Pineapple Research Articles

Appraisal of the Diagnosis and Recommendation Integrated System and Nutrient Status of Pineapple (Ananas Comosus L.) Growing Fields

ABSTRACT The diagnosis and recommendation integrated system (DRIS) has such high reliability that it can be used to evaluate many crops. Therefore, in order to have a practical database for these norms, this study was conducted to evaluate the established DRIS norms for plant pineapples (Ananas comosus L.) and to assess their nutrition status in an acid sulfate soil. Healthy and disease-free leaf samples of 8-month-old pineapple plants without fruits were collected from experimental fields with nutritional omission trials and from farmers’ fields at four cultivating sites. Nutrient concentrations were analyzed to determine DRIS indices. The result showed that the + 7 leaf was highly reliable to diagnose the macro-nutrition status, while the + 1 leaf and + 3 leaf lacked the nutrient ratios pair to assess P and Mg nutrition status. Based on the average DRIS indices of the four sites, the nutrient surplus was observed in the order P>Mn>Fe>Ca (81.7 > 52.8 > 15.7 > 13.3), while nutrient deficiency varied in the order K>Zn>N>Mg (−88.2<-20.3<-16.4<-10.7) at the + 7 leaf. The DRIS norms needed to be calibrated to obtain nutrient ratio pairs for P in the + 1 leaf, and P and Mg at the + 3 leaf.

Growth rate of pineapple production in India

Pineapple (Ananas comosus) is one of the most important tropical and subtropical fruit of Bromeliaceae family, cultivated almost one third part of the world. Pineapple takes almost 16 -22 months to mature for harvesting. The main objective of this paper is to analyzed the growth rate in area, production and productivity of pineapple in India as well as Karnataka. The time series data from 2002-03 to 2021-22 for the study. The results revealed that the area (1.94%), production (2.56%) and productivity (0.64%) showed that positive and significant at one per cent level of probability in India. In Karnataka, the growth rate of productivity (0.99%) showed that positive and significant at five per cent level of productivity due to area expansion. For area (0.14%) and production (1.04%) showed positive and non-significant. Whereas, Cuddy Della Valle index (CDVI) for area, production and productivity were 6.79, 7.66 and 3.76, respectively in India. In Karnataka, the Cuddy Della Valle index (CDVI) for area, production and productivity were 10.55, 22.37 and 8.78. The slight variation in productivityof pineapple in India are mainly because inadequate farm management techniques i.e., less use of chemical fertilizer, pesticides, improper suckers, inadequate knowledge and insufficient use of other input, which are the result of less production and productivity.

First Report of Leaf Spot of Pineapple (Ananas comosus (L.) Merr Caused by Neoscytalidium dimidiatum in Malaysia.

