Ambient Laboratory Conditions Research Articles

Characterization of aerosol composition: Insights from SEM-EDX analysis and CALIPSO overpasses

The effect of atmospheric aerosols on the earth’s radiation budget is primarily through their direct effects. Understanding aerosols’ morphology and elemental composition is crucial in this context. For two years, from January 2017 to December 2018, aerosol samples (PM10) were collected on quartz filter papers using a high-volume sampler (PM10) in Chennai, a semi-urban coastal environment located at 12.81°N, 80.03°E. These filter papers were stored under ambient laboratory conditions and were subsequently subjected to ultrasonication using ethanol as the solvent to separate the aerosols from the filters. The extracted samples were then analyzed using scanning electron microscopy (SEM) for the morphology and energy dispersive X-ray analysis (EDX) for elemental composition. The EDX analysis of the samples revealed the presence of various elements such as carbon (C), oxygen (O), aluminum (Al), silicon (Si), sulfur (S), potassium (K), iron (Fe), magnesium (Mg), calcium (Ca), vanadium (V), bismuth (Bi), sodium (Na), chlorine (Cl), phosphorus (P), and technetium (Tc). High concentrations of carbon, oxygen, and aluminum–silicate particles indicated the presence of carbonaceous aerosols and wind-blown dust particles. Concentration-weighted trajectory (CWT) analysis was carried out to assess the transport pathways of aerosols in the region. CALIPSO overpasses during the study period were selected, and the Vertical Feature Mask (VFM) identifiers for different aerosol types were compared with the local experimental results. The findings show that CALIPSO possess a reasonably effective capability in detecting and characterizing the local aerosol types. CALIPSO detected Dusty marine, Clean marine, Elevated smoke and Polluted dust in the study area across all four seasons. These findings closely match the characteristics of such aerosol types obtained from SEM/EDX analysis, HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory) modeling, and the Angstrom exponent derived from sunphotometer readings.

Feeding and Biotic Potential of Coccinellid Predators on Coriander Aphid

The work on feeding and biotic potential of coccinellid predators on coriander aphid was studied under ambient laboratory condition at the Department of Entomology, SKN College of Agriculture (SKNAU), Jobner and observed that the first, second, third and fourth instar grubs of Coccinella septempunctata were consume 33.60, 55.22, 129.11 and 193.88 aphids during their respective stages. A grub of C. septempunctata consumed 411.13±10.82 aphids during its total life span. The adult male and female beetles consumed 1425.50±231.82 and 1983.25±177.92 aphids during their adult longevity with daily aphid consumption ability of 54.35±2.95 and 64.14±3.90 aphids per day, respectively.

METACASPASE8 (MC8) Is a Crucial Protein in the LSD1-Dependent Cell Death Pathway in Response to Ultraviolet Stress.

LESION-SIMULATING DISEASE1 (LSD1) is one of the well-known cell death regulatory proteins in Arabidopsis thaliana. The lsd1 mutant exhibits runaway cell death (RCD) in response to various biotic and abiotic stresses. The phenotype of the lsd1 mutant strongly depends on two other proteins, ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1) and PHYTOALEXIN-DEFICIENT 4 (PAD4) as well as on the synthesis/metabolism/signaling of salicylic acid (SA) and reactive oxygen species (ROS). However, the most interesting aspect of the lsd1 mutant is its conditional-dependent RCD phenotype, and thus, the defined role and function of LSD1 in the suppression of EDS1 and PAD4 in controlled laboratory conditions is different in comparison to a multivariable field environment. Analysis of the lsd1 mutant transcriptome in ambient laboratory and field conditions indicated that there were some candidate genes and proteins that might be involved in the regulation of the lsd1 conditional-dependent RCD phenotype. One of them is METACASPASE 8 (AT1G16420). This type II metacaspase was described as a cell death-positive regulator induced by UV-C irradiation and ROS accumulation. In the double mc8/lsd1 mutant, we discovered reversion of the lsd1 RCD phenotype in response to UV radiation applied in controlled laboratory conditions. This cell death deregulation observed in the lsd1 mutant was reverted like in double mutants of lsd1/eds1 and lsd1/pad4. To summarize, in this work, we demonstrated that MC8 is positively involved in EDS1 and PAD4 conditional-dependent regulation of cell death when LSD1 function is suppressed in Arabidopsis thaliana. Thus, we identified a new protein compound of the conditional LSD1-EDS1-PAD4 regulatory hub. We proposed a working model of MC8 involvement in the regulation of cell death and we postulated that MC8 is a crucial protein in this regulatory pathway.

