Rates of cuticular penetration of 1-naphthylacetic acid (NAA) as affected by adjuvants, temperature, humidity and water quality

When NAA is used for fruit thinning, results can be unpredictable. Problemswith foliar penetration of NAA can contribute to this variability. Usingisolated pear leaf cuticles we have investigated effects of humidity,temperature, hard water and selected adjvants on rates of cuticularpenetration of NAA. If NAA was dissolved in deionised water about 40% ofthe applied dose penetrated in 8 h, while water having a pH > 7 practicallyeliminated cuticular penetration of NAA, even at high humidity (100%) andmoderate temperatures (20°C). Rates of penetration were much lowerat 10°C and 55% humidity. Adding urea, ammonium sulphate or Tween20 increased rates of penetration but not to a great extent. Highest rates ofpenetration were obtained when solutions were buffered at pH 4 with DL-lactic acid and the accelerator adjuvant Genapol C-100 was added. Withthis combination, about 70% of the applied NAA dose penetrated within 8 hat 20°C and 40% at 10°C, respectively, even at low humidity(55 to 60%) and when hard water was used as carrier. It is argued thatpoor performance of NAA as chemical thinner must be expected when hardwater is used for spraying and when the pH of the spray liquid is notadjusted to values around 4, such that a significant proportion of the NAAis non-ionised. Only non-ionised NAA can penetrate cuticles. Rates of foliarpenetration of NAA can be greatly increased, especially at low temperatures,by adding 0.2 to 2.0 g l^–1 Genapol C-100. Since NAA is destroyed byUV light, spraying should be done in the evening. High humidity during thenight is favourable for foliar penetration, but low temperatures aredetrimental and addition of an accelerator adjuvant (i.e. Genapol C-100) isnecessary. If NAA must be sprayed during cold weather (5–10°C),higher NAA concentrations may be used because rates of penetrationduring the night are proportional to dose and excess NAA left on the foliagewill be destroyed by UV light after sunrise.     

Growth and biochemical composition with emphasis on the fatty acids of Tetraselmis sp.

Summary The influence of temperature (15–32°C) and the ratio of nitrogen to phosphorus (N/P) in the culture medium (0.5–80) on the growth kinetics and protein, chlorophyll, lipid and fatty acid content of the marine microalga Tetraselmis sp. have been studied. Below an N/P of 20, growth was determined by N limitation and above 20 by P limitation. Protein increased with a rise in N content at any test temperature. The chlorophyll content increased with temperature, with maximum values at 25°C. The lipid content decreased with increasing N/P ratio above 20°C. The polyunsaturated fatty acid content tends to be inversely proportional to the growth rate within the N/P range 20–80. The quotient of the n ₃ and n ₆ polyunsaturated-fatty-acid fractions, an indicator of the nutritive value of microalgae, was found to be within the range 2–3. These values were obtained either between 25 and 28°C independent of the N/P ratio used at 20°C for N/P ratios higher than 40.0. Offsprint requests to: Emilio Molina     

High-speed autoradiography of 3H-thymidine-labelled nuclei

Summary High-speed autoradiography with stripping film of ³H-thymidine-labelled cells was tested. The tests involved: (a) various times of immersion of emulsion-covered cell preparations in the mixture of dioxane-PPO-POPOP, at 20°C, (b) exposure of cell preparations and blanks for various times at either –70°C or +20°C, with different humidity levels. Autoradiographs of good quality could be produced by 2-min immersion in the scintillator, exposure time 1 h at either temperature and relative humidity 20–30%. A linear relationship between autoradiographic efficiency and exposure time of 1–7 h was found at either temperature, although the efficiency of autoradiographs exposed at –70°C was by approximately 30% higher than that of autoradiographs exposed at +20°C. Background values of autoradiographs dried with a fan and exposed for 1/4–7h at either –70°C or +20°C were 0.6–0.8 grain/100 m². Theoretical calculations and experimental data showed that high-speed autoradiographs are 30–50 times more efficient as compared with conventional stripping film autoradiographs, thus allowing a shortening of the respective exposure time. Theoretical aspects of efficiency and resolution of high-speed autoradiography are considered.This investigation was supported in part by MR II.1 grant. The technical assistance of Mrs. S. Bie is gratefully acknowledged     

Energy budgets for Stentor coeruleus Ehrenberg (Ciliophora)

