PAR Treatments Research Articles

Efficacy of fungicides for management of banded leaf and sheath blight of Kodo millet caused by Rhizoctonia solani Kühn

Five fungicides viz. validamycin, hexaconazole, propiconazole, tricyclazole and carbendazim were evaluated as seed treatment alone and in combination with one foliar spray to manage the banded leaf and sheath blight (BLSB) incidence of Kodo millet caused by Rhizoctonia solani in susceptible cv. JK 155 under field conditions. Significant differences in relative lesion height (%) and grain yield was recorded in different treatments. Seed treatment with validamycin (2g kg−1 seed) followed by one foliar spray (0.2%) was found best by reducing the 85.3% disease severity and increasing the grain yield (25.8%) over check. Seed treatment and one foliar spray of hexaconazole (0.2%) and propiconazole (0.2%) were at par and next best treatments after validamycin by decreasing the disease severity 78.2 and 76.8%, respectively.

Effects of UV Radiation on Photosynthesis, Antioxidant Capacity and the Accumulation of Bioactive Compounds in Gracilariopsis longissima, Hydropuntia cornea and Halopithys incurva (Rhodophyta).

The red macroalgae Hydropuntia cornea, Gracilariopsis longissima and Halopithys incurva were cultured for 14d under laboratory conditions, in enriched seawater with a high nutrient content (N-NH4+ and P-PO43- ) and two radiation regimes: PAR (400-700nm) and PAB (280-700nm). The UV radiation effects under high availability of nutrients on growth, photosynthetic pigments (chlorophyll a, carotenoids and phycobiliproteins), photosynthetic activity and biochemical composition were studied. Maximum quantum yield (Fv /Fm ) was not significantly different among the PAR and PAB treatments during the experiment. However, the maximum electronic transport rate (ETRmax ) increased over time, showing the highest values in PAR for H.incurva and H.cornea, whereas for G.longissima it was found in PAB. Photosynthetic efficiency (αETR ) decreased over time in the first two species, but increased in G.longissima. Saturation irradiance (EkETR ) and maximum nonphotochemical quenching (NPQmax ) increased in PAB with time up to 80% and 30%, respectively, indicating a photosynthetic acclimatization like that of sun-type algae. Five MAAs were identified in all species using high performance liquid chromatography (HPLC). The total content of MAAs increased over time, being 30% higher in H.incurva, 40% in G.longissima and 50% in H.cornea in PAB than in the PAR treatment. Finally, the antioxidant activity was also higher in the PAB treatment. All of the species presented an effective mechanism of photoprotection based on the accumulation of photoprotective compounds with antioxidant activity, as well as a high dissipation of excitation energy (high NPQmax ).

Effect of Par Frying on Composition and Texture of Breaded and Battered Catfish.

Catfish is often consumed as a breaded and battered fried product; however, there is increasing interest in breaded and battered baked products as a healthier alternative. Par frying can improve the texture properties of breaded and battered baked products, but there are concerns about the increase in lipid uptake from par frying. The objective of this study was to examine the effect of different batters (rice, corn, and wheat) and the effect of par frying on the composition and texture properties of baked catfish. Catfish fillets were cut strips and then coated with batters, which had similar viscosities. Half of the strips were par fried in 177 °C vegetable oil for 1 min and the other half were not par fried. Samples were baked at 177 °C for 25 min. Analysis included % batter adhesion, cooking loss, protein, lipid, ash, and moisture, plus hardness and fracture quality measured using a texture analyzer. A trained sensory panel evaluated both breading and flesh texture attributes. Results found the lipid content of par fried treatments were significantly higher for both corn and wheat batters than for non-par fried treatments. Sensory analysis indicated that the texture of the coatings in the par fried treatments were significantly greater for hardness attributes. Fillet flakiness was significantly greater in the par fried treatments and corn-based batters had moister fillet strips compared to the wheat flour batters. Texture analyzer hardness values were higher for the par fried treatments.

Endothelial nitric oxide synthase in rat brain is downregulated by sub-chronic antidepressant treatment.

