Littérature scientifique sur le sujet « 005.1/4 »

A fusuline fauna consisting of 9 species of 4 genera from the Xiala Formation of the Mujiucuo section, Xainza County, Tibet, China is described. The fusuline fauna is dominated byNankinellaandChusenellaand indicates a Midian (Late Guadalupian) age. The earliest record of fusuline fauna during the Midian in the Lhasa Block suggests that the block rifted later than the Qiangtang Block to the north and the Baoshan and Tengchong blocks to the east, all of which yield much earlier fusuline faunas of Yakhtashian (Artinskian) age, but had drifted away from Gondwana to a relatively warm temperate zone in the Late Guadalupian (Middle Permian).

The study was conducted in areas of Granja Santa Inés, the experiment was based on the application of nitrogen fertilizer from two sources of nitrogen (N), 50% mineral and 50% organic; the experimental design was completely random blocks, four increasing doses of N (0-225-450-675 kg N ha-1) were evaluated. For vegetative variables the following characteristics were valued: fresh matter, chlorophyll, fruit number, fruit length, fruit width and for production variables: yield; 30% of the total N was applied during the first stage, 50% during the second stage and 20% during the final stage; for data collection was executed at the end of each stage at 37, 67 and 97 days after transplantation (DDT). For fresh matter accumulation data the highest weight was obtained at 97 days at a dose of 675 kg N ha-1 obtaining a total weight of 9 455.46 kg ha-1; while for the chlorophyll variable the highest value recorded in the same days was obtained with an average of 79.8 SPAD units. In performance, the best result was recorded at 97 days in treatment 4, with 4 005.31 kg ha-1

We evaluated the use of ornamental plants as phenological indicators for predicting giant foxtail emergence and compared their performance with predictions based upon Julian day, cumulative growing degree–days (GDD), and the WeedCast program. From 1997 to 2001, we monitored giant foxtail emergence in a field experiment with and without fall and spring tillage to estimate the dates of 25, 50, and 80% emergence; we also recorded dates of first and full bloom of 23 ornamental plant species. Dates of weed emergence and ornamental blooming for 1997 to 2000 were compiled in a phenological calendar consisting of 54 phenological events for each year, and events were ordered by average (1997 to 2000) cumulative GDD (January 1 start date, 10 C base temperature). Bloom events occurring just before the giant foxtail emergence events were chosen as the phenological indicators for 2001. The Julian day method used the average (1997 to 2000) dates of foxtail emergence to predict 2001 emergence. The GDD model (October 1 start date, 0 C base temperature) was chosen by determining the combination of start date and base temperature that provided the lowest coefficient of variation for the 1997 to 2000 data. The WeedCast prediction was generated using local soil and environmental data from 2001. The rank order of the 54 phenological events in 2001 showed little deviation from the 4-yr (1997 to 2000) average rank order (R2= 0.96). The phenological calendar indicated that, on average, 25% of giant foxtail seedlings had emerged when red chokeberry was in first bloom, and 80% of seedlings had emerged around the time multiflora rose was in full bloom. We compared the phenological calendar predictions for 25, 50, and 80% emergence with those based on Julian day, cumulative GDD, and WeedCast. The average deviation in predictions ranged from 4.4 d for the phenological calendar to 11.4 d for GDD. In addition to being generally more accurate, the phenological calendar approach also offers the advantage of providing information on the order of phenological events, thus helping to anticipate the progress of emergence and to plan and implement management strategies.