R. Hulasare

Purdue University, West Lafayette, Indiana, United States

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Publications (10)6.08 Total impact

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    ABSTRACT: The influence of sanitation on responses of life stages of the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), was investigated in a pilot flour mill subjected to three, 24-h heat treatments by using forced-air gas heaters fueled by propane. Two sanitation levels, dusting of wheat flour and 2-cm-deep flour, were created in 25 plastic bioassay boxes, each holding eggs, young larvae, old larvae, pupae, and adults of T. castaneum plus two temperature sensors. Data loggers (48) were placed on the five mill floors to record air temperatures. The time required to reach 50 degrees C, time above 50 degrees C, and the maximum temperature among mill floors and in bioassay boxes were measured. The maximum temperature in bioassay boxes and in the mill was lower on the first floor than on other floors. This trend was apparent in time required to reach 50 degrees C and time above 50 degrees C, especially in compartments with 2-cm-deep flour. The mean +/- SE mortality of T. castaneum life stages on the first floor was 55.5 +/- 12.9-98.6 +/- 0.8%; it was 93.2 +/- 6.7-100 +/- 0.0% on other floors. Adults were the least susceptible stage. Mortality of T. castaneum stages in compartments with 2-cm-deep flour was generally lower than those with flour dust. Costs for the three heat treatments ranged from US$27,438 to $28,838. An effective heat treatment can be conducted within 24 h, provided temperatures on mill floors reach 50 degrees C in 8-12 h and are held above 50 degrees C for at least 10-14 h, with maximum temperatures held between 50 and 60 degrees C.
    Journal of Economic Entomology 04/2012; 105(2):709-17. DOI:10.1603/EC11114 · 1.61 Impact Factor
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    ABSTRACT: Elevated CO2 levels in localized pockets of a grain mass are caused by insects, fungi, and grain metabolism. These hotspots may occur away from temperature cables in bins, silos, tanks and warehouses making early detection of spoilage difficult. For grain stored in ground piles or bunkers that typically do not have temperature cables, considerable economic loss may result in the absence of CO2 monitoring. The primary objective of this study was to monitor CO 2 levels for early detection of spoilage. Three large tanks and two ground piles were monitored at a commercial grain handling facility (grain elevator) in the Midwestern U.S. Each tank held approximately 12,500 t and the ground piles held approximately 40,000 and 50,000 t of maize each. Four CO2 sensors each were installed at the top (near the vents) and base (exhaust air stream of fans) of each tank. The CO 2 sensors were connected to master radios that received signals from the sensors and transmitted data wirelessly to a slave radio connected to a PC located in the office about 300 m away. For each ground pile, a sensor was installed in the air stream of several exhaust fans. The study was conducted from April - Sept 2005 in the large tanks and from January - May 2006 for the ground piles. The CO2 levels ranged from 500 ppm (0.05 %) to 5,000 ppm and higher levels of up to 2.5 % were recorded with a portable CO 2 monitor. The high CO2 levels were confirmed by the extent of spoilage which ranged from 15 to 25 % when maize was moved out from the large tanks in September 2005. CO2 monitoring of the ground piles storing newly harvested maize became an important decision-making tool for the operations manager with respect to early detection of spoilage.
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    D. E. Maier, R. Hulasare, D. J. P. Moog
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    ABSTRACT: The objective of this study was to compare the efficacy of physical exclusion (PE) with ambient aeration (= 23.5 °C) versus ambient aeration (= 23.5 °C) (AA) versus chilled aeration = 18.0 °C (CA) without physical exclusion to prevent migration or cross-infestation by stored product pests in maize stored in 12.5-tonne pilot bins. Physical exclusion tactics implemented were: sealing all joints around the roof vents, placing a nylon mesh inside the roof vents, and placing a circular collar with nylon mesh over the main entry opening. The trials were conducted during the summers of 2004 and 2005 (June to October) and measures for PE were implemented ahead of the summer storage season. For the PE treatment, a strict bin-entry protocol was implemented to avoid any cross- infestation or migration of insects during frequent sampling requiring bin entry. Natural insect infestation levels in all bins were monitored weekly by placing probe traps (WB-II), pheromone baited flight traps, and cardboard rolls. While insect counts were not significantly different between CA and AA in pitfall traps and cardboard rolls, results showed that infestation levels of Indianmeal moths caught in flight traps were significantly lower in bins with PE measures compared to AA. CA generally gave the least insect count among the three strategies and compared to PE, infestation levels between these were not significantly different until the first week of August. PE delayed Indianmeal moth infestation for the first two months of summer storage as compared to AA. Therefore, PE has potential as an effective measure to prevent migration or cross-infestation of insects from outside and minimize if not avoid the use of chemical control methods.
