Cluster Weight Research Articles

Participatory tomato variety selection in the lowland areas of North Shewa

The production and productivity of tomatoes in Ethiopia as well as in Amhara Region are very low because of lack of improved and adapted varieties, inadequate knowledge of production and management, and a poor marketing system. The field experiment was carried out during the 2018 irrigation seasons at Ataye and Shewarobit to identify adaptive, high yielding and disease tolerant varieties of tomato. Eight improved tomato varieties were laid out in a randomized complete block design and replicated three times. The collected biological data were analyzed using SAS statistical software version 9.4, and farmers’ preferences for those varieties were also assessed based on selection attributes set by them. The combined analysis of variance revealed that there was significant difference between the varieties on the number of fruits per cluster, plant height, marketable number, unmarketable number and average weight of a tomato. The highest number of fruits per cluster was recorded from variety Mersa (3.83), followed by Melkasalsa (3.73) and Melkashola (3.7). The variety Mersa was the tallest followed by Weyno with plant heights of 110.5 cm and 110.96 cm, respectively. The highest average fruit weight was recorded for the variety D2 (61.25 g) followed by Cochoro (46.46 g). Even though it was not statistically significant, the variety Melkashola has given the highest marketable yield (32.98 t ha-1) and showed a better reaction to late blight disease as low as 27.5 %. In addition to this, variety Melkashola was highly preferred by the farmers. Based on the biological data and farmer’s preference variety Melkashola has been recommended for Ataye and Shewarobit as well as for other similar agro-ecologies.

Shelved–Retrieved Method for Weakly Balanced Constrained Clustering Problems

Clustering problems are prevalent in areas such as transport and partitioning. Owing to the demand for centralized storage and limited resources, a complex variant of this problem has emerged, also referred to as the weakly balanced constrained clustering (WBCC) problem. Clusters must satisfy constraints regarding cluster weights and connectivity. However, existing methods fail to guarantee cluster connectivity in diverse scenarios, thereby resulting in additional transportation costs. In response to the aforementioned limitations, this study introduces a shelved–retrieved method. This method embeds adjacent relationships during power diagram construction to ensure cluster connectivity. Using the shelved–retrieved method, connected clusters are generated and iteratively adjusted to determine the optimal solutions. Further, experiments are conducted on three synthetic datasets, each with three objective functions, and the results are compared to those obtained using other techniques. Our method successfully generates clusters that satisfy the constraints imposed by the WBCC problem and consistently outperforms other techniques in terms of the evaluation measures.

Grapevine stem water potential seasonal curves: response to meteorological conditions, and association to yield and red wine quality

Managing grapevine water status is a key component for achieving optimal yield and wine quality. Stem water potential (SWP) is used for determining the drought stress and is associated with physiological, vegetative, and reproductive processes. SWP seasonal curves (SWP-SCs) represent the seasonal stress levels. SWP-SCs may change within and between growing seasons according to environmental and irrigation factors. The objective was to analyze the temporal dynamics of SWP-SCs, their response to meteorological and irrigation conditions, and their impact on yield and wine quality. A dataset was assembled from a six-year experiment (2014-2019) in a ‘Cabernet Sauvignon’ vineyard, including meteorological features, irrigation treatments, field measurements of SWP, yield components (i.e., yield, number of clusters, cluster weight, and berry mass), and wine-quality scores from experimental wines. Between- and within-seasonal variations of SWP-SCs were assessed using ANOVA and discriminant analysis. The effects of meteorology and irrigation on SWP-SCs were quantified using random forest. Clustering of SWP-SCs was conducted using a fuzzy c-means algorithm and the clusters (groups) were analyzed against yield components and wine quality using ANOVA. Our findings show that the mean seasonal SWP values were significantly different among seasons, while SWP values during the weeks proximal to veraison were the major discriminators. Temperature was a strong driver of SWP, followed by relative humidity and precipitation. Three clusters were generated according to stress levels throughout the season. The moderate-severe stress group (Cluster 2) was associated with similar yield components levels compared to the moderately-stressed group (Cluster 1) and significantly higher wine quality components, with a minimal SWP threshold of -1.5 - -1.6 MPa before harvest. The extreme drought stress group (Cluster 3) was associated with significantly lower yield and wine quality. Increasing temperatures and shifting patterns of precipitation are projected to continue excessively, inducing disruptive conditions to the target vine drought stress levels.