Viability and virulence of freeze-dried Beauveria bassiana, Metarhizium acridum, and Hirsutella thompsonii isolates under non-refrigerated conditions in Ghana

ABSTRACT The necessity of cold storage for mycoinsecticides poses a logistical challenge in tropical Africa, where maintaining consistent refrigeration is a major obstacle. To investigate alternative preservation methods, our study evaluates conidial-based freeze-dried formulations of Beauveria bassiana (IMI 389521), Metarhizium acridum (IMI 330189), and mycelial-based freeze-dried formulations of Hirsutella thompsonii (IMI 327488 and IMI 391722). Propagules were cryoprotected with lactose, mannitol, and raffinose, encapsulated, and freeze-dried in plastic and glass vials. Bioformulations in glass vials were cryoprotected with mannitol only. Viability (CFU/g each day) of bioformulations, following 16-weeks-storage, and their virulence (at 1 × 107 conidia mL−1 in six days) against key pests of maize and cassava in Africa (larger grain borer, variegated grasshopper and cassava green mite) were determined under ambient laboratory conditions in Ghana. Our results show that non-freeze-dried conidia of B. bassiana and M. acridum had significantly higher viability and efficacy than freeze-dried versions, when stored under non-refrigerated conditions (averaging 27.7°C, 78.8% RH). Freeze-dried H. thompsonii mycelia were neither viable nor virulent against cassava green mite. Freeze-dried B. bassiana and M. acridum in plastic vials remained viable for 12 weeks, while in glass vials they were viable for seven weeks. Freeze-dried B. bassiana in both plastic and glass vials caused 38–43% mortality in larger grain borer, and M. acridum caused 45–82% mortality in variegated grasshopper. Further, conidia cryoprotected with lactose had significantly higher viability and mortality than raffinose and mannitol. Our research contributes to mycoinsecticide development, particularly in the context of storage and application challenges in tropical climates.

Controlling the Fluctuating Tip-Enhanced Raman Spectra of Chloramben on Silver Nanocubes.

Tip-enhanced Raman (TER) scattering from molecules residing at plasmonic junctions can be used to detect, identify, and image single molecules. This is most evident for flat molecules interrogated under conditions of extreme temperatures and pressure. It is also the case for (bio)molecular systems that feature preferred orientations/conformations under ambient laboratory conditions. More complex molecules that can adopt multiple conformations and/or feature different protonation or charge states give rise to complex TER spectra. We illustrate how the latter can be controlled in the case of chloramben molecules coated onto plasmonic silver nanocubes. We show that characteristic molecular Raman spectra cannot be obtained when tunneling plasmons are operative, i.e., when the tip is in direct contact with the chemically functionalized plasmonic nanoparticles. We rationalize these observations and propose an approach to less invasive and hence more analytical TER spectral imaging.

Studies on the physiological quality of stored sorghum seed concerning germinative parameters

Seed germination and the field crop stand that is necessary for the higher yield area ffected by the physiological quality of the seed i.e. the seed viability and vigor. The Rabi sorghum seed is considereda”moderate storer” as its viability fluctuates drastically under warm and humid storage conditions. In the present research,we evaluated the stored Rabi sorghum seed material for its physiological quality particularly vigor and viability as germinative evaluation criteria. The seeds of Rabi sorghum variety, SPV-1411, SPV-1595, CSV-22R, CSV-29R and SPV2407 were stored in air-tight plastic containers and kept under ambient laboratory conditions were evaluated for germinative criteria. The storage of seeds resulted in the deterioration of seed vigor as evidenced by the decline in the various parameters investigated.

