Guinea Grass In The Virgin Islands


 By
 P. Joy Michaud
 Extension Specialist Natural Resources

 Of the three main U.S. Virgin Islands, St. Croix has92%of
 the grazing land and 84% of the ruminant livestock (Table
 1). The majority of these pastures are unimproved, com-
 posed of local grasses and other broad leaf species. While
 considering means to improve production a farmer might
 consider plowing up these native pastures and planting a
 commercial viable agricultural grass species. Before pursu-
 ing this course, however, a farmer should first consider the
 pastures he has. Do they need improving? Will the new pas-
 ture be much better than the native one? Isthecost and risk
 involved in pasture improvement worth it?

 The native pastures in the Virgin Islands are normally
 dominated by one of two grasses: guinea grass (Panicum
 maximum) and hurricane grass (Bothriochloa pertusa).
 These two pasture grasses are quite different in their char-
 acteristics and value.

 Guinea grass is the natural pasture grass of the Virgin
 Islands. Land which is kept clear of bush and is ungrazed, or
only lightly grazed, will have a thick guinea grass pasture. It
is an excellent pasture grass, which produces high dry
matter yields and performs well in the low-input farming
system normally practiced in the Virgin Islands, i.e. little or
no fertilizer applied.

 In comparison, hurricane grass is very unproductive and
 is of poor quality (Oakes, 1968). A pasture composed mainly
 of hurricane grass is considerably less productive than a
 guinea grass pasture, and, consequently, can support far
 fewer animals.

 It is clear, therefore, that a reseeding program should
 only be considered by a farmer if his pastures are domi-
 nated by hurricane grass or any other non-productive grass.
 A farmer with guinea grass pastures should instead be con-
 cerned about conducting good management techniques
 that will maintain their fields' quality.


 The reason so many pastures are dominated by hurricane
 grass is due to the growth habits of the two grasses and their
 respective responses to poor management and in particular
 to overstocking.

 Guinea grass exhibits a tufted growth habit, i.e. it grows in
 clumps with many areas of bare ground between. A healthy
 guinea grass pasture will often have between 70 85% bare
 ground. The bare ground is shaded by the large guinea grass
 leaves and, as plants need light to grow, little can grow
 there. With overgrazing the bare ground is not shaded and
 hurricane grass can become established. The greater the
 overgrazing the faster this happens. Furthermore, over-
 grazing retards regrowth capacity of guinea grass, thus
 making it less competitive against weeds.
 A stocking rate which will maintain a guinea grass pasture
 is generally much lower than many farmers realize. For
 example, in mid-island a very productive guinea grass
 pasture has been maintained for over ten years, with a
 stocking rate of about 2.5 sheep or goats per acre. If the
 stocking rate were increased for a long period of time the
 pastures would deteriorate. This stocking rate may seem
 low. However, under these conditions no extra feed need
 be bought for the animals, even in the dry season. Under
 these circumstances not many animals need to be sold
 before the enterprise starts to make a profit. In comparison,
 where a large number of animals are kept on hurricane grass
 pastures, food has to be bought to maintain the animals.
 Every bag of food or load of green chop costs money and
 reduces profits that could be made on the enterprise. Many
 livestock farmers in the Virgin Islands probably spend more
 money on feeding their animals than they get in return from
 the sales (Brown and Michaud, 1986) an expensive hobby.

 There are many local pasture legumes that grow well in
 conjunction with guinea grass. Some examples are blue wiss
(Clitoria ternetea), Desmanthus spp., Teramnus labialis and
Rhynchosia minima. Legumes growing in the pastures are
very desirable. They contain a high level of protein, which
improves the livestock's diet, and they improve the fertility


-------------------------------------------