hydrangeas

Hydrangeas (Hydrangea macrophylla) contain an anthocyanin pigment within the sepal that naturally produces a pink color. In the presence of aluminum (Al) the pigment will bind with the Al producing a blue or purple color. The current method for producing blue hydrangeas is to apply 4 weekly applications of aluminum sulfate (Al(2)(SO(4))(3)) as a liquid drench. The purpose of this study was to determine if a slow release coated polymer Al(2)(SO(4))(3) could be used to produce the desired blue hydrangeas as a standalone alternative to Al(2)(SO(4))(3) drench applications. To complete this study 'Early Blue Rose' hydrangeas were grown in 15-cm pots with 0, 5, 10, 20, and 40 g of slow release Al(2)(SO(4))(3) (15% Al) incorporated into the substrate. There were 5 replications of each treatment. The substrate pH and EC were monitored every other week by pour-thru extraction, as well as the leaf tissue nutrient concentrations. Plants were visually analyzed for marketable color at the end of the study. The untreated and the plants that received 5 g of Al(2)(SO(4))(3) produced bright pink sepals. The plants that received 10 g of Al(2)(SO(4))(3) displayed a mix of pink and purple sepals and had optimal plant growth. Plants treated with 20 g of AlSO(4) displayed primarily purple sepals and growth was inhibited. The highest application of 40 g of Al2(SO(4))(3) inhibited plant growth and produced necrosis on most of the leaves. The use of a slow release coated polymer aluminum sulfate applied at these rates did not produce the desired blue hydrangea. Based on this study the use of the slow release coated polymer aluminum sulfate at these specific concentrations with 'Early Blue Rose' hydrangeas should not be used as the sole method of Al application to produce blue sepals.

Leaf Tissue Nutrient Sufficiency Ranges of Four Heuchera Cultivars by Chronological Age

Coral bells (Heuchera sp.) are popular herbaceous perennials grown for their colorful foliage and venation and their aesthetic appeal in mixed containers and landscapes. Commercial coral bell production requires greenhouse or nursery growers to optimize production inputs such as managing mineral nutrition, thereby maximizing plant growth potential and foliage color. The objective of this study was to determine the optimum fertilizer concentrations, identify leaf tissue nutrient sufficiency ranges by chronological age, and to expand leaf tissue nutrient standards of coral bells grown in soilless substrates during container production. Coral bells (H. hybrida ‘Black Beauty’, ‘Cherry Cola’, ‘Marmalade’, and ‘Peppermint Spice’), varying in leaf color, were grown under one of six constant liquid fertilizer concentrations [50, 75, 100, 200, 300, or 400 mg·L−1 nitrogen (N)] with a constant level of water-soluble micronutrient blend in a greenhouse. Fertilizer concentrations for optimal plant growth and development were determined by analyzing plant height, diameter, growth index, and total dry mass, and were found to be 50 to 75 mg·L−1 N after a nine-week crop cycle. Recently mature leaf tissue samples were collected and analyzed for elemental content of 11 nutrients at 3, 6, and 9 weeks after transplant (WAT) from plants fertilized with 50 to 75 mg·L−1 N. The black- (‘Black Beauty’) and red- (‘Cherry Cola’) colored-leaved cultivars contained higher total N, phosphorus (P), potassium (K), calcium (Ca), sulfur (S), zinc (Zn), and boron (B) than the orange- (‘Marmalade’) and green- (‘Peppermint Spice’) colored-leaved cultivars. For instance, in mature growth, total N concentration for ‘Black Beauty’ and ‘Cherry Cola’ ranged between 3.45 to 3.63% and 3.92% to 4.18% N, respectively, whereas for ‘Marmalade’ and ‘Peppermint Spice’, ranges were between 2.98% to 3.25% and 2.78% to 3.23% N, respectively. Optimal leaf tissue concentration sufficiency ranges determined in this scientifically based study were narrower and often times higher than previously reported survey values for coral bells.

