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Bambusa rigida was investigated to study the growth changes under different treatments, dynamic changes of non-structural carbohydrates (NSC) in the mother and new bamboos during rapid growth, and their correlation. In this study, we aimed to understand NSC supply from mother to new bamboos, optimize forest stand structure and harvesting methods, and reveal inherent rules of bamboo rapid growth. The aim of this study was to investigate the NSC supply pattern from mother bamboo to new bamboo, aiming to optimize stand structure and harvesting methods and provide insights into the rapid growth dynamics of bamboo. Two harvesting modes were implemented:retaining 1-year-old female bamboo (treatment Ⅰ) and retaining 1-and 2-year-old female bamboo (treatment Ⅱ), with non-harvested hard-headed yellow bamboo clumps serving as the control (CK) . This study analyzed bamboo shoot characteristics, bamboo formation, and biomass across different harvesting modes, comparing quantitative and qualitative changes in bamboo growth among the three treatments. The study examined dynamic changes in NSC content and water content in leaves, branches, culms, and roots of female bamboos during five critical growth stages of hard-headed yellow bamboo. This aimed to explore the supply-demand relationship of NSC between female bamboos and new bamboos at different developmental stages. Results showed that the reproduction rate of hard-headed yellow bamboo varied across treatments, with treatmentⅠ＞treatmentⅡ＞CK. Conversely, bamboo formation rate and new bamboo biomass were higher in CK＞treatmentⅡ＞treatmentⅠ, demonstrating significant differences between treatment Ⅰ and CK, and treatment Ⅱ (P＜0. 05), with no significant differences observed between CK and treatment Ⅱ. New bamboos originating from 1-year-old parent bamboos in different treatments exhibited the largest diameter at breast height, with their shoots, bamboo formation, and biomass accounting for over 90%of the total. During the rapid growth phase from shoot sprouting to growth cessation, NSC content in new bamboo generally increased initially before decreasing, peaking during rapid internode growth. NSC content in all organs of mother bamboo decreased gradually with age, with branches, leaves, culms, and roots of treatment Ⅰmother bamboo decreasing by 49. 70%, 54. 05%, 39. 85%, and 60. 86%, respectively, which were higher than those in treatmentⅡ's 1-year-old and 2-year-old female bamboos, with non-significant differences observed between the decreases of each organ in treatmentⅡ's 1-year-old and 2-year-old female bamboos. Correlation analysis indicated significant positive correlations between starch content in leaves, roots, and culms of treatmentⅠmother bamboo and NSC content, as well as between starch content in leaves, roots, and branches of 1-year-old mother bamboo and roots and culms of 2-year-old mother bamboo in treatmentⅡ (P＜0. 05) . In harvesting operations of hard-headed yellow bamboos, removing female bamboos aged 3 years and older while retaining 1-and 2-year-old female bamboos effectively enhanced bamboo forest productivity and reproductive capacity. Different harvesting treatments significantly influenced NSC transfer from parent bamboo to new bamboo. Specifically, when only 1-year-old mother bamboo was present, starch transfer to new bamboo primarily involved leaves, culms, and roots. When 1-and 2-year-old mother bamboos were present together, starch transfer involved branches, leaves, and roots of 1-year-old mother bamboo, with additional NSC transport from 2-year-old mother bamboo to new bamboo originating from 1-year-old mother bamboo. Thus, retaining 1-and 2-year-old mother bamboos during harvesting and management of hard-headed yellow bamboo forests is crucial to ensure sufficient nutrient supply during the rapid growth phase of new bamboos. [ABSTRACT FROM AUTHOR] more...

Soil loss due to surface water erosion is one of the degradation processes that most affects the physical quality of the soil and produces the largest area of degradation worldwide. This study compared soil loss in two methods of harvesting sugarcane for panela production, considering factors such as rainfall intensity, slope of the land, and time of plant growth. It was observed that the moment just after harvesting is when the greatest differences between cutting methods occur, the loss of soil being greater when harvesting by "parejo" than when harvesting by "entresaque". As the crop develops, this difference decreases, and soil loss is more influenced by the intensity of precipitation. Finally, the measurements made after cutting were compared with a soil condition without vegetation cover, where it was observed that soil losses in crops already established with sugarcane were notably lower concerning this condition. This study establishes the importance of leaf mulch as a soil protection factor in sugarcane crops for panela. [ABSTRACT FROM AUTHOR] more...

