Canopy Diameter Research Articles

Estimating coffee crop parameters through multispectral imaging and machine learning algorithms

Abstract. Brazil plays a crucial role in the global economy due to its significant contribution to the agricultural sector, particularly in coffee production, where it stands out as the largest producer and exporter of processed coffee. Various disturbances can influence coffee plants, causing abnormalities that can hinder their successful growth. Parameters such as plant height and canopy diameter play an essential role in assessing the health and productivity of the plants, reflecting their growth, development, and ability to capture sunlight. Additionally, height is also related to the balanced distribution of nutrients and water, providing valuable information about overall performance and the capacity for healthy production. In this regard, the application of methodologies involving remote sensing and machine learning algorithms has shown promising results in the rapid and safe acquisition of information about agricultural systems. This study evaluates different machine learning algorithms, using radiometric values from multispectral images obtained by remote sensing platforms as input datasets for estimating plant height and canopy diameter in coffee cultivation. The best performance was observed for architectures that showed lower RMSE and RMSE% values. For the plant height parameter (m), the RGB sensor exhibited the best performance using the Random Tree algorithm, with an RMSE (0.27) and RMSE% (8.80). For the canopy diameter (m), the sensor showed the best performance using the Random Forest algorithm, with an RMSE (0.15) and RMSE% (8.16).

Sources and splitting of special fertilizers application in coffee crop

This study assesses special and mineral fertilizers and the splitting of fertilizer application in coffee - a crop with high nutritional requirements for full yield potential. A 4 × 3 factorial scheme was implemented with four fertilizers [mineral, mineral with polymer, organomineral with cellulosic residue (OM-CR), or sugarcane filter cake (OM-FC)] and three application times, or splits (100% at once, 50%+50%, 33.3%+33.3%+33.3%). Coffee plant height, canopy diameter, plagiotropic branch growth, leaf chlorophyll, nutrient contents in the soil and leaves, and harvest yield after fruit maturation were evaluated in two consecutive crop cycles. The results indicated that organomineral fertilizers performed similarly to other fertilizers regarding coffee leaf chlorophyll and plant height. Only one fertilizer application effectively increased canopy diameter in both crop cycles. In the first crop cycle, OM-FC and conventional mineral fertilizers were significantly better for coffee foliar N content. In contrast, in the second crop cycle, mineral-P, OM-CR, and OM-FC achieved satisfactory results with one fertilizer application, whereas conventional mineral fertilizer required three applications for superior results. There are no differences in leaf P content among different sources and frequencies of application. Still, mineral-P and OM-CR had better soil P content than the conventional mineral fertilizer. OM-CR required two applications to reach high levels of leaf K content, while other fertilizers achieved it with one application. Organomineral and protected mineral fertilizers performed similarly in both crop cycles, with two applications resulting in greater coffee yield in the second cycle, regardless of the fertilizer used.

Impact of organic mulch and exposure to shallow groundwater levels on Cnidoscolus aconitifolius in a tropical wetland, South Sumatra, Indonesia

Agricultural land in Indonesia is decreasing due to its conversion for various non-agricultural interests, which are economically more profitable. The remaining land available for agricultural activities is a suboptimal wetland. The reduction in cultivable areas has led to the evaluation of alternative crops in suboptimal land conditions. Chaya (Cnidoscolus aconitifolius) is a fast-growing perennial plant, its leaves are edible and rich in vitamins, minerals, and dietary fiber. However, the chaya plant has not been intensively tested for its adaptation to shallow groundwater tables in tropical lowlands. This study aimed to assess chaya’s adaptability to shallow groundwater table conditions and the benefits of using organic mulch. This research consisted of two separate parts, one part was related to organic mulch benefits (planting media without watering, with organic mulch but not watered, and with organic mulch and watering), while the other one was related to shallow groundwater table tolerance. The study followed a randomized complete block design consisting of three replications. Results showed that chaya plants negatively responded to the shallow groundwater table conditions. Growth retardation due to shallow groundwater levels is reflected in the averages of leaf length, leaf width, leaf area, canopy diameter, and canopy area; fresh and dry weight of stem, petiole, and leaf blade; development of roots; SPAD value at 7 weeks after transplanting and it was based on visual appearance. However, despite the increase in substrate humidity due to the application of organic mulch, the effects were not significant on most of the measured morphological traits. In conclusion, chaya plants are not able to adapt to shallow groundwater levels and do not require organic mulch on the soil surface.

