Fresh Yield Research Articles

Influence of Nutrient Solutions in an NGS® Soilless System on the Yield, Quality and Shelf Life of Fresh-Cut Commercial Mint at Different Harvest Times

The optimal fertilizer concentration for Mentha plants is contingent on the growing systems and harvest time, serving as operational solutions to control and enhance quality and yield. This study aimed to determine the effects of three macronutrients concentration in hydroponic nutrient solution (HNS) during three harvest times on the growth, quality, yield, and shelf life of three mint species (M. spicata L. var. viridis (MV); M. piperita L. (MP); M. spicata L. var. rubra (MR)) grown in a New Growing System (NGS®). Total dry matter (DM), nitrate (NO3−), phosphate (PO43−), and calcium carbonate (CaCO3) concentrations were increased with the addition of higher levels of nutrient fertilization in three species. When the ion concentration of the HNS was increased, total fresh yield decreased. The highest total bacterial count (TBC) was obtained in MR species in the three harvests in all the levels of HNS. The lowest browning potential (BP) and soluble o-quinone (So-Q) levels were observed at second harvest in the MR species with the application of one of the two HNS high in nitrogen (N). In conclusion, the combination of optimal HNS ion concentration and appropriate species is considered essential to obtain suitable yield, quality, and ensure shelf life of mint.

Adaptation of basil to salt stress: Molecular mechanism and physiological regulation

Although many molecular and physiological mechanisms behind plant responses to osmotic and nutritional stresses (primarily salinity) have been identified, the strong impact of genetics makes understanding their interconnections complex. Moreover, the dominant genetic effect often masks other potentially influential factors modulating plant response to environmental stimuli. Using three types of basil (Dark Opal, Italiano Classico, and Purple Ruffles) that have different counteracting potentials to react to NaCl (60 mM) salt stress, we showed that higher constitutive concentrations of osmolytes and antioxidant molecules improve basil adaptation to a saline environment. An already active ROS scavenging mechanism and unaltered NUE allowed Purple Ruffles to remain unaffected by the toxic effects of salt, unlike Italiano Classico and Dark Opal, which incurred fresh yield reduction by 46.34 and 33.33 %, respectively. Up-regulation of secondary metabolism in response to biostimulant treatments (protein hydrolysate and protein hydrolysate+leaf liquid integrator) ensured a higher fresh yield in all basil types, regardless of salt treatment. Understanding the key molecular traits implicated in plant response to salinity is undoubtedly valuable for future genetic improvement programs of tolerant genotypes and for the application of products with biostimulatory and ameliorative action.

Yield and biochemical fruit quality of irrigated peach cultivars subjected to conventional farmer’s fertilization practices in warm production area

Water and fertilization management are the main concerns of farmers in order to achieve an economic yield and high fruit quality. This study evaluates conventional farmer’s fertilization practices in commercial peach orchards (Regueb region) and sets suitable nitrogen (N), phosphorus (P), and potassium (K) supplies to improve yield and fruit quality. Different farmers’ N-P-K supply practices (called FarmNPK) were applied during the different developmental stages of the growing season (S1 budburst and swelling; S2 flowering and fruit set; S3 fruit development; and S4 fruit ripening). Seven cultivars (Flordastar, Plagold5, Plagold10, Plagold15, Plawhite5, Plawhite10, and UFO3) were considered. Depending on cultivars and growth stage, the ranges of total N-P-K supplies were 95–208, 44–84, and 67–103 kg ha−1, respectively. Total fresh yield was quantified, and fruit quality (pomology, phenolic composition, main sugars, and organic acids) was determined in the mesocarp and exocarp. The results revealed that NPK supplies from 95–65–76 to 165–84–103 kg ha−1 induced the highest yield that varied between 50 and 68 kg tree−1, especially with high N supplies during S2. In all cultivars, high N and K supplies in S3 and S4 induced the best weight and fruit size, with the highest total soluble solid content in the fruit, while P supply appeared to be negatively correlated with total sugar content. Analysis of phenolic composition showed that flavan-3-ols varied between 209 and 7114 mg kg−1 DW. In conclusion, the optimum supply of N, P, and K at the appropriate stages, mainly S2 for N supply, and S3 and S4 improved color and ensured appreciable quality.