Copyright of Mustafa Kemal University Journal of Agricultural Sciences / Mustafa Kemal Üniversitesi Tarım Bilimleri Dergisi is the property of Mustafa Kemal University, Faculty of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) more...

Coffee is a stimulant crop with high socio-economic cultural value including economical significance in Ethiopia. This study was conducted in 2019-2020 to investigate the effect of harvesting methods and drying surfaces on the physical quality of the coffee beans. The experiment was carried out with two factors, harvesting methods and drying surfaces laid out in a two factorial completely randomized block design with three replications using a landrace coffee variety. The result showed that the interaction of harvesting methods and drying surfaces was highly significant (P more...

In view of the problem of plant entanglement threshing roller in the process of mechanized flax harvesting, a comb-brush air-suction composite flax capsule harvesting test stand was designed based on the harvesting method of harvesting capsules independently and then breaking the capsules to thresh them. The following four parameters were selected as experimental factors: the shape of comb tooth cross-section, the rotational speed of comb roller, the relative speed of machine travel and the air volume of centrifugal fan. The following four indicators were chosen as the experimental indicators: capsule removal rate, capsule breakage rate, capsule collection rate and plant winding rate. A four-factor and three-level orthogonal test was conducted. The results showed that the optimal combination of test factors was as follows: the shape of comb tooth crosssection was rectangular, the rotational speed of the brush roller was 90 rad/min, the speed of machine travel relative to the plant was 80 mm/s and the air volume of centrifugal fan was 6000 m3/h. Under the condition of better experiment parameters combination, the capsule removal rate was 96.45%, capsule shell breaking rate was 98.79%, capsule collection rate was 95.65% and flax plants winding rate was 2.52%. The comb-brush airsuction composite flax capsule harvesting test bench provided the feasibility scheme for the problem of plant winding thresher roller and capsule collection. [ABSTRACT FROM AUTHOR] more...

In eastern China, on the southern end of the Yangtze Valley, early Holocene hunter-gatherers were foraging various plants, including wild rice – Oryza rufipogon Griff. – an aquatic and perennial plant which is the wild progenitor of domesticated rice. According to optimal foraging theory, these foragers should have tried to enhance the efficiency of harvesting wild rice seeds by draining water around the plants before seeds ripened and shattered. This proto-cultivation practice led to unintended consequences given that wild rice responds to drought stress owing to its phenotypic plasticity. Plant and panicle architectures were modified with transitions to more compact and erect tillers and to a closed panicle shape. They provide incentives to early foragers for intensifying their proto-cultivation practices and so could have also triggered initial cultivation of rice. They also triggered incipient domestication of rice, starting by the transition to selfing. According to this narrative, it is even possible that rice incipient domestication preceded cultivation. [ABSTRACT FROM AUTHOR] more...

The aim of this paper is to determine how different harvesting methods of olives and the waiting period before the extraction of the extra virgin olive oil affect the viscosity and some thermal properties, namely thermal conductivity and thermal resistivity. Olive trees in the Aegean region of the western part of Turkey were harvested by using six different harvesting methods: by hand, harvesting by a beating pole on a synthetic fabric, harvesting by a beating pole on a platform, harvesting by machine on a synthetic fabric, harvesting by machine on a platform and direct collecting of dropped olives by hand. Olive oil samples were obtained in certain intervals between the harvesting and processing that was made by using a laboratory type system. The viscosity values of oil samples were measured by using a vibro-viscometer. The thermal conductivity and thermal resistivity of oil samples were measured simultaneously by using the KD2 Thermal properties analyzer. As a result, viscosity, thermal conductivity and thermal resistivity values changed related to the harvesting method and the waiting period after harvesting to obtain olive oil. While viscosity (dynamic) and thermal conductivity values increased with the increase of the waiting time, thermal resistivity values decreased. The lowest viscosity and thermal conductivity values and the highest resistivity values were found for oils that were obtained from olives harvested by hand. more...