In June 2017, severe leaf spots symptoms were observed by growers on pineapple leaves of Josapine variety in in Alor Pongsu (5°01'60.00" N, 100°34' 59.99" E), Perak,northwest of Peninsular Malaysia. The early infection stage shows that several brown spots could be observed, which then would merge to form large brown to creamy white lesions that cover all the leaf surface. This infection finally caused the plant to die after a while. Disease observations conducted from 2018 - 2023 showed that 10-15% incidences of the disease were observed in several pineapple farms located in Johor, Kedah, and Sarawak. The aim of this study to confirm the causal pathogen of the disease by performing isolation, pathogenicity testing, and identification of the primary causal pathogen from 20 samples of infected leaves collected from Alor Pongsu. The leaf tissues between infected and healthy were cut into small pieces (0.5 cm 0.5 cm), and surface sterilized with 1% sodium hypochlorite for 30 seconds, followed by 70% ethanol for 30 seconds, and rinsed thrice with sterilized water before placing on Potato Dextrose Agar (PDA). The PDA plates were incubated at room temperature (28 ± 2℃) in natural light. After five days of incubation, the potential causal pathogen was purified using a single conidial isolation technique for morphological and molecular characterizations. All 32 isolates displayed similar phenotypes. Based on morphological observation on PDA, the colonies were initially white of aerial mycelia but gradually darkened as the culture aged. Microscopic features of the 14-day-old fungal culture showed that the mycelia were branched with 0- 1 septa, pigmented, and brown. Arthroconidia were ellipsoid to ovoid or round shaped, hyaline, with rounded apex, truncate base, and occurring singly or in chains averaging 9 ± 3 × 5 ± 2 μm (n = 20). Based on the morphological characteristics, the fungal isolates were tentatively identified as Neoscytalidium species. A representative isolate of Neoscytalidium coded as UiTMPMD2 was further identified through PCR implication of the internal transcribed spacer (ITS) region using ITS1 and ITS4 primers and BLAST homology search as Neoscytalidium dimidiatum (Penz.) Crous & Slippers based on 100% similarity (575 bp out of 575 bp) to a reference sequence (accession no. KU204558.1). The sequence was deposited in Gen Bank (accession no. OR366479) with reference sequence code of INBio:30A. Pathogenicity tests were performed on 10 whole plants of Josapine pineapple (4 months old) using a leaf inoculating method (Wu et al. 2022) in a glasshouse (25-32°C) and repeated twice. Four mature leaves per each plant were wounded at two points and inoculated with mycelium PDA plugs from 7-days-old cultures of N. dimidiatum. Control plants were wounded in the same manner but inoculated with sterilized PDA plugs. Seven days post inoculation, leaf spot symptoms were observed on treated plants with the pathogen, while the control plants remained symptomless. Pathogen was successfully reisolated from brown leaf spot symptoms in which the cultural and morphological characteristics were identical to those of the originals. Neoscytalidium dimidiatum has a wide range of hosts and it has been reported in Malaysia to cause stem canker on pitahaya (Mohd et al. 2003; Khoo et al. 2023 ) and fruit rot of guava (Ismail et al. 2021). To the best of our knowledge this is the first report of N. dimidiatum causing leaf spots on pineapples in Malaysia. This report establishes a foundation for further study ofN. dimidiatum that can effectively address the disease in pineapple.

Formulation and Evaluation of Anti-Acne Activity of Gel Pineapple Peel (Ananas comosus L.) Extract on the Growth of Propionibacterium acnes

Pineapple peel contains many compounds, namely flavonoids, tannins, saponins, phenolics, steroids, alkaloids and bromelin enzymes. Acne is a chronic inflammatory disease of the pilosebaceous glands. One of the bacteria that causes acne is Propionibacterium acne. Preparations that can be made for anti-acne are gel preparations. This study aims to determine whether the ethanol extract of pineapple peel (Ananas comosus L.) can be made into an anti-acne gel preparation and to find out at what concentration the ethanol extract of pineapple peel (Ananas comosus L.) in an anti-acne gel preparation can provide inhibitory activity on the development of Propionibacterium acne bacteria. This research method is true experimental by making anti-acne gel preparations of pineapple peel extract (Ananas Comosus L.) with various concentrations of 2%, 3%, 5% and testing the activity of the preparation against Propionibacterium acne using the agar well method. The results of the gel preparation formula showed that there were significant differences before and after the cycling test in both organoleptic, homogeneity, pH, viscosity, spreadability and adhesion tests. The activity test results obtained were that the largest inhibition zone was the 5% concentration, namely 12.7 mm, which was in the strong category, while the 3% concentration, which was 11.03 mm, and the 2% concentration, which was 8.8 mm, was included in the moderate category.

