Root Dry Matter Content Research Articles

Production of organic melon seedlings under different growing medias and doses of aqueous humic extract

Aiming to determine the viability of organic compost (OC) as a component of commercial growing media (CGM), as its potential in the formulation of humic extract (HE), an experiment was developed with organic melon seedlings. A completely randomized design with 4x5 factorial arrangement and four replicates was adopted. The treatments consisted of four compost proportions (0, 10, 20 and 30%), mixed to the growing media (v:v), associated with the application of five doses of aqueous extract obtained from the same compost (0, 5, 10, 15 and 20%). The following variables were evaluated: total percent emergence (TPE), emergence rate index (ERI), emergence rate (ER), leaf area (LA), number of leaves (NL), dry and fresh mass of shoot and root (SDM, SFM, RDM and RFM); length (RL) and volume of root (RV); and shoot (SDMC) and root dry matter content (RDMC). Only NL provided interaction between the analyzed factors. ER, RFM, RDM, and RDMC showed no statistically significant differences across the various concentrations of OC and HE. SFM and SDM presented a negative quadratic term in relation to OC increase. SDMC and LA had inferior results at greater OC amount. OC is not recommended as a conditioner for growing media, at the conditions and variables analyzed in this study.

Stability and genetic parameters for cassava yield attributes in the tropical humid region of Brazil

The performance differences in cassava genotypes arising from genotype vs. environment interactions (G × E) often lead to responses that are significantly lower than expected for selection. The objective of this study was to evaluate different stability methods, both parametric and non-parametric, such as additive main-effects and multiplicative interaction (AMMI), main effect of genotypes plus G × E (GGE), and weighted average of absolute scores (WAASB), in order to quantify the G × E in multi-environmental trials. A total of 12 genotypes were assessed across 12 environments using a completely randomized block design, with three replicates for traits such as fresh root yield (FRY) and dry matter content in the roots (DMC). The data were subjected to analysis of variance and the Scott Knott test (p < 0.05). The sum of squares (SQ) of genotypes, environment, and G × E effects were equally distributed for FRY, whereas for DMC, these effects accounted for 64.1%, 21.9%, and 13.8% of the SQ, respectively, indicating a lower environmental effect on this characteristic. Using the AMMI, GGE, and WAASB methods, genotypes with high agronomic performance and stability for FRY (BR11-34–41 and BR11-34–69) (> 32 t ha−1) and DMC (BRS Novo Horizonte, BR12-107–002, and BR11-24–156) (> 37%) were identified. The broad-sense heritability (h2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$${h}^{2}$$\\end{document}) for FRY and DMC was estimated to be 0.45 and 0.75, respectively. Approximately 72% of the methods identified BRS Novo Horizonte as the genotype with the highest stability and performance for DMC, while 47% identified genotypes BR11-34–41 and BR11-34–69 for FRY and intermediate DMC. Genotype BR11-24–156 exhibited high static stability according to 50% of the methods. Significant correlations were observed between stability and agronomic performance across the different methods, enabling the formation of groups based on stability concepts. Additionally, it was found that two mega-environments existed for FRY, whereas DMC displayed a single mega-environment with similar patterns, indicating an absence of G × E. We identified superior genotypes that could be promoted to national performance trials to develop stable cultivars with better yield attributes in cassava.

Standardization of Propagation Techniques in Annual Moringa (Moringa oleifera Lam.) for Enhancing Crop Uniformity