Biostimulant application and green basil biomass production

The aim of this study was to evaluate the influence of the use of the biostimulant Stimulate® on the biomass production of green basil. A randomized block design was used, in a 5x2 factorial scheme with six replications, analyzing different concentrations (0, 5, 10, 15 and 20 mL L-1 of water) and application method (single application and split into 2 times). Harvesting was performed 60 days after transplanting. The variables evaluated were plant height, counting of the number of secondary and tertiary shoots, root length and volume, fresh and dry matter mass, leaf area and essential oil yield. There was no interaction between the concentrations of Stimulate® and the application method. However, there was an increase in all variables analyzed with the concentration of 20 mL per L of water. The application of the biostimulant Stimulate® had an effect on biomass production, plant height, canopy diameter, secondary and tertiary shoots, length and volume of the root system, fresh matter mass of the aerial part and root. Increases in these variables were also observed in response to increased concentrations of Stimulate® and accumulation of green basil essential oil.

Chasing Cool: Unveiling the Influence of Green-Blue Features on Outdoor Thermal Environment in Roorkee (India)

Urban environments in humid subtropical climates, like Roorkee, India, often experience high summer temperatures and uncomfortable outdoor thermal conditions. However, the impact of green-blue landscape configurations on cooling intensity (ΔTa) and outdoor thermal comfort (OTC) is insufficiently understood. This study, conducted in Roorkee during summer 2022, assessed the effect of green-blue landscape configurations on OTC using Physiological Equivalent Temperature (PET) and mean radiant temperature (Tmrt). PET values ranged from slight to extreme heat stress, with statistically significant differences in cooling intensity across varied landscape configurations. Tree shaded canal front locations registered lower Ta (1.6°C) and Tmrt (9.3°C). Similarly, shaded canal front locations registered 4.7°C lower PET than sun-exposed locationsDifferent tree species showed significant variation in ΔTa, with the highest cooling effect (maximum average ΔTa of 3°C) occurring during the morning hours. Notably Morus alba and Mangifera indica yielded the highest cooling effect, outperforming artificial and mixed shade. Eucalyptus alba, on the other hand, registered adverse comfort conditions. Denser tree canopies and attributes - canopy diameter, leaf area index, and height were strongly correlated to improved cooling performance.Additionally, increasing pervious surfaces and tree cover within 100 m of intervention areas enhanced cooling, with significant effects noted within a 25–50 m radius. This study highlights the role of green-blue infrastructure, particularly the combination of low sky-view factor (SVF), dense canopy trees, and proximity to water, in reducing heat stress. These findings offer crucial insights for climate-responsive open space design, particularly in Indian cities facing rampant urbanization and global warming.

Optimizing Soil Moisture, Mulching, and Spacing for Yield and Water Productivity in Irrigated Elephant Foot Yam (Amorphophallus paeoniifolius)