Summary Growth and feeding rates in Stentor coeruleus fed on Tetrahymena are described in relation to prey concentrations ranging from 10:1–50:1 at 15°C and 20°C. Feeding rate was independent of temperature, but governed by prey concentration. Stentor decreased in size where less than 1,000 J were consumed in 24 hrs. A maximum level of growth was attained at 15°C, but not at 20°C within the range of prey concentration offered. Energy budgets, constructed using respiratory data published elsewhere (Laybourn, 1975), are presented. Assimilation efficiencies ranged from 74.4–76.4% at 20°C and 65.1–83.2% at 15°C. Gross growth efficiencies were between 70.9–73.6% at 20°C and 63.7–81.6% at 15°C. Net growth efficiencies were very high, 95.6–96.3% at 20°C and 97.5–97.9% at 15°C. The results are explained and discussed in relation to other Protozoa.     

Methanotrophs of the Psychrophilic Microbial Community of the Russian Arctic Tundra

In tundra, at a low temperature, there exists a slowly developing methanotrophic community. Methane-oxidizing bacteria are associated with plants growing at high humidity, such as sedge and sphagnum; no methanotrophs were found in polytrichous and aulacomnious mosses and lichens, typical of more arid areas. The methanotrophic bacterial community inhabits definite soil horizons, from moss dust to peat formed from it. The potential ability of the methanotrophic community to oxidize methane at 5°C enhances with the depth of the soil profile in spite of the decreasing soil temperature. The methanotrophic community was found to gradually adapt to various temperatures due to the presence of different methane-oxidizing bacteria in its composition. Depending on the temperature and pH, different methanotrophs occupy different econiches. Within a temperature range from 5 to 15°C, three morphologically distinct groups of methanotrophs could be distinguished. At pH 5–7 and 5–15°C, forms morphologically similar to Methylobacter psychrophilus predominated, whereas at the acidic pH 4–6 and 10–15°C, bipolar cells typical of Methylocella palustris were mostly found. The third group of methanotrophic bacteria growing at pH 5–7 and 5–10°C was represented by a novel methanotroph whose large coccoid cells had a thick mucous capsule.     

Significance of leaf orientation for leaf temperature in an amazonian sclerophyll vegetation

Summary The influence of leaf orientation on leaf temperature has been studied in an sclerophyll vegetation of the Amazon basin, which grows on white sandy soils of very low water retention capacity and variable depth of the water table.Leaf size of the species studied is mainly mesophyllous (sensu Raunkiaer). The high degree of leaf inclination in all species is very characteristic; 55% of the leaves present inclination angles (relative to the vertical) smaller than 45°.Water potential is generally high, not being lower than –14 bars. Leaf resistance increases toward noon during the course of sunny days, indicating either water stress at leaf level or the influence of low relative humidity on stomata opening.Leaf temperature under sunny conditions reflects the influence of leaf orientation on the amount of radiation absorbed by the leaf. Temperature differences recorded range from 1.8–5.4° C. The difference depends on leaf angle, leaf color and leaf diffusion resistance during the period of measurement.Analysis of the relationship between leaf angle and leaf temperature, using Gates leaf energy balance, shows that under the conditions prevailing at noon in sunny days, leaf angles smaller than 50° are effective in reducing leaf temperature within a wide range of leaf resistances to water vapor transfer.Contribution from the Venezuela MAB-1 Programm, partially supported by the National Research Council (CONICIT) and the Organization of American States (OEA)     