Neuroprotective effect of bromelain on BDNF-TRKB signalling pathway in chronic unpredictable stress-induced depression model

BackgroundBromelain is a mixture of protease enzyme extract from the fruit or stem of the pineapple plant. It has a wide range of biological actions, and it is most commonly used as an anti-inflammatory agent. This study was designed to investigate the antidepressant effect of bromelain on chronic unpredictable stress (CUS)-induced depression in rat models by targeting various molecular mechanisms.ResultWe studied the in silico analysis of the antidepressant potential of bromelain by docking with various proteins involved in the pathophysiology of depression. As a result of in silico studies, bromelain showed good binding energy with IL1β, 5-HT, BDNF, CREB, and TrkB. The mRNA expression of BDNF, TrkB, AKT, ERK, and IL-1β was studied by qRT-PCR. Gene expression studies showed a significant decrease in BDNF, TrkB, AKT, and ERK in chronic unpredictable stress, whereas there was a significant increase in the case of the bromelain- and fluoxetine-treated group. Since neuroinflammation is also one of the major concerns in the pathophysiology of depression, pro-inflammatory cytokines were also studied along with apoptotic markers using ELISA. ELISA results showed a significant increase in inflammatory cytokines in CUS, and it was significantly decreased in the case of the bromelain- and fluoxetine-treated group. Similarly, there was an increased concentration of pro-apoptotic protein in the CUS group, whereas it was decreased in the bromelain and fluoxetine groups.ConclusionsFrom the results, it is clear that bromelain exerts an antidepressive effect by preventing neuroinflammation and neurodegeneration and by enhancing neurogenesis and neuroplasticity.Graphical abstract

Exploring New Fruit- and Vegetable-Derived Rennet for Cheese Making

Cheese production is an ancient practice to preserve a perishable food, such as milk, for a long time. The first step of cheese processing involves the addition of rennet, which contains the enzymes necessary for the hydrolysis and coagulation of the caseins present in milk. Typically, animal-derived rennet, such as calf rennet containing chymosin, are used as source of enzymes for cheese processing. Alternatively, microbial chymosin or recombinant chymosin is used. However, recently, plant-derived rennet such as the ones derived from thistle and bitter orange flowers and from artichoke (Cynara cardunculus var. scolymus) have also been demonstrated to be valid sources of enzymes for cheese processing. Therefore, herein, different plant and fruit extracts were tested and compared for their ability to coagulate milk caseins. In particular, beyond artichoke and cardoon (Cynara cardunculus) extracts, those from pineapple (Ananas comosus (L.) Merr.), papaya (Carica papaya L.), common fig (Ficus carica L.) milky sap, and oyster mushroom (Pleurotus ostreatus (Jacq. ex Fr.) P. Kumm.) were investigated for their proteolytic, esterase, and milk-clotting activities. The extracts were then exploited as vegetable and fruit rennet for the experimental production of cheeses, which were examined, after 30 days of maturation, for their moisture, fat, protein, and free fatty acid (FFA) content. Interestingly, the artichoke, cardoon, and thistle mushroom extracts showed high proteolytic activity compared to calf rennet, while the level of esterase activity appeared to be similar for all the extracts. The papaya extract showed the lowest proteolytic and esterase activity. Although the pH, moisture, fat, and protein contents were very similar to those of cheese made with calf rennet, the medium- and long-chain FFAs broadly differed among produced cheeses, with variations in the lipid quality indices.

Use of plant extracts in fabricating manganese-based film electrode for capacitor

The possibility of using plant extracts to fabricate manganese-based film electrode for capacitor was explored in this study. This was achieved by using manganese sulfate as the source of manganese as well as triethylenetetramine (TETA) and extracts from pineapple leaf (ananas comosus), hibiscus rosa leaf, and ginger root (zingiber Officinale) to prepare the ink. During the experimentation, it was discovered that the application of different plant extract solutions led to the production of several manganese oxides. Moreover, electrode fabricated from Mn-TETA-GE had different forms of MnO, Mn2O3, and Mn3O4 as well as the highest average specific capacitance of 38 F g−1 which was almost a steady value. The results also showed that the presence of gingerol in the ginger extract solution led to the reduction of manganese ion to Mn. Furthermore, the oxidation state of Mn was varied to Mn2+ and Mn3+ due to the acidic condition of gingerol content. The variation of manganese oxide was not found to be significant in film electrode fabricated using hibiscus rosa and pineapple extracts. This confirmed that gingerol had the potential to be applied in fabricating electrode for capacitor.