EVALUATION OF DIFFERENT PASTEURIZATION AND STERILIZATION METHODS FOR OYSTER MUSHROOM SUBSTRATES

Oyster mushrooms can be cultivated with great spatial efficiency, on nutrient-poor plant materials, without light and under diverse climatic conditions. Their production therefore has a great potential for improving food security, especially in impoverished and overpopulated areas. However, the pasteurization or sterilization of mushroom substrates uses a lot of energy and water. This study investigates the impact of different pasteurization and sterilization techniques on the growth and yield of oyster mushrooms, and evaluates their water and energy usage. The efficacy of heat-based methods, including hot water, hot air, and pressurized steam, as well as a chemical method utilizing hydrated lime (Ca(OH)2) were assessed. The results show that sterilizing mushroom substrates through autoclaving can significantly increase the dry yields, up to 50% compared to pasteurization methods. However, pasteurization methods also achieved excellent results compared to untreated substrates, with good harvests and low pest occurrence. The mushroom water content was significantly higher in pasteurization methods where the substrate is submerged in water. In terms of fresh yield, hot water pasteurization was as good as autoclaving and significantly better than the other pasteurization methods. Hot air pasteurization has, on balance, a better water and energy efficiency than autoclave sterilization (about 75 % less energy) or hot water pasteurization (about 85 % less water). When performed at an air temperature of 75° C, which was found to be sufficient for successful mushroom cultivation, as little as 1068 kJ was needed to pasteurize one kg of dry substrate (e.g. maize straw). While hydrated lime pasteurization could use as little as 270 kJ per kg of dry substrate, it is very wasteful of water, as is hot water pasteurization and could lead to nutrient leaking. The success of mushroom cultivation, especially with hot air pasteurization, could also be influenced by the duration of substrate soaking before treatment. The study provides slight evidence, although inconclusive, for a positive effect of prolonged soaking periods on yield. Lastly, the study discusses the applicability of different disinfection techniques at varying production scales and for different mushroom species, focusing on African countries, where comparably small mushroom economies are growing rapidly, but often through the use of unsustainable pasteurization technology.

Estimation of land and manpower needs for year-round supply of green fodder (Super Napier) to dairy cattle through time studies and crop cutting experiments

The present study was undertaken to determine the land and manpower needed for the production of Super Napier fodder for the year-round feeding of dairy cattle present in Livestock Research Station, Mahanandi, Nandyal district, Andhra Pradesh through time studies and crop cutting experiments. The occasional activities of fodder production such as tillage, planting, irrigation and fertilizer application required 113.97 ± 7.31, 35.81 ± 0.98, 8.45 ± 0.31 and 0.56 ± 0.03 man-hours per acre, respectively, while the daily activities of fodder production such as harvesting of fodder, loading of fodder bundles, transport, chaffing and feeding took 5.64 ± 0.19, 1.86 ± 0.11, 0.24 ± 0.01, 0.93 ± 0.06 and 0.34 ± 0.01 man-hours per ton, respectively. Among the tillage operations, weeding required the most time (105.83 ± 6.90 man-hours per acre) and the application of an adjusted cultivator required the least time (0.64 ± 0.07 man-hours per acre). The cutting of planting material into stem cuttings and the harvesting of the planting material consumed the highest (16.52 ± 0.62 man-hours per acre) and lowest (3.97 ± 0.28 man-hours per acre) time, respectively, among the planting operations. There was a significant difference between two labourers of the same age in the application of adjusted cultivator (P < 0.01) and furrow irrigation (P < 0.05). The mean fresh yield of fodder in the farm was 16.73 ± 1.62 tons per acre per harvest or 100.40 ± 9.72 tons per acre per annum. Based on the results, it was concluded that one acre of cultivable land managed by a single person is sufficient for ensuring the year-round feeding of seven dairy animals under Super Napier fodder production.