An investigation on annual Moringa, Moringa oleifera Lam., var., (PKM 1 and PKM2) with the objective of standardizing the method of vegetative propagation was carried out at Horticultural College and Research Institute, Periyakulam. the treatment consisted of three factors viz., cultivars (Factor 1: Moringa variety PKM 1 and PKM2), propagation methods (Factor 2: hardwood cuttings, semi hardwood cuttings and air layering) and application of different concentration of growth regulator IBA (Factor 3:0, 1500, 2500 and 4000 ppm) and the trial was laid out with twenty four treatments using Factorial Randomized Block Design with three replications. The overall result revealed that the treatment combinations of PKM 1 air layering treated with IBA 4000 ppm registered the highest dry matter content of root (70.00%) and PKM 1 hardwood cuttings treated with IBA 4000 ppm recorded the highest dry shoot to root ratio (9.19). In PKM 2 semi hardwood cuttings treated with IBA 1500 ppm registered the highest root length (16.30cm) and dry matter content of shoot (61.99%). PKM 2 air layers treated with IBA 4000 ppm took minimum number of days to root (17.99 days), days to sprout (9.85 days) had the highest root fresh weight (2.70g), root dry weight (1.80g), shoot fresh weight (12.52g) and shoot dry weight (6.90g). This study concluded that air layering with 2500 to 4000 ppm IBA treatment is best pro pragation method for PKM1 and PKM 2 annual moringa.

Use of processed grape pomace and whey bio ferment to improve the agronomic performance of radish (Raphanus sativus L.) in arid soils

Agro-industrial wastes representing a significant problem can be revalued as biofertilizers. The present paper aims to determine the effect of processed grapevine pomace (PGP) and whey bio-ferment (WB) on radish cultivation under conditions of arid zone soil. A 3x3 factorial arrangement of completely randomized design was used, with three levels of PGP (0, 1.25, and 2.50 g kg-1 soil applied in total dose before planting) and three levels of WB (0, 50, and 100 mL L-1 applied in irrigation water). Radish leaves were evaluated for length and chlorophyll; root dry matter content, length, diameter, weight, and total soluble solids (TSS) were measured; organic matter (OM), N, P, K, pH, electrical conductivity (EC) and cation exchange capacity (CEC) was determined in the soil. Specific differences in means were determined by the LSD-Fisher method applied after analysis of variance (ANOVA); the significance of differences was defined at P&lt;0.05. The most remarkable result to emerge from the data is that using PGP and WB improved soil attributes and promoted crop development. Specifically, the higher the PGP dose, the greater the benefits; in the case of WB, the dose of 50 mL L-1 showed the best results.

Intraspecific variation in fine-root traits is larger than in aboveground traits in European herbaceous species regardless of drought.

Differences within species (Intraspecific trait variation - ITV) contribute substantially to overall trait variability and environmental harshness can reduce among-species variation. While aboveground traits have received considerable attention, knowledge about ITV in fine-root traits and how it differs from ITV in aboveground traits remains limited. This study examined the partitioning of trait variation aboveground and fine-root traits in 52 European herbaceous species and how such proportions change in response to drought, offering valuable insights for accurate functional species characterization and inter-species comparisons. We studied seven morphological aboveground and fine-root traits under drought and well-watered conditions in a greenhouse experiment. Linear mixed effect models and permutational multivariate analysis of variance (PERMANOVA) were employed to decompose trait variation, ensuring the robustness of our results. We also calculated variance partitioning for the combination of aboveground traits and the combination of fine-root traits, as well as pairs of analogous leaf and fine-root traits (i.e., traits that fulfill similar functions) for each treatment (control and drought). Among-species trait differences explained a greater proportion of overall variance than within-species variation, except for root dry matter content (RDMC). Height and leaf area stood out, with species' identity accounting for 87-90% of total trait variation. Drought had no significant effect on the proportions of variation in any of the traits. However, the combination of fine-root traits exhibited higher intraspecific variability (44-44%) than aboveground traits (19-21%) under both drought and control. Analogous root traits also showed higher ITV (51-50%) than analogous leaf traits (27-31%). Our findings highlight substantial within-species variation and the nuanced responses of fine-root traits, particularly RDMC, suggesting root traits' flexibility to soil heterogeneity that fosters less differentiation among species. Among-species trait differences, especially aboveground, may underscore distinct strategies and competitive abilities for resource acquisition and utilization. This study contributes to elucidate the mechanisms underlying the multifunctionality of the above- and belowground plants compartments.