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    ABSTRACT: Scale-up and demonstration trials were conducted at the pilot bin facility of the Purdue University Post-Harvest Education & Research Center in June 2005 with conventional maize, at a popcorn facility in July 2005, and at an organic maize storage and processing facility in September 2005. The primary objective of these trials was to determine the efficacy of ozonation to control insect pests. The basic setup for ozonation at these sites consisted of generating ozone with commercially available generators, introduction in the headspace, drawdown to the plenum with a suction fan, and re-circulation of ozone back into the bin headspace. Ozonation was done to attain an ozone concentration of 50 ppm in the plenum and maintained for a period of 3 days to achieve mortality of insects comparable to phosphine fumigation. The trials were performed using insect bioassays with adults of maize weevil, red flour beetle and larvae of Indianmeal moth that were placed 0.6 m below the grain surface and in the plenum of silos. The concept of two phases of ozonation and the airflow rates needed to achieve the required treatment levels of 50 ppm were confirmed. The trials proved the efficacy of ozonation in achieving stored product insect mortality comparable to phosphine fumigation. The trials at the popcorn and organic maize facilities confirmed that end-use parameters like popping volume of popcorn and milliability of organic maize were not affected.
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    ABSTRACT: The objective of this study was to determine the effect of two temperature management strategies: chilled aeration (CA) = 18.0 °C and ambient aeration (AA) = 23.5 °C on confined populations of maize weevil (MW) and red flour beetle (RFB) in maize stored in 12.5-tonne pilot bins. Three bins were used for each of the two strategies with temperature thresholds maintained by a PC-based software to control fan operation. Confined populations of MW and RFB were investigated for survival and progeny development using insect bioassays that made use of PVC pipes filled with maize, sealed with fine mesh, and embedded in the grain bulk. A cage of each insect species was removed monthly (June to October) for insect counts and incubated at optimum conditions for progeny development over two months. Considering all five years, maximum progeny counts of MW were lower for CA (90 to 1,200) compared to AA (400 to 1,830). Similarly, for RFB, CA (1 to 190) yielded lower maximum progeny counts compared to AA (11 to 630). The results demonstrated that CA effectively suppressed natural infestation levels as well as confined populations of MW and RFB compared to AA.
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    ABSTRACT: Eleven-kilogram parcels of durum wheat (Triticum durum L. cv. Melita) at 16% and 20% initial moisture content (m.c.) were kept in storage in a Manitoba farm granary for 20 weeks (May–September 2000) to determine changes in storage quality indicators and mycotoxin production. Temperature, moisture, CO2 levels, ergosterol content, odor volatiles, microfloral infection, and levels of major mycotoxins were monitored. Ochratoxin A and citrinin reached mean levels of 6.5 and 11.6 mg/kg, respectively, by 20 weeks at 20% m.c., but were absent at 16% m.c., and no other mycotoxins were found. Penicillium species were the predominant microflora. Ergosterol levels remained between 3.9 and 8.4 mg/kg at 16% m.c., but increased from 3.9 to 55.5 mg/kg at 20% m.c. during the 20-week trial period. A 12-element metal-oxide chemosensor array was used to monitor odor volatile evolution. Nine of the 12 sensors were able to track odor volatile changes at 20% and could consistently distinguish between volatiles from the two moisture treatments. Signals from these nine chemosensors showed a good correlation with ochratoxin A formation at 20% m.c. with r values between 0.84 and 0.87. Signals from two of these nine sensors also correlated well with citrinin formation (r=0.83) and very well with ergosterol production (r=0.98).
    Journal of Stored Products Research 01/2005; DOI:10.1016/j.jspr.2003.11.002 · 1.49 Impact Factor
  • R HULASARE
    Journal of Stored Products Research 05/2004; DOI:10.1016/S0022-474X(04)00015-3 · 1.49 Impact Factor
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    ABSTRACT: Eleven-kilogram parcels of hulless barley (Hordeum vulgare L. cv. Condor) at 15 and 19% initial moisture content were kept in simulated storage in a Manitoba farm granary for 20 weeks (June 1996–October 1996) to determine biotic and abiotic changes and mycotoxin production. Temperature, moisture content, CO2 levels, ergosterol content, seed germination, microfloral infection, and the presence of major mycotoxins were monitored. Ochratoxin A, citrinin and sterigmatocystin reached mean levels of 24, 38 and 411 ppb by 20 weeks in the 19% moisture content barley, but were absent in the 15% moisture content barley; no other mycotoxins were detected. Penicillium species and Aspergillus versicolor (Vuill.) Tiraboschi comprised the predominant microflora. The effect of storage time was apparent at both 15 and 19% moisture content for grain temperature, Alternaria alternata (Fr.) Keissler, Penicillium species and Aspergillus versicolor. At 19% moisture content, storage time also affected moisture content, CO2 level, ergosterol content, seed germination, and mycotoxin production. At 19% moisture content, elevated ergosterol levels at weeks 4 and 8 appear to offer early warning of the appearance of sterigmatocystin at week 12, and of ochratoxin A and citrinin at week 20.