Synthesis and characterization of a novel copper carboxylate complex and a copper complex-coated polyether sulfone membrane for efficient degradation of methylene blue dye under UV irradiation: the single crystal X-ray structure of the copper carboxylate complex.

Synthesis of a novel binuclear Cu(II) carboxylate complex under ambient laboratory conditions is presented. The complex exhibits a paddle wheel structure in which the axial positions are occupied by two copper atoms instead of two water molecules. The synthesized complex was characterized by single-crystal X-ray crystallography, FT-IR, X-ray diffraction, and UV-visible spectroscopy techniques. The thermal stability of the metal complex was studied by the thermogravimetric analysis study. The synthesized metal complex was employed for the synthesis of metal complex-coated polyether sulfone (PES) membranes which were characterized before and after filtration using the FESEM technique. The photocatalytic efficiency of the metal complex was studied for the degradation of methylene blue dye under UV irradiation in the presence of H2O2 and was compared with the photodegradation efficiency of the metal complex-coated polyether sulfone (PES) membrane.

Biology of the Endemic Endangered Swallowtail Butterfly, Papilio desmondi teita (Lepidoptera: Papilionidae), on Wild Citrus Species in Taita Hills, Kenya

The Taita Hills swallowtail butterfly, Papilio desmondi teita, was reared in captivity on wild citrus (Rutaceae), Toddalia asiatica and Clausena anisata, in Ngangao Forest, Taita Hills, Kenya. The butterflies were exposed to the host plants for oviposition inside the laying buckets under ambient laboratory conditions. Results revealed that P. desmondi teita could only complete development on T. asiatica and but not on C. anisata in both seasons. The egg incubation period on T. asiatica was significantly shorter ( P < 0.001) compared to C. anisata during the first season ( P = 0.595) but not in the second season. The development period of the butterfly in 1st and 2nd seasons on T. asiatica was 81.13 ± 0.44 days and 112.15 ± 1.20 days, respectively, while a female-biased sex ratio was observed in the first and second seasons. Findings from this study indicate that T. asiatica was the most suitable host plant for development of P. desmondi teita.

Detection Capability Evaluation of Lunar Mineralogical Spectrometer: Results from Ground Experimental Data

The Chang’E-6 mission will first land on the far side of the moon and bring lunar samples back. As a hyperspectral imager aboard the Chang’E-6 lander, the Lunar Mineralogical Spectrometer (LMS), will achieve the goal of spectral detection and mineral composition analysis in the sampling area, and the data of LMS will also be compared with the results of the returned sample laboratory measurements. Visible and near-infrared hyperspectral remote sensing is an effective tool for lunar minerals identification and quantification. The ground validation experiment can be used to evaluate the detection ability of the LMS. According to the modal abundances of lunar minerals and glasses of APOLLO samples, binary mixed samples, ternary mixed samples, and seven-membered mixed samples were prepared. The samples were ground and stirred homogeneous to about 200 mesh (median particle size about 75 μm), to simulate the soil state of the lunar surface. Under the laboratory ambient condition, the 480–3200 nm spectral data of the samples were acquired using the Engineering Qualification Model (EQM) of Chang’E-5 LMS, the performance of which is consistent with the flight model of Chang’E-6 LMS. By fitting the mixed samples’ spectral data of the EQM using the Modified Gaussian Methods, the following conclusions can be drawn: The subtle spectral changes of mixed samples can be detected. The modal abundance of low-Ca pyroxene, high-Ca pyroxene, and plagioclase can be derived based on the spectral parameters such as absorption position, depth or width of the mixed samples, and the correlation coefficients R 2 are better than 82%, indicating that the LMS has good quantitative detection capability.