Trade‐offs in rooting strategy dimensions along an edaphic gradient in a grassland ecosystem

Abstract Roots are essential to the diversity and functioning of plant communities, but trade‐offs in rooting strategies are still poorly understood. We evaluated existing frameworks of rooting strategy trade‐offs and tested their underlying assumptions, guided by the hypothesis that community‐level rooting strategies are best described by a combination of variation in organ‐level traits, plant‐level root:shoot allocation and symbiosis‐level mycorrhizal dependency. We tested this hypothesis using data on plant community structure, above‐ and below‐ground biomass, eight root traits including mycorrhizal colonisation and soil properties from an edaphic gradient driven by elevation and water availability in sandhills prairie, Nebraska, USA. We found multidimensional trade‐offs in rooting strategies represented by a two‐way productivity‐durability trade‐off axis (captured by root length density and root dry matter content) and a three‐way resource acquisition trade‐off between specific root length, root:shoot mass ratio and mycorrhizal dependence. Variation in rooting strategies was driven to similar extents by interspecific differences and intraspecific responses to soil properties. Organ‐level traits alone were insufficient to capture community‐level trade‐offs in rooting strategies across the edaphic gradient. Instead, trait variation encompassing organ, plant and symbiosis levels revealed that consideration of whole‐plant phenotypic integration is essential to defining multidimensional trade‐offs shaping the functional variation of root systems. Read the free Plain Language Summary for this article on the Journal blog.

Avaliação precoce da interação genótipo x safras na cultura da mandioca sob déficit hídrico

ABSTRACT The aim of this study was to evaluate the effect of genotype x harvest interactions on different agronomic traits, the genetic correlation between traits in early selection under water stress, and early selection in cassava. 25 cassava genotypes were evaluated in a randomized block experimental design with four replications. The variables root weight (RW), root number per plant (RN), root diameter (RD), root length (RL), root dry matter content (DMC), stem number per plant (SN), plant height (PH), stem diameter (SD), mite severity (MS), and harvest index (HI) were evaluated under water stress conditions in two harvests. Broad-sense heritability (h²), realized heritability ( ( h R 2 )), and the index of coincidence (IC) were estimated. Accuracy estimates ranged from 0.62 for RL to 0.86 for DMC. A significant genotype effect was identified on all traits, except for RW, RL and SD. Significant genotype x harvest interactions occurred for the variables SN, PH, SD, and HI. (h²) estimates ranged from 0.27 for RL to 0.79 for SN. The estimates of the index of coincidence ranged from 100% to 25%. A positive correlation was observed between all variables under study, except for MS, RN and SN, and the other traits. The genotypes showed similar performance in the two harvests for most variables, except for SN, PH, SD, and HI.

Teor de água e temperatura de armazenamento na conservação de sementes de pupunha

ABSTRACT: The peach palm (Bactrisgasipaes) is an important alternative for heart-of-palm extraction, showing precocity, rusticity and high tillering. The seeds of this species are considered recalcitrant making storage for long periods and production of seedlings difficulty. This identified a combination of moisture content of peach palm seeds and temperature during storage for longer seed longevity. Seeds with 35% and 45% of moisture content (wet basis - wb) were storage at 20 °C and 25 ºC during 180 days. The evaluations were carried out every 60 days by the germination test, emergence in sand, shoot length, diameter of stem, shoot dry matter, root dry matter and moisture content. It was observed that seeds with moisture content of 45% wb showed better performance during storage. The storage at 20 ºC provides higher seed quality maintenance. Peach palm seeds maintain their viability for 120 days when stored with moisture content of 45% wb at 20 ºC.

Response of carrot (Daucus carota Linn.) to different doses and sources of nitrogen in Sindhuli, Nepal