    Journal of Stored Products Research 07/1999; 35(3-35):297-305. DOI:10.1016/S0022-474X(99)00013-2 · 1.49 Impact Factor
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    ABSTRACT: Eleven-kilogram parcels of hulless barley (Hordeum vulgare L. cv. Condor) at 15 and 19% initial moisture content were kept in simulated storage in a Manitoba farm granary for 20 weeks (June 1996–October 1996) to determine biotic and abiotic changes and mycotoxin production. Temperature, moisture content, CO2 levels, ergosterol content, seed germination, microfloral infection, and the presence of major mycotoxins were monitored. Ochratoxin A, citrinin and sterigmatocystin reached mean levels of 24, 38 and 411 ppb by 20 weeks in the 19% moisture content barley, but were absent in the 15% moisture content barley; no other mycotoxins were detected. Penicillium species and Aspergillus versicolor (Vuill.) Tiraboschi comprised the predominant microflora. The effect of storage time was apparent at both 15 and 19% moisture content for grain temperature, Alternaria alternata (Fr.) Keissler, Penicillium species and Aspergillus versicolor. At 19% moisture content, storage time also affected moisture content, CO2 level, ergosterol content, seed germination, and mycotoxin production. At 19% moisture content, elevated ergosterol levels at weeks 4 and 8 appear to offer early warning of the appearance of sterigmatocystin at week 12, and of ochratoxin A and citrinin at week 20.
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    R Hulasare, Dirk Maier, M Leitman
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    ABSTRACT: Use of high temperatures to control stored product pests is increasing due to the need for pesticide free products, international treaties (Montreal Protocol), and increased resistance of insects to chemicals. Methyl bromide, a widely used ozone-depleting fumigant has been phased out but critical use exemption continues as alternatives like heat and sulfuryl fluoride are adopted by the industry. Heat treatment involves raising temperatures inside whole or a part of the plant to 50 to 60°C and holding for up to 24 h. The 24 h is necessary for the heat to penetrate wall voids and equipment for effective kill of insects. Many processing plants are located in remote areas adjacent to crop production areas. Propane is readily available here and is a fuel of choice in absence of infrastructure for natural gas. Mobile propane fueled heaters were developed and demonstration trials conducted to convince the producers and processors on efficacy of heat to control pests. A propane fueled mobile heat treatment unit (MHT-1500) was designed, tested and field trials were conducted in empty farm bins at sites in Indiana and Kansas State. The objectives were to determine the mortality rates of all life stages of major stored product pests at 55°C and 65°C. Heat treated bins and had lower insect populations compared to control bins over a year of storage. The time of heat treatment ranged between 3-5 h and cost of propane per bin ranged from $30.95 to $46.19. A commercial heat treatment of Sunflower plant was conducted at St. Louis, MO under the EPA grant. The temperature and insect mortality were monitored by Kansas State University researchers. Propane fired heaters were used for heat treatment. The heat treatment was effective in killing all the life stages of insects. Introduction: The contamination of high-value identity-preserved food and specialty grains (as well as conventional commodity grains and oilseeds) due to residual insect populations below the perforated floor (plenum) of corrugated steel farm bins (as well as tanks, silos and flat storage buildings at grain elevators) is a major concern of growers, handlers and processors. Empty bin treatment with residual protectants such as inert diatomaceous earth dusts (ProtectIT) and cyfluthrin (Tempo) products have shown limited success because of the inherent inaccessibility of the plenum area. Although inert dusts can be blown into the plenum via the fan, they are not widely used by producers because dusts are ineffective under humid conditions that develop when high moisture grain is placed in a bin for drying (Le Patourel, 1986). Similarly, the dousing of the perforated drying floor with cyfluthrin spray generally does not result in a uniform drip-through application of the hidden concrete floor and bin sidewalls.

Publication Stats

65 Citations
6.08 Total Impact Points

Institutions

  • 2006
    • Purdue University
      • Department of Agricultural and Biological Engineering
      West Lafayette, Indiana, United States
  • 1999–2005
    • University of Manitoba
      • Department of Biosystems Engineering
      Winnipeg, Manitoba, Canada