Research on New Liberal Arts Professional Talent Cultivation Model Based on OBE Concept

Abstract In this paper, an evaluation model is constructed to evaluate the new talent cultivation model of liberal arts under the OBE concept by analyzing the steps and ways of the model. The system of talent cultivation is determined by establishing the sample value and the whitening weight function of the gray class, and the system indicators are represented using the gray clustering weights, clustering coefficients, and clustering vectors. Then the system indexes are processed, and a multi-level DEA model is introduced on the basis of the gray clustering talent cultivation evaluation system. Finally, the multi-level gray clustering talent cultivation comprehensive evaluation model was constructed. The evaluation of the talent cultivation model is B=(0.4, 0.51, 0.09, 0, 0), and the overall evaluation result of the talent cultivation model is “excellent” according to the principle of maximum affiliation according to the calculation results.

Modification of extended chemical percolation devolatilization model for application to low-rank coals

For understanding coal gasification reactions, primary pyrolysis reaction is important as the first stage of the gasification reactions. Recently, the authors developed a primary pyrolysis model to predict tar formation behavior by extending the chemical percolation devolatilization (CPD) model which is often used to predict pyrolysis behavior. The extended CPD (Ex-CPD) model predicts gas and tar components as respective chemical species. Consequently, the secondary tar decomposition behavior can be calculated by elementary step-like reaction models. However, some of the coal structure parameters used in the model contradict the 13C NMR data. That is, the molecular weight of the aromatic ring clusters calculated by the original Ex-CPD decreases with the aromatic index obtained by 13C NMR. In this study, this problem was resolved by modifying the calculation procedure to determine the coal structure parameters. The recalculated aromaticity index agreed with that calculated from the 13C NMR data. The modified Ex-CPD model was validated through comparison with coal gasification experiments using a pressurized drop tube furnace. The calculation results successfully described the trend of light gases, soot, and char yield in the experiments.

Imbalanced Clustering With Theoretical Learning Bounds

Imbalanced clustering, where the number of samples varies in different clusters, has arisen from many real data mining applications. It has gained increasing attention. Nevertheless, due to its unsupervised nature, imbalanced clustering is more challenging than its supervised counterpart, i.e., imbalanced classification. Furthermore, existing imbalanced clustering methods are empirically designed and they often lack solid theoretical guarantees, e.g., the excess risk estimation. To solve these important but rarely studied problems, we first propose a novel <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$k$</tex-math></inline-formula> -Means algorithm for imbalanced clustering problem with Adaptive Cluster Weight (MACW), together with its excess clustering risk bound analysis. Inspired by this theoretical result, we further propose an improved algorithm called Imbalanced Clustering with Theoretical Learning Bounds (ICTLB). It refines the weights and encourages the optimal trade-off among per-cluster weights by optimizing the excess clustering risk bound. A theoretically-principled justification of ICTLB is provided for verification. Comprehensive experiments on many imbalanced datasets verify the effectiveness of ICTLB in solving cluster imbalanced problems.

The Effects of Rootstock-Scion Relationships on Yield and Quality in Grapevine cv. Ekşi Kara (Vitis vinifera L.)

Vineyards are usually established by grafting onto vine rootstocks. Vine rootstocks affect the grafted varieties directly or by environmental factors and by changing the physiology of rootstock and scion varieties. There may be great differences in mineral nutrition of grape rootstocks and grape varieties in grafted and nongrafted combinations. The choice of grape variety and vine rootstock for vineyard ecology is vital for the sustainability of viticulture, as they affect the mineral nutrient balances, biotic and abiotic stress tolerances, yield and product quality of grape rootstocks and grafted varieties, and these change with edaphic factors. This study was carried out in ~20 years old vineyards established with vines on their own roots of Ekşi Kara grape variety (Pollinator is Gök Üzüm), which is most used in production in Konya province, and seedlings grafted onto 41B, 110R and Rupestris du Lot rootstocks. The effects of rootstock and scion nutrition were searched. Yield per vine, cluster weight, cluster number, cluster length and cluster width data showed the highest values from vines on their own roots, while the order of grafted combinations changed according to the trait measured. While the differences between °Brix and total acidity (TA) values of berry were significant (p&lt;0.05), differences in pH and must yield were insignificant in grafted and nongrafted combinations. Nutrient contents of leaf and root samples were different compared to grafted and nongrafted combinations. Since our study area is infested with phylloxera (Daktulosphaira vitifoliae Fitch) and rootstock use is obligatory, the order of preference for grapevine rootstocks was 41 B, Rupestris du Lot and 110 R, considering yield and quality characteristics.