As a root crop known for its substantial nitrogen requirements, carrot responds well to both organic and inorganic fertilizers that supply different amounts of nitrogen. This study aimed to assess the efficacy of various proportions of farmyard manure (FYM) and recommended dosages of chemical fertilizers (RDF) in carrot production to address the issues posed by their sole use. A Randomized Complete Block Design (RCBD) was used to plan the field study, which consisted of five treatments and five replications with different nitrogen rates and sources, viz., T1 (100% FYM), T2 (25% RDF+75% FYM), T3 (50% RDF+50% FYM), T4 (75% RDF+25% FYM), and T5 (100% RDF) during December 2019 to April 2020 in the tropical region of Sindhuli, Nepal. Among the treatments, T3 exhibited the earliest germination (7.60 DAS) and the most desirable plant height (42.61 cm), root length (20.41 cm), root diameter (3.01 cm), fresh root weight plant-1 (96.04 g), total root dry matter content (15.01%), root biomass plant-1 (55.44 g), and total biomass plant-1 (85.33 g) at harvest. However, T5 resulted in the highest leaf count plant-1 (8.6) and fresh foliage weight plant-1 (42.96 g) at harvest. Similarly, T3 was significantly higher for quality parameters, such as cortex diameter (1.36 cm), pH (6.72), TSS (12.48 0Brix), TA (0.22 g liter-1), and organoleptic score (7.60). Although there were minimal root disorders in T3 (17%), T1 also had insignificant cases of cracking (8%) and postharvest weight loss (1.63%). Thus, reducing nitrogen input from the recommended dose and adding FYM improves carrot yield, quality, and shelf life. Furthermore, this guarantees higher economic returns with a B:C ratio of 1.65. Despite these positive results, the efficacy of the tested nutrient combinations needs to be analyzed on a larger scale, as well as in different ecological regions.

Response of grassland ecosystem function to plant functional traits under different vegetation restoration models in areas of karst desertification.

Plant functional traits serve as a bridge between plants, the environment, and ecosystem function, playing an important role in predicting the changes in ecosystem function that occur during ecological restoration. However, the response of grassland ecosystem function to plant functional traits in the context of ecological restoration in areas of karst desertification remains unclear. Therefore, in this study, we selected five plant functional traits [namely, plant height (H), specific leaf area (SLA), leaf dry matter content (LDMC), root length (RL), and root dry matter content (RDMC)], measured these along with community-weighted mean (CWM) and functional trait diversity, and combined these measures with 10 indexes related to ecosystem function in order to investigate the differences in plant functional traits and ecosystem function, as well as the relationship between plant functional traits and ecosystem functions, under four ecological restoration models [Dactylis glomerata (DG), Lolium perenne (LP), Lolium perenne + Trifolium repens (LT), and natural grassland (NG)]. We found that: 1) the Margalef index and Shannon-Wiener index were significantly lower for plant species in DG and LP than for those in NG (P<0.05), while the Simpson index was significantly higher in the former than in NG (P<0.05); 2) CWMH, CWMLDMC, and CWMRDMC were significantly higher in DG, LP, and LT than in NG, while CWMSLA was significantly lower in the former than in NG (P<0.05). The functional richness index (FRic) was significantly higher in DG and LP than in NG and LT, but the functional dispersion index (FDis) and Rao's quadratic entropy index (RaoQ) were significantly lower in DG and LP than in NG and LT (P<0.05), and there was no significant difference between DG and LP, or between NG and LT (P>0.05); 3) ecosystem function, including ecosystem productivity, carbon storage, water conservation and soil conservation, was highest in LT and lowest in NG; and 4) CWMLDMC (F=56.7, P=0.024), CWMRL (F=28.7, P=0.024), and CWMH (F=4.5, P=0.048) were the main factors affecting ecosystem function. The results showed that the mixed pasture of perennial ryegrass and white clover was most conductive to restoration of ecosystem function. This discovery has important implications for the establishment of vegetation, optimal utilization of resources, and the sustainable development of degraded karst ecosystems.