BACKGROUND Traditionally, peppers (Capsicum annuum L.) of Jaranda variety used for the production of smoked paprika are harvested manually in the north of Extremadura (Spain). Mechanical harvesting is necessary to improve the profitability of this crop. The present study aimed to evaluate the effect of plant density (D1 = 36 765 and D2 = 73 530 plants ha−1) and harvesting type (manual or mechanical) on the yield and quality of fresh, dried and powdered peppers. RESULTS: The increase in plant density increased marketable yield per hectare, although the yield per plant decreased. With mechanical harvesting, the optimal density was D2 (15 151 kg ha−1) over D1 (12 493 kg ha−1). After processing the fruits, the application of D2 and mechanical harvesting significantly improved quality parameters, such as a*, ASTA (American Spice Trade Association) units and carotenoide concentration, primarily capsanthin. CONCLUSION: The cultural practices tested provided an adequate productivity of fresh pepper and a better quality of the final product. According to the results of the present study, the increase in plant density and the substitution of manual harvesting by mechanical harvesting could be profitable practices with respect to the Jaranda variety of pepper used for the manufacture of smoked paprika. These practices maintain the main quality parameters of dried peppers and paprika. © 2018 Society of Chemical Industry [ABSTRACT FROM AUTHOR] more...

Maize and wheat are two of the most widespread crops worldwide because of their high yield and importance for food, chemical purposes and livestock feed. Some of the residues of these crops (i.e., maize cob and wheat chaff) remain in the field after grain harvesting. In Europe, just maize cob and grain chaff could provide an annual potential biomass of 9.6 Mt and 54.8 Mt, respectively. Collecting such a biomass could be of interest for bioenergy production and could increase farmers’ income. Progress in harvest technology plays a key role in turning untapped by-products into valuable feedstocks. This article presents a study of the performance and the quality of the work of Harcob, an innovative system developed for maize cob collection. Furthermore, the feasibility of using the Harcob system to also harvest wheat chaff during wheat harvesting was also verified. The results showed that it was possible to harvest 1.72 t ha−1 and 0.67 t ha−1 of cob and chaff, respectively, without affecting the harvesting performance of the combine. The profit achievable from harvesting the corn cob was around 4%, while no significant economic benefits were observed during the harvesting of wheat chaff with the Harcob system. The use of cereal by-products for energy purposes may allow the reduction of CO2 from fossil fuel between 0.7 to 2.2 t CO2 ha−1. The Harcob system resulted suitable to harvest such different and high potential crop by-products and may represent a solution for farmers investing in the bioenergy production chain. more...

This work assesses the costs of exploiting the biomass feedstock chaff. Chaff is a harvest residue generated during the conventional grain harvesting process and usually remains on the field. In this paper, the costs of collecting and supplying chaff to the end user with different harvesting methods and supply chains are analyzed. The costs are estimated for a base case defining a set of general assumptions. The impact of these assumptions is analyzed in a sensitivity analysis by means of tornado diagrams. A full costing method based on the VDI guideline 2067 part 1 is applied for the cost estimation. The cost analysis reveals that ceasing the fractioning of grain, straw and chaff during harvesting and transporting them as a mixture reduces the harvesting costs significantly. The costs are decreased due to a reduction in agricultural operations and processing large amounts of material. The lowest total costs originate from the production of chaff-straw bales. Harvesting chaff as a single fraction leads to the highest costs with the investigated supply chains. Comparing the costs of chaff supply to potential revenues shows that an exploitation of the harvest residue can be economically feasible. more...

