Evaluation Of Onion Production On Sandy Soils By Use Of Reduced Tillage And Controlled Traffic Farming With Wide Span Tractors

Growing of vegetables is often characterised by intensive field traffic and use of heavy machines. By implementing controlled traffic farming (CTF), compaction of the growth zone can be avoided. An experiment was established in an onion field on a coarse sandy loam. Treatments were applied in the field that for five years had been managed by seasonal CTF (SCTF), where harvest is performed by random traffic due to lack of suitable harvest machines. The main treatment was compaction with a fully loaded potato harvester. The split treatment in the crossed split plot design was mechanical loosening. Bulk density, macroporosity, penetration resistance, water retention characteristics and yield were measured. Mechanical loosening caused improvements in the physical soil measurements and more roots were found in the upper soil layers. The highest yield was however found in the CTF simulation plots (19% higher than in the SCTF simulated plots). Using wide span tractors as a harvest platform will enable CTF in vegetable production. Avoidance of compaction will enable reduced tillage intensity and productivity can be improved both through higher yield of the area that is cropped and by a larger percentage of fields can be cropped area as less area will be needed for tracks.

Phytotoxicity levels in a wet year in an experiment on maize sensitivity to herbicides

The phytotoxic effects of herbicides applied pre-, early post- and post-emergence were studied in maize in a herbicide sensitivity experiment were set up in Martonvásár and Törökszentmiklós. The herbicides were applied in normal and in double doses to 37 Martonvásár inbred lines and to six parental single crosses. The small-plot experiments were set up in two replications. The wet weather that followed the pre- and early post-emergence treatments promoted the appearance of phytotoxic symptoms on maize. The degree of phytotoxicity was recorded on the 14th day after post-emergence treatment and on the 14th and 28th days after the pre- and early postemergence treatments. Herbicides applied pre-emergence only caused slight symptoms on maize. Although the double dose increased the damage, it was still not more than 5% on average. The symptoms caused by herbicides applied in the early post-emergence stage were more intensive than those detected in the pre-emergence treatments. However, the damage caused by the double dose of isoxaflutol + thiencarbazone-methyl and by the split treatment with nicosulfuron remained below 10%. The symptoms became somewhat more severe at the 2nd scoring date. Among the post-emergence treatments the maize genotypes had the least tolerance of the mesotrione + nicosulfuron combination of active ingredients, where the double quantities resulted in 13–14% damage in average.

125 A COMPARISON OF SEQUENTIAL MEDIUM WITH NON-SEQUENTIAL MEDIUM: DO SOME PATIENTS' EMBRYOS CULTURE BETTER IN ONE THAN IN THE OTHER?

The development of sequential media is often reported as one of the reasons why human IVF pregnancy rates have increased over the last 10 years. The objective was to determine if a single culture medium (global) is as effective in human embryo culture as a sequential medium (G series) and whether embryos of some patients prefer one medium over the other. Patients (n = 144) were placed into one of three treatment arms. Treatment 1, sequential: culture in G Series medium. Treatment 2, nonsequential: culture in global medium. Treatment 3, split: After fertilization, a patient’s embryos are split between the above two treatments. All patients with embryos from April 2007 to January of 2008 (PGD patients were excluded) were allocated to one of the three treatments. Eggs were collected in and fertilized in vitro Life media (GMOPS and GFert, respectively). In treatment 1, patients’ embryos (n = 346) were cultured in sequential media. In treatment 2, patients’ embryos (n = 482) are cultured in nonsequential media. In treatment 3, embryos (n = 420) from each patient are split between sequential and nonsequential media after rinsing in the treatment medium. Patients whose embryos met the criteria (at least 2 embryos, >6 cells, grade excellent to good) were transferred on day 5. All embryos remaining after embryo transfer were frozen on day 5. A maximum of 2 embryos was transferred per patient. Frequencies were compared with a chi square test. Results: The percentage of cases that achieved transfers on Day 5 (an indication of embryo quality) were 44.0%, 50.0% and 68.4% for sequential, nonsequential and split, respectively. Split was significantly different from the sequential (P < 0.05). The percentage of transferrable blastocysts was 27% for sequential, 43% for nonsequential and 39% for split (difference between sequential and the other two was significant at P < 0.0005). Pregnancy rates and implantation rates were 32%/19.0%, 36%/22.5% and 50%/32.2% for sequential, nonsequential and split. (Only implantation rates between split and sequential were significant P < 0.05). For embryos in the split treatment, development to transferable blastocysts was 37.0% in sequential media v. 41.6% in nonsequential medium (not significant). In conclusion, a single medium (nonsequential) for culture to blastocyst yields results similar to embryos cultured in the more complex sequential medium. There is some evidence that a benefit can be gained by splitting embryos between two culture media to increase implantation rates. Further studies need to be done to see if this will result in increased pregnancy rates.

On interpreting studies of tracer transport by deep cumulus convection and its effects on atmospheric chemistry

Global chemistry-transport models (CTMs) and chemistry-GCMs (CGCMs) generally simulate vertical tracer transport by deep convection separately from the advective transport by the mean winds, even though a component of the mean transport, for instance in the Hadley and Walker cells, occurs in deep convective updrafts. This split treatment of vertical transport has various implications for CTM simulations. In particular, it has led to a misinterpretation of several sensitivity simulations in previous studies in which the parameterized convective transport of one or more tracers is neglected. We describe this issue in terms of simulated fluxes and fractions of these fluxes representing various physical and non-physical processes. We then show that there is a significant overlap between the convective and large-scale mean advective vertical air mass fluxes in the CTM MATCH, and discuss the implications which this has for interpreting previous and future sensitivity simulations, as well as briefly noting other related implications such as numerical diffusion.