Antagonistic, additive and synergistic interactions in the fumigant toxicity of binary mixes of powders of cloves and citrus fruit peels to adults of Callosobruchus maculatus Fabricius (Coleoptera: Chrysomelidae: Bruchinae)

The study evaluated the fumigant toxicity of cloves (Eugenia aromatica Baill.) and citrus peels (Citrus spp.) powders applied singly and binary combinations (1:1 ratio) to the cowpea storage beetle, Callosobruchus maculatus Fabricius under ambient laboratory conditions (28 ± 4°C and 75 ± 10% rh). The powders (singles and mixtures), placed in empty tea bags, were tested at the dosages of 0.0 (control), 0.5, 1.0 1.5 and 2.0 g/20 g of grain in plastic bottles with airtight lids against freshly emerged adult beetles. Adult mortality was observed 24, 48, and 72 h post fumigation. To determine antagonistic, additive and synergistic interactions, corrected mortality data was used to compute co-toxicity factors. Co-toxicity factor for the binary combinations of powders at different dosages at 24 hours indicated antagonistic interaction, ranging from - 40 to -100. Co-toxicity factor at 48 hours ranged from -30 to -90 indicating mainly antagonistic interaction except for Clove + Tangerine, Clove + Lime and Clove + Grape applied at 2.0 g/20 g of grain with -6.7, 0.0, and 6.6 respectively, indicative of additive interaction. Co-toxicity factor at the 0.5 g/20 g of grain dosage at 72 hours ranged from -53.3 to -56.6 indicating antagonistic interaction; at the 1.0 and 1.5 g/20 g ranged from -20 to 6.7 indicating additive interaction; and at the 2.0 g/20 g was 19.7 for Clove and Sweet orange mixture also indicating additive interaction, but 40, 46.7 and 46.7 for Clove and Grape, Clove and Tangerine, and Clove and Lime mixtures, respectively, indicating synergistic interactions.

The impact of Ag/Co nanocomposite on organic charge transport medium for improved photocurrent in polymer solar cell

AbstractTuning charge transport properties using silver‐cobalt bimetallic nanoparticles is investigated to enhance the photo‐current collection in polymer solar cells. The silver‐cobalt nanoparticles were not only augmenting the charge transport processes but also expected to trap light by way of reflection. The polymers blend consisting of poly‐(3‐hexylthiophene) (P3HT):[6,6]‐phenyl C61 butyric acid methyl ester (PC61BM) is used in the fabrication of polymer solar cells. The experimental results indicated that the solar cells' performance depended on the concentration of Ag/Co in the hole transport layer (HTL). Nevertheless, the high‐power conversion efficiency value of up to 4.21% was observed, at the concentration of 0.1% by weight, which is much higher than pristine solar cells due to improved measured photocurrents from the devices. This is a significant improvement in PCE by 66.4% compared to the undoped transport medium. Ag/Co nanocomposite is found to be more stable under ambient laboratory conditions.

First report of Colletotrichum shisoi causing anthracnose of Perilla frutescens in the United States.