Properties of enzymes from bacteria grown in the 70–100°C range

In chemostat cultures of Bacillus caldolyticus, adaptation in a single step from 70–100°C was followed under aerobic and oxygen-limited conditions and was found to proceed more smoothly under the latter circumstances. Variations of the medium (e.g. yeast extract or silicate concentrations) showed that growth at 100°C is in all respects similar to that of cultures at moderate temperatures.Enzyme preparations derived from cultures at 5°C intervals between 70 and 100°C were used to determine the temperature range. For all nine enzymes tested, the optimum temperature was found to be 67°C; the latter was independent of the growth temperature. Differences were found, however, with respect to the maximum temperature of individual enzymes, and three groups, with maxima between 70 and 80°C, 80 and 90°C and 90 and 100°C can be distinguished. Again, there was no correlation with the growth temperature.Stability experiments also revealed that enzymes from the same organism can have different thermal properties: Some were found to be quite thermolabile (e.g. the pyruvate kinase), while others (e.g. hexokinase and glutamate-pyruvate transaminase) exhibited a high thermostability. These properties were not related to the growth temperature within the 70–100°C range, too.Six of the enzymes tested could be stabilized by their respective substrates, but the degree of protection varied for individual enzymes. Three enzymes (acetate kinase, glutamate dehydrogenase and myokinase) could not be stabilized by their substrates.Comparative experiments with the hexokinase suggested, that the thermal integrity of the enzymes is better protected within the cell as compared to the stability of the enzyme preparations.Abbreviations used AK acetate kinase - Ala-DH alanine dehydrogenase - Ald aldolase - GIDH glutamate dehydrogenase - G6P-DH glucose-6-phosphate dehydrogenase - GTP glutamate-pyruvate transaminase - HK hexokinase - ICDH isocitrate dehydrogenase - MK myokinase - PK pyruvate kinase     

Effects of temperature and relative humidity on development times and mortality of eggs from laboratory and wild populations of the European house-dust miteDermatophagoides pteronyssinus (Acari: Pyroglyphidae)

As part of a study on passive physical control of house-dust mites, a total of 6000 eggs from a population ofDermatophagoides pteronyssinus (Trouessart, 1897) from 17-year-old laboratory cultures were incubated at 60 temperature and relative humidity combinations between 10–35°C and 55–100% RH. Eggs hatched at every combination, although mortality and development time increased between 10–20°C and 30–35°C and below 65% RH. Optimum conditions were 35°C and 80–85% RH. In temperate dry conditions, eggs from a wild population were found to be more resistant to mortality: they developed faster, with 7 times lower mortality than eggs from the laboratory population. This may have been because the laboratory population had become acclimated to the constant near-optimum conditions at which it was kept. Therefore it has been suggested that where laboratory cultures have been used in studies relating to passive physical control, caution should be taken in applying the conclusions to wild populations in the natural house-dust environment.     

Autecological investigations on marine diatoms. 5:Coscinodiscus concinnus W. Smith andRhizosolenia setigera Brightwell

The cold oligo-eurytherm diatomsCoscinodiscus concinnus W. Smith andRhizosolenia setigera Brightwell were cultured to determine their best competitive position by growth. Comparison of their generation times with those of other diatoms indicate that they reach this position between 6°C and 12°C. Both species grew between –1.5°C and about 20°C. The experiments indicate thatC. concinnus flowerings are possible in a deep water column, during periods of high light intensities. The simultaneous death of species in the upper layer is also caused by high light intensities.C. concinnus appeared in two morphological forms; the normal voluminous form, and a flatter form with a few intercalary bands only, filled with large oil-droplets. The latter appeared at 0°C and below, and at the upper temperature limit for growth of about 19°C–20°C. The separation of nov. spec. fromC. concinnus based on the absence or presence of a hyaline area and intercalary bands as identification characteristics should be reconsidered.     

Studies on the rust,Maravalia cryptostegiae,a potential biological control agent of rubber-vine weed,Cryptostegia grandiflora (Asclepiadaceae: Periplocoideae), in Australia,II: Infection

The parameters which govern infection of rubber-vine weed by the rustMaravalia cryptostegiae were investigated. The infection process, from appressorial formation to sporulation, is described and illustrated. Uredinioid teliospores have an optimum temperature range for germination at 22–27 °C, both in vitro and in vivo. However, germination on the rubber-vine leaf was more than double (81–92%) that in the absence of the host, and appressoria were formed only in vivo. An optimum temperature of 20–22°C and a dew period of 12 hours or more gave the highest level of infection as measured by sporulation density. The latent period from inoculation to pustule formation decreased with increasing temperature; the shortest period (8–11 days) being recorded at 25–27°C. At the lower temperatures (18°C), this was significantly extended (19–21 days). Four successive inoculations significantly reduced plant height and dry weight, although a compensatory growth flush occurred after the third inoculation. The addition of cryoprotectants had a negative affect on spore viability and subsequent infectivity. Cooling dry spores to –196°C at the rate of 10°C min^–1 gave the best results, with high germination (93–65%) up to 8 days after thawing.     