Aims: To standardize crop spacing and irrigation requirements under different mulching situation for better yield and water productivity. Study Design: The experiment was designed in RBD with two replications. Place and Duration of Study: The experiment was conducted at Agronomic Research Station, Kerala Agriculture University (KAU), Chalakudy for three consecutive years from 2016 -17, 2017 – 18 and 2018 – 2019. Methodology: Study conducted with 18 treatments, includes three levels of irrigation, three types of mulching and with two different crop spacing. Observations on weed count and weed dry matter production were also taken to study the effect of different mulches on weed growth. Biometric observations of crop growth and yield were recorded. Results: Observations on biometric characters revealed that both the height and diameter of the crop canopy were significantly influenced by mulching and found to be highest in the plot where leaf was used as the mulching material and the yield of Amorphophallus during 2016 - 2017 showed that corm weight was greatly influenced by irrigation levels, mulching and spacing. Corm yield was lowest in the plot where irrigation frequency was once in three days (21.02 t/ha). Yield in leaf mulched plot was 38.11 t/ha while in plastic mulched and no mulched plots were 23.50 and 19.50 t/ha. Effect of treatments on water productivity and BC ratio showed that leaf mulching of the crop has significant effect. In leaf mulched plot, water productivity in 2016-17 was 2.03 while it was only 1.854 and 0.886 in 2017-18 and 2018-19. Similarly, BC ratio was highest for leaf mulched plot followed by no mulch and plastic mulch plot. Conclusion: The experimental results from 2016 -17, 2017 – 18 and 2018 – 2019, showed that Amorphophallus planted at a spacing of 90 cm x 90 cm, irrigated at a frequency of once in three days along with leaf mulching can increase the yield and water productivity along with effective control of weed population.

Climatic Variations Influenced Distribution and Productivity of Different Agroforestry Systems in Rajasthan, India

Farmers of Rajasthan conserve and promote scattered trees and shrubs growing on farmlands to dealwith climatic adversities. These woody perennials sustain livelihoods by providing economic, social, and environmental benefits. Tree-based farming systems were surveyed in all 10 agroclimatic zones (ACZs) of Rajasthan for screening best models and suggests for further improvement. Trees were assessed for density, and growth parameters in 0.5 ha plots, whereas agricultural crops yields were estimated in1 m2 plots laid at 1 m from tree trunk, canopy edge and 5 m away from trees canopy (control). There were 107 tree-crop combinations involving 14 trees and 21 crop species. P. cineraria-based systems were dominant in the arid western, whereas A. nilotica dominated in semi-arid to dry sub-humidregions. Average tree density was 11.7 trees ha-1 ranging from 3.3 tree ha-1 in ACZ-IIIb to 23.6 tree ha-1 in ACZ-IIa. Senegalia senegal showed highest (27.6 tree ha−1) density. Height and canopy diameter were 11.73 m and 10.35 m respectively, in irrigated ACZ- IIIb and decreased to 6.53 m and 5.02 m in ACZ-IIb, respectively. Both height and density decreased with the decrease in rainfall from south-east to north-west. D. sissoo and T. grandis were taller, S. oleoides was thicker and Z. mauritiana was shorter and thinner than other species. Grain yields varied from 0.66 in ACZ-Ia to 1.85 Mg ha-1 in ACZ-IIIa, but exhibited low yield as compared to control. Crop yield reduced by 22.9-47.3% between ACZs, 20.3-56.5% between agroforestry systems, and 15.9-79.8% between intercrops highlighting the interactive effects of these components. S. senegal, T. undulata, P. cineraria, Z. mauritiana, S. oleoides, V. tortilis and P. juliflora based systems showed 29.1-54.9% low, whereas V. nilotica, D. sissoo, A. indica, T. grandis and V. leucophloea based systems showed 4.5-51.7% high yield over the state average. The yield of groundnut (IIIa), cotton (IVa), barley (IIIa), jowar (IVa), maize (IVa), paddy (V), pearl millet (IIIa) and wheat (V) with A. nilotica was above state average

Grazing and precipitation addition interactions alleviate dominant species overgrowth and promote community productivity and biodiversity in a typical steppe