Nitric oxide (NO) is a neurotransmitter that may be related to major depressive disorder (MDD) because the selective neuronal NO synthase (NOS) inhibitor, 7-nitroindazole, induces a dose-dependent antidepressant-like effect. NO modulates major neurotransmitters involved in the neurobiology of MDD, such as norepinephrine, serotonin, dopamine, and glutamate. In this study, we investigated the effects of antidepressants as NO modulators in acute and sub-chronic treatments. Rats were injected with the SSRI paroxetine (PAR, 10mg/kg), the SNRI milnacipran (MIL, 30mg/kg), or the NaSSA mirtazapine (MIR, 10mg/kg) for acute (1h) or sub-chronic (3weeks) treatment prior to analysis of nine brain regions (frontal cortex, temporal cortex, striatum, thalamus, hippocampus, midbrain, pons, cerebellum, and olfactory bulb). The mRNA expression levels of three NOS subtypes (neuronal: nNOS, inducible: iNOS, and endothelial: eNOS) were analyzed using real-time PCR with Taqman probes. Acute MIR treatment significantly increased nNOS mRNA expression in the hippocampus, midbrain, cerebellum and olfactory bulb, and iNOS mRNA expression in the frontal cortex and midbrain. Acute PAR and MIR treatments significantly increased eNOS mRNA expression in most brain regions. Conversely, sub-chronic treatment with all types of antidepressants resulted in significant decreases of eNOS mRNA expression in most brain regions. Sub-chronic treatment with the three types of antidepressants consistently decreased eNOS mRNA expression levels in the rat brain. These effects may be associated with the involvement of the NO system in the mechanism of action of antidepressants.

Effect of integrated nutrient management on seed yield and quality in cowpea

A study was carried out to assess effect of inorganic fertilizers, vermicompost, Vesicular Arbuscular Mycorhizae (VAM) and biofertilizers [Rhizobium and Phosphate solubilizing bacteria (PSB)] inoculation on seed yield and quality of cowpea (Vigna unguiculata). The experiment was conducted in a split plot design for two consecutive cropping season, kharif 2012 and 2013, with two main plot treatments of inorganic fertilizers i.e. 100% and 75% recommended dose of fertilizers (RDF) and nine sub plot integrated nutrient management (INM) treatments including control (No organic fertilizer). Main plot treatments were at par but sub plot INM treatments differed significantly for plant height, seed yield, number of pods/plant, pod length, number of seeds/pod, 1000-seed weight, seed germination and vigour indices. Integrated use of inorganic fertilizers + Vermicompost 2.5 t ha-1 (4.76, 4.16 q ha″1) performed significantly better than the control (3.32, 2.79 q ha″1) for seed yield and its attributes as well as seed quality parameters during Kharif 2012 and 2013, respectively. It was at par with combined use of inorganic fertilizers + biofertilizer inoculation (Rhizobium + PSB) + VAM 10 Kg ha-1 Also, the mean cost benefit ratios (2.04, 1.90) were highest for combination of biofertilizer inoculation (Rhizobium + PSB) + VAM 10 Kg ha-1 +inorganic fertilizers 100% and 75% RDF, respectively.

UV-B induces leaf reddening and supports photosynthesis in the seagrass Thalassia testudinum

Numerous seagrass species growing in intertidal and shallow subtidal areas around the world produce red leaves, but the factors responsible for the induction of leaf reddening in seagrasses are poorly understood. We investigated the responses of transplanted green-leafed and in situ red-leafed Thalassia testudinum shoots growing in high light areas in the lower Florida Keys, USA, to four light treatments: 1) full solar radiation with UV excluded (PAR); 2) full solar radiation with UV–B excluded (PAR + UV–A); 3) full solar radiation reduced by 50% (50% Ambient); and 4) full solar radiation (Ambient). In our first experiment, green-leafed shoots were transplanted from a 1 m depth (MLW) to the four light treatments in 0.2 m depth (MLW). In our second experiment, in situ red-leafed shoots growing at depths between 0.2 m and 0.5 m were exposed to the four light treatments. Within one week, new leaf tissue from green-leafed shoots transplanted into shallow water accumulated anthocyanins and began to turn red in treatments receiving full spectrum solar radiation (Ambient; 50% Ambient) while transplanted green-leafed shoots in the two treatments that excluded UV–B (PAR and PAR + UV–A) had low anthocyanin content and remained green. Although we quickly induced red coloration in leaves of green-leafed shoots, reducing light levels (including UV–B) for seven weeks did not cause leaves of in situ red leafed shoots to decrease anthocyanin content or turn green. Instead, red leaves increased photosynthetic pigments in all treatments except Ambient. In addition, the PAR+UV -A treatment had lower effective quantum yields at midday compared to the PAR, 50% Ambient, and Ambient treatments, as well as lower relative electron transport rates compared to the PAR and Ambient treatments. We conclude that exposure to UV–B induces anthocyanin accumulation and red coloration in green-leafed shoots and contributes to the maintenance of high levels of photosynthesis in red-leafed shoots of T. testudinum. We also propose that T. testudinum in the clear, shallow waters of the lower Florida Keys produces a red-leafed variant, a genetically differentiated form of this species, with permanently red leaves since anthocyanin accumulation and red coloration in leaves of red-leafed shoots was not reversible in this and a longer-term study.