Effects of mechanical box pruning intensity on bud development, vegetative growth, and yield components on cv. Cabernet-Sauvignon in Mendoza, Argentina

Mechanised winter pruning is increasingly being used to reduce the high costs of manual pruning. Mechanised pruning is non-selective, and for its optimal application, the definition of pruning intensity is necessary to achieve the target yield and grape quality. Our objectives were to evaluate the effects of three intensities of mechanical box pruning compared to a manual pruning treatment on spur length, the number of retained buds, budburst, shoot growth, and development; yield components and berry composition, and vine balance. Treatments corresponded to three mechanical pruning intensities leading to different bud loads at the beginning of the experiment by pruning at different distances from the cordon (i.e., box size): MP1 (1 cm height × 7 cm width), MP2 (14 cm × 14 cm), and MP3 (21 cm × 21 cm). MP2 treatment was also compared to a traditional manual pruning treatment (SP) that was pruned to the same bud/plant in the first season. In the first season, MP2 retained the same bud/plant as SP, but in the second and third seasons, MP2 retained 88 % and 100 % more buds/plant than SP, respectively. Accordingly, MP2 and SP showed no difference in yields in the first season, but in the second season, MP2 showed a 39 % higher yield than SP. Regarding the intensity of mechanical pruning, after treatments were applied, the number of retained buds increased as box size increased. Treatments modified the length of spurs, budburst percentage and their pattern. In the first season, the yield on the highest box (MP3) was four times higher than the smallest box (MP1), but they showed similar yields in the second season. The intensity of mechanical box pruning, applied after two seasons, generated regulatory and compensation mechanisms (i.e., lower budburst and cluster weight), leading to similar yields independently of the pruning intensity. Our results show that (i) after two seasons, mechanical pruning was more productive than manual pruning, and (ii) mechanical pruning intensity had a marked influence on yield only during the first year of application, while some compensation mechanisms among yield components equilibrate yield afterwards.

Effect of Spraying with Micro-Elements, Gibberellic Acid and Salicylic Acid on Some Yield Traits of Date Palm CV. Khastawi.

The study was conducted in one of the private palm orchards in the Euphrates district on date palm trees (CV. Khastawi) aged 30 years to find out the response of the date palm cultivar Khastawi to spraying with micro-elements at concentrations (0, 1 g L-1 ) and symbolized by (M0 and M1), and spraying with gibberellic acid at concentrations (0, 100, 200 mg L-1 ) and symbolized by (G0, G1, and G2) respectively, and spraying with salicylic acid in concentrations (0, 100, 200 mg L-1 ) and symbols symbolized by (S0, S1, S2) respectively. 54 trees were selected as homogeneous as possible, and the number of fronds for palms and fruit clusters was unified. All service operations of the orchard were carried out similarly to adding animal manure, pruning, pollination, watering, pest control and other service operations for all experimental units. The results showed that spraying with microelements at a concentration (M1) significantly affected all studied traits except for the non-reducing sugar content of the fruits. It amounted to (10.76 g, 15.63 kg cluster-1 , 125.03 kg palm-1 , 69.37%, 33.78%, 53.61%) this is for the traits (fruit weight, cluster weight, yield, total soluble solids, reducing sugars, total sugars), respectively. Also, spraying with gibberellin showed a significant effect on the traits (fruit weight, cluster weight, yield, total soluble solids), and the treatment (G2) gave the highest values for the traits (fruit weight, cluster weight, yield), with 10.53 g, 15.46 kg cluster-1 , 123.71 kg palm-1 , respectively. At the same time, treatment (G0) achieved the highest value of total soluble solids (67.50%). On the other hand, salicylic spraying did not significantly affect the studied traits, except total soluble solids and reducing sugars. The concentration (S2) showed the best values for the two traits, with 67.59% and 34.36%, respectively. The two-way interactions between the study factors showed a significant effect that varied according to the type of trait and the interaction factors. Whereas the three-way interaction between the study factors reached the level of significance in all the studied traits. The most significant effect of the interactions was achieved according to the type of trait and the interacting factors, while the control treatment showed the lowest values of most of the traits. Keywords: Date palm, Micro-elements, Gibberellic acid, Salicylic acid, yield.