Linking root traits to phytoremediation in trees and shrubs: Implications of root economics spectrum

Abstract Phytoremediation is a promising technique for removing or stabilizing metal ions from metallic trace elements (MTEs) contaminated soils. Despite the significant role of roots in plant growth and survival, limited information is available on the functional covariation of root traits under MTE stress, and linkages between root resource‐use strategies and phytoremediation functioning. Sixteen root traits were measured across 11 trees and shrubs grown in Pb–Zn mine tailings in Southeastern China, to examine whether a hypothesized root economics spectrum (RES) exists under extremely high levels of multiple MTEs stress and evaluate the importance of root functional traits in explaining phytoremediation functioning. Our findings offer evidence supporting the widely accepted resource‐use strategy of acquisitive‐conservative. Furthermore, we have identified a distinct dimension of RES representing the trade‐off between root system size and root tissue density. This new dimension highlights the critical importance of root size, shape and proliferation strategy in the context of metal‐contaminated soil. Moreover, a trade‐off between root cadmium concentration and root dry matter content was observed, which implies the existence of a presumable biomass cost for MTEs accumulation. We identified specific key root traits and their contributions to MTE translocation and bioconcentration, and established linkages between root resource‐use strategy and phytoremediation: roots with more acquisitive traits promote MTE translocation, while conservative roots foster bioconcentration. In addition, acquisitive roots usually exhibit lower biomass costs for accumulating MTEs than do conservative roots. Synthesis and applications. Our results highlight the important role of root size‐related traits in the root economics spectrum (RES) framework in metal‐contaminated soil. Furthermore, we discovered that woody species exhibit different capacities for accumulating or translocating metallic trace elements (MTEs), depending on their root system shapes and their position on axis of RES. These findings provide valuable support for the accurate selection of suitable plant species for ecological restoration purposes. And they hold significant potential in guiding the development of efficient phytoremediation strategies specifically targeting sites contaminated with MTEs.

Development and validation of near-infrared spectroscopy procedures for prediction of cassava root dry matter and amylose contents in Ugandan cassava germplasm.

Cassava utilization for food and/or industrial products depends on inherent properties of root dry matter content (DMC) and the starch fraction of amylose content (AC). Accordingly, in the present study, near-infrared reflectance spectroscopy (NIRS) models were developed to aid breeding and selection of DMC and AC as critical industrial traits taking care of root sample preparation and cassava germplasm diversity available in Uganda. Upon undertaking calibrations and cross-validations, best models were adopted for validation. DMC in calibration samples ranged from 20 to 45 g 100g-1, whereas, for amylose content, it ranged from 14 to 33 g 100g-1. In the validation set, average DMC was 29.5 g 100g-1, whereas, for amylose content, it was 24.64 g 100g-1. For DMC, a modified partial least square regression model had regression coefficients (R2) of 0.98 and 0.96, respectively, in the calibration and validation set. These were also associated with low bias (-0.018) and ratio of performance deviation that ranged from 4.7 to 5.0. In addition, standard error of prediction values ranged from 0.9 g 100g-1 to 1.06 g 100g-1. For AC, the regression coefficient was 0.91 for the calibration set and 0.94 for the validation set. A bias equivalent to -0.03 and a ratio of performance deviation of 4.23 were observed. These findings confirm the robustness of NIRS in the estimation of dry matter content and amylose content in cassava roots and thus justify its use in routine cassava breeding operations. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Nutritional Changes In Anchote [Coccinia Abyssinica (Lam.) Cogn.] Root Cultivar Under The Use Ofmixed NPSB And FYM Fertilizers Rates

Anchote (Coccinia abyssinica (Lam.) Cogn.) is a critically important root crop native to Ethiopia on the African continent. In terms of nutrition, economics, medical, and social welfare, it is a highly valued food source that is abundant throughout the Western part country. The nutrient makeup of the crop may be affected by the application of various organic and inorganic fertilizers. The effects of organic and inorganic fertilizers on the nutritional content of the Anchote food crop, on the other hand, are unknown. As a result, during the 2019-20 cropping season, a field experiment was conducted in the southwestern part of Ethiopia to see how the Anchote variety (Desta 01) responded to various levels of NPSB and farmyard manure in terms of yield and nutritional components. Six rates of mixed NPSB fertilizer (0, 58,116,175,233, and 291 kg ha-1) and three levels of Farmyard Manure (FYM) (0, 5, and 10 t ha-1) were treated within the experimental plot in the field to assess the yield and nutritional composition of the Anchote variety. In a randomized complete block design, the experiment was set up in 3 x 6 factorial patterns with three replications.For laboratory analysis, samples of its roots from all three replications were collected separately after the crop maturity and subjected to SAS (version 9.3) software, which was used to assess nutritional characteristics such as dry matter content of roots (DMC) (percent), crude fat (percent), moisture content (percent), total soluble solid (TSS), and total ash (percent). The results of the laboratory analysis revealed that the interaction effects of blended NPSB fertilizer and FYM levels significantly changed nutritional features such as dry matter and moisture content (P0.01). DMC, ash percent, TSS, moisture content, and crude fat were all significantly (P0.01) affected by FYM and NPSB application in the field, whereas the interaction effects of both NPSB and FYM treatment in the field had a significant (P0.01) impact on laboratory parameters like ash and crude fat content of Anchote cultivar. Finally, the results of the laboratory experiment showed that applying blended NPSB fertilizer and FYMtogether to the field had an effect on the quality and nutritional attributes of the Anchote cultivar gathered for laboratory testing in the research region.