Responses of heterotrophic bacteria to solar irradiance in the eastern Pacific Ocean

We investigated the effects of sunlight on bacterial 3 H-leucine (Leu) and 3 H-thymidine (TdR) incorporation at 12 locations, from 41° S to 4° N in the eastern Pacific Ocean, during July and August 2000. Surface water samples amended with Leu and TdR were incubated under ambient sun- light using optical filters corresponding to the following wavebands: UVB+UVA+PAR, UVA+PAR, long-wavelength UVA+PAR, and PAR. Incorporation rates of Leu and TdR in dark controls were statistically compared to rates in the light treatments to determine the effect of solar irradiance on bacterial production at each station. We observed robust photo-stimulation of TdR incorporation with UVA+PAR and long-UVA+PAR treatments at 17° S and in all light treatments at 13° S. PAR stimu- lation of Leu incorporation occurred over much of the south to north survey. Bacterial community structure analyses indicated the presence of 4 communities that exhibited unique responses to ambi- ent solar irradiance. Between 21° S and 4° N, the δ 13 C of dissolved inorganic carbon (δ 13 CDIC) was significantly and inversely correlated with UVB, UVA, PAR, and dark Leu incorporation, but not to sea surface temperature, or concentrations of nitrate and chlorophyll. Our results demonstrate wide- spread direct dependence on solar irradiance, especially longer wavelengths, for bacterial produc- tion in surface water of the southeastern Pacific Ocean. Additionally, our data suggest that latitudinal trends in δ 13 CDIC are strongly associated with trends in solar UVB and bacterial production in upwelling waters, with implications for carbon cycling in tropical and subtropical waters.

Aborted fruits of Opuntia microdasys (Cactaceae): insurance against reproductive failure

New individuals in clonal populations arise through the recruitment of sexual or clonal offspring. The predominance of one type of regeneration over the other has been correlated with different selective environmental pressures. We compared the reproductive mode (sexual through seeds and vegetative through plantlets or detached cladodes) of Opuntia microdasys from three desert habitats of the Chihuahuan Desert: bajada (BH), hill-piedmont (HPH), and an interdune (IDH). Successful establishment and growth of plantlets were determined in two experiments: (1) the effect of light (three levels of photosynthetically active radiation [PAR]: full, low, and medium) and two levels of watering and (2) maternal effects and provenance of plantlets. Adult plant densities did not differ among habitats (639 individuals/ha), but the number of offspring and fruit production increased significantly at BH. Plantlets (94.3%) dominated the form of recruitment for all habitats, followed by cladodes (3.1%) and seedlings (2.6%). A higher proportion of plantlets established in the low and medium PAR treatments (76%) in comparison to full exposure (39%). Maternal factors affected survival and growth, but plantlet provenance did not. The high fruit abortion rate resulting from environmental and maternal effects provided suitable conditions for establishment of plantlets.

Transient effects of solar ultraviolet radiation on the diversity and structure of a field-grown epibenthic community at Lüderitz, Namibia

While the majority of research on ultraviolet radiation (UVR) has focused on UVR-induced changes in the productivity and abundance of single taxonomic groups, only a few field studies have considered the influence of ambient UVR on complete assemblages, in particular of the macrobenthos. Using cutoff filters, we followed the effects of three radiation treatments, (1) PAR+UVAR+UVBR, (2) PAR+UVAR, (3) PAR, on macrobenthic community structure at Lüderitz, Namibia, SE Atlantic, for 3 months. Species composition, biomass, evenness, and species richness were not significantly affected by UVR, while the diversity H′ of PAR+UVAR+UVBR-exposed communities was significantly lower compared to PAR treatments. However, this effect was only observed early in succession. Increased abundance of the red alga Ceramium sp. coincided with vanishing UVR effects on the community, suggesting a muted UVR microclimate under the Ceramium canopy. Our results demonstrate that UVR could neither decrease diversity persistently, nor affect any of the other tested community parameters. Single UVR-tolerant species may provide protective shading for UVR-sensitive species, thus buffering harmful UVR effects at the community level. Missing UVBR effects suggest a limited influence of ozone depletion on shallow water macrobenthic diversity.