A clustering-based method for large-scale group decision making in the hesitant fuzzy set environment

The hesitant fuzzy set (HFS) has received wide attention because it can neatly describe the fuzziness and hesitancy of decision information with several possible values. Hence, this paper proposes a clustering-based method for resolving large-scale group decision making problems with HFSs. Considering the different risk attitudes of decision makers (DMs), a new score function of hesitant fuzzy elements (HFEs) is defined by introducing weight factors of all possible values. According to the scores of attribute values, a neighborhood-based approach is put forward to detect and process abnormal evaluations that may influence decision results. Afterwards, a two-stage clustering approach along with three algorithms is presented to cluster DMs into sub-groups. The first stage clusters DMs with finite possible cluster numbers based on the supporters of each DM and the separations between DMs. In the second stage, according to intra and inter-differences among DMs, an index is introduced to evaluate clustering results and select the best cluster number from the finite ones given in the first stage. Finally, by fusing the information densities and cluster sizes, cluster weights are determined and ranking values of alternatives are generated by aggregating evaluation information of the alternatives. At length, a case study is provided to illustrate the applications of the proposed method. Furthermore, the experiments and comparative analyses are conducted to show the effectiveness and superiority of the proposed method.

Mean-Field Approximations With Adaptive Coupling for Networks With Spike-Timing-Dependent Plasticity.

Understanding the effect of spike-timing-dependent plasticity (STDP) is key to elucidating how neural networks change over long timescales and to design interventions aimed at modulating such networks in neurological disorders. However, progress is restricted by the significant computational cost associated with simulating neural network models with STDP and by the lack of low-dimensional description that could provide analytical insights. Phase-difference-dependent plasticity (PDDP) rules approximate STDP in phase oscillator networks, which prescribe synaptic changes based on phase differences of neuron pairs rather than differences in spike timing. Here we construct mean-field approximations for phase oscillator networks with STDP to describe part of the phase space for this very high-dimensional system. We first show that single-harmonic PDDP rules can approximate a simple form of symmetric STDP, while multiharmonic rules are required to accurately approximate causal STDP. We then derive exact expressions for the evolution of the average PDDP coupling weight in terms of network synchrony. For adaptive networks of Kuramoto oscillators that form clusters, we formulate a family of low-dimensional descriptions based on the mean-field dynamics of each cluster and average coupling weights between and within clusters. Finally, we show that such a two-cluster mean-field model can be fitted to synthetic data to provide a low-dimensional approximation of a full adaptive network with symmetric STDP. Our framework represents a step toward a low-dimensional description of adaptive networks with STDP, and could for example inform the development of new therapies aimed at maximizing the long-lasting effects of brain stimulation.

A diagnosis method for imbalanced bearing data based on improved SMOTE model combined with CNN-AM

Abstract A boundary enhancement and Gaussian mixture model (G) optimized synthetic minority oversampling technique (SMOTE) algorithm (BE-G-SMOTE) is proposed to improve diagnostic accuracy under imbalanced bearing fault data conditions. It is designed to solve the problem that the diversity of samples generated by the original SMOTE model is limited, as well as the deep learning model is limited by the size of training samples and processing speed. Firstly, a few bearing fault data are clustered by G to achieve cluster division. Secondly, according to the cluster density distribution function designed in this paper, the weights of different clusters and sample weights to achieve intra-class balance are determined and data quality is improved. Then, to take full advantage of the limited fault data, based on the sensitivity of the support vector machine (SVM) to imbalanced data, the enhanced boundary is established between generated data and the SVM classifier under different penalty factor (PF) values. According to the accuracy, the optimal PF is determined, and fault datasets satisfying diversity are obtained. To improve the classification accuracy, a convolutional neural network with an attention mechanism is built. Finally, analysis using two practical cases shows the effectiveness of the proposed method.