Heterotic gains, transgressive segregation and fitness cost of sweetpotato weevil resistance expression in a partial diallel cross of sweetpotato

Heterosis-exploiting breeding schemes are currently under consideration as a means of accelerating genetic gains in sweetpotato (Ipomoea batatas) breeding. This study was aimed at establishing heterotic gains, fitness costs and transgressive segregation associated with sweetpotato weevil (SPW) resistance in a partial diallel cross of sweetpotato. A total of 1896 clones were tested at two sites, for two seasons each in Uganda. Data on weevil severity (WED), weevil incidence (WI), storage root yield (SRY) and dry matter content (DM) were obtained. Best linear unbiased predictors (BLUPs) for each clone across environments were used to estimate heterotic gains and for regression analyses to establish relationships between key traits. In general, low mid-parent heterotic gains were detected with the highest favorable levels recorded for SRY (14.7%) and WED (− 7.9%). About 25% of the crosses exhibited desirable and significant mid-parent heterosis for weevil resistance. Over 16% of the clones displayed superior transgressive segregation, with the highest percentages recorded for SRY (21%) and WED (18%). A yield penalty of 10% was observed to be associated with SPW resistance whereas no decline in DM was detected in relation to the same. Chances of improving sweetpotato through exploiting heterosis in controlled crosses using parents of mostly similar background are somewhat minimal, as revealed by the low heterotic gains. The yield penalty detected due to SPW resistance suggests that a trade-off may be necessary between maximizing yields and developing weevil-resistant cultivars if the current needs for this crop are to be met in weevil-prone areas.

MAGNETIC WATER EFFECTS ON GROWTH AND SOME PHYSIOLOGICAL CHARACTERISTICS OF PAULOWNIA TOMENTOSA THUNB UNDER CADMIUM STRESS CONDITIONS

Paulownia (Paulownia tomentosa) is considered as one of the world's fastest-growing species of trees and most widely used for commercial. This research was done as a factorial experiment in Koya city, Erbil, Iraq during 2021-2022 to study the effects of magnetic water (MW) at (0, 500,1000, 1500 and 2000) gauss and cadmium chloride (Cd) at (0, 3.33, 6.66 and 10 mg Kg-1soil) on some growth, physiological and biochemical properties of this plant. Results demonstrate that MW had non-significant differ regarding the survived and the velocity of cutting outgrowth compare to using tap water, whereas Cd application increased the velocity of cutting outgrowth. At least one of MW powers increased significantly each of plant leaf-area, stem diameter, shoot and root fresh weight and dry matter content, as well as all Cd concentrations increased the plants leaves number, leaf-area, stem diameter. Cd had more effects on roots than plant shoots, where it has non-significant effects on shoot high or dry matter, whereas it increased each of shoot and root fresh weight significantly compared to the control treatment. Low power MW (500 and 1000) gauss performed better than high powers (1500 and 2000) gauss in increasing the content of photosynthesis pigments. Utilizing magnetic water greatly enhanced total carotenoids and chlorophyll a, b, regardless to device power. Chlorophyll (a and b) were both significantly reduced by high Cd concentrations; however it was significantly increased at low concentrations as compared to other treatments. High power MW decreased significantly peroxidase enzyme activity and proline content whereas it decreased the percent of total carbohydrate compared to other treatments. Cd application decreased each of peroxidase enzyme activity, percent of total carbohydrate content, increased ascorbic acid and proline significantly in comparing to the control.

