Bijeenkomst: EGF2015
Auteur: Halling M.A.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
Classifying earliness, or adaptation to a certain climate, is very important in varieties of maize (Zea mays L.). The most common classification system is the Food and Agriculture Organization (FAO) maturity class. This study systematically explored the response of maize varieties with different earliness in the maize-growing area in Sweden and examined possible alternatives to the FAO system for classifying earliness in maize varieties in Sweden. Based on differences in maturation rate according to the FAO index, four maize varieties were selected from variety trials in Sweden 2009-2011. At four sites (56°02- 59°71N), the development of these varieties was determined on four occasions, when the standard variety Avenir was at silking, milk, dough and dent. Aboveground dry matter (DM) yield, DM content and starch content were measured on the latter three occasions and at final harvest of Avenir. Ontario Corn Heat Units (CHU) were calculated for all sites. DM and starch content in the varieties Avenir and Jasmic showed a significant high linear correlation with CHU (R2=0.79 and 0.75, respectively). It was concluded that an index based on the correlation between DM or starch concentration and CHU could be an alternative to the FAO maturity class system for ranking earliness in maize varieties in the Nordic countries.
DM-yield
Effect of chloride fertilisation on dietary cation-anion difference forage species
Bijeenkomst: EGF2015
Auteur: Nesheim L., Synnes O.M. and Langerud A.
ISBN: 978-9090-289-61-8
Jaar van uitgifte: 2015
Producttype: Paper
The dietary cation and anion difference (DCAD) is an important property when assessing feed for dry cows in order to avoid hypocalcaemia following calving. Low values of DCAD may reduce the risk of milk fever. DCAD is often calculated as the difference between the cations Na+ and K+ and the anions Cl- and S2-. Research has shown that chloride fertilization may reduce DCAD, and that there might be differences in DCAD between commonly used grass species. In a research project in Central Norway the effects on DCAD of different rates of chloride fertiliser application were investigated. Fertilization with 70, 140 or 210 kg Cl per hectare in calcium chloride did significantly reduce DCAD in forage from leys dominated by timothy and meadow fescue. Pure stands of seven grass species were fertilized with either 0 or 140 kg Cl per hectare in spring. The lowest values of DCAD were found in reed canary grass and perennial ryegrass.