Study on the genetic variability and adaptability of turmeric (Curcuma longa L.) genotypes for development of desirable cultivars.

Turmeric, a globally cultivated spice, holds significance in medicine, and cosmetics, and is also a very popular ingredient in South Asian cuisine. A study involving 53 turmeric genotypes evaluated for rhizome yield and related traits at Spices Research Center, Bogura, Bangladesh over three years (2019-22). A randomized complete block design was followed with two replications. ANOVA revealed significant trait variations among genotypes. Genotype T0015 emerged as the highest yielder at 28.04 t/ha. High heritability (0.58-0.99) and genetic advance characterized plant height (PH), mother rhizome weight (WMR), primary and secondary finger weights (WPF and WSF), and yield per plant (YPP) across seasons. Genetic gain (GG) was prominent in these traits. Genotypic and phenotypic coefficient variations (GCV and PCV) (6.24-89.46 and 8.18-90.88, respectively) across three years highlighted mother rhizome weight's importance followed by numbers of primary finger (NPF), and WPF. Positive and significant correlations, especially with PH, WMR, WPF, and YPP, emphasized their relevance to fresh yield (FY). Multiple linear regression identified PH, number of mother rhizome (NMR) and WMR as key contributors, explaining 37-79% of FY variability. Cluster analysis grouped genotypes into five clusters with maximum distance observed between clusters II and III. The geometric adaptability index (GAI) assessed adaptability and superiority, revealing nine genotypes outperforming the best existing cultivar. Genotype T0117 as the top performer based on GAI, followed by T0103 and T0094. Mean rank analysis favoured T0121 as the best performer, succeeded by T0117, T0082 and T0106. The top ten genotypes (T0015, T0061, T0082, T0085, T0094, T0103, T0106, T0117, T0121 and T0129) were identified as superior based on yield and overall ranking, warranting further evaluation. These findings may induce a window for improving turmeric research and ultimately play a role in enhancing its cultivation and productivity.

Understanding salinity stress responses in sorghum: exploring genotype variability and salt tolerance mechanisms.

Salinity, a significant abiotic stressor, adversely affects global plant growth. To address this, monitoring genetic diversity within a plant species germplasm for salt tolerance traits is vital. This study investigates the responses of ten sorghum genotypes to varying salt stress levels (control, 60 mM NaCl, and 120 mM NaCl), aiming to assess genetic diversity. Using a randomized complete block design with three replications and a split-plot arrangement, salt treatments were assigned to main plots, and genotypes were placed in sub-plots. Physiological attributes, including photosynthetic rate, stomatal conductance, CO2 concentration, leaf area index, chlorophyll concentrations, and antioxidant enzyme activity, were measured during the 50% flowering stage. Fresh forage yield was evaluated at the early dough stage, while dry forage yield and sodium/potassium concentrations were determined post-drying. Salinity induced 10-23% and 21-47% reductions in forage fresh yield at 60 mM and 120 mM NaCl, respectively, across sorghum genotypes. Forage dry yield also declined by 11-33% at 60 mM NaCl and 30-58% at 120 mM NaCl. Increased oxidative stress markers, proline, soluble carbohydrates, and antioxidant enzyme activity accompanied salinity. Genotypes exhibited diverse responses, with Payam showing significant chlorophyll and yield reductions at 60 mM NaCl and notable stress indicators at 120 mM NaCl. Pegah and GS4 demonstrated robust osmoregulation. In stress tolerance indices, Sepideh excelled at 60 mM NaCl, while GS4 outperformed at 120 mM NaCl. Pegah demonstrated high tolerance at 120 mM NaCl. Our findings highlight the importance of combating oxidative stress, managing water-related stress, and maintaining ionic homeostasis for sorghum's salt stress resilience. Key indicators like K/Na ratio, MDA, MSI, SOD, and proline effectively differentiate between tolerant and sensitive genotypes, offering valuable insights for sorghum breeding. Salt-tolerant sorghum genotypes exhibit stable photosynthesis, improved stomatal function, and membrane integrity through efficient osmotic regulation and robust antioxidant enzyme activity. This capability enables them to sustain performance, minimizing final product loss. The results suggest cultivating salt-tolerant sorghum in saline areas for increased sustainable production, with Pegah and GS4 emerging as promising candidates for further testing in salt-affected environments to obtain reliable yield data.