Varietal screening for identification of postharvest physiological deterioration tolerance in storage roots of cassava

ABSTRACT Postharvest physiological deterioration (PPD) is a constraint in cassava (Manihot esculenta Crantz) and a threat to effective utilization of cassava roots. This study determined the magnitude of variability for PPD tolerance among cassava genotypes and identified new sources of tolerance to PPD. Seventy-six cassava genotypes were evaluated for PPD tolerance at postharvest evaluation intervals of 3, 5, 7, 10, 15, or 20 days after harvest. Repeated measure analysis indicated that differences for PPD reliably depend on time in conjunction with genotype and years. The genotypes were categorized into nine classes using rank-sum statistics involving standardized mean range, PPD, and PPD per day. Nineteen genotypes were tolerant and three were free of symptoms up to 20 days postharvest. Released varieties had tolerance to PPD compared to local varieties and pre-breeding lines. The PPD symptoms were mostly found in peripheral regions and in proximal and distal ends rather than in the mid-region of the root. The presence of the root neck reduced deterioration. Root length, weight, and dry matter content were positively correlated with PPD. The new sources of tolerance may improve the adoption and utilization of cassava.

Performance and Stability of Improved Cassava (Manihot esculenta Crantz) Clones in Demand Creation Trials in Nigeria

Cassava fresh root yield and dry matter content constitute major determinants of demand by end-users. Increased demand for the seeds of improved varieties will facilitate the development of a sustainable seed system. However, for wide acceptability, there is a need to continuously evaluate candidate varieties for stability across different agroecological zones. Participatory Demand Creation Trials (DCTs) were established to evaluate cassava varieties with farmers and processors utilizing the best agronomic practices. The multi-year DCTs were conducted in 20 environments (7 locations) during the 2016–2017, 2017–2018, 2018–2019, and 2019/2020 cropping seasons with two replications. The plot sizes were 320 m2 with a spacing of 1 m × 0.8 m. The traits evaluated were Plant Vigor (PV), root number, fresh yield, dry yield, Dry Matter Content (DMC), and bundle estimation. The traits were subjected to a GGE biplot in R software to identify high-yielding and stable genotypes. Results obtained from the 20 environments showed that genotype (G), environment (E), and GXE interaction effects were significant (p &lt; 0.01) for all the traits but PV. The heritability ranged from 56% (PV) to 96% (DMC). The average fresh yield t/ha ranged from 25.5 (IBA30572) to 35.4 (IBA980505). The DMC ranged from CR36/5 (36.1%) to IBA010040 (30.7%). The dry yield ranged from 8.8% (IBA30572) to 11.4 (IBA980505). Estimated bundles ranged from 13.5 (CR36-5) to 15.7 (IBA950289). Three varieties, IBA961632, TMEB419, and CR36/5, were identified as the most promising high dry matter content varieties for cassava processors and farmers in Nigeria, and genotype IBA961632 was the most stable. The study revealed greater genotypic effects than from the environment and high genetic advances.

Interrelations of α- and β-amylase activity with starch, sugars, and culinary and nutritional quality attributes in sweetpotato storage roots.