Perilla mint (Perilla frutescens (L.) Britt.) is an annual plant native to Asia and considered invasive in North America where it has escaped cultivation as an ornamental (Miller 1947; Swearingen et al. 2010). In August 2021, an anthracnose disease was observed on invasive perilla found along the disturbed margins of a forest in Frederick County, Maryland, United States. Symptoms included necrotic lesions with chlorotic halos, were concentrated in the lower canopy, and caused premature defoliation of lower leaves (Figure S1). Leaves from four plants were surface sterilized by rinsing for 30 s in 70% ethanol, 60 s in 0.8% NaClO, and 60 s in sterile water and then incubated on 2% water agar under ambient laboratory conditions to permit sporulation. After three days, spores that exuded from individual lesions were streaked onto acidified potato dextrose agar. Two single-conidium isolates were recovered from each plant. All eight isolates were identified to species using DNA sequences. A single isolate (21-067) was selected at random for morphological characterization and completion of Koch's postulates. Morphological features were recorded after seven days of growth on synthetic low-nutrient agar (SNA) and potato dextrose agar (PDA) incubated at 22°C under 12 hr UV-B and white fluorescent lighting. Measurements were based on a minimum of 20 observations per structure. Cultures on SNA were flat, hyaline to pale salmon, lacked sporodochia and grew at a rate of 1.3 mm day-1 (n = 3). Vegetative hyphal width was (minimum-maximum) 1.5-4.0 μm, (average ± standard deviation) 2.7 ± 0.9 μm. Conidiophores arose directly from hyphae, were hyaline, smooth, unbranched and measured 40.0-180.0 x 1.5-4.5 μm, 102.3 ± 33.9 x 2.7 ± 0.8 μm. Conidia were single celled, straight, hyaline, glabrous, rounded at both ends and measured 10.0-20.0 x 3.8-6.3 μm, 15.4 ± 2.5 x 4.9 ± 0.7 μm. Setae, observed only on PDA, were pale brown, 1-2 septate, straight, blunt tipped and measured 42.5-97.5 μm, 70.8 ± 13.4 μm. Appressoria formed on PDA were single-celled, pigmented, smooth, and obovoid with entire margins, measuring 5.2-7.7 x 8.6-13.8 μm, 6.8 ± 0.6 x 10.8 ± 1.4 μm. These characteristics were consistent with members of the Colletotrichum destructivum species complex. Partial DNA sequences from five loci were amplified following the procedures of Damm et al. 2014: internal transcribed spacer region of rDNA (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), chitin synthase 1 (CHS-1), actin (ACT), and beta-tubulin (TUB2). Pairwise sequence comparisons to references using the Blastn algorithm found 99.8% similarity between isolate 21-067 and ex-type C. shisoi isolate JCM 31818: MH660930 (ITS, 545/546 bp), MH660931 (GAPDH,192/192 bp), MH660929 (CHS-1, 278/280 bp), MH660928 (ACT, 262/262 bp), and MH660932 (TUB2, 511/511 bp) (Altschul et al. 1990; Gan et al. 2019). Subsequently, sequences from all eight isolates were aligned with Clustal Omega (Sievers and Higgins 2018), concatenated, and used in a Bayesian phylogenetic reconstruction (Huelsenbeck and Ronquist 2001) of the C. destructivum species complex (Figure S2), confirming the species identity as C. shisoi. Sequences were deposited in NCBI GenBank under accession numbers OM865277-OM865284 and OM885059-OM885090. Koch's postulates were fulfilled using perilla grown in a greenhouse until second true leaves emerged. Inoculum washed from two-week-old fungal cultures grown on potato dextrose agar was adjusted to 4 x 104 conidia mL-1 and applied to three replicate plants with an aspirator until runoff. Three plants were sprayed with sterile water as a negative control. Plants were covered with plastic bags for 72 hrs and maintained in a growth chamber at 20°C and 80% RH for 14 days. Inoculated plants displayed disease symptoms similar to those observed under field conditions, and control plants did not develop symptoms. Colletotrichum shisoi was reisolated from symptomatic tissue and reidentified based on morphology. The experiment was completed twice. To the authors' knowledge, this is the first report of C. shisoi on P. frutescens in the United States. Colletotrichum shisoi has not been reported as a pathogen on other plants in the United States and may have potential use as a biological control agent for invasive perilla.

Bistable Boron-Related Defect Associated with the Acceptor Removal Process in Irradiated p-Type Silicon—Electronic Properties of Configurational Transformations

The acceptor removal process is the most detrimental effect encountered in irradiated boron-doped silicon. This process is caused by a radiation-induced boron-containing donor (BCD) defect with bistable properties that are reflected in the electrical measurements performed in usual ambient laboratory conditions. In this work, the electronic properties of the BCD defect in its two different configurations (A and B) and the kinetics behind transformations are determined from the variations in the capacitance-voltage characteristics in the 243–308 K temperature range. The changes in the depletion voltage are consistent with the variations in the BCD defect concentration in the A configuration, as measured with the thermally stimulated current technique. The A→B transformation takes place in non-equilibrium conditions when free carriers in excess are injected into the device. B→A reverse transformation occurs when the non-equilibrium free carriers are removed. Energy barriers of 0.36 eV and 0.94 eV are determined for the A→B and B→A configurational transformations, respectively. The determined transformation rates indicate that the defect conversions are accompanied by electron capture for the A→B conversion and by electron emission for the B→A transformation. A configuration coordinate diagram of the BCD defect transformations is proposed.