The aim of this paper is to determine how different harvesting methods of olives and the waiting period before the extraction of the extra virgin olive oil affect the viscosity and some thermal properties, namely thermal conductivity and thermal resistivity. Olive trees in the Aegean region of the western part of Turkey were harvested by using six different harvesting methods: by hand, harvesting by a beating pole on a synthetic fabric, harvesting by a beating pole on a platform, harvesting by machine on a synthetic fabric, harvesting by machine on a platform and direct collecting of dropped olives by hand. Olive oil samples were obtained in certain intervals between the harvesting and processing that was made by using a laboratory type system. The viscosity values of oil samples were measured by using a vibro-viscometer. The thermal conductivity and thermal resistivity of oil samples were measured simultaneously by using the KD2 Thermal properties analyzer. As a result, viscosity, thermal conductivity and thermal resistivity values changed related to the harvesting method and the waiting period after harvesting to obtain olive oil. While viscosity (dynamic) and thermal conductivity values increased with the increase of the waiting time, thermal resistivity values decreased. The lowest viscosity and thermal conductivity values and the highest resistivity values were found for oils that were obtained from olives harvested by hand. [ABSTRACT FROM AUTHOR] more...

Concentrating methods generally affect the vitality of the microalgae and may alter its feeding and environmental effect. This article studied the concentrating methods (centrifugation and settlement) on primary productivity of the microalgae Cylindrotheca fusiformis. The effects of free settled C. fusiformis, centrifuged C. fusiformis and macroalgae Sargassum polycystum on growth of the sea cucumber, farming water and sediment quality under two light intensities (1500 lx and 500 lx) were studied by a six-week rearing experiment. The results showed that the primary productivity of free settled C. fusiformis was 3-4 times higher than that of those centrifuged, indicating centrifugation inhibited the photosynthesis process. In the rearing experiment, feed, light intensities and their interactions significantly affected the specific growth rate ( SGR) of the animals ( P < 0.01). The animals reared in higher light intensity also had higher SGR, but only those fed free settled C. fusiformis reached a significant level ( P < 0.05). The group also had the highest SGR ( P < 0.05), suggesting that the photosynthesis ability of C. fusiformis directly contributed to the growth of the animals. During the experiment, the soluble inorganic nitrogen, reactive phosphorus in farming water, total nitrogen and total organic carbon in the sediment gradually increased in all treatments. The S. polycystum group had slightly higher level of nutrients in water and sediment at the end of the experiment for its high organic content. These results provide evidence that the harvesting methods of C. fusiformis directly affect its vitality, which consequentially alter the feeding and environmental effect, especially under higher light densities. [ABSTRACT FROM AUTHOR] more...

The growing demand for naturally-synthesized fucoxanthin has driven increased focus on microalgae-based production methods. However, the high costs associated with microalgae harvesting and processing remain a significant challenge. To overcome this obstacle and promote the development of the microalgae-based fucoxanthin industry, this study aimed to develop an efficient and cost-effective methods for harvesting Phaeodactylum tricornutum , a promising microalgal strain for fucoxanthin production, while maximizing the reuse of the culture medium. This study investigated the feasibility of reusing the FeCl 3 -based flocculation medium for P. tricornutum cultivation, and explored the optimal proportion of recycled supernatant and fresh medium for maximizing biomass and fucoxanthin yield of P. tricornutum. It also examined the effect of residual iron on harvested biomass and pigment and proposed a simple washing method for its removal. The results showed that FeCl 3 -based flocculation was highly effective (>93 %) in harvesting P. tricornutum , and a 50/50 proportion of recycled medium and fresh medium can be used without significant negative effects on biomass and fucoxanthin productivity, allowing a reduction of approximately 43 % water consumption. Although a negative effect on algal fucoxanthin content was observed, the productivity of fucoxanthin per unit volume (mg/L) did not decrease compared to centrifugation-based algae cells. Furthermore, simple washing with water can effectively remove the residual iron from the harvested biomass or pigment, resulting in a reduction of approximately 42 % and 64 %, respectively. These findings suggest that the reuse of FeCl 3 -based flocculation medium for P. tricornutum cultivation is feasible and holds promise for cost-effective fucoxanthin production. This study contributes to develop a sustainable approach for microalgae-based fucoxanthin production at a lower cost and higher production capacity, benefiting both society and industry. [Display omitted] • FeCl 3 was highly effective (>93 %) in harvesting P. tricornutum. • FeCl 3 flocculation slightly decreased fucoxanthin content but not biomass yield. • Recycling 50 % of flocculated medium affected biomass and fucoxanthin yield little. • Reusing flocculated medium is feasible for P. tricornutum fucoxanthin production. [ABSTRACT FROM AUTHOR] more...