Effects and rates of broiler and layer manures on the leaf yield and tissue nutrient contents of moringa (Moringa oleifera Lam.) in Swaziland

Moringa (Moringa oleifera Lam) has been gaining increasing attention in Swaziland as a medicinal plant increasingly being exploited due to its medicinal value especially amongst people living with HIV/AIDS. The tree is being cultivated in most homesteads and fertilized using poultry manure. A pot experiment was conducted in the greenhouse during the 2016/2017 cropping season. The aim was to investigate the effects two sources of manure (i.e. broiler and layer) at five rates (0, 15, 30, 45 and 60 tonnes/ha) on dry matter yield (i.e. leaves, petioles, stems and roots) and tissue nutrient contents of moringa. The experimental design was a randomized complete block design (RCBD) in a factorial arrangement with four replicates. Data collected (i.e. number of leaves/plant, dry matter of leaflets, stems, roots and tissue nutrients- Fe, Mn, Zn, Cu and Cd) were analyzed using Statistical Analysis Software. Results showed that the application of broiler and layer manures at different rates had no significant effect (p > 0.05) on the number of leaves/plant. The dry matter yields were significantly different considering the sources and rates of manure applications. Furthermore, results showed that the tissue nutrient contents of micronutrients (i.e. Fe, Mn, Zn and Cu) and Cd were generally higher than the maximum permissible limits (MPL) of the World Health Organization as well as daily dietary intake for medicinal plants. Evidence from this study suggest that moringa can successfully be grown using poultry manures however, the application of the aforementioned manures was found to result in elevated contents of micronutrients and cadmium in plant tissue which may be harmful for human consumption.

Foliar Fertilization as a Strategy to Increase the Proportion of Mature Pods in Peanut (Arachis hypogaea L.)

ABSTRACT Foliar application of nutrients is used by growers to remediate crop nutrient deficiencies, but anecdotal reports indicate there may be associated effects of accelerated crop maturity, particularly for irrigated peanut (Arachis hypogaea L.). Research was conducted to determine whether application of foliar fertilizers during early pod set could increase the proportion of early-maturing pods, and thereby increase the mature proportion of the profile under irrigated conditions. Field experiments were conducted in Florida at Citra in 2016, Jay in 2016 and 2017with a randomized complete block with four foliar fertilizer treatments, applied to GA-06G at R1 and again two wks later at R2. Treatments consisted of no foliar fertilizer (control), 10.0 kg N/ha, 1.0 kg P2O5/ha, and 0.34 kg B/ha at each application and two harvest timings. Harvest treatments were based on the adjusted growing degree d model for peanut and were timed to represent early and optimal crop maturity. Leaf tissue nutrient concentrations were determined from samples collected 24h after each foliar treatment application. Yield and proportion of mature pods were quantified after each digging date. Normalized difference vegetation index data showed no treatment differences. The maturity profile (percentage of mature pods present in the sample) was not consistently different from respective controls during either harvest period. Results indicate foliar fertilizer applied during flowering had little effect on maturity acceleration in peanut, though foliar fertilization may still be effective at alleviating in-season nutrient deficiencies. Within site-year, application of foliar fertilizer did not increase yield. Under sound soil fertility management programs, foliar fertilizers did not increase yield or the maturity profile of peanut.

Root-zone hypoxia reduces growth of the tropical forage grass Urochloa humidicola in high-nutrient but not low-nutrient conditions.