Factors affecting spore germination in Aspergillus niger

Temperature markedly affected germination and germ tube length of A. niger. More than 90% of the spores were germinated in the range 30°–34 °C and formed maximum length of germ tubes. At temperatures from 38° to 43 °C, the proportion of the spores that germinated as well as the germ tube length were both gradually decreased. However, at 47°C germ tube formation was completely inhibited up to 15 hrs. after inoculation.High relative humidity was found necessary for the spore germination of A. niger. Germination failed to occur at 76% relative humidity. At 78 and 81% relative humidity germination was detected 15 hrs. after inoculation while at the higher humidities germination was started after 6 hrs. only.Conidiospores of A. niger were very sensitive to changes in the hydrogen ion concentration, pH. Complete inhibition of germination was found at pH less than 3.5. The germination and the length of the formed germ tubes increased with pH to reach their maximum rates at pH 4.5.     

Study of physicochemical factors limiting the growth ofKluyveromyces marxianus

Summary The effects of various physicochemical parameters on the growth of twoKluyveromyces marxianus strains were investigated, including: pH values, sodium chloride, water activity in the medium and temperature. Both yeast strains were unaffected by pH changes. Optimal pH for growth was found to be 4 with both strains, but they were able to develop within the pH 3–8 range. Suitable growth was obtained at temperatures of 4–44°C and the optimal temperature for growth was 36°C for both strains. Modelling of this latter parameter is described. Growth of both microorganisms was considerably modified by increased NaCl or decreased water activity in the medium.     

Water relations and photosynthesis in the cryptoendolithic microbial habitat of hot and cold deserts

Two cryptoendolithic microbial communities, lichens in the Ross Desert of Antarctica and cyanobacteria in the Negev Desert, inhabit porous sandstone rocks of similar physical structure. Both rock types adsorb water vapor by physical mechanisms unrelated to biological processes. Yet the two microbial communities respond differently to water stress: cryp-toendolithic lichens begin to photosynthesize at a matric water potential of –46.4 megaPascals (MPa) [70% relative humidity (RH) at 8°C], resembling thallose desert lichens. Cryptoendolithic cyanobacteria, like other prokaryotes, photosynthesize only at very high matric water potentials [> –6.9 MPa, 90% RH at 20°C].     

Interactions between photoperiodism and temperature with respect to the control of dormancy in the adult stage of Pterostichus oblongopunctatus F. (Col., Carabidae)

Summary Pterostichus oblongopunctatus belongs to the type of spring breeding carabids with adult hibernation. Ovarian maturation is under the control of photoperiod: the females need a change of day length to mature. The first step of egg maturation (previtellogenesis) is bound to short day, the second step (vitellogenesis) to long day.The short day effect is achieved almost only at temperatures of 10 to 15°C; it is completely suppressed by 20°.The males mature under very different photoperiods and temperatures, but long day diminishes the percentage of mature males slightly, as well as does the higher temperature of 20°C in short day as compared with 15°C.Simulation of climatic conditions as experienced by the beetles from autumn throughout winter until spring in the laboratory showed that a short span of favourable temperatures at short day as experienced in nature in autumn allows the females to accomplish the short day development. But this maturation effect is still more diminished the longer temperatures below 5°C act on the beetles. Following that, a second period of temperatures between 10–15°C must restore the short day maturation effect if full maturity shall be gained in the following long day.The beetles are able to store reserve materials under long day at 20°C. After such a period they are able to have a normal previtellogenesis in spite of a severe shortage of food during short day. These experiments indicate that the failure in short day development outside the temperature range of 10–15°C is not a matter of an especially well balanced over-all metabolism in this favourable temperature range. It seems rather that hormonal systems involved in the short day phase of oogenesis act only within this span of temperature.Supportet by the Deutsche Forschungsgemeinschaft.     

Studies on the effects of climate on livestock production in Iraq

Measurements were made of the roughage and water intake of young Friesian cross males and females throughout a 12-month period. Results showed that the roughage consumption fell by 10–16% between the temperature range 11°–20°C and 21°–30°C and by 20–43% between the temperature range 11°–20°C and 31°–40°C. Water intake increased from 30–44% between 11°–20°C and 21°–30°C and by 45–92% between 11°–20°C and 31°–40°C.