The wide range of microalgae applications has increased in the last decade, due to their importance as the source of biofuel and biomass. The potential of wastewater as a culture media lies in the presence of high contents of nutrients and elements required to improve the growth of microalgae and, thus, the high quantity of biomass. However, these properties might be the limitations in the harvesting of microalgae biomass from wastewater. This review discussed the potential of wastewater as the production media for biomass and focused on the harvesting methods, because it represented a major challenge in the quality and quantity of microalgal cells. It can be concluded that among several technologies used for harvesting microalgae biomass from wastewater, the natural flocculant method was the most efficient due to the absence of toxic by-products and secondary effects on the quality of biomass yield, as well as the high biomass quantity. [ABSTRACT FROM AUTHOR] more...

Low cell concentrations of Dunaliella salina in production scale cultivations require high energy input for biomass harvesting. Flocculation is a potential preconcentration method to lower the dewatering costs for the β -carotene production. In the present study, optimal flocculant dosages were determined for several metal salts, NaOH, Ca(OH) 2 and Al-electrolysis. Beside harvesting efficiency η H and concentration factor CF , also the recyclability of the separated medium as well as the influence of the cell physiology on the harvesting performance were analyzed for selected flocculants. To assess the possible recycle of non-sedimented cells for the inoculation of new cultivations, cell vitality and the photosynthetic activity of D. salina were analyzed after the flocculation. As a result, the flocculation with NaOH led to a clear inhibition of both, the algal growth on recycled medium and the algal photosynthetic activity. The addition of FeCl 3 seems most promising to flocculate D. salina . [ABSTRACT FROM AUTHOR] more...

A new evaluation concept to assess microalgal harvesting methods was introduced using β -carotene production with Dunaliella salina as a case study. Detailed experiments were conducted, analyzing different effects caused by the first harvesting step. As harvesting methods, centrifugation and flocculation by electrolysis, addition of aluminium sulfate (alum), ferric chloride or pH increase via NaOH were considered. A special focus was set on the influence of the harvesting method on interlinked units of the whole process system. Thereby, the samples harvested by NaOH flocculation negatively affected the reusability of the separated medium for cultivation and the efficiency of β -carotene extraction. Furthermore, a process model was developed to estimate the overall process energy demand and the operating costs based on the experimental data. In the case of D. salina centrifugation without flocculation was identified as the most cost effective harvesting method. In consequence, the here developed concept provides a general platform to evaluate the quality of microalgal harvesting procedures in a reliable manner. [ABSTRACT FROM AUTHOR] more...

In the Tunguavita experimental farm of Universidad Pedagógica y Tecnológica de Colombia there is a 10 years old variety Rubidoux peach crop with 1500 plants in 4 has which has yield fruit loss that increases every year. Because of this situation the research group CERES conducted a study to estimate the loss of peach during the harvest of 2013 and they could determine its percentages at harvesting, as well as the identification of the principal causes. The study ended with the estimation in market prices of the loss of the fruit harvest. This was the reason to make the tracking from the first day of the harvest until it ended through 6 weeks. A precise methodology with the selection of a sample (150 trees) was established, and a system of fruit harvesting was planned describing the methods, times and movements of harvesters, the fruit harvesting, the manipulations and the handling of the fruit, and the movements of the harvesters in the crops (Montavez, 2003). Each day of harvesting data was taken which was later organized, analyzed and discussed. As a result, it was found that loss of the fruit during harvesting was about 14.1%, which means 13.510 kg while harvested fruit corresponds to 94.480 kg with an average yield of 23.87 tons per ha. The causes that led to the losses were: inadequate manipulation, incidence of plagues and diseases, birds peck, and overripe fruit. All this aspects take to find fruit with physical, mechanical and physiological damage. [ABSTRACT FROM AUTHOR] more...