Production of silicon nanoparticles and surface modification through photochemical nanocatalysis reaction

In this research, a novel method for manufacturing silicon (Si) nanoparticles (NPs) has been proposed. The process involves the use of ultraviolet (UV) irradiation and acrylic acid (AA) to induce Si NPs-AA polymerization. Si particles of varying sizes and an AA dispersion solution were subjected to UV radiation, leading to the formation of Si NPs coated with AA polymer, which separated to the top due to the volume increase. The Fourier-transform infrared (FT-IR) spectra confirmed the reaction between Si and AA by verifying the peak positions of the newly formed Si–C bond. The physical and chemical particle size measurements revealed that the Si NPs were surrounded by short-chain AA polymer clusters, accounting for approximately 15% of the cluster weight. Moreover, the Si particles' oxidation temperature in the Si NPs-AA cluster significantly decreased to about 450 °C. This technology holds promising potential for use in luminescent semiconductor materials, as it enables the selective separation of Si NPs.

Effect of foliar calcium and nitrogen treatments on yield and fruit quality of table grapes cv. ‘Cardinal‘

The foliar fertilization has been used as an important agrotechnical measure to avoid deficiencies and to improve quality. During the three consecutive years, a study has been performed on Vitis vinifera L. (cv. ‘Cardinal’) to examine whether a yield and grape berry quality have been affected by the foliar application of Ca and N fertilizers. A liquid mineral fertilizer containing 40% Ca(NO₃)₂ as Variant I and 31% N with 0,015 % Fe-chelate; 0,01 % Mg – chelat as Variant II (in text) has been sprayed four times during the growing period (before and after blooming, buckshot berries, and verasion). Results showed that foliar application of calcium and nitrogen increased the yield of table grapes in all three years of research, in comparison with a control variant. The highest yields of grapes in all three years of investigations were achieved in Variant II – 4.57 kg/vine (14.85 t/ha). During the tree years of investigations, the largest mass of grape bunch and berries were recorded in Variant II (382g and 368.68g), while the lowest cluster weight was in the control variant (344g and 330.92g). With a reference to the mechanical properties of the grape berries, the highest resistance to pressure (2229.70g) and breaking resistance (364.52g) were found in Variant I, treated with Ca fertilizer. The foliar application significantly affects the mechanical properties (resistance of the berry to pressure and breaking), especially in Variant I. The application of different types of foliar fertilizers did not have any significant effect on sugar contents and total acids, compared with the control variant.

A comparison of Nine Grape Vitis vinifera L. Cultivars Growing in Iraq’s Kurdistan Region in Terms of Their Vegetative Growth and Physicochemical Traits

This research was conducted in 2022 to evaluate nine grape cultivars Mkyaj (Manicure finger), Sheery (Riesling), Yaghute-Rash (Moon drops black seedless), Superior (Superior sugraone), Super-Kamale (Super Kamali), Ukraine (Pinot noir), Kakawi (Pecorino), Bokhur (Bhokri) and Gulawi (Gulab) which were chosen from Shar-Bazher, Sitak, Sulaimani governorate, Kurdistan region, Iraq. The purpose of this research was to compare growth and physio-chemical characteristics of the nine cultivars grape. The results showed that there were differences amongst cultivars in terms of the characteristics studied, in term of leaf area cm2 and number of berries cluster−1 Sheery cultivar is over-topped, and firmness followed by Super-Kamali cv. which recorded the highest value for chlorophyll content index (CCI), the weight of 100 berries, weight pulp of 100 berries, and size of 100 berries. Gulawi cultivar had the highest weight of seed berry−1 and the diameter of berries was significantly overtopped. The Superior cultivar was significantly superior to other cultivars regarding weight of cluster. The results showed the cultivar of Sheery obtained the maximum values of total sugar percentage and total phenolic (mg 100g−1 FW), with 16.839 %, and 335.794 mg 100g−1 FW, respectively. Gulawi cultivar gave a higher value of TTA% and TSS% with (0.912% and 20.833%). Yaghute-Rash cultivar achieved maximum values of pH and anthocyanin (mg 100g−1 FW), 3.570 and 96.359 mg 100g−1 FW respectively. While the Ukraine cultivar gave the maximum values of ascorbic acid mg 100g−1 FW with 756.176 mg 100g−1 FW. Mkyaj and Superior cultivars gave a higher value of juice and moisture content with (82.833% and 84.252%).

