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Effects of crop properties, weather conditions and mechanical treatments on the wilting rate of dipliod and tetraploid Italian ryegrass for silage
Author(s) -
Borreani G.,
Tabacco E.
Publication year - 1998
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1046/j.1365-2494.1998.5320179.x
Subject(s) - water content , agronomy , crop , wilting , cultivar , forage , evapotranspiration , silage , environmental science , sowing , moisture , field capacity , dry matter , permanent wilting point , biology , mathematics , chemistry , irrigation , ecology , geotechnical engineering , organic chemistry , engineering
The relationship between rate of water loss of Italian ryegrass ( Lolium multiflorum ) and crop properties, weather conditions and mechanical treatments were studied on a field scale, as was the importance of the variables and their combined effects on influencing the wilting process. Eleven forage‐drying experiments were performed between 1992 and 1994 on diploid and tetraploid cultivars cut at different growth stages, ranging from early elongation to flowering, under environmentally variable conditions. The rate of drying was measured until a moisture content of 1 g water g −1 dry matter (DM) (500 g kg −1 ) was reached, or for a maximum of 2 days by calculating the rate of water loss from two consecutive hourly weights of swath portions placed on trays. Multiple regression analysis was used to correlate the drying rate ( k ) with crop properties and with meteorological and mechanical treatment variables. The interaction between potential evapotranspiration (ET 0 ) and the moisture content of grass at cutting ( M grass appeared to be the most important variable, from the twenty‐one tested, in influencing K. This variable shows that the same quantity of energy available for evaportaion acts in different ways when the water content of the crop at cutting differs. The rate of water loss is also influenced by the M grass itself, surgacae density of the swath, tedding and the weather conditions on the first day of drying. The value of M grass at cutting is greatly greatly dependent on crop maturity and ploidy. The tetraploid cultivars, with a higher inital moisture content, lost water more slowly than diploid cultivars did. Because the date of cutting cannot be delayed, owing to the decline in nutrive value, it is helpful to select for cultivars with low moisture contents at cutting, as well as applying mechanical treatment (spreading and tedding), in order to keep the wilting period as short as possible. A validated drying model can be useful for operational purposes to understand the drying process and to assess technological choices for forage drying.