Grazing and precipitation are pivotal factors influencing the productivity and biodiversity of grassland ecosystems, largely through their effects on the growth and reproduction of dominant species. Approximately 50 % of terrestrial ecosystems are concurrently affected by grazing and precipitation addition (PA), yet the interactive effects of these factors remain underexplored. To elucidate the combined impacts of grazing and PA on the growth of dominant species and their influence on community structure and function, we initiated a four-year combined grazing and PA experiment based on a long term of grazing experiment in a typical steppe. The synergistic interaction between PA and grazing enhanced canopy diameter (CD), tiller density (TD), and seedling density (SD) in dominant species, while decreasing reproductive branch density (RB). Conversely, an antagonistic interaction increased plant height (PH) and TD but reduced SD. These responses suggest that dominant species adapt to combined grazing and PA pressures by shifting growth strategies towards lateral growth and asexual reproduction. The growth characteristics of dominant species exhibited four response patterns to grazing and PA interactions: full saturation, sufficient saturation, equal saturation, and deficit saturation, each with three corresponding thresholds: adaptation, optimum, and saturation points. Grazing decreased the precipitation response thresholds for PH, CD, RB, and population density, while increasing the optimal points for TD and SD. These changes in the growth of the dominant species resulted in a 33 % reduction in the aboveground biomass (AGB) of the community and triggered a 18 % increase in the coupling index between AGB and species richness within the community. Our findings highlight the role of dominant species in facilitating community adaptation to increased precipitation and rotational grazing, offering critical insights for developing sustainable grazing strategies under climate change.

Morphological Diversity in Litchi Based on Tree and Leaf Characteristics

On the basis of tree and leaf characteristics, twenty litchi genotypes were evaluated to select promising genotypes. Numerous differences have been observed between the genotypes. The genotypes KT-1 and GC-2 recorded the highest (5.35 m) and lowest (4.50 m) height, respectively. The girth was greatest for the genotype KD-1 (63.01 cm) and lowest for the genotype GC-2 (49.99 cm). The genotype DP-2 had the smallest canopy diameter (5.29 m) and the genotype KS-1 the greatest (6.40 m) among the ones investigated. In GC-2 and KT-1, the plant volumes ranged from 20.35 m3 to 26.79 m3. Leaf exhibited a great deal of variability among them, nine genotypes showed vivid pink in their new leaves, whereas eleven genotypes showed yellowish green. Comparably, the colour of the leaves varied among the genotypes; nine had dark green, whereas eleven had green. Nine genotypes showed a downward curve from the midrib, whereas eleven genotypes showed an upward curve. According to an analysis of the number of leaflets on each compound leaf, Shahi had the most (7.24), while GC-1 had the fewest (6.16). The longest rachis measured 11.10 cm in KD-2 and the shortest 9.75 cm in GP-2. The genotype DT-1 exhibited the smallest petiole length, while the genotype KS-1 had the longest. The length of the leaflets varied significantly between genotypes, ranging from 10.86 cm (KD-1) to 13.81 cm (China). The genotype DP-2 had the shortest breadth (3.70 cm), while genotype KD-1 had the widest (4.36 cm). The genotypes GC-2, GP-2 and KD-1 can be promoted in close spacing orchard.

Optimal Light Intensity for Lettuce Growth, Quality, and Photosynthesis in Plant Factories.

In agriculture, one of the most crucial elements for sustained plant production is light. Artificial lighting can meet the specific light requirements of various plants. However, it is a challenge to find optimal lighting schemes that can facilitate a balance of plant growth and nutritional qualities. In this study, we experimented with the light intensity required for plant growth and nutrient elements. We designed three light intensity treatments, 180 μmol m-2 s-1 (L1), 210 μmol m-2 s-1 (L2), and 240 μmol m-2 s-1 (L3), to investigate the effect of light intensity on lettuce growth and quality. It can be clearly seen from the radar charts that L2 significantly affected the plant height, fresh weight, dry weight, and leaf area. L3 mainly affected the canopy diameter and root shoot ratio. The effect of L1 on lettuce phenotype was not significant compared with that of the others. The total soluble sugar, vitamin C, nitrate, and free amino acid in lettuce showed more significant increases under the L2 treatment than under the other treatments. In addition, the transpiration rate and stomatal conductance were opposite to each other. The comprehensive evaluation of the membership function value method and heatmap analysis showed that lettuce had the highest membership function value in L2 light intensity conditions, indicating that the lettuce grown under this light intensity could obtain higher yield and better quality. This study provides a new insight into finding the best environmental factors to balance plant nutrition and growth.