Characterization of dried pineapple (Ananas comosus L.) peel powder and its application as a novel functional food ingredient in cracker product

The study utilized dried pineapple peel powder (PP) as a novel functional cracker ingredient. The PP comprised 3.94 % moisture, 2.53 % fat, 3.98 % ash, 4.20 % protein, 12.05 % crude fiber, and 73.30 % carbohydrate. PP also had total phenolic content (TPC) of 729.93 mg GAE/100 g DW, total flavonoid content (TFC) of 267.97 mg QE/100 g DW, and antioxidant capacities (AOC) of 2,364.08 mg Trolox/100 g DW and 1,365.14 mg FeSO4/100 g DW, as determined by DPPH and FRAP assays, respectively. According to HPLC analysis, catechin (29.85 μg/g), vanillic acid (21.63 μg/g), and sinapic acid (13.16 μg/g) were the three most significant phenolic compounds, followed by ferulic acid, rutin, caffeic acid, quercetin, gallic acid, and coumaric acid, respectively. The substitution of PP in crackers significantly increased ash, crude fiber, TPC, TFC, and AOC (p ≤ 0.05). The sensory attributes were accepted up to 10 % PP. HPLC analysis detected phenolic compounds in the 10 % PP crackers, namely vanillic acid (4.38 μg/g), ferulic acid (1.20 μg/g), sinapic acid (0.90 μg/g), and quercetin (0.24 μg/g). This study highlights the potential of utilizing PP in functional crackers, offering a sustainable solution for pineapple peel waste management.

Enzymatic conversion of pineapple plant stem starch and lignocellulosic materials into sugar syrups

Managing pineapple waste amid increasing demand is crucial and repurposing this waste offers a sustainable solution. Pineapple stems, an overlooked resource rich in starch and lignocellulosic materials, were explored in this study. Enzymatic hydrolysis was used to convert the stems into sugar syrup. Optimal conditions resulted in a sugar concentration of 107.88 ± 1.56 g/L from 10% starch, using 1% (v/v) Dextrozyme and Celluclast 1.5 L. Hydrolysis was most efficient at 70 °C for starch and 40 °C for lignocellulose. The produced syrups match high fructose corn syrup (HFCS) in water activity, moisture content, and color, making them a promising alternative in food industry.

Role of Pineapple and its Bioactive Compound Bromelain in COVID 19

Background:: Ananas comosus (L.) Merr., which is commonly known as pineapple, is a well-studied plant for its medicinal properties. In terms of commercial importance, it ranks third among tropical fruits. It has been used for its antidiabetic, antimalarial, anticancer, abortifacient, antioxidant, and antidiarrhoeal activities. The review aimed to study the effects of pineapples and their bioactive compounds on the SARS-CoV-2 virus. Methods:: Research methods comprise significant studies on the treatment of COVID-19 utilizing pineapple and its bioactive compounds. To carry out the e-literature review, articles were downloaded from online search engines, including Elsevier, PubMed, and Google Scholar, using pineapple, bioactive compounds, bromelain, clinical trial, and COVID-19. Results:: The literature showed that pineapple and its bioactive compounds showed antiviral effects in COVID-19 patients by inhibiting the proinflammatory cytokines and affecting various signaling molecules, including NF-κB, proinflammatory cytokines, and cyclooxygenase-2. They modulate apoptotic protein levels and also cause a reduction of ACE-2 and TMPRSS2 expression. Conclusion:: For the development of phytomedicine that adheres to all safety regulations, pineapple, and its bioactive compounds can serve as lead molecules for clinical studies in SARS-CoV-2 infection treatment and therapy.