Photosynthetic performance and pigment content in the aquatic liverwort Riella helicophylla under natural solar irradiance and solar irradiance without ultraviolet light

The effects of solar radiation and solar radiation deprived of ultraviolet radiation ( λ<395 nm) on photosynthetic performance and pigment content of the aquatic liverwort Riella helicophylla (Bory et Mont.) Mont. was investigated throughout a natural daily-light cycle, from sunrise to sunset. Photosynthetic performance was estimated by means of pulse amplitude-modulated (PAM) fluorescence and oxygen production. Photosynthetic characteristics changed daily and between the two solar radiation conditions. The lowest values of optimal quantum yield ( Φ PS II ) took place at noon (70 and 55% lower than early in the morning under UV- and non UV-screened plants, respectively), in agreement with the highest amounts of solar radiation. However, at this time, the electron transport rate (ETR) achieved the highest values of the day (63 and 125 μmol −1 m −2 s −1 under PAR+UVA+UVB and PAR treatments, respectively). Significant differences ( P<0.05) in F v/ F m, ETR, initial slope of ETR versus irradiance curve, photosynthetic capacity, chlorophyll a and phenolic compounds were found between the two radiation conditions, especially at noon. Recovery of inhibited photosynthesis took place in the afternoon, so the current ultraviolet radiation does not seem to cause, irreversible damage to the photosynthetic apparatus of R. helicophylla in the short term.

Effect of high visible and UV irradiance on subtidal Chondrus crispus: stress, photoinhibition and protective mechanisms

Stress and the mechanisms of protection under excessive photosynthetically active (PAR) and ultraviolet radiation (UVR) were examined in the red alga Chondrus crispus Stackh. collected from the subtidal zone (6 m depth) at Helgoland, North Sea, Germany. Three PAR (400–700 nm) treatments without UVR and three UVR-A/B (290–400 nm) treatments supplemented with 30 μmol m −2 s −1 PAR were given twice. All three stages of plant stress, irritation, damage and acclimation, were observed under high light conditions. In the earlier stages of photoinhibitory PAR and UVR treatment, an induction phase occurred. It was characterized by a significant increase in chlorophyll a and carotenoids. The capacity to cope with high light stress in C. crispus increased with increasing duration of the induction phase. Prolonged exposures to high irradiance induced a substantial decline in the potential quantum yield of photosynthesis ( F v/ F m) and progressive pigment destruction that may be responsible for the damage stage of stress. In plants exposed to elevated PAR (3600 μmol m −2 s −1) and UVR (57.3 and 3.6 W m −2 of UVRA and UVRB, respectively), photoinhibition of F v/ F m exceeded 95% of control. Even after 20 h in low irradiance it was similar to values measured immediately after stress, indicating severe photodamage. The 1800 μmol m −2 s −1 PAR treatment also decreased the pigment content and F v/ F m, although damage was not permanent and the tissue gradually recovered. In contrast, naturally high doses of UVR (37.7 and 2.3 W m −2 of UVRA and UVRB, respectively) resulted in less photoinhibition of photosynthesis with rapid recovery of F v/ F m and pigment content, indicating the dynamic nature of photosynthetic acclimation to growth irradiance. Thus, photoinhibitory PAR damage and its repair predominate in subtidal C. crispus during the process of acclimation to a full-sun environment. Comparison between the acclimation conditions suggests that fluorescence quenching is related to the concentration of carotenoids. The increase in concentration, not only in the first but also after repeated exposures to PAR and UVR, was attributed to a protection of the photosynthetic apparatus. Additionally, accumulation of mycosporine-like amino acids (MAAs), mainly during the repeated exposures to UVR, led to substantially less inhibition of photosynthesis than expected given the practically double UVR dose. This suggests incomplete protection of C. crispus by MAAs during UVR shock. Thus, these experiments indicate that a few basic physiological strategies seem to be active during acclimation to high solar irradiance: a prolonged induction phase, dynamic photoinhibition, increased concentration of carotenoids, and accumulation of MAAs, UV-screening substances.