PHYSICOCHEMICAL EVALUATION OF THE GRAPE AND WINE OF THE BLATINA, TRNJAK AND VRANAC IN DIFFERENT VINTAGES

Typicality and style of wine are closely related to the varietal character of grapes, ecological properties of the locality, and the specificities of the winemaking process. For this reason, autochthonous and indigenous grape varieties are increasingly the subject of many studies. To protect their uniqueness, in the region of Hercegovina (Bosnia and Herzegovina), indigenous grape varieties are part of the current grape and wine production. Therefore, the subject of a two-year study (2018-2019) were indigenous wine varieties: Blatina, Trnjak, and Vranac. Variations in the values of the analyzed parameters were a consequence of the significant and/or highly significant influence of the variety and year. Blatina stood out from other varieties with the highest average cluster weight (364.90 g) and the highest wine color intensity (10.71). Trnjak had the highest total anthocyanin content in the grape skin and total polyphenol content in the grape seeds (1090.198 mg/kg grapes; 1755.195 mg/kg grapes), while Vranac had the highest polyphenol content in the grape skin (1823.961 mg/kg grapes), the highest TSS level (21.55% Brix), and consequently, the highest alcohol content in the wine (12.07% v/v).

Berry shattering phenomena in vineyards: The influence of maximum temperatures during flowering period in an extreme year

Phenological stages, vine yield, and quality of grapes are increasingly affected by extreme temperature conditions caused by climate change. This study aimed to investigate the impact of high temperatures over 40 °C at the flowering period of cv. Sultana Seedless (Vitis vinifera L.) vineyards on the berry shattering problem. A total of 79 vineyards were examined in the western region of Türkiye, and a level of berry shattering (0–4) was defined rapidly to determine the extent of the damage caused by high temperatures. When the two years were compared, it was found that the flowering period was eight days shorter in the first year due to the high temperatures. The study found that the berry shattering problem was more severe in the first year than in the following year among vineyards in Saruhanli, Yunusemre, and Ahmetli locations. High temperatures during the flowering period in the 2020 growing season had a more significant impact on vine yield, resulting in more berry-shattering problems compared to the second year. However, the overall number and weight of clusters increased by between 15.15%-39.52% and 20.51%-42.49% in all locations respectively, under seasonal norms in the following year. Two-year analyzes made in the same vineyards revealed that high temperatures during the flowering period are more effective than the subsequent year, affect the yield of the vines, and more berry shattering problems occur. This study also recommended that the maximum temperatures be examined during specific days and hours during the flowering period, as well as the duration of exposure. Temperatures above seasonal norms can decrease yield and cause berry shattering.

Combined treatment with gibberellic acid and thidiazuron improves fruit quality of ‘Red Dream’ grape cultivar

This study was conducted to investigate the effect of treatment conditions of plant growth regulators on the marketability of ‘Red Dream’, a triploid grape. In order to achieve the purpose of this study, gibberellic acid 3 (GA3) 100 ppm single use treatment group was set as a control group. In addition, the fruit characteristics expressed when cytokinins such as thidiazuron (TDZ) or forchlorfenuron (CPPU) 2.5 ppm or 5.0 ppm mixed with GA3 100 ppm were compared with the control group. Cluster weight was commonly higher in the mixed treatment of TDZ or CPPU than in the GA3 single use treatment, and it was found that the cytokinin mixed treatment could effectively induce the enlargement of ‘Red Dream’ berries. Although the harvesting period was slightly delayed compared to GA3 single use treatment in the case of mixed treatment of GA3 and TDZ or CPPU, there was no inhibition of coloration, soluble solid sugar content and functionality, which are important indicators of marketability. In particular, in the GA3 100 ppm + TDZ 5 ppm treatment group, where the enlargement of fruits was the largest, the occurrence rate of non-commercial berry was also found to be the lowest. Therefore, it is expected to contribute to strengthening the marketability of ‘Red Dream’ if such plant growth regulator treatment condition is applied during cultivation.