The perennial C4 grass Urochloa humidicola is widely planted on infertile acidic and waterlogging-prone soils of tropical America. Waterlogging results in soil anoxia, and O2 deficiency can reduce nutrient uptake by roots. Interestingly, both nutrient deficiencies and soil waterlogging can enhance root cortical cell senescence, and the increased gas-filled porosity facilitates internal aeration of roots. We tested the influence of nutrient supply and root-zone O2 on root traits, leaf nutrient concentrations and growth of U. humidicola. Plants were grown in pots in a completely randomized design under aerated or stagnant deoxygenated hydroponic conditions and six nutrient regimes, with low to high concentrations of all essential elements, for 28 d in a controlled-temperature greenhouse. The standard acid solution (SAS) used was previously designed based on infertile acidic soils of the tropical America savannas, and step increases in the concentration of SAS were used in aerated or deoxygenated 0.1 % agar solution, which mimics changes in gas composition in waterlogged soils. Measurements included shoot and root growth, root porosity, root anatomy, radial O2 loss, and leaf tissue nutrient concentrations. Shoot dry mass was reduced for plants in stagnant compared with aerated conditions at high, but not at low, levels of mineral nutrition. In low-nutrition stagnant solution, roots were shorter, of greater porosity and had smaller radial thickness of the stele. Suberized lamellae and lignified sclerenchyma, as well as a strong barrier to radial O2 loss, were documented for roots from all treatments. Leaf nutrient concentrations of K, Mg and Ca (but not N, P and S) were higher in aerated than in stagnant conditions. Under low-nutrient conditions, plant growth in stagnant solution was equal to that in aerated solution, whereas under higher-nutrient regimes growth increased but dry mass in stagnant solution was less than in aerated solution. Slow growth in low-nutrient conditions limited any further response to the low O2 treatment, and greater porosity and smaller stele size in roots would enhance internal O2 movement within roots in the nutrient-limited stagnant conditions. A constitutive barrier to radial O2 loss and aerenchyma facilitates O2 movement to the tips of roots, which presumably contributes to maintaining nutrient uptake and the tolerance of U. humidicola to low O2 in the root-zone.

Nutrient sufficiency levels for haskap (Lonicera caeruleaL.) using the boundary-line approach

Adequate supply of plant nutrients is crucial for haskap plant growth and increased productivity. A study was carried out to determine the variability in haskap (Lonicera caerulea L. cv. Indigo Gem) plant characteristics in relation to soil and leaf tissue nutrient status. A total of 19 composite soil samples and corresponding plant leaf tissue samples were collected in 2016 from 12 locations in Nova Scotia. Plant parameters measured include growth rate, leaf size, leaf chlorophyll content, and visual observations. A boundary-line approach was used to determine nutrient sufficiency ranges in leaf tissues of 2.23%–2.96% for N, 0.22%–0.28% for P, 0.84%–1.32% for K, 1.63%–2.10% for Ca, and 0.14%–0.50% for Mg. Principal component and correlation analysis suggested a possible antagonistic interaction between leaf K and Mg. Negative associations were observed most frequently between Ca and Mg and other nutrients, especially K. Plant parameters such as bush volume, leaf size, and growth rate were closely related to soil and leaf K. Deficiencies in leaf tissue K and P were identified as potentially important factors limiting growth. Therefore, there is a need to adjust or balance the application of these nutrients. In conclusion, the sufficiency ranges derived can be used as a guiding principle in diagnosing the nutritional status of haskap cv. Indigo Gem on representative farms in Nova Scotia.

Hibiscus Leaf Tissue Nutrient Sufficiency Ranges by Chronological Age

Perennial hibiscus (Hibiscus sp.) are popular summer-flowering plants that are grown in greenhouses or nurseries, where growers must optimize production inputs such as fertility to maximize plant growth and produce high-quality flowering crops. The objective of this study was to determine the optimum fertilizer concentrations, identify leaf tissue nutrient sufficiency ranges by chronological age, and to expand leaf tissue nutrient standards of Hibiscus hybrid L. (hibiscus) grown in soilless substrates during container production. Two cultivars of hibiscus (H. hybrid L. ‘Mocha Moon’ and ‘Starry Starry Night’) were grown under one of six constant liquid fertilizer concentrations [50, 75, 100, 200, 300, or 400 mg·L−1 nitrogen (N)] with a constant level of water-soluble micronutrient blend in a greenhouse. The fertilizer concentrations sufficient for optimal plant growth and development were determined by analyzing plant height, diameter, growth index (GI), primary shoot caliper (PSC), and total dry mass, and they were found to be 100–300 mg·L−1 N after an 8-week crop cycle. Recently, mature leaf tissue samples were collected and analyzed for elemental content of 12 nutrients at 2, 4, 6, and 8 weeks after transplant (WAT) from plants fertilized with 100–300 mg·L−1 N. An overall trend of increasing sufficient tissue concentration over time was observed for total N, phosphorus (P), calcium (Ca), sulfur (S), zinc (Zn), copper (Cu), and boron (B), whereas a decreasing trend was observed for potassium (K), iron (Fe), manganese (Mn), and aluminum (Al). For instance, at 2 WAT, total N ranged from 3.1% to 5.1% N and increased to a range of 4.2% to 4.7% N at 8 WAT. At 2 WAT, Fe and Mn ranged from 79.2 to 103.6 mg·L−1 Fe and 66.3–82.8 mg·L−1 Mn and decreased to ranges of 75.6–82.9 mg·L−1 Fe and 18.1–99.7 mg·L−1 Mn at 8 WAT, respectively. Optimal leaf tissue concentration sufficiency ranges determined in this scientifically-based study were narrower than previously reported survey values for the genera Hibiscus.