Identification of Hsp90 inhibitors from Ananas comosus potential phytochemicals for lung cancer treatment

Lung cancer is a significant global health issue, with thousands of lives lost each year. One potential approach to preventing lung cancer is the use of heat shock protein 90 (Hsp90) inhibitors, which have been shown to induce substantial cell death in both chemo-sensitive and chemo-resistant small cell lung cancer cells. In this study, we conducted in silico computational molecular docking of pineapple phytochemicals with Hsp90 to investigate their potential inhibitory effects on Hsp90 and, consequently, their ability to prevent lung cancer. Our findings demonstrate that the phytochemicals found in Ananas comosus, specifically caffeic acid, ferulic acid, 4-Hydroxycinnamic acid, Sinapic acid, and D-Galacturonic Acid, exhibit notable inhibitory activity against Hsp90. Beyond their Hsp90 inhibition, these phytochemicals also demonstrate promising biological activities, serving as effective agents against neoplastic conditions, particularly lung cancer, and displaying pro-apoptotic properties. Moreover, the ADME (Absorption, Distribution, Metabolism, and Excretion) and toxicological assessments conducted on these compounds yielded satisfactory results. These findings suggest that pineapple phytochemicals may have potential in the development of novel therapeutic strategies for lung cancer prevention.

Development of Eco-friendly Handmade Paper and Paper Board from Soft Bamboo, Whole Banana &amp; Pine Apple Leaves Fibre- Available in N.e. Region of India

The studies were carried out to established suitability of lingo-cellulosic raw materials namely Soft Bamboo (Dendrocalamus arundinacea), Banana (Musa Sapientum) &amp; Pineapple (Ananas Comosus) for making pulps for handmade paper industry which are abundantly available in north eastern part of India. This should help in providing a cost effective, good quality cellulosic raw material as an alternate to cost prohibitive traditionally used cotton hosiery waste traditionally used for manufacturing good quality handmade paper &amp; it’s products. This will help in improving the cost economics &amp; competitiveness of the Indian paper industry in the global market besides addressing the problems of environment &amp; global warming. The Studies thus carried out provide useful information about the nature of these raw materials, suitable pulping process to produce an eco-friendly handmade paper and board &amp; converted products. The research work provides a good quality cost effective lingo-cellulosic raw material for handmade paper industries with a possibility of replacement of the expensive and traditionally used cotton hosiery waste. The paper thus produced using environmental friendly pulping and bleaching process is characterized for its strength properties like tensile, tear, bursting, folding endurance and other parameters. Further the study will be useful in providing opportunities for employment generation and income enhancement among the rural masses as well as addressing the bio-mass dumping.

Potential bottom‐up control of Metamasius callizona in Florida, USA

AbstractMetamasius callizona (Chevrolat) (Coleoptera: Curculionidae) is an invasive weevil destroying Tillandsia utriculata L. (Bromeliaceae) populations in Florida, USA. A T. utriculata population in Belize coexists with M. callizona without adverse effects. Tillandsia utriculata and M. callizona from Belize and Florida were studied in the laboratory to determine how Belize T. utriculata can coexist with Belize M. callizona, using Florida and Belize T. utriculata, as well as pineapple, Ananas comosus (L.) Merr. (Bromeliaceae), as host plants. Florida M. callizona on pineapple leaves produced more eggs per female per day and had a shorter developmental time and pupation period, as well as a smaller adult width, than Belize M. callizona. Florida and Belize weevils did not differ significantly in rates of egg hatch, pupation, and adult emergence. Florida M. callizona laid similar numbers of eggs per day on Florida and Belize T. utriculata. Egg hatch rates were similar on pineapple and Florida and Belize T. utriculata. Pupation rates were similar on pineapple and Florida T. utriculata leaves; no larvae on Belize T. utriculata attained fourth instar. Field and laboratory observations revealed that Belize and Florida M. callizona mined Belize T. utriculata without destroying the meristem, allowing plants to survive, but Belize M. callizona destroyed the core of pineapple tops. Soluble solids were greatest in pineapple and least in Belize T. utriculata. Leaf toughness was greatest in pineapple and least in Florida T. utriculata. Metamasius callizona biology and behavior and T. utriculata plant characteristics may drive the severity of weevil damage on populations of T. utriculata. The discovery of a T. utriculata population in Belize coexisting with M. callizona offers a possible way to control M. callizona in Florida.