PRODUCTION AND QUALITY OF Physalis peruviana FRUIT APPLYING DIFFERENT DOSES OF SIMPLE SUPERPHOSPHATE IN THE SOUTHERN REGION OF MINAS GERAIS, BRAZIL

The present study aimed to investigate and determine the most relevant fertilization levels of Simple Superphosphate to increase fruit production and improve fruit quality for fresh consumption. The experiment was conducted at the EPAMIG Experimental Field in Lambarí, Minas Gerais, from September 2021 to November 2022. Five fertilization levels were tested: 150 grams/plot, 300 grams/plot, 600 grams/plot, and 1200 grams/plot, along with a control group (no fertilization). A significant increase in fruit production was observed at the higher dose (1200 grams/plot) compared to the control, representing a 54.06% increase in fruit production. Additionally, the total fresh biomass production increased by 19.43%, the number of primary and secondary branches per plant increased by 48.99%, the branch length increased by 4.26%, and the canopy diameter increased by 6.83% when compared to the control. All these characteristics were significantly different at the 95% confidence level according to the Scott-Knott test. We concluded that 300 grams/plot was the best fertilization dose to achieve higher production and acceptable quality.

The inclusion of cereal crops with maize and soyabean rotations impacts the morphology and phenology of Amaranthus tuberculatus

AbstractSimple crop rotations like maize and soyabean grown in succession often coincide with simple weed management tactics, resulting in weed infestations that are highly adapted to the conditions maintained for the selected crops. Amaranthus tuberculatus is a prominent weed species which possesses biological characteristics that allow it to persist in maize–soyabean rotations. Spring wheat and oats emerge earlier than A. tuberculatus and are grown in narrower rows than maize and soyabean, which may increase their competitive capability. A field study which measured morphological and phenological characteristics of three A. tuberculatus cohorts that emerged under fallow, maize, soyabean, spring wheat and oats was conducted to compare their competitive ability. Early emerged A. tuberculatus grew similarly in fallow, maize and soyabeans and grew to heights of >150 cm but was significantly reduced in spring wheat and oats, never exceeding 40 cm. Heights of the last emerged cohorts were more influenced by crop canopies never reaching 15 cm in spring wheat and oats compared to >70 cm in fallow. Early emerged A. tuberculatus canopy diameter and branches plant−1 were reduced by >80% in spring wheat and oats compared to fallow. Flowering was delayed in spring wheat and oats compared to fallow and seed production and biomass were reduced by 99% across cohorts. Growth suppression of A. tuberculatus, based on the findings, can be achieved under dense, competitive crop canopies such as in spring wheat and oats and these crops should be considered as additional crops in maize–soyabean rotations.

Growth response of dominant species and companion species to grazing and precipitation addition in a typical steppe

Growth strategies of plant populations plays an important role in biodiversity and productivity of community while over half 77% of global terrestrial ecosystem is used for grazing and simultaneously 30%-40% is exposed to precipitation addition (PA). However, the combined effects of grazing and PA on plant population growth and their relationship with community characteristics remain poorly understood, largely due to the limited number and quality of field experiments. Hereby, a four-year PA experiment was conducted in long-term grazed paddocks in a typical steppe, which aimed to compare the effects of both grazing and PA on the growth, reproduction, and trade-offs between dominant and companion species. The interaction between grazing and PA prompted the dominant species to adopt a horizontal growth strategy and sexual reproduction, allocating 69 % of its resources to offspring production, whereas the companion species opted for a vertical growth strategy and asexual reproduction, allocating 87 % of its resources to individual survival and dispersal. This trade-off strategy increased the proportion of dominant species while companion species remained stable, and PA mitigated this trend while concurrently decreasing the proportion of other species within the community. The interaction between grazing and PA promotes the coupling of aboveground biomass and species riches in community by decreasing plant height of dominant and companion species and increasing canopy diameter of companion species. There were mainly four biotic response curves of dominant and companion species to grazing and PA interaction: full saturation, sufficient saturation, equal saturation, and deficit saturation. Correspondingly, there were three pairs of threshold values for three phases of each pattern. Our study reveals how communities improve their adaptability by regulating population growth, providing important insights for developing sustainable grazing management strategies under global climate change.