Use of Dry Dairy Manure Pellets as Nutrient Source for Tomato (Solanum lycopersicum var. cerasiforme) Growth in Soilless Media

A sustainable dairy manure amendment for soilless crop growth systems was evaluated for its ability to provide nutrients and serve as a major component of the growing media. After manure liquid/solid separation, the solids stream containing organic N and P was pelletized and used as a nutrient source for cherry tomato (Solanum lycopersicum var. cerasiforme) culture in soilless media. The pellets are low in moisture, odor, and pathogens, and they can be hauled at lower cost over longer distances and more easily stored than raw or composted manure. Manure pellet additions to soilless media were evaluated at 0%, 2.5%, 5%, 10%, 15%, 20%, 25%, 30%, 40%, and 50% by volume. Manure pellets had a total N content of 3.7%. Fruit size, ripeness, and biomass, plant height, nutrients value in tissue/pellets/media, and time to complete growth cycle were analyzed. Overall, manure pellet treatments improved plant height and growth rate compared to the negative control, especially when pellets were 15% to 50% of the soilless media. This indicates that the nutrients in the manure were being mineralized, and plants were able to utilize the manure-based nutrients for growth. Leaf tissue nutrient analysis revealed that N, K, Zn, and Fe in leaf tissue were not at sufficiency levels at any level of manure pellet addition. Phosphorus and Cu reached sufficiency levels with 10% or greater manure pellet additions. Calcium, Mg, S, Mn, and B were sufficient in all plants, regardless of fertilizer or manure pellet treatment. Manure pellets demonstrate the potential to be used as a substrate and partial growth medium to reduce synthetic fertilizer use for more sustainable soilless container culture.

Improvement of Cymbopogon flexuosus Biomass and Essential Oil Production With Organic Manures

Cymbopogon flexuosus is a medicinal species with relevant commercial value and widely used in flavors, fragrances, toiletries, cosmetics, soaps, detergents, and pharmaceutical products. The objective of this study was evaluate the effects of different doses and sources of two manures and one compost on plant growth, leaf nutrient accumulation, content, yield, and chemical composition of the essential oil. The sources were cattle manure, quail manure, and organic compost applied in four doses and control treatment. The species increased the growth and productions of secondary metabolites by use the manures and organic compost. The highest weight gain was obtained with fertilization between 300 and 450 g pot-1 of quail manure, but the yield of essential oil in the doses from 150 to 300 g pot-1. Overall, lemon grass plants fertilized with quail manure accumulated greater concentrations of nutrients in leaf tissue than cattle manure and compost. The neral content in the essential oil was increased with the use of quail manure compared to compost and cattle manure. The results from this study demonstrated that dose and source can alter dry weight, leaf nutrients accumulation, and essential oil content and yield.