Little information is available on α- and β-amylase activity and their associations with starch, sugars and other culinary qualities in sweetpotato. The present study aimed to assess sweetpotato storage root α- and β-amylase activity in relation to starch, sugars, β-carotene content and storage root flesh color. α- and β-amylase activity (α-AA and β-AA) were assayed from a Tanzania (T) × Beauregard (B) genetic mapping population in their uncured (raw), cured and stored (approximately 11 weeks) forms during 2016 and 2017. Ceralpha and Betamyl methods, with modifications to suit a high-throughput microplate assay format, were used to quantify α-AA and β-AA, respectively. Storage root dry matter, starch, glucose, fructose, sucrose and β-carotene content were predicted using near infrared reflectance spectroscopy. There was little relationship (r2 = 0.02-0.08, P ≤ 0.05 in 2016 and r2 = 0.05-0.11, P ≤ 0.05 in 2017) between α-AA and β-AA. We observed negative linear associations between α-AA and dry matter content and generally no correlations between β-AA and dry matter content. β-AA and sugars were weakly positively correlated. β-AA and β-carotene content were positively correlated (r = 0.3-0.4 in 2016 and 0.3-0.5 in 2017). Generally, the correlation coefficient for amylase enzyme activity and sugar components of storage roots at harvest increased after curing and during post-harvest storage. The present study is a major step forward in sweetpotato breeding in terms of providing a better understanding of how α- and β-amylase activity are inter-associated with several culinary quality attributes. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Different soil textures can interfere with phosphorus availability and acid phosphatase activity in soybean

To achieve sustainable agricultural activity, phosphatase determination is an important practice for improving the efficiency of phosphorus (P) management in tropical agriculture. The objective of this study was to evaluate acid phosphatase activity in different soil textures and P stress levels affecting the nutritional, chemical, biochemical, and agronomic aspects of soybean. Treatments resulted from factorial combination in a 3 × 3 factorial scheme, consisting of three soil textures (clay, medium, and sandy) and three P stress levels (severe, moderate, and control) with four replications. Three different soil textures were used in the research: Latossolo Vermelho Distrófico (LVd) with clay texture, collected in the native forest, equivalent Oxisol (Soil Taxonomy); Cambissolo Háplico Tb Distrófico (CXbd) with medium texture collected in the natural field equivalent Inceptisols (Soil Taxonomy); and Latossolo Amarelo Distrófico (LAd) with sandy texture collected in the natural field equivalent Oxisol (Soil Taxonomy). Soil electrical conductivity, P available (method Mehlich-1), and acid phosphatase activity (ρ-nitrophenol released) (μg h−1 g−1 soil) were analyzed and the samples were collected at a depth of 0–20 cm. Also evaluated were the height of plants, number of leave and branches, dry mass (root, leave, and stem), P total concentration in leaf, and P translocation (transport from root to shoot) of soybean plants 45 days after sowing. Results showed the clayey textured soil provided the best results for plant growth, root, stem, and leaf dry matter content, P total concentration of P in leaf, P translocation (transport from root to shoot), P available in the soil, and higher acid phosphatase activity of under P stress. Results showed that the Latossolo Vermelho Distrófico (LVd) provided the best results in managing P in different soil textures. However, based on growth and development results, a reduction in phosphate fertilization (P stress moderate) may favor acid phosphatase activity. Acid phosphatase activity can be used as an option in the management of P soluble activity in different soil textures. However, in front of the complexity of soil–plant–P–environment interactions, further research needs to be conducted to investigate better these effects of the da acid phosphatase on different soil textures.

Species phylogeny, ecology, and root traits as predictors of root exudate composition.

Root traits including root exudates are key factors affecting plant interactions with soil and thus play an important role in determining ecosystem processes. The drivers of their variation, however, remain poorly understood. We determined the relative importance of phylogeny and species ecology in determining root traits and analyzed the extent to which root exudate composition can be predicted by other root traits. We measured different root morphological and biochemical traits (including exudate profiles) of 65 plant species grown in a controlled system. We tested phylogenetic conservatism in traits and disentangled the individual and overlapping effects of phylogeny and species ecology on traits. We also predicted root exudate composition using other root traits. Phylogenetic signal differed greatly among root traits, with the strongest signal in phenol content in plant tissues. Interspecific variation in root traits was partly explained by species ecology, but phylogeny was more important in most cases. Species exudate composition could be partly predicted by specific root length, root dry matter content, root biomass, and root diameter, but a large part of variation remained unexplained. In conclusion, root exudation cannot be easily predicted based on other root traits and more comparative data on root exudation are needed to understand their diversity.