Optimizing Peat and Wood Fiber Blends: Impacts of Liming and Fertilization on Growth of Petunia (Petunia x hybrida Vilm.) and Basil (Ocimum basilicum L.)

This study investigated the effects of substrates composed of various ratios of wood fiber and peat (0, 25, 50, 75, and 100% peat (v/v)) mixed with different amounts of lime (0, 2, 4, 6, and 8 g L−1) and start fertilizer (0, 2, and 4 g L−1 Multimix) on the growth and biomass accumulation of petunia (Petunia x hybrida Vilm ‘Finity F1 Purple’) and basil (Ocimum basilicum L. ‘Marian’) in an ebb-and-flow greenhouse system. Growth parameters included plant height, weight, canopy diameter, and chlorosis symptoms for petunia, along with substrate pH and EC measurements. Petunia showed optimal growth in substrates with higher peat content, while basil produced satisfactory biomass across a pH range of 5–7 regardless of substrate type. Optimal petunia cultivation in 100% wood fiber required a significant dose of start fertilizer without lime. Monitoring pH and EC using pour-through and press methods revealed a pH decrease in substrates with added start fertilizer, while substrates with higher wood fiber content were less acidic. Substrates with over 50% (v/v) wood fiber without lime showed a rapid pH increase over five weeks. The pour-through method generally underestimated EC values compared to the press method. These findings contribute to optimizing the wood fiber/peat blends for sustainable horticulture.

Non-composted and blended agro-industrial by-products an as alternative soilless substrate affect potted zonal geranium (Pelargonium x hortorum) and murva (Murraya paniculata) production

Due to their hiking prices and import restrictions, peat moss and coco coir are not readily available in many developing countries including Pakistan. Therefore, it is necessary to explore alternative soilless substrates having low cost and comparable physico-chemical properties with peat moss and coco coir for local and global market. For this purpose, indigenous agro-industrial by-products, viz., sesame straw, date palm coir, sugarcane pressmud, sugar beet waste and pine bark were collected, cleaned, crushed (where needed) and blended for physico-chemical analyses. Zonal geranium ‘Pinto White’ and murva (Murraya paniculata Kaneh.) were used to evaluate the efficacy of various combinations of substrates on plant growth and production. Three experiments were conducted with six treatments of each experiment replicated three times. Blending of sesame straw with sugarcane pressmud and pine bark (4:4:2 by volume) yielded best results and marketable plants were produced with tallest height (35.8 cm), canopy diameter (20.8 cm), leaf area (29.2 cm2), leaf total chlorophyll contents (62.1 SPAD) and flowers per plant (5.0 No.) along with shortest production time (103 days). Same results were recorded when murva plants were grown in 4:4:2 blending of sesame straw, sugarcane pressmud and pine bark. Zonal geranium and murva plants did not perform well when sesame straw was blended with date palm coir and sugar beet waste. Blending of sesame straw with sugarcane pressmud and pine bark had low pH (7.0), electrical conductivity (1.37 mS cm-1), bulk density (0.29 g cm-3) while high water retention (34.7 %) as compared to other blended substrates. However, shrinkage of substrates in containers was highest (7.7 %) when sesame straw was blended with sugarcane pressmud and pine bark in 5:3:2 followed by 4:4:2. pH value of all blended substrates decreased at termination except when sesame straw, sugarcane pressmud and pine bark were blended in 4:4:2 and 5:2:3, which was increased from 7.0 to 7.1. Electrical conductivity of all blended substrates was decreased at termination of the experiments. It can be concluded that blending of sesame straw, sugarcane pressmud and pine bark in 4:4:2 (v/v/v) significantly improved physico-chemical characteristics of substrates as well as plant growth and production attributes of zonal geranium and murva. Therefore, this indigenous soilless substrate, which is cheaper and readily available to nurserymen can be used as alternative of peat moss and coco coir for containerized plant production.