Prediction of Sugarcane Yield Based on NDVI and Concentration of Leaf-Tissue Nutrients in Fields Managed with Straw Removal

The total or partial removal of sugarcane (Saccharum spp. L.) straw for bioenergy production may deplete soil quality and consequently affect negatively crop yield. Plants with lower yield potential may present lower concentration of leaf-tissue nutrients, which in turn changes light reflectance of canopy in different wavelengths. Therefore, vegetation indexes, such as the normalized difference vegetation index (NDVI) associated with concentration of leaf-tissue nutrients could be a useful tool for monitoring potential sugarcane yield changes under straw management. Two sites in São Paulo state, Brazil were utilized to evaluate the potential of NDVI for monitoring sugarcane yield changes imposed by different straw removal rates. The treatments were established with 0%, 25%, 50%, and 100% straw removal. The data used for the NDVI calculation was obtained using satellite images (CBERS-4) and hyperspectral sensor (FieldSpec Spectroradiometer, Malvern Panalytical, Almelo, Netherlands). Besides sugarcane yield, the concentration of the leaf-tissue nutrients (N, P, K, Ca, and S) were also determined. The NDVI efficiently predicted sugarcane yield under different rates of straw removal, with the highest performance achieved with NDVI derived from satellite images than hyperspectral sensor. In addition, leaf-tissue N and P concentrations were also important parameters to compose the prediction models of sugarcane yield. A prediction model approach based on data of NDVI and leaf-tissue nutrient concentrations may help the Brazilian sugarcane sector to monitor crop yield changes in areas intensively managed for bioenergy production.

Secondary and Micronutrient Uptake, Partitioning, and Removal across a Wide Range of Soybean Seed Yield Levels

Micronutrient uptake was strongly influenced by environment and/or variety. Leaf tissue micronutrient concentrations varied largely between growth stages and within each specific growth stage. Total micronutrient uptake for soybean yield of 6,700 kg ha−1 was <0.9 kg ha−1 for Zn, Mn, Cu, Fe, and B. Late season S supply is critical as sulfur uptake during seed fill increased with yield, while remobilization from vegetative tissue was relatively less than that of N. Reduced atmospheric S deposition, in conjunction with higher grain sale prices and steadily increasing yields of soybean [Glycine max (L.) Merr.], has many growers considering an increase in secondary and micronutrient applications. Limited information exists quantifying requirements of S, Mg, Ca, Zn, Mn, Cu, Fe, and B across a wide yield range for modern soybean production systems. Using six site‐years and eight varieties, plants were sampled at six growth stages and partitioned into their respective plant parts and analyzed. Nutrients were acquired heavily (48–73%) from R1 through R5.5 with peak uptake rates near R3. Yet, uptake after R5.5 represented a greater portion of total S uptake as yield increased from the low (24.9%) to high (32.2%) yield level (3608 vs. 5483 kg ha−1). This coincided with seed S accumulation, which relied more heavily on continued uptake after R5.5 (58%) vs. vegetative S remobilization (42%). Across all environments (site × year) and varieties, total S uptake (0.004 kg S kg grain−1) and removal (0.003 kg S kg grain−1) showed moderate (R2 = 0.58) and strong (R2 = 0.76) relations with yield, respectively. These relations for each micronutrient were much weaker (R2 = 0.13–0.66), due largely to the main effects of environment and variety along with their respective interactions with yield. Furthermore, micronutrient concentrations in leaf tissue varied considerably (CV = 28–46%) during recommend testing stages. Thus, previously reported inconsistent yield responses to foliar application of these micronutrients may primarily be due to the large variability in leaf tissue concentrations and nutrient requirements.

Canola Nutrition and Variety Affect Oviposition and Offspring Performance in the Generalist Herbivore, Mamestra configurata (Lepidoptera: Noctuidae).