Shade and leaf loss affect establishment of grove-forming ectomycorrhizal rain forest tree species.

• The poor regeneration of Microberlinia bisulcata in groves in Korup, Central Africa was investigated in the forest to highlight factors that interact with light. • Survival and growth of nursery-grown seedlings of M. bisulcata with four other species in each of two 1-yr trials were recorded after transplantation into quadrats differing in PAR. Total mass was predicted for PAR treatments in nursery trials reported separately. • Plant mass was strongly dependent on PAR for all species. At low PAR, across species, plant mass was positively related to seed mass. Forest : nursery mass ratios decreased with increasing PAR; M. bisulcata had the lowest ratios of all species at high PAR. Leaf weight ratio declined more steeply with increasing PAR in the forest than in the nursery and this was particularly marked for M. bisulcata. • Herbivory was the most probable cause of leaf loss. Forest : nursery ratios were negatively correlated with species' abundances in the forest. Besides its small seed size and shade intolerance, M. bisulcata is highly susceptible to leaf loss when illuminated. Opportunities for seedling release are thus very low.

EFFECTS OF UV‐B‐INDUCED DNA DAMAGE AND PHOTOINHIBITION ON GROWTH OF TEMPERATE MARINE RED MACROPHYTES: HABITAT‐RELATED DIFFERENCES IN UV‐B TOLERANCE

The sensitivity to UV‐B radiation (UVBR: 280–315 nm) was tested for littoral (Palmaria palmata[L.] O. Kuntze, Chondrus crispus Stackhouse) and sublittoral (Phyllophora pseudoceranoides S. G. Gmelin, Rhodymenia pseudopalmata[Lamouroux] Silva, Phycodrys rubens[L.] Batt, Polyneura hilliae[Greville] Kylin) red macrophytes from Brittany, France. Algal fragments were subjected to daily repeated exposures of artificial UVBR that were realistic for springtime solar UVBR at the water surface in Brittany. Growth, DNA damage, photoinhibition, and UV‐absorbing compounds were monitored during 2 weeks of PAR + UV‐A radiation (UVAR) + UVBR, whereas PAR + UVAR and PAR treatments were used as controls. The littoral species showed a higher UV tolerance than the sublittoral species. After 2 weeks, growth of P. palmata and C. crispus was not significantly affected by UVBR, and DNA damage, measured as the number of cyclobutane‐pyrimidine dimers per 106 nucleotides, was negligible. Photoinhibition, determined as the decline in optimal quantum yield, was low and decreased during the course of the experiment, coinciding with the production of UV‐absorbing compounds in these species. In contrast, no UV‐absorbing compounds were induced in the sublittoral species. Growth rates of P. pseudoceranoides and R. pseudopalmata were reduced by 40% compared with the PAR treatment. Additionally, constant levels of DNA damage and pronounced photoinhibition were observed after the UVBR treatments. Growth was completely halted for Phycodrys rubens and Polyneura hilliae, whereas DNA damage accumulated in the course of the experiment. Because Phycodrys rubens and Polyneura hilliae showed the same degree of photoinhibition as the other sublittoral species, it appears that the accumulation of DNA damage may have been responsible for the complete inhibition of growth. The results suggest an important role of DNA repair pathways in determining the UV sensitivity in red macrophytes.

Impact of solar ultraviolet radiation on hatching of a marine copepod, Calanus finmarchicus