The effect of light emitting diode (LED) spectrum and light duration on growth and yield of Brassica sinensis L. grown on floating raft hydroponic system

Recent technology in agriculture allows vegetable cultivation in controlled environment by utilizing energy derived from an artificial lighting. Light Emitting Diodes (LED) is a source of artificial light which produce light with the wavelength ranged from ultraviolet - 100 nm to infrared - 3,000 nm. Under natural or artificial lighting condition, plants require energy for photosynthesis from light between 380 nm to 700 nm. In this study we examined the use of two types of 45-watt LED (red and blue – C1, full spectrum – C2) with three different light durations (12 h – D1, 16 h – D2, and 18 h – D3) on the growth and yield performance of brassica under hydroponic technique. Research result showed that full spectrum LED provided better performance in plant height, leaves number and width, fresh yield, root length, and biomass in all combinations with light duration as compared to red and blue LED. The combination of full spectrum LEDs with a duration of 16 h showed the best fresh yield (3.96 kg m-2) followed by 18 h (3.57 kg m-2) and 12 h (3.22 kg m-2). Although the highest production was resulted from the combination of full spectrum LED and 16 h light duration, the most efficient in electric energy utilization was showed in the combination of full spectrum LED and 12 h light duration. All in all, we concluded that the use of full spectrum LED in combination with 16 h light duration feasible to be implemented in brassica cultivation under controlled environment.

Effect of Training Method to Separate Sink and Source Organs on the Fresh Yield and Dry Matter Production of Cucumber (<i>Cucumis sativus</i> L.) under Greenhouse Conditions

Effect of Training Method to Separate Sink and Source Organs on the Fresh Yield and Dry Matter Production of Cucumber (<i>Cucumis sativus</i> L.) under Greenhouse Conditions

Developing Sterilization and Lighting Systems for Sprouting Rooms Using Ozone and Optical Fibers

The increasing population has led to the widespread adoption of hydroponics. Hydroponic production of fresh green forage requires minimal space, does not use soil, and allows for rapid harvesting. A fully controlled sprouting room can yield a substantial amount of green fodder from a small area with less water consumption. This study aims to investigate the effectiveness of ozone on seed germination, seedling growth, and microbial sterilization during germinated barley processing. Additionally, the sterilization of the barley sprouting room was conducted using ultraviolet and infrared light, which provides optimal sprouting conditions.The study comprises three experimental variables: three levels of ozonized water (13, 26, and 39 mg L-1) combined with three light sources (fluorescent, infrared, and ultraviolet) and three light duration times (8, 16, and 24 h). The measurements include shoot length, fresh yield weight, dry yield weight, conversion factor, chlorophyll content, N, P, K, crude protein, ash, and log reduction.The results indicated that the maximum values were observed when using ozonized water at 39 mg L-1, Ultraviolet LED as a light source, and a sterilizing medium with a light duration time of 24 h. Conversely, the minimum values were observed when using ozonized water at 13 mg L-1, fluorescent LEDs as a light source, and a light duration time of 8 h. Based on the findings, it is highly recommended to utilize the developed sprouting room throughout the year for the production of fresh forage.

