Large estragole fluxes from oil palms in Borneo

During two field campaigns (OP3 and ACES), which ran in Borneo in 2008, we measured large emissions of estragole (methyl chavicol; IUPAC systematic name 1-allyl-4-methoxybenzene; CAS number 140-67-0) in ambient air above oil palm canopies (0.81 mg m−2 h−1 and 3.2 ppbv for mean midday fluxes and mixing ratios respectively) and subsequently from flower enclosures. However, we did not detect this compound at a nearby rainforest. Estragole is a known attractant of the African oil palm weevil (Elaeidobius kamerunicus), which pollinates oil palms (Elaeis guineensis). There has been recent interest in the biogenic emissions of estragole but it is normally not included in atmospheric models of biogenic emissions and atmospheric chemistry despite its relatively high potential for secondary organic aerosol formation from photooxidation and high reactivity with OH radical. We report the first direct canopy-scale measurements of estragole fluxes from tropical oil palms by the virtual disjunct eddy covariance technique and compare them with previously reported data for estragole emissions from Ponderosa pine. Flowers, rather than leaves, appear to be the main source of estragole from oil palms; we derive a global estimate of estragole emissions from oil palm plantations of ~0.5 Tg y−1. The observed ecosystem mean fluxes (0.44 mg m−2 h−1) and mean ambient volume mixing ratios (3.0 ppbv) of estragole are the highest reported so far. The value for midday mixing ratios is not much different from the total average as, unlike other VOCs (e.g. isoprene), the main peak occurred in the evening rather than in the middle of the day. Despite this, we show that the estragole flux can be parameterised using a modified G06 algorithm for emission. However, the model underestimates the afternoon peak even though a similar approach works well for isoprene. Our measurements suggest that this biogenic compound may have an impact on regional atmospheric chemistry that previously has not been accounted for in models and could become more important in the future due to expansion of the areas of oil palm plantation

Effect of dietary ascorbic acid supplementation in japanese quail raised in a tropical environment on nutrient intake, productive performance and egg quality

The objective of this study was to evaluate the effect of adding 0, 0.01, 0.02 and 0.03% ascorbic acid to the diet of laying Japanese quail raised in the tropics on nutrient intake, productive performance and egg quality. Eighty Japanese quail were divided to receive four inclusion levels of ascorbic acid. A completely randomized design was used and the results were submitted to analysis of variance. The differences observed were analyzed by regression at a 5% level of significance. The addition of 0, 0.01, 0.02% and 0.03% ascorbic acid to the diet of quail did not influence dry matter intake (DMI), organic matter intake (OMI) or crude protein intake (CPI), expressed as g/animal/day, g/kg0.75 and % body weight. Mean DMI, OMI and CPI were 46.53, 44.0 and 11.0 g/animal/day, respectively. However, there was a quadratic effect on neutral detergent fiber intake (NDFI). Maximum NDFI was 9.19 g/animal/day for the inclusion level of 0.01% ascorbic acid in the diet of laying Japanese quail. The addition of ascorbic acid to the diet of laying quail did not alter (P>0.05) egg production or productivity, with a mean egg production of 3.06 eggs/cage/day and 0.77 eggs/animal/day and mean productivity of 76.5%. The addition of 0, 0.01, 0.02 and 0.03% ascorbic acid also did not alter egg weight (g), yolk and albumen weight (g), or egg and yolk diameter (mm). However, the addition of ascorbic acid to the quail diet exerted a quadratic effect (P<0.05) on egg height (mm) and shell weight (g). The lowest egg height and shell weight were 2.99 mm and 1.25 g, respectively, for inclusion levels of 0.017% and 0.023% ascorbic acid in the quail diets. For shell thickness (mm) and yolk height (mm), the addition of ascorbic acid exerted a quadratic effect (P<0.05), with maximum values of 0.031 mm and 1.42 mm, respectively, for 0.024% and 0.017% ascorbic acid in the diets. The addition of up to 0.03% ascorbic acid to the diet of laying quail raised in the tropics does not alter nutrient intake, egg production or productivity. However, better shell thickness and yolk height are obtained with the addition of 0.02% ascorbic acid to the diet