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 193:85-93 (2000) - doi:10.3354/meps193085 Impact of solar ultraviolet radiation on hatching of a marine copepod, Calanus finmarchicus Carolina Alonso Rodriguez1,2, Howard I. Browman1,*, Jeffrey A. Runge1, Jean-François St-Pierre1 1Maurice-Lamontagne Institute, Department of Fisheries and Oceans Canada, Division of Ocean Sciences, PO Box 1000, 850 Route de la Mer, Mont-Joli, Québec G5H 3Z4, Canada 2Département d'océanographie, Université du Québec à Rimouski, 310, allée des Ursulines, Rimouski, Québec G5L 3A1, Canada *Corresponding author. Present address: Institute of Marine Research, Aquaculture Centre, Austevoll Aquaculture Research Station, 5392 Storebø, Norway. E-mail: howard.browman@imr.no ABSTRACT: The calanoid copepod Calanus finmarchicus is a key component of the zooplankton community in the estuary and Gulf of St. Lawrence, Canada. During the spring and summer months, C. finmarchicus eggs are released into the shallow (0 to 15 m) mixed surface layer, where they incubate for 1 to 3 d. Radiometric measurements in this region show that biologically significant levels of solar ultraviolet radiation (UV = 280 to 400 nm) penetrate into the mixed surface layer. Thus, C. finmarchicus eggs are potentially susceptible to UV-induced mortality. This possibility was evaluated by incubating C. finmarchicus eggs in an outdoor reservoir under natural sunlight. There were 3 spectral exposures regimes [UV-B (280-320 nm) + UV-A (320-400 nm) + PAR (400-700 nm); UV-A+PAR; PAR only]. Control groups were kept in the dark. Incubations were conducted at depths of 2 and 60 cm and the percentage of eggs that hatched was determined following 2 to 3 d exposures in 3 independent experiments. Both the UV-B+UV-A+PAR and the UV-A+PAR treatments exhibited low percent hatching compared to the PAR and dark treatments: UV radiation had a strong negative impact on C. finmarchicus eggs. Further, percent hatching in UV-B-exposed eggs was not significantly lower than that in eggs exposed to UV-A only: under natural sunlight, UV-A radiation appeared to be more detrimental to C. finmarchicus embryos than UV-B. UV penetration into the experimental reservoir was similar to that observed in estuarine waters of this region, but lower than the clearer waters of the Gulf of St. Lawrence. This suggests that, at current levels of exposure, UV radiation has a negative effect on C. finmarchicus eggs residing in the first few meters of the water columns in this geographic region. KEY WORDS: UV-B · UV-A · Ozone depletion · Estuary and Gulf of St. Lawrence · Secondary production Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 193. Publication date: February 28, 2000 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 2000 Inter-Research.

Natural ultraviolet radiation and photosynthetically active radiation induce formation of mycosporine-like amino acids in the marine macroalga Chondrus crispus (Rhodophyta)

The UV-absorbing mycosporine-like amino acids (MAAs) are hypothesized to protect organisms against harmful UV radiation (UVR). Since the physiology and metabolism of these compounds are unknown, the induction and kinetics of MAA biosynthesis by various natural radiation conditions were investigated in the marine red alga Chondrus crispus collected from Helgoland, Germany. Three photosynthetically active radiation (PAR, 400–700 nm) treatments without UVR and three UV-A/B (290–400 nm) treatments without PAR were given. Chondrus crispus collected from 4–6 m depth contained only traces of the MAA palythine. After 24 h exposure to 100% ambient PAR, traces of three additional MAAs, shinorine, palythinol and palythene, were detected, and their concentrations increased strongly during a one-week exposure to all PAR treatments. The concentration of all MAAs varied directly with PAR dose, with palythine and shinorine being four- to sevenfold higher than palythinol and palythene. Likewise, naturally high doses of both UV-A and UV-B resulted in a strong accumulation of all MAAs, in particular shinorine. While shinorine accumulation was much more stimulated by UVR, the content of all other MAAs was more affected by high PAR, indicating an MAA-specific induction triggered by UVR or PAR.

Effect of Light Intensity and Carbohydrate Reserves on Flowering in Olive

Abstract Experiments were designed to alter the carbohydrate status of olive (Olea europaea L.) leaves during the presumed flower induction period. Bearing and nonbearing ‘Oblonga’ olive trees were exposed to either 850 μmol s-1n-2 PAR for 14 hr daily in a 1000 ppm CO2-enriched atmosphere, 150 μmol s-1m-2 PAR for 14 hr daily in 340 ppm CO2, or maintained in a lathhouse at ambient winter conditions of about 350 μmol s-1m-2 PAR and daily temperature fluctuations from 5° to 20°C. The trees exposed to 850 μmol s-1m-2 had 3 to 5 times the starch concentrations of either the 150 μmol s-1m-2 PAR or lathhouse treatments. There were few and inconsistent differences in sucrose, fructose or mannitol concentrations between treatments. The high levels of starch in the 850 μmol s-1m-2 PAR treatment had no effect on the flowering pattern of bearing or nonbearing trees. Gross levels of carbohydrates do not appear to limit flower induction of olive.