Assessing the effects of urban green spaces metrics and spatial structure on LST and carbon sinks in Harbin, a cold region city in China

In the face of accelerated urbanization, urban green spaces (UGSs) are crucial in alleviating urban heat island effects. This study investigates the link between UGS landscape patterns, plant community characteristics, Land surface temperature (LST), and Annual carbon sequestration of plant community (ACSPC) across different seasons and scales in Harbin by remote sensing and field measurements. The results show that (1) The LST in urban built-up areas shows an increasing trend, and its correlation with UGS exhibits seasonal fluctuations. (2) Landscape pattern metrics significantly relate to LST, particularly at 1500 and 1260 m window scales. (3) In summer and winter, Aggregation index (AI) , Mean patch area (AREA_MN), Edge density (ED), Percentage of landscape (PLAND), Mean patch shape index (SHAPE_MN), Mean diameter at breast height (MDBH), Mean canopy diameter (MCD), Average carbon sequestration capacity(ACSC), and Leaf area index (LAI) are positively correlated, whereas Sky view factor (SVF) is negatively correlated with ACSPC. (4) LAI, SVF and MCD (winter) significantly affect LST. MDBH, MCD, and SVF in summer significantly influence ACSPC. This research elucidates the effect of UGS landscape patterns and plant community characteristics on urban heat islands and carbon sinks, providing vital insights for urban ecological improvement.

Identification of SNP Markers and Candidate Genes Associated with Major Agronomic Traits in Coffea arabica.

Genome-wide association studies (GWASs) allow for inferences about the relationships between genomic variants and phenotypic traits in natural or breeding populations. However, few have used this methodology in Coffea arabica. We aimed to identify chromosomal regions with significant associations between SNP markers and agronomic traits in C. arabica. We used a coffee panel consisting of 195 plants derived from 13 families in F2 generations and backcrosses of crosses between leaf rust-susceptible and -resistant genotypes. The plants were phenotyped for 18 agronomic markers and genotyped for 21,211 SNP markers. A GWAS enabled the identification of 110 SNPs with significant associations (p < 0.05) for several agronomic traits in C. arabica: plant height, plagiotropic branch length, number of vegetative nodes, canopy diameter, fruit size, cercosporiosis incidence, and rust incidence. The effects of each SNP marker associated with the traits were analyzed, such that they can be used for molecular marker-assisted selection. For the first time, a GWAS was used for these important agronomic traits in C. arabica, enabling applications in accelerated coffee breeding through marker-assisted selection and ensuring greater efficiency and time reduction. Furthermore, our findings provide preliminary knowledge to further confirm the genomic loci and potential candidate genes contributing to various structural and disease-related traits of C. arabica.

Influence of higher levels of NPK fertilizers on growth, yield, and profitability of three potato varieties in Surma, Bajhang, Nepal

Potato is a crucial food and cash crop with high yield potential in many parts of the Bajhang district. However, achieving optimal yields can be hindered by inconsistent NPK fertilizer application rates and suboptimal potato variety selection, including instances where no fertilizers are used at all by the farmers. To address these challenges and determine the most effective NPK fertilizer rates and potato varieties, a field experiment was conducted in Surma rural municipality of Bajhang district. The experiment utilized a randomized complete block design (RCBD) with three replications, to evaluate the effects of four NPK fertilizer rates (0:0:0, 50:50:50, 100:100:60, and 150:150:90 kg NPK/ha) and three potato varieties (Khumal Seto, Cardinal, and Bajhang Local), on growth, yield, and economic profitability. Statistical analysis, including analysis of variance and Duncan's multiple range test (DMRT), indicated that the highest values for plant height, canopy diameter, number of leaves, number of main stems, tuber weight, fresh weight of leaves and stems, average tuber diameter and number of marketable tubers per hill were consistently observed higher in either the Khumal Seto or Bajhang Local potato varieties. Similarly, these results were particularly prominent with the application of 150:150:90 kg NPK/ha. Economic analysis demonstrated that the Khumal Seto variety showed superior performance in terms of gross benefit, net benefit, and benefit-to-cost ratio (NPR 1,805,714.29, NPR 1,306,168.83, and 3.61, respectively) when compared to other varieties. Similarly, the application of 150:150:90 kg NPK/ha resulted in higher economic returns (NPR 1,645,714.29, NPR 1,129,908.83, and 3.19). In conclusion, using higher levels of mineral fertilizers (150:150:90 kg NPK/ha) with high yielding and well adapted potato varieties such as Khumal Seto and Bajhang Local significantly enhances growth, yield, and profitability in potato cultivation, as demonstrated by the findings of this study.