A diminutive snake species can maintain regional heterothermy in both homogeneous and heterogeneous thermal environments.

Regional heterothermy is a pattern whereby different body regions are maintained at different temperatures, often to prioritize the function of certain body parts over others, or to maximize the function of organs and tissues that vary in thermal sensitivity. Regional heterothermy is relatively well understood in endotherms, where physiological mechanisms maintain heterogeneity. However, less is known about regional heterothermy in ectotherms, where behavioral mechanisms are more important for generating thermal variation. In particular, whether small and elongate ectotherms with high surface area to volume ratios such as diminutive snakes can maintain regional heterothermy, despite rapid thermal equilibration, is not yet known. We measured regional variation in body temperature and tested whether environmental heterogeneity is used to generate regional heterothermy in the ring-necked snake (Diadophis punctatus) using both field and laboratory studies. We found that ring-necked snakes have robust regional heterothermy in a variety of contexts, despite their small body size and elongate body shape. Temperature variation along the length of their bodies was not detectable when measured externally. However, snakes had higher mouth than cloacal temperatures both in the field and in laboratory thermal gradients. Further, this regional heterothermy was maintained even in ambient laboratory conditions, where the thermal environment was relatively homogeneous. Our results indicate that regional heterothermy in ring-necked snakes is not solely driven by environmental variation but is instead linked to physiological or morphological mechanisms that maintain regional variation in body temperature irrespective of environmental context.

Triaxial Cell for Determining Shielded Cable Transfer Impedance During Environmental Stress

Transfer impedance is a main characteristic to describe the shielding performance of shielded cables at least up to 1 GHz. Traditionally, methods, such as line-injection and triaxial cell, have been used to characterize it at ambient laboratory conditions. While the ambient laboratory conditions might represent appropriate environmental conditions for some industries, in others, such as automotive, they are only a small subset of the real conditions. Thus, there is a need to characterize the transfer impedance over different environmental conditions. In this article, the authors present and verify a new triaxial cell design that is aimed to provide reliable measurements during high thermal and mechanical stresses. First, the cell performance is compared with a commercial cell at laboratory ambient conditions. Then, measurements are performed with the new cell at highly accelerated life testing conditions. Under these high thermal and mechanical stress conditions, the cell performance is verified, and results on typical shielded cable performance under the same conditions are given.

Effect of Dry Storage on Seed Germination of <i>Ephedra monosperma</i> (Ephedraceae)

Abstract—Effects of dry storage under ambient laboratory conditions on germination and survival was tested for seeds of rare species Ephedra monosperma. The seeds without pregermination treatment were placed in Petri dishes with a moistened filter paper at room temperature 20 ± 3 °C. Seeds maintain high germination when dry stored for 5 years (mesobiotic), further storage leads to a sharp decrease in germination. At the same time, dry storage of seeds does not change the time of the beginning of germination, the duration of germination and the curve of seed germination. Freshly harvested seeds and seeds stored at room temperature germinate 2–4 days after seeding, 50% of seeds – in 7 days, and 98–100% – within 2 weeks. The seed germination curve has two peaks; the highest one is the first, which is observed on the 3rd day from the start of germination.