Experimental Design of the Interaction Effect of Independent Variables on Pineapple (Ananas comosus) Fruit Bromelain Activity

Background: Certain factors are known to influence the rate of enzyme activity. It is paramount to study such independent factors to obtain the ideal conditions required to maximize enzyme activity. The time-consuming traditional one-factor-at-a-time (OFAT) approach of evaluating the effect of independent variables on enzyme activity does not consider the interaction effects of the independent variables on dependent responses. Methods: The impact of four independent variables on fruit bromelain activity was evaluated using the complete factorial design of the experiment approach. Results: The highest actual fruit bromelain activity (76.83 U/ml) and predicted activity (74.81 U/ml) were recorded at an optimum pH of 7.5, temperature of 50oC, and incubation period of 10 minutes using azocasein substrate. All tested variables except temperature; the interaction between substrate type and incubation time significantly affected fruit bromelain activity (p &lt; 0.05). Conclusion: The design model analysed the main and interaction effect of the variables on bromelain activity. Therefore, complete factorial design is a better approach than OFAT to determine the effect of independent variables on fruit bromelain activity.

Effect of pineapple waste biochar and compost application on the growth and yield of pineapple varieties in Ghana

IntroductionBiochar is one of the commonly used soil amendments for sustainable agriculture. The effect of biochar on crop yields depends on the quality of the biochar, which is influenced by feedstock type and pyrolysis conditions. Sole application of pineapple waste biochar and compost, and their combination has not been rigorously investigated. In this study, we investigated the effects of pineapple waste biochar and compost applied solely or in combination on growth and yield of pineapple on a coastal savanna Acrisol in Ghana.MethodsThe split-plot design with three replications was used, with pineapple varieties as the main plot and fertilizer application rates as the sub-plots.Results and discussionThe results showed that sole application of biochar and compost or their combination as a soil amendment increased pineapple growth and yield as compared to the unamended soil. Biochar applied in combination with compost/or inorganic NPK (nitrogen, phosphorus, and potassium) fertilizer significantly increased plant height and the number of leaves of pineapple plant, which resulted in improved fruits yield of the three (sugar loaf, MD2 and smooth cayenne) pineapple varieties at maturity over control, sole application of biochar, compost and inorganic NPK fertilizer. The Smooth cayenne variety outperformed MD2 and Sugar loaf variety.ConclusionIn conclusion, the results revealed that biochar applied solely or in addition to compost or inorganic NPK fertilizer has the capability to enhance soil quality and improve pineapple yield. Application of biochar in combination with compost/or inorganic NPK improves pineapple growth and yield.

Enhancing Sustainability and Performance of Pineapple Leaf Fibres in Textile Applications: A Comprehensive Review