The study was conducted in the apiculture post of INIAV, Hunting Reserve Aid, Superior Institute of Agronomy, having as objective the evaluation of propolis, over a period of 60 days, in full flowering season. Were selected and standardized twenty colonies of Apis bees in hives installed melifera iberiensis model "Lusitanian". Analyses were performed from biological cycle and the colonies were classified, by estimated, by direct observation, the number of bees from the colony, and the percentage of honey and pollen create present. Overall, the assessments made, the colonies found themselves strong and healthy. Propolis was collected using mosquito net type and evaluated every two weeks. At the end of the test proceeded to cleaning the propolis, the networks were frozen during a 48 hours period and quantitated propolis obtained. The total production of propolis were quite disparate, among hives on average 65.4 ± 19.4 g, a value which is in line with the literature. Overall, mean values were obtained at higher production colonies with greater strength, although the genetics of each colony was an important aspect in the production of propolis. The mosquito type network used proved to be inefficient in the removal of propolis, having managed to get only 23.8% of propolis produced. [ABSTRACT FROM AUTHOR] more...

A Rubidoux peach crop of 10 years of age, and 1,500 plants in 4 ha is located in the Experimental Tunguavita's farm at Universidad Pedagógica y Tecnológica de Colombia which has had loss of fruit increasing every year. Because of this situation, the CERES research group developed a study to estimate the loss of peach during the harvest of 2013, when it was possible to determine its pecentages at harvesting and to identify its main causes. The study was completed with the valuation in market prices of the loss of the harvest. To do this, a tracking from the first day of harvesting until it ended through 6 weeks was carried out. A strict methodology with the selection of samples (150 trees) was established, the system of harvesting was planned, describing the methods, times and movements of harvesters, the harvesting of the fruit, manipulation and handling of the fruit, and also the movement of the harvesters in the crop (Montavez, 2003). Data was recorded every harvesting day which were organized analyzed and discussed later. As a result it was found that the loss of peaches during harvesting was about 14.1%, which corresponds to 13,510 kg while harvested fruit corresponds to 94,480 kg with an average yield of 23.87 tons per ha. Inadequate manipulation, incidence of plagues and diseases, birds peck, overripe fruit were the causes of the loss and are the aspects leading to find physical, mechanical and physiological damage. [ABSTRACT FROM AUTHOR] more...

Numerous in vitro ruminal fermentation techniques have been developed to estimate forage digestibility. However, these methods are costly, time consuming, and require access to fistulated animals. This study aims to develop predictive models for in vitro ruminal organic matter digestibility (IVOMD) from pasture chemical components (CP, NDF, ADF, ADL, cellulose and hemicellulose) by examining the relationships between chemical composition and IVOMD of tropical pastures harvested at ground level (G-L) or by hand-plucking (H-P) during the dry, intermediate and wet season in Jamaica. Relationships were determined using simple linear and multivariate forward step-wise regression procedures. Selection of the best approximating multivariate models was done by finite Akaike Information Criterion. Chemical components were better predictors of IVOMD in the dry season than in intermediate and wet seasons. Dry season ADF was the best single predictor of IVOMD (R2 = 0.76). Crude protein accounted for 63.8% of variability of IVOMD during the dry season; 30.8% and 11.5% higher than in the intermediate and wet seasons, respectively. Neutral detergent fiber (R2 = 0.60 - 0.63) was consistently a moderate predictor of IVOMD across seasons. Hemicellulose poorly predicted IVOMD. Crude protein was the best single parameter for predicting IVOMD of G-L harvested herbage, but, with low accuracy (R2 = 0.31). Multivariate models improved the prediction accuracy of IVOMD. The best approximating models for dry, intermediate and wet season IVOMD prediction were; Y= 992 - 0.61ADF + 0.99CP - 1.24ADL - 0.32NDF, Y= 1306 - 0.81NDF - 0.46ADF + 0.83CP - 1.39ADL and Y=1211 - 1.02NDF + 0.90CP - 1.10ADL, respectively. The optimum predictive models for G-L and H-P harvested herbage were; Y= 1225 + 1.05CP - 0.75NDF - 0.73ADF and Y= 1093 - 0.70NDF = 0.78CP - 0.40ADF, respectively. It was concluded that the accuracy of predicting IVOMD from chemical components was greatest during dry season. [ABSTRACT FROM AUTHOR] more...