Multi-Locations Evaluation of Garden Pea Genotypes for Pod Characters and Yield

Pea genotypes developed by national breeding program exhibit wide geographical adaptation. To identify the best high yielding and wide adaptive genotypes, fourteen garden pea genotypes (13 improved and commercial) were studied for their phenotypic traits at two locations (Horticulture Research Station, Dailekh and Agriculture Research Station, Dhankuta) during 2018–2019. Field experiments were conducted at randomized complete block design with three replications in both locations. Combined analysis over the locations revealed that genotypes had highly significant (p ≤ 0.01) effect on pod length, pod diameter, seed number/pod, pod weight and fresh pod yield. HRSDGP-11-18-1 produced the highest (12.5 t/ha) fresh pod yield, followed by HRSDGP-11-18-11 (12.3 t/ha) and the lowest (8.2 t/ha) fresh yield was recorded in HRSDGP-11-18-9. HRSDGP-11-18-1 and HRSDGP-11-18-11 had 25.0 and 23.0% higher yield advantage over Sikkim Local variety, respectively. Pod length, pod diameter and seed number/plot were significantly (p ≤ 0.01), and positively correlated with fresh pod yield, and selection of these traits aid for the improvement of yield in garden pea genotypes. HRSDGP-11-18-1 and HRSDGP-11-18-11 were found superior at both locations and can be recommended to evaluate them at on-farm condition for further verification.

NANO FERTILIZERS WITH ALGAE EXTRACT AS BIOSTIMULANT AFFECTING GROWTH, BULB YIELD, AND QUALITY OF ONION (ALLIUM CEPA L.)

Biostimulants (nano fertilizers, algal extract) are synthetic or natural compounds for application to seeds, plants, and soil to increase crops, particularly onion yields. These substances cause changes in vital structural processes to influence plant growth through improved tolerance to abiotic stresses and enhance seed and grain yield and quality. The presented study aims to determine if biostimulants beneficially increase onions’ vegetative growth, harvest, and quality of onions (Allium cepa L.). A randomized complete block design with three replications helped compare various rates of Nano NPK fertilization (0.1, 0.2, 0.4, 0.6, 0.8, and 1.0 g/L Nano NPK + 0.5 g/L algae extract, 1.0 g/L mineral NPK + 0.5 g/L algae extract, 1.0 g/L mineral NPK, 1.0 g/L Nano NPK, and 0.5 g/L algae extract) with the control treatment (spraying distilled water only). The results showed as the Nano NPK + 0.5 g/L algae extract levels decreased, all studied parameters gradually declined. Foliar application of Nano NPK 1.0 g/L combined with 0.5 g/L algae recorded the highest significant effects, followed by 1.0 g/L mineral NPK + 0.5 g/L algae and 0.8 g/L Nano NPK + 0.5 g/L algae compared with the control. The highest values of bulb diameter (10.1 cm/plant), plant height (108.7 cm/plant), plant fresh weight (254.7 g/plant), and fresh yield (25.67 t/ha) emerged with foliar application of Nano NPK 1.0 g/L combined with 0.5 g/L algae, and the lowest values, obtained from the control treatment, were 4.2 cm/plant, 62.3 cm/plant, 100.23 g/plant, and 10.09 t/ha, respectively. The results suggested that using the algae extract combined with nano fertilizer treatment as a biostimulant will maximize onion growth parameters, yield production, and nutrient contents

Substituting green light for partial red light promoted the growth and quality, and regulated the nitrogen metabolism of Medicago sativa grown under red-blue LEDs

