Re. Pitt et Re. Muck, ENUMERATION OF LACTIC-ACID BACTERIA ON HARVESTED ALFALFA AT LONG AND SHORT WILTING TIMES, Transactions of the ASAE, 38(6), 1995, pp. 1633-1639
Preservation of alfalfa as silage relies on the presence and activity
of lactic acid producing bacteria (LAB) at ensiling. Counts of LAB wer
e determined on standing, mowed, and harvested alfalfa for two growing
seasons under Northeast conditions, and were used to test prediction
equations based on Wisconsin data (Muck, 1989b, 1990, 1991). Wilting t
imes, rainfall quantities, and wilting temperatures were outside the r
ange of the Wisconsin data in 60 of 70 trials. The equations performed
well when conditions were in the range of the original data. For shor
t wilting times, the inoculation associated with chopping was assumed
to be affected by rainfall and wilting time only up to 4 mm and 72 h,
respectively, and to be unaffected beyond that. LAB counts at wilting
times greater than 72 h were predicted best by average ambient tempera
ture and rainfall during wilting. The equation for long wilting times
was independently verified with separate data from Wisconsin not used
in previous regressions. Use of inoculants is projected to be cost eff
ective on direct cut material when the average temperature in the 24 h
prior to harvest is less than 23 degrees C with no rainfall. For long
wilting times, average wilting temperature must be less than 20 degre
es C for inoculants to be cost effective, but the temperature must be
lower as rainfall increases.