Effect of Biochar on Dwarf Green Coconut Orchard Yield and Irrigation Water Productivity

ABSTRACT The high irrigation water demand of coconut trees in semiarid regions makes rational use crucial for crop sustainability. Additionally, it produces residues that could improve the soil water holding capacity. This research aimed to evaluate the application of coconut shell biochar to an irrigated dwarf green coconut palm orchard. The study was carried out from January 2019 to December 2021 at Campo Experimental do Curu, Paraipaba, Brazil, belonging to Embrapa Agroindústria Tropical. The experiment consisted of a completely randomized design with five treatments and four replications and included the application of 0, 5, 10, 20, or 40 g of biochar per kg of soil, equivalent to 0.0 kg, 0.5 kg, 1.0 kg, 2.0 kg or 4.0 kg of biochar per plant, respectively. The following biometric variables were evaluated: number of leaves per plant (NL), plant height (PH), number of leaflets per leaf (LFT), canopy diameter (CD) and fruit production: number of bunches per plant (NB), number of fruits per plant (NF), volume of coconut water per fruit (CWF) and total soluble solids (TSS) (°Brix), as well as the daily soil moisture average. The results showed beneficial effects on the number of leaves per plant, fruits per plant, soil moisture and irrigation water productivity in terms of liters per fruit, liters per coconut water and fruits per cubic meter (m3) applied with ideal biochar doses estimated to be 1.40 kg, 1.72 kg, 1.79 kg, 1.56 kg, 1.48 and 1.68 kg of biochar per plant, respectively.

The impact of trees on the peak cooling load of detached rural residences

Trees can reduce heat radiation for adjacent farmhouses, achieving cooling and energy-saving effects in summer. However, there is still a lack of research on the quantitative influence of trees’ parameters and their spatial orientation on the cooling load of farmhouses. This knowledge gap hampers the scientific greening of residences from an energy-efficiency perspective and leads to wasted ecological benefits. Taking Gao Hong Town’s residences in China as an example, by comprehensively applying remote sensing technology, frequency statistics, and numerical simulation, the representative tree-farmhouse information model was constructed. The ENVI-met software was used to simulate and extract the temperatures of external walls under 54 scenarios. The Radiant Time Series Method (RTSM) was then used to calculate peak cooling load with trees under different scenarios. Sensitivity analysis indicates that trees on the south side have the most significant impact on the disturbance rate of peak cooling load of trees to farmhouses (PCLTD), reaching up to 4.4 %, followed by the west, east, and north sides with PCLTD of 1.6 %, 1.1 %, and 0.8 %, respectively. According to the sensitivity of the minimum distance between wall and tree canopy (DW-T) to PCLTD, the 1 m-5 m range of DW-T can be divided into three zones: high-sensitivity (1 m-2 m), medium-sensitivity (2 m-4 m), and low-sensitivity (4 m-5 m).For trees on the south side with leaf area density (LAD) of 1 m2/m3, 2 m2/m3, and 3 m2/m3, the corresponding PCLTD are 3.4 %, 4.4 %, and 4.9 %; for Diameter of Tree Canopy (DC) of 5 m, 7 m, and 9 m, the respective PCLTD are 4.4 %, 6.2 %, and 8.3 %.To maximize the energy-saving effects of trees on farmhouses, it is recommended that the DW-T for trees on the south be less than 3 m, and for trees on the west and east, less than 2 m.These findings support optimizing tree planting strategies adjacent to rural residences in China from an energy-saving perspective, contributing to the improvement of thermal environments and the assessment of energy efficiency.