Light quality can affect the growth of plants, regulate the accumulation and metabolism of substances, thereby improving the growth and quality of plants. Alfalfa is a vital forage with wide distribution and high value for feeding. However, few studies have investigated the effects of light quality on growth, quality, and nitrogen (N) metabolism regulation of alfalfa under artificial light control environment. In this study, the light intensity was 400 μmol·m−2·s−1 and photoperiods was 16/8 h. Five light quality treatments were used for alfalfa production, red-blue ratio of 3:1, 4:1 and 5:1, respectively, and on the basis of red-blue ratio of 4:1, 5% and 10% red light were replaced by green light were also used (R3B1, R4B1, R5B1, R19B5G1 and R18B5G2). The results showed that although the stomatal conductance and lysine content of the R3B1 treatment were significantly higher than other treatments, but the leaf area, fresh yield, contents of soluble sugar, sucrose, nitrate and ammonium, as well as the enzyme activities of NR, NiR, GOGAT and GS were the lowest among all treatments. The R3B1 treatment resulted in growth inhibition and reduced N metabolism levels. Strikingly, compared with the R4B1 treatment, the synthesis of Chl a+b, Chl a, Chl b, and free amino acid, as well as the accumulation of nitrate and crude protein, and the activity of GS also increased significantly in the two treatments which green light replaced partial of red light. However, the contents of soluble sugar, glutamate and lysine, as well as the activities of GOGAT and GDH, were significantly reduced in the R19B5G1 and R18B5G2 treatments. The carotenoids and sucrose contents of R19B5G1 treatment were significantly higher than R4B1 treatment, and the fresh weight and NR activity of R18B5G2 were significantly higher than R4B1 treatment. In addition, the content of starch and soluble protein and AK activity were not affected by light quality. In general, green light instead of partial red light increased the content of photosynthetic pigment and promoted the growth of alfalfa. Although the levels of glutamate, cysteine and lysine were reduced, it was beneficial to the accumulation of nitrate, free amino acid and crude protein, maintained the stability of N metabolism and improved the feeding value. These findings provide valuable insight into the effects of light quality regulation on value of feeding and N metabolism of alfalfa.

Modelling the response of tomato on deficit irrigation under greenhouse conditions

To optimize crops irrigation strategy is crucial to improve the production sustainability in a climate change scenario characterized by an ever-increasing water shortage. Crops simulation models, combined with experimental data, can be useful tools. AquaCrop, a crop water productivity model, has been widely used to reach this aim in open field condition but it has been limited adopted under greenhouse conditions. This study aims to calibrate and validate AquaCrop model through a greenhouse tomato cultivation using a split plot experimental design. Crop irrigation management was the main treatment [full irrigation (FI) at 100 % crop evapotranspiration (ETc) vs. deficit irrigation (DI) at 75 % of FI] and fertilization [no fertilization, mineral fertilization, organic fertilization with compost, and organic fertilization with sieved (< 2 mm) compost] the subplots. Fresh yield, above-ground biomass, water productivity, and net irrigation requirements were simulated. The validated model also permitted to evaluate the impacts of changing temperature outside the greenhouse on fruits yield, biomass, and water productivity using 30 years of historical weather data. The results showed that the model accurately estimated crop parameters, although it tended to overestimate soil water content. On average, DI reduced fruit yield by 14.1 % compared to FI. Over the last 30 years, the validated model permitted to calculate an average fruits yield reduction due to DI of 12.6 %. Our findings suggest that models like AquaCrop can assist in optimizing greenhouse agriculture by predicting crop performance under different conditions. Our study also highlights that external temperature and AquaCrop can be used to estimate tomato yields in the greenhouse by providing decision support tools for end-users (farmers, farmer associations, and policymakers) seeking sustainable and efficient greenhouse farming practices in a changing climate.

HYPERSPECTRAL UAS IMAGERY FOR GRASS SWARDS BIOMASS AND NITROGEN ESTIMATION

Abstract. Monitoring agricultural grass fields is particularly important for meat and milk production in Northern Europe, where three harvests occur during a growing season to maximize yields. Reliable data on forage, including biomass and nitrogen concentration, are essential for making informed decisions regarding seed mixtures, fertilizer rates, and harvest timing. Miniaturized hyperspectral cameras mounted on unmanned aerial systems (UAS) have become increasingly accessible and efficient. These cameras, operating in the visible to near-infrared (VNIR) range, have shown potential in estimating grass sward quantity and feeding quality. Additional advancements in hyperspectral technology have emerged the short-wave infrared (SWIR) range for UAS applications, previously utilized mainly in laboratory and aircraft-based systems. This study aims to explore the potential of VNIR and SWIR hyperspectral UAS-based remote sensing in biomass and nitrogen estimation during primary and re-growth stages. Grass fresh yield and nitrogen concentration prediction models were built after selecting the most significant features from the cameras to cope with the high dimensionality of the data. Using best features and machine learning, both fresh yield and nitrogen concentration were estimated with normalized root mean square error better than 10%. This work contributes to the development of accurate remote sensing techniques, supporting sustainable agricultural practices and climate change studies.