Performance of ‘Chambourcin’ Winegrape on 10 Different Root Systems in Southern Missouri, USA

In the midwestern United States, especially Missouri, winegrape (Vitis sp.) growers mostly plant interspecific hybrids, which are well adapted to the climate and pests of the region. ‘Chambourcin’ (an interspecific French-American hybrid) is one of the most widely planted winegrape cultivars in the area. It is usually grown as own-rooted (nongrafted) vines because the economic and horticultural benefits of grafting this cultivar to rootstocks have not been well developed. Further, few significant winegrape rootstock evaluations have been conducted in the midwestern United States, including evaluations of newer rootstocks developed and released by private and public breeding programs. The aim of this study was to assess the potential value of using rootstocks in ‘Chambourcin’ production in southern Missouri, with implications for the midwestern United States. Fruit yield, vine growth, and fruit composition metrics from ‘Chambourcin’ on 10 different root systems [own-rooted, and grafted to rootstocks ‘Couderc 3309’, ‘Couderc 1616’, ‘Paulsen 1103’, ‘Sélection Oppenheim 4’, ‘Millardet et de Grasset 420A’, ‘Millardet et de Grasset 101-14’, ‘Kingfisher’, ‘Matador’ (all Vitis sp.), and ‘Gloire de Montpellier’ riverbank grape (Vitis riparia)] in an experimental vineyard in southwest Missouri were compared. Following three establishment years (2008–10), data were collected across four growing and vintage seasons (2011–14). Yield components evaluated included total fruit production, clusters per vine, cluster weight, berry weight, weight of cane prunings, and crop load. Petiole mineral analysis was conducted in 2011, 2013, and 2014. Grape juice attributes measured were soluble solids concentration, juice pH, titratable acidity (TA), potassium (K), anthocyanins, tannins, phenolics, and organic acids. When simply comparing grafted vs. ungrafted vines, grafting generally induced higher plant vigor and a higher pH in the juice, whereas the other parameters did not differ. When the performances were compared among the 10 root systems, vines grafted to ‘Couderc 3309’ had higher yields compared with vines grafted to six other rootstocks and own-rooted vines. Grafting to ‘Millardet et de Grasset 101-14’ induced higher cluster weight compared with the other rootstocks. The ‘Millardet et de Grasset 420A’ rootstock promoted a higher pH and TA as well as a higher concentration of K in the juice, and ‘Paulsen 1103’ also promoted high pH, TA, and malic acid in the juice, and higher concentrations of phosphorous (P) and K in the petiole compared with most rootstocks. ‘Gloire de Montpellier’ induced a lower P content in the petiole and a higher tartaric/malic acid ratio. Rootstock use can strongly influence some vineyard production metrics as well as nutrient uptake and K levels in the juice (the latter further influencing juice pH). The results of this study provide insights into the complex viticultural and enological interactions resulting from the use of rootstocks in hybrid winegrape production in Missouri, USA.

Diallel analysis of yield and its components in processing hot pepper (Capsicum chinense Jacq.)

ABSTRACT Capsicum chinense Jacq. plays a pivotal role in imparting pungency and flavour to cuisines in the Caribbean. Despite its popularity, hot pepper production in the region has declined. A major constraint has been the low yields associated with cultivation of uncharacterised landraces, high cost of production and poor profitability. Although breeding high yielding varieties has been recognised as critical to expanding production and profitability, it has been impeded by the limited understanding of yield components and their genetics. The objective of the study was to understand the inheritance of yield, yield components and partitioning components. Progenies of a 9 - 9 half diallel mating design were evaluated in an open field experiment in a randomised complete block design with three replications. Considerable genetic variation was observed for all 12 yield components except for flowers per node. Diallel analysis revealed predominance of non-additive genetic effects for most yield components except fruits per cluster, clusters per plant and reproductive efficiency. The narrow sense heritability for clusters per plant, fruits per cluster, reproductive efficiency, harvest index and shoot dry weight was moderate to high, but was low for yield, fruit number and average fruit weight. Breeding methods to improve yield are discussed.