302 QUEENSLAND AGRICULTURAL JOURNAL. [1 Szpr., 1899. 
Science. 
FOOD VALUE OF GUINEA-GRASS (PANIOUM MAXIMUM). 
Tn order to ascertain the food value of this well-known forage plant, the Director 
of the Botanical Department, Trinidad, experimented with a plot of one-tenth 
of an acre, planted during the year 1897. 
After four cuttings had been taken off, it was determined to weigh the crop 
of a cutting, to ascertain what was the yield per acre when freshly cut. The 
grass obtained at the first cutting weighed 3,012 lb., or at the rate of 18°4 tons 
er acre. 
: The above result led to the determination to keep a year’s record. 
F In order, however, to obtain correct values, several deductions must be 
made. 
Tt is a well-known fact to all who use it that a very large proportion of 
this grass is wasted by animals, and not consumed—i.e., wasted—as food, but 
serves as bedding, and eventually becomes available to the agriculturist as 
manure; but when we are considering food value simply, the waste must be ~ 
properly ascertained. 
In order to discover how much loss actually occurs, a known weight of 
freshly-cut grass was taken, and all the waste portions carefully removed by 
hand, so that its value might be compared with fodders where the waste is com- 
paratively trifling. The average waste of two samples of 100 lb. each was 
nearly 33 per cent., so that the actual weight of undried fodder, per acre, at 
the one cutting, is 8°98 tons. _ 
Compared with English or American hay at 4 or 5 tons to the acre of dried 
material, we obtain a fair idea of its value. The yield of 8°98 tons, when 
reduced to air-dry weight, is lessened by 5°65 tons, leaving 3°33 tons as a crop. 
The air-dry weight of the European analysis is always less than the air-dry 
weight of the tropics, and this must be taken into account when attempting to 
ascertain the relative value of any kind of fodder. The air-dry weight of 
guinea-grass will, therefore, be more in proportion than the air-dry weight of 
hay ascertained in Europe. How much is to be allowed for this cannot be 
ascertained until we have an analysis of European or American hay made im 
the tropics. 
In the tropics there is little or no real cessation of growth, and the rest of 
plants is generally taken in the dry season, when there is less growth than at 
any other time of the year; but growth goes on all the time with guinea-grass, 
the rate being regulated by the rainfall. Hence, from the tenth of an acre 0 
which we write, no less than six crops were obtained during the year 1898, cut 
at the times detailed in the following table :-— . 
12th February... xx: on ... 98,012 lb. 
2nd April... ei of ite menos 20 ne 
15th July ... od dtr; 00 nas BLADE oe, 
GAGS IRNANTE ey ee ay BLY ep 
22nd October... ors Apt) rr PES 
9th December .,,, aes a x, Ish) 5 
16,803 Ib. 
The cuttings were made when the grass was fit to cut—i.e., when in the 
condition it is generally used for horse feed—and the total weight reaped during 
the year, as seen by the table, was 16,803 lb., or at the rate of 168,030 lb. or 75 
tons per acre. ; 