Determination of Combined Effects of Organic and Mineral Fertilizer on Forage Yield and Quality of Annual Ryegrass

The widespread practice of using high doses of nitrogen to increase unit area yield in annual ryegrass introduces ecological and economic problems. This research was carried out over two years and aimed to determine the potential forage yield and quality of annual ryegrass by applying manure, humic acid, and low doses of nitrogen fertilizer, within the framework of sustainable forage crop cultivation. The study was carried out from 2020 to 2022 with three replications according to the randomized block split plots experimental design. According to the study results, the highest values were achieved with combinations that included manure application, and even higher values were observed when manure was applied along with low doses of humic acid and nitrogen. The M20 + H20 + N100 treatment yielded the highest fresh yield, dry matter, and crude protein. The treatments with manure, humic acid, and nitrogen fertilizer had varying effects on the ADF and NDF content of annual ryegrass, resulting in fluctuating values. In conclusion, 20 t manure, 20 L humic acid, and 100 kg ha−1 N application can be suggested for sustainable and higher dry matter production with good quality for annual ryegrass cultivation under semi-humid climatic conditions. The results obtained from this research hold promise for sustainable agricultural practices.

Evaluation of e-vermicompost for tomato production

Vermicompost has a plethora of benefits that restores nutrient, stabilizes soil, and enhances soil fertility. The experiment was conducted at farmers’ field of Mymensingh and Jamalpur to evaluate the effect of e-vermicompost on tomato production during October 2019 to March 2020. There were five fertilizer treatments combination (T1: RCF-Recommended fertilizer (N120 P35 K70 S15 Zn2 B0.5), T2: 85 % RCF+3 t ha-1 vermicompost, T3: 85% RCF+1 t ha-1 e-vermicompost, T4: 70% RCF+3 t ha-1 e-vermicompost and T5: 70% RCF+1 t ha-1 e-vermicompost). The experiment was laid out in a Randomized Complete Block Design with three replications. The fresh tomato fruits were harvested in three times. The fresh weight of tomato at Mymensingh ranged from 53.3 to 68.5 t ha-1 with the highest yield of 68.5 t ha-1 from the treatment T2 (85% RCF + 3 t ha-1 e-vermicompost). At Jamalpur, the yield ranged from 50.4 to 65.3 t ha-1 and the highest yield of 65.3 t ha-1 was recorded also from the treatment T2 (85% RCF+3 t ha-1 e-vermicompost). The lowest yield was obtained from the treatment T5 in both locations. The percent fresh yield increased over control (T1), was 24.5 and 18.3% in Mymensingh and Jamalpur, respectively. The highest gross margin was Tk. 762,225/-, which was obtained from the treatment T2 (85% RCF+3 t ha-1 e-vermicompost). The highest MBCR 2.80 (average of two locations) was obtained from the same treatment T2 (85% RCF+1 t ha-1 e-vermicompost). The results indicates that the application of e-vermicompost along with 85% recommended dose of chemical fertilizer is more profitable than the application of chemical fertilizer alone. Bangladesh J. Nuclear Agric, 37(1): 31-40, 2023

Modeling Short-term Yield Changes in Sweet Pepper Based on Dry Matter Production and Fruit Growth