Beverages derived from wild plant species play an important role in local and traditional food systems in rural communities such as in the Vhembe District, South Africa. Conducting research on such foodstuffs may help to prevent loss of indigenous knowledge on potential dietary sources for needy households. Through surveys and focussed group discussions, 41 different beverage-making plant species were identified. Traditional beverage making processes are of three types. Preparing teas involve a boiling process while juices are manually extracted following overnight soaking of the fruit pulp mixture. Brewing traditional beer usually requires a spontaneous fermentation process lasting 2–3 days. [ABSTRACT FROM AUTHOR] more...

Microalgae have shown tremendous potentials as a feedstock for biofuel productions. Nevertheless, microalgae utilization is not economically sustainable mainly due to the high cost of harvesting. Among existing technologies, mechanical-based harvesting methods are considered the most effective means of microalgae recovery because these methods are highly reliable in separating suspended cultures from the growth medium, and they require no additives. To further advance these technologies in broader areas, a comprehensive review that covers the performance, limitations, and associated costs of these methods is needed. This review presents an inclusive assessment of all mechanical-based methods, particularly centrifugation and filtration, with a complete evaluation of their economic facets. The mechanical-based methods are used as a single-step harvesting process or as a sequence of operations for increased harvesting efficiency. This study reveals that centrifugation offers the utmost cell removal efficiency in a timely manner while having the highest capital and operational cost demands (2.18 $ k g produced oil). Conversely, the sedimentation process is comparatively inexpensive (0.3 $ k g produced oil) and is ideal as the initial step to reduce the load on the following steps, although it is a lengthy process. Flotation has to be utilized in conjunction with filtration to complete cell removal, and it may not be suitable for all agal cultures due to the necessity of chemical additives. The use of these additives essentially increases the maintenance requirements. • An inclusive assessment of all mechanical-based methods for microalgae harvesting is presented. • Economic facets of all mechanical-based methods are discussed. • Centrifugation offers the utmost cell removal efficiency while having the highest cost demands. • Sedimentation is comparatively inexpensive and ideal as a preliminary step to increase concentration. [ABSTRACT FROM AUTHOR] more...

The yield loss during the process of harvesting is a great challenge in rice production. A suitable harvesting time and harvesting method can help to reduce the yield losses of rice, and decisions about the harvest date have important implications for labor management as well as for agricultural machinery scheduling. Nonetheless, the comprehensive composition of timeliness harvesting loss (THL) and its changing rules for different harvesting methods remain poorly understood. The objective of this study was to determine the effect of harvest date and mechanical harvesting methods on grain dry matter timeliness loss (GDMTL) and mechanical timeliness losses (MTL) of rice in the cold region. To this end, the field experiment was conducted from 45 days after heading (45 DAH) to 59 days after heading (59 DAH), adopting a full-feeding and semi-feeding combine harvester (FCH and SCH) from 2019 to 2020. The results showed that harvest date had a significant effect on GDMTL and four kinds of MTL including header timeliness loss (HTL), cleaning timeliness loss (CTL), un-threshed timeliness loss (UTTL), and entrainment timeliness loss (ETL, only under FCH). With the prolonged harvest date, the HTL and CTL increased and the UTTL and ETL decreased, which ranged from 0.15–0.31%, 0.36–0.67%, 0.72–0.18%, and 0.69–0.31%, respectively for FCH. For SCH, the variation range of HTL, CTL, and UTTL was 0.41–0.59%, 0.66–0.98%, and 0.64–0.21%, respectively. The GDMTL increased first and then decreased, ranging from 2.84–0.87%. The mechanical harvesting methods had no significant effect on the GDMTL of rice, but the MTL could be large between FCH and SCH. In general, optimal harvest period was 52 DAH~53 DAH for both harvesting methods, which exhibited the highest yield and the lowest loss, i.e., 9269.3 kg/hm2 and 1.70%, respectively, and the mechanical operating mode on different harvest dates was recommended to minimize the mechanical loss. The optimal harvest date for rice in a cold region ensured both quality and quantity for mechanized harvesting, and provided a reference for the reasonable allocation of operating harvesters in the harvesting season. [ABSTRACT FROM AUTHOR] more...