Bertha armyworm Mamestra configurata Walker (Lepidoptera: Noctuidae) is a generalist herbivore that feeds on several crops in different plant families. Canola Brassica napus L. (Capparales: Brassicaceae) is one of the most favored host plants making the bertha armyworm a significant insect pest in the Canadian Prairie Provinces. The performance of the bertha armyworm on canola may vary with the quality of the canola plant. We tested the impact of plant nutrition and canola variety on oviposition and subsequent larval development of the bertha armyworm. A range of fertilization levels (0.0, 1.0, 3.0, and 5.0 g/pot) were applied to three different canola varieties: Clearfield 5535 CL, Roundup Ready hybrid 6060RR, and Q2. The total number of eggs laid on plants in a no-choice experiment increased with fertilizer level but a similar number of eggs were laid on plants that received moderate and high fertilizer treatments. Larvae reared on plants that received the moderate fertilizer application yielded heavier pupae than those reared on plants with low and high fertilizer treatments. Most eggs were laid on the Q2 variety when compared to Clearfield 5535 CL and Roundup Ready 6060 RR. Bertha armyworm females preferred to lay eggs on plants that received moderate or high fertilization over plants with the low fertilizer treatment. Plant leaf tissue nutrient content and plant growth were highest in plants that received moderate and high fertilizer treatment. We conclude that bertha armyworm oviposition behavior and larval performance are influenced by fertilizer treatment and canola variety.

Molecular distribution and toxicity assessment of yttrium in Elodea canadensis

Aquatic plants are known to accumulate and bioconcentrate metals. In the present study, Elodea canadensis was subjected to different concentrations of yttrium (Y), ranging from 0 to 200μM, for 7 days and analysed for subcellular distribution and molecular localisation of Y, accumulation of mineral nutrients in leaf tissue, changes in photosynthetic pigments, oxidative stress and leaf and organelle ultrastructure. Leaf fractionation by differential centrifugation indicated that 68–76% of Y was accumulated in the cell wall, with higher levels of accumulation in cellulose and pectin than in other biomacromolecules. At all Y concentrations tested, Ca, Mg and Mn levels decreased in E. canadensis, whereas P levels increased; Fe and K levels increased initially and then declined. There was a marked concentration-dependent reduction in photosynthetic pigments following exposure to Y. Responses of components of the antioxidant system to Y treatment varied, whereas there were marked increases in reactive oxygen species and malondialdehyde at all Y concentrations tested. In addition, morphological symptoms of aging, such as chlorosis and damage to chloroplasts and mitochondria, were induced even by the lowest Y concentration. The results reveal that exogenous Y is widely available to this aquatic plant, which may have negative effects on aquatic organisms.

Yield, Fruit Quality Traits, and Leaf Nutrient Concentration of ‘Prolific’ Sapodilla Grafted onto Seedlings of 16 Sapodilla Rootstocks in Puerto Rico

Research on sapodilla (Manilkara zapota) has been very limited. A field study was conducted to determine the yield potential, fruit quality traits, leaf nutrient composition, and scion/rootstock compatibility of ‘Prolific’ sapodilla grafted onto 16 sapodilla rootstock seedlings. For this purpose, seedlings (maternal half-sibs) of cultivars Adelaide, Arcilago, Aruz, Blackwood, Blocksberg, Guilbe, Hanna, Jamaica-1, Larsen, Mendigo-1, Gallera, Morning Star, Russel, Prolific, Timothe, and Vasallo-1 were used as rootstock seedlings and evaluated during 7 years of production at Isabela, PR. Year showed a significant effect on the number of fruit per hectare, yield, individual fruit weight, fruit length and diameter, and total soluble solids. Rootstock seedlings had a significant effect on the number of fruit per hectare, yield, and individual fruit weight but had no effect on other fruit traits. The year × rootstock interaction was not significant for any of the variables measured in the study. Rootstock seedlings ‘Timothe’, ‘Vasallo-1’, ‘Larsen’, and ‘Aruz’ had the highest 7-year mean for number and the yield of fruit averaging 4479 fruit/ha and 1245 kg·ha−1, respectively. ‘Timothe’ and ‘Vasallo-1’ significantly out yielded the ‘Prolific’ rootstock seedling. The number of fruit per hectare and corresponding yield obtained in this study were very low probably as the result of wind exposure, the presence of the fungus Pestalotia causing floral necrosis, or both. Scion/rootstock incompatibility was not the cause of the low yield performance of grafted trees. The average individual weight of fruit was 282 g and ranged from 264 to 303 g. Averaged over rootstock seedlings, leaf tissue nutrient concentration did not vary greatly over time. Moreover, tissue nutrient concentration was similar before and after fertilization events.