Large fluctuations in fruit set and fresh yield are issues associated with the production of sweet pepper. Fluctuations in fresh yield (i.e., flush) result in improper labor distributions and price fluctuations for growers. Modeling the fruit set is a promising way to improve the profits of growers and allow the arrangement of labor distribution and logistics. Therefore, this study aimed to develop a model for predicting the short-term yield changes of sweet pepper by integrating two sub-models: one model for predicting the production of total dry matter and one model for predicting the individual fruit growth. We hydroponically grew four sweet pepper cultivars (Artega, Nagano, Nesbitt, and Trirosso) in a greenhouse to investigate the accuracy of the proposed model. Comparisons between observed and predicted fresh yields showed that the peaks and troughs of fresh yields were accurately predicted, regardless of cultivar differences. The average root mean square error between them was within the range of 0.24 to 0.39 t⋅ha−1⋅d−1. Therefore, growers will be able to predict short-term yield changes of sweet pepper by obtaining coefficients for predicting the production of total dry matter and fruit growth curve of the cultivar scheduled to be cultivated.

The effects of deficit irrigation on water use efficiency, yield and quality of drip-irrigated tomatoes grown under field conditions in Zimbabwe

Water availability in the root zone directly affects the yield and quality of tomatoes yet in most cases in sub-Saharan Africa water is either expensive or scarce. It is therefore important to establish and utilise suitable irrigation strategies in order to produce the crop in a sustainable way. In this study the effect of conventional and deficit irrigation treatments on yield, fruit quality and water use efficiency (WUE) were determined. Four trials were conducted at the University of Zimbabwe Farm from 2014-2017 with four treatments per trial: T1 = 100%, T2 = 80%, T3 = 60%, and T4 = 50% of crop water requirements (ETc). Treatments had equal number of plants per trial with an in-row plant spacing of 0.3 m and 0.5 m between adjacent rows. ETc was determined daily for each treatment and the corresponding volume applied through one drip emitter per plant. Fruits from each treatment were gathered while ripening and the total yield obtained. WUE was calculated by dividing the total fresh yield by total irrigation water applied. Maximum yield was obtained where 100% ETc was applied, with no significant difference between yield of plants at 80% and 60% ETc, except in 2016. Yield decreased with 50% ETc in 2014, 2015, and 2017 with no significant difference in yield between 60% and 50% ETc treatments in 2016. The 2015 season recorded the highest yield when compared to other trials showing that we can save 40% of water resulting in high WUE with minimum loss in yield. Deficit irrigation reduced fruit water but increased fruit soluble solids (°brix), vitamin C and fruit acid concentrations. Firmness was best when 60% ETc was applied. These results show that deficit irrigation is feasible for crop water management options for the production of high-quality field-grown tomatoes without major yield reductions.

Using bio-based fertilizer derived from peri‑urban wastes affects soil properties and lettuce yield and quality

The use of waste-derived fertilizers, also known as bio-based fertilizers (BBFs), for the production of ready-to-eat vegetables can efficiently contribute to sustainability and circularity. However, studies on the efficiency and safety of these fertilizers are needed. Thus, this study aimed to examine and characterize the effects of combined application of BBFs on lettuce yield and quality and soil properties in a trial conducted under open field conditions. The eight experimental treatments included green- or food waste compost combined with either human urine, food waste digestate or synthetic fertilizer and compared to treatments with synthetic fertilizer alone or in combination with manure. The control treatment received no BBF or other type of fertilizer. The results showed statistically similar fresh lettuce yields after 48 days among the treatments, all of which were larger than the yield of the unfertilized control treatment. The highest fresh yield (73 t ha−1) was observed with the combination of manure and synthetic fertilizer. Yield in treatments that received green waste or food waste composts tended to decrease slightly, more likely due to nitrogen immobilization after the application of incompletely stabilized composts and the low initial mineral N. Nitrate contents in fresh lettuce leaves were below the EU limits (3000 mg kg−1) in all the treatments. Analysis of pathogens and trace elements present in aboveground lettuce showed no significant risk. The application of BBFs also appeared to maintain the soil pH compared to synthetic fertilizer treatments. The important nutrient and carbon contents of BBFs and their positive effect on lettuce yield associated with their non-harmful impact on lettuce quality suggest that BBFs can be used for vegetable production and to increase the soil carbon stocks and contribute to city sustainability.