&#x0D; The utilization of pineapple leaves (Ananas comosus) has gained significant momentum as a source of value-added products, owing to the myriad benefits offered by Pineapple Leaf Fibres (PALF). PALF presents a range of advantages, including its contribution to a greener environment and sustainability. PALF production plays a pivotal role in reducing environmental pollution and minimizing waste. Moreover, PALF stands out due to its availability, remarkable thermal and acoustic insulation properties, cost-effectiveness, and exceptional tensile strength. Further, the extraction of PALF can be accomplished manually or mechanically, and various methods have been explored to enhance its compatibility with textile applications. In this context, extensive research has been carried out to modify PALF for its application in the textile industry. Researchers have primarily focused on surface modifications. These modifications encompass chemical treatments, physicochemical treatments, physical treatments, and thermal treatments. All of these contribute to improved interfacial adhesion and enhanced physical, mechanical, and thermal properties of PALF. Additionally, investigations into bleaching and dyeing of PALF have led to achieving superior whiteness and the ability to impart various colours to the fibres. PALF fibres exhibit remarkable qualities, including excellent sweat absorption, breathability, durability, and notable air and water permeability. These attributes make PALF a sought-after material for creating blended fabrics in conjunction with other polymers, such as polyester and wool, enhancing the performance of resulting textiles. The versatility of PALF enable its integration into an extensive range of textile products, underscoring its significance in the industry. This review also explores innovative approaches, such as blending PALF with jute, resulting in the creation of home textiles and carpets, while simultaneously improving the quality of blended yarns. Furthermore, within the textile industry, PALF fibres find diverse applications in the production of an array of products. This involves the crafting of wedding dresses, casual attire, and formal garments. It also includes the manufacturing of table linens, mats, bags, shoes, belts, cords, transmission cloths, airbag tying cords, and carpets. This comprehensive review delves into the wealth of research conducted on PALF modifications, shedding light on the potential of PALF as a sustainable and high- performance material in the textile industry, contributing to further eco-friendly and innovative future.&#x0D; &#x0D; Keywords: Pineapple Leaf Fibres (PALF), Textile Industry, Sustainability, Greener environment

Effect of pineapple peel addition on sorghum ensilage

Silage mixed with forage and byproducts is an alternative nutritional strategy for ruminant production. This study aimed to characterize chemical–nutritional aspects, fermentative profile, and digestibility of sorghum (Sorghum bicolor L. Moench) silage with different contents of pineapple (Ananas comosus L. Merr.) peel inclusion at 0%, 20%, 40%, 60%, or 80% of fresh matter. The experimental design was completely randomized with five replicates per treatment. Mixed feeds were ensiled in experimental silos for 65 days, subsequently opened, and samples were analysed. The increase in the proportions of pineapple peel caused a linear increase in dry matter, crude protein, mineral matter, ether extract, soluble carbohydrate, cellulose, lignin, and in vitro digestibility of dry matter in sorghum silage. The mean concentrations of neutral detergent fibre (NDF) and acid detergent fibre (ADF) had a negative quadratic relationship with the inclusion of pineapple peel, reducing from 0% to 40% (-2.56% for NDF and -3.14% for ADF) followed by stabilization at subsequent contents. Silage pH was not influenced, however, acetic and propionic acids increased linearly, while butyric acid decreased linearly with pineapple peel inclusion. The highest losses in gases and effluents were obtained in silage with 0% pineapple peel inclusion (1.77% of dry matter and 4.06 kg t-1 of dry matter), which resulted in lower dry matter recovery (93.56%). Adding pineapple peel to sorghum benefits composition, fermentation, in vitro digestibility, and decreases silage losses. An inclusion of 40–80% sorghum can be recommended.

Determination of Mealybug Population Density for Transmission of Pineapple Mealybug Wilt Disease in Central Uganda

Pineapple mealybug wilt disease (PMWD) is a complex and most destructive viral disease constraining pineapple production world over. Pineapple mealybug wilt disease is transmitted by mealybugs (Dysmicoccus species). Currently, in Uganda, the population of Dysmicoccus brevipes that can transmit PMWD is not known. Yet, closing this knowledge gap would provide a better understanding of PMWD etiology and development of sound management strategies. Experiment was laid out in a completely randomized design (CRD) with four replications in the screenhouse at the Faculty of Agriculture, Kyambogo University during the period 2017 and 2018. Pineapple variety Smooth Cayenne was inoculated with five levels of viruliferous mealybugs including one (1), five (5), ten (10), fifteen (15), and a control (uninoculated). Data collection commenced on symptoms appearance and continued on a 15-day interval for a period of two months. Data were collected on the incidence and severity of PMWD. All the data collected were analysed using Genstat computer programme. Results showed that the number of mealybugs significantly (p&lt;0.05) affected the incidence and severity of PMWD during both trials. Although one viruliferous mealybug was able to transmit PMWD virus, the efficacy of transmission was recorded with the highest number of mealybugs per plant. It was, therefore, concluded that the higher the number of viruliferous mealybugs colonising a pineapple plant, the higher the incidence and severity of PMWD. The result of this study, therefore, adds to the pool of knowledge on the understanding the population density of mealybugs transmitting PMWD as well as provide insights to improvement of mealybug vector monitoring as a key component of integrated PMWD management.