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Zusammenfassung Rauhfutterverzehr und Wasserkonsum junger schwarzbunter Kreuzungsrinder wurden während eines Zeitraumes von zwölf Monaten gemessen. Die Ergebnisse zeigen, dass der Rauhfutterverzehr um 10–16% zurückging wenn die Lufttemperatur von 11°–20°C auf 21°–30°C stieg, und um 20–43% beim Anstieg von 11°–20°C auf 31°–40°C. Der Wasserkonsum nahm zwischen 11°–20°C und 21°–30°C um 30–44% und zwischen 11°–20°C und 31°–40°C um 45–92% zu.

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Resume Pendant une période de douze mois, on a cherché à mesurer la quantité d'eau et de foin consommée par un jeune bétail de race Friesian en Irak. Les résultats furent les suivants: Lors d'une augmentation de température de 11°–20°C à 21°–30°C, la consommation de foin diminua de 10 à 16%, allant même jusqu'à diminuer de 20 à 43% lors de températures augmentant de 11°–20°C à 31°–40°C. La consommation d'eau, quant à elle, augmenta de 30 à 44% dans le premier cas et de 45 à 92% dans le second.

     

Effects of temperature and salinity on survival of toxigenicVibrio cholerae O1 in seawater

In 1991 and 1992, the Latin American epidemic strain of Vibrio cholerae O1 was isolated from ballast water, bilge water, and sewage taken from cargo ships docked in Mobile Bay, Alabama. The findings raised questions regarding the organism's ability to survive long-term aboard ships and to withstand the exchange of ballast at sea. The effects of temperature (6, 18, and 30°C) and salinity (8, 16, and 32 ppt) on survival of V. cholerae O1 strains C6706 and C6707 and a ballast water isolate in sterile seawater were determined. The ballast water isolate, which had a D-value (number of days required to produce a 1 log₁₀ reduction in colony-forming units per milliliter) of 240 days at 18°C, 32 ppt salinity, had the longest survival time. The range of D-values was 36–240 days at 18°C, 60–120 days at 30°C, and 5–20 days at 6°C. In sterile seawater short-term survival was temperature dependent, whereas long-term survival was salinity dependent. In raw seawater, survival time of the ballast water isolate was reduced to 12–27 days, implying the existence of biological influences. As also shown in our previous work, the organism appeared to be able to survive for several months under relatively stable conditions in ballast water aboard ships; however, viability may be reduced to only a few weeks after the organism is introduced into estuarine or marine environments. Correspondence to: Susan A. McCarthy.     

Temperature-dependent dry receptor on antenna ofPeriplaneta. Tonic response

Summary Identified as a dry receptive unit by transitory impulse frequencies up to about 200 imp/sec during rapid drops in humidity (Fig. 3) and which no other modality elicited, the dry unit on the antenna ofPeriplaneta americana is characterized by a regular (Fig. 4) and relatively high stationary impulse frequency (10–65 imp/s). Without exception the stationary discharge rate (tonic frequency) rose with falling values of stationary absolute humidity at constant temperature, and with rising values of stationary temperature of ambient air at constant humidity. Enthalpy and evaporation cooling appear to be ruled out as exclusive adequate explanations for this double dependence. No matter whether tonic frequency is plotted against absolute humidity based on either volume of moist air or weight of dry air, or against partial pressure of water vapor in ambient air, or the difference between saturation and partial vapor pressure, or against relative humidity, the dependence on the temperature is not eliminated (Figs. 5–7). Because a temperature range of about 20 °C and all humidities between 0 and 100% occupy the same large segment of the unit's tonic frequency spectrum (Fig. 8), the unit is termed bimodal.The author wishes to express indebtedness and gratitude to Prof. Dr. Hansjochem Autrum for backing the early stages of this project with the assistance of the Deutsche Forschungsgemeinschaft, to Prof. Dr. Helmut Altner for his prolonged support, to Dr. Hans-Jürgen Hinz for his helpful discussion of questions involving thermodynamics, to Prof. Dr. Friedrich Earth for helpful criticism of the text, and to Miss Christel Praeg for tireless technical assistance.     

Effect of temperature on osmotic and ionic regulation in goldfish,Carassius auratus L.