A structural, optical and electrical comparison between physical vapour deposition and slot-die deposition of Al:ZnO (AZO)

Aluminium-doped zinc oxide (AZO) is a potential low-cost alternative to indium tin oxide (ITO) for application in optoelectronic devices as a transparent conducting thin film. Typically, AZO thin films are deposited using expensive, high vacuum equipment with high energy cost and materials wastage. In this study, slot-die coating was used as an inexpensive alternative to vacuum deposition to form AZO nanoparticle thin films under ambient laboratory conditions. The films were characterised structurally, optically and electrically and compared with a commercially obtained AZO film fabricated using physical vapour deposition (PVD). Structural characterisation of the nanoparticle film shows uniform coverage across the substrate with increased crystal quality following annealing in Ar up to 500 ^{circ }C. The optical properties of the nanoparticle film exhibit a wider band gap than the PVD film, while the high density of grain boundary defects between the nanoparticles inhibits sheet conductivity.Graphical abstract

Ambient Tip-Enhanced Two Photon Photoluminescence from CdSe/ZnS Quantum Dots

Nonlinear nano-optical measurements that combine ultrafast spectroscopy with tools of scanning probe microscopy are scarce. This is particularly the case when high spatial resolution on the order of a few nanometers is sought after in experiments performed under ambient laboratory conditions. In this work, we demonstrate the latter through measurements that track two-photon photoluminescence from aggregates of CdSe/ZnS quantum dots with sub-5 nm spatial resolution. Our proof-of-principle measurements that only take advantage of a plasmonic probe (as opposed to a gap mode) pave the way for nonlinear photoluminescence-based spectral nanoimaging of realistic/heterogeneous (bio) molecular and (bio) material systems.

Relationship Between Mass Loss and Fruit Quality of Sweet Orange at Two Different Storage Conditions.

Mass loss from fresh produce is linked to areduction of its aesthetic value. However, arelationship between mass loss and biochemical quality parameters at different storage conditions has not been widely explored. Therefore, the current study is designed with the objectives to determine the behavior of fruit quality parameters and arelationship between fruit mass loss and fruit quality at two different storage conditions. Sweet orange fruit stored in azero energy cool chamber (ZECC) had greater shelf-life of more than 15 days, fruit size (62.40 mm) and peel (35.15%) and lower mass loss (4.94%), juice (32.19%) and electrical conductivity (EC) (2.06 S/m) as compared to ambient conditions in laboratory during 25 days of storage. In ZECC, only EC was positively correlated (r = 0.57) with mass loss, whereas at room temperature EC (r = 0.76), total soluble solids (TSS) (r = 0.60) and fruit internal temperature (r = 0.64) were positively and peel (%) (r = -0.52) and fruit diameter (r = -0.49) were negatively correlated with mass loss. Correlation of combined storage conditions revealed that EC (r = 0.47) and TSS (r = 0.50) were positively and peel (%) (r = -0.77) and fruit diameter (r = -0.55) were negatively correlated with mass loss (%). The principal component analysis (PCA) revealed that the scores of room temperature were strongly associated with TSS, pH, EC, mass loss (%), juice (%) and internal temperature (°C), whereas scores ofZECCwere strongly associated with pulp (%), ascorbic acid (mg 100 mL-1), acidity (%), and fruit diameter (mm).

Insecticidal Effect of Bularafa Raw Diatomaceous Earth (BRDE) Against Rhyzopertha dominica (F.) on Stored Maize (Zea mays L.) and Sorghum (Sorghum bicolor [L.] Moench) Grains

The toxicity of Bularafa raw diatomaceous earth (BRDE) to Rhyzopertha dominica adults on stored maize and sorghum grains was conducted under ambient laboratory conditions (31-34oC and 24 – 30% R.H.). The BRDE was tested at doses: 0 (untreated control), 250, 500, 1,000 1,500, and 2000 mg/kg and Protect-It® at 1000 mg/kg of grain which served as a check. Thirty (30) mixed-sex adult insects were exposed to 50 g of freshly treated grains, and mortality was observed after 7 and 14 days. The results showed that a higher number of exposed Rhyzopertha dominica adults died on maize than on sorghum, and mortality increased with an increase in dose and exposure period. After 7 days of exposure to treated maize and sorghum grains, the LD95 values were 4981 and 5890 mg/kg of BRDE, respectively. The corresponding values after 14 days were 1561 and 3206 mg/kg, respectively