EVALUATION OF RESPONSE PANELIST ABILITY SOLUTION OF YOUNG PINEAPPLE IN CLUMPING MILK PROTEIN INTO MILK TOFU

&#x0D; &#x0D; &#x0D; This study aims to evaluate the response of the panelists to milk tofu with the use of a natural coagulation agent, namely young pineapple juice. The study was conducted using a completely randomized design (CRD) with four treatments and four replications. Each replication using 1000 ml of cow milk, the four treatments were adding 30cc of pineapple juice (P1), adding 40cc of pineapple juice (P2), adding 50cc of pineapple juice (P3), and adding 60cc of pineapple juice (P4). The observed variables were the hedonic test for the level of preference and the sensory quality test, namely color, taste, scent, elasticity and overall acceptance. The results of this study indicated that the manufacture of milk tofu using natural coagulation ingredients of young pineapple juice (Ananas comosus) from all variables (color, taste, scent, elasticity, and overall acceptance) and each treatment (P1, P2, P3, P4) showed that the results were significantly different (P&lt;0.05). The hedonic test value (preferred level) on color, taste, scent, and overall acceptance was highest in P1 with a sequential value of 4.12; 4.16; 4.08; and 3.88, while the highest value for elasticity was found at P3. The conclusion of this study can be suggested using 30 cc of young pineapple juice as a natural coagulation material in the manufacture of milk tofu because it produces milk tofu with a milky white color, the scent of cow milk, a slightly chewy texture, and a slight milk taste.&#x0D; &#x0D; &#x0D;

Yield gap reduction of pineapple (Ananas comosus L.) by site-specific nutrient management

Acid-sulfate soils and overuse of chemical fertilizers have been obstacles to sustainable agriculture. The variation of fertilization due to poor soil fertility has remarkably affected the yield gap and the quality of the environment, so an optimal fertilizing rate should be formulated. Therefore, this study aimed at (i) detecting obstacles in soil characteristics reducing pineapple yield between farms and (ii) assessing the effects of NPKCaMg fertilizers on soil fertility, uptakes, and pineapple yield. The on-farm experiment was carried out according to site-specific nutrient management (SSNM) arranging in acid-sulfate soil for pineapple, including (i) no fertilizers used; (ii) NPKCaMg: fully fertilizing with nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg); (ii) PKCaMg: fertilizing without N; (iii) NKCaMg: fertilizing without P; (iv) NPCaMg: fertilizing without K; (v) NPKMg: fertilizing without Ca; (vi) NPKCa: fertilizing without Mg; and (vii) FFP: farmers’ fertilizing practice. The result of the principal component analysis revealed that the soil had low availability of N, P, and K nutrients. Available P concentration was negatively correlated with concentrations of Al3+, Fe2+, and total Mn, whose correlation coefficients were −0.34 to −0.59, −0.52 to −0.74, and −0.63 to −0.70, respectively. Fertilizing NPKCaMg obtained the highest result in the uptakes of N, P, K, Ca, and Mg, which were 289.1–327.4, 25.4–29.3, 137.4–166.0, 41.9–48.9, and 39.8–43.1 kg ha−1, respectively. Fertilizing by SSNM has increased pineapple yield by 22.9 %–44.9 % compared to the FFP. This fertilizer formula should be transferred to the local farmers in order not only to enhance productivity, but also to limit the damage of chemical fertilizers on the environment. Moreover, this formula should be tested globally in other places that share similar soil characteristics.