Summary Urine flow increased with acute temperature increases and showed temperature acclimation. When measured at 20 °C the urine flow of 10 °C acclimated fish was 3.2 times greater than the urine flow of 30 °C acclimated fish. In fish acclimated to 24 °C renal reabsorption of Na and Cl was independent of temperature over an intermediate range of temperatures (14–24 °C) but near the lower lethal temperature (6.5 °C) renal Na and Cl reabsorption was inhibited. Water permeability of the renal tubules was not affected by acute temperature change between 6.5 and 24 °C. Urine osmolality and urine Na, K and Cl concentrations showed nearly perfect temperature compensation in fish acclimated to 10 °C and 30 °C. The rate of renal excretion of Na and Cl showed temperature acclimation in that Na and Cl ecxretion measured at 20 °C was 7 to 8 times greater in 10 °C acclimated fish than in 30 °C acclimated fish. The rate of excretion of Na and Cl measured at 30 °C in 30 °C acclimated fish was approximately 1.7 times the rate of excretion measured at 10 °C in 10 °C acclimated fish.The branchial uptake of Na, measured in tap water, of fish acclimated to 10, 20 and 30 °C in demineralized water increased with acute increases in temperature. When the three acclimation groups were compared at an intermediate temperature (20 °C), the 10 °C acclimated group showed the highest rate of net uptake, and the 30 °C group the lowest rate of uptake. This apparent temperature acclimation of Na uptake was correlated with differences in the plasma Na concentration of the three acclimation groups. Plasma Cl concentrations were also correlated with acclimation temperature in fish acclimated in demineralized water, but the rate of net Cl uptake was considerably less than that for Na. Sodium and Cl uptake in fish which had been acclimated in tap water was very variable and was not clearly affected by acute changes in temperature. Uptake of Na and Cl by fish held in tap water did not show temperature acclimation. The difference between uptake and excretion of fish acclimated in tap water was not significantly different from zero, indicating that the fish were in salt balance.The study was supported by National Institutes of Health Grant GM 16932-02 to Dr. Bodil Schmidt-Nielsen. I am grateful to Dr. Schmidt-Nielsen for many useful discussions during the course of this work.     

Factors affecting oviposition and fecundity in the grain miteAcarus siro L. (Acarina:Acaridae), especially temperature and relative humidity

Oviposition and fecundity in the grain miteAcarus siro were studied at 5–30°C and 62.5–90% RH. At and above 20°C, 80% RH, mating and oviposition occurred soon after emergence, but at lower temperatures and humidities egg laying was progressively delayed from one to several days. Females needed to mate repeatedly in order to achieve maximum egg production, optimum conditions for which were 15°C, 90% RH, where total output per female averaged 435 with a maximum of 858. Oviposition rates were highest at higher temperatures, the mean daily rate at 20 and 25°C, 90% RH, rising to maximum levels of 28/29 eggs per female per day on day six.Oviposition followed clearly defined patterns, favourable conditions producing rapid increases in the mean daily oviposition rate to high peak levels reached at an early stage in the oviposition period. Less favourable conditions resulted in reduced outputs and lower, more uniform rates of egg laying. The mean oviposition period, varying with humidity, fell from 72–122 days at 5°C to 9–13 days at 30°C and the mean incubation period from 42–70 days at 5°C to 3–4 days at 30°C. Egg viability increased with increasing humidity but was little affected by temperature and unaffected by age of the female at time of oviposition.Males tended to live longer than females at most conditions; longevity—depending on humidity—averaging 13–15 days at 30°C and 129–175 days at 5°C. Adult life for females averaged 12–19 days at 30°C and 88–169 days at 5°C. An index of suitability, calculated from egg number, viability and duration of the egg stage and oviposition period, indicated that the most favourable conditions for oviposition and hatching were 20–25°C and 80–90% RH.     

Microbiological degradation of the herbicide dicamba

Summary Pseudomonas paucimobilis was isolated from a consortium which was capable of degrading dicamba (3,6-dichloro-2-methoxybenzoic acid) as the sole source of carbon. The degradation of dicamba byP. paucimobilis and the consortium was examined over a range of substrate concentration, temperature, and pH. In the concentration range of 100–2000 mg dicamba L^–1 (0.5–9.0 mM), the degradation was accompanied by a stoichiometric release of 2 mol of Cl^– per mol of dicamba degraded. The cultures had an optimum pH 6.5–7.0 for dicamba degradation. Growth studies at 10°C, 20°C, and 30°C yielded activation energy values in the range of 19–36 kcal mol^–1 and an average Q₁₀ value of 4.0. Compared with the pure cultureP. paucimobilis, the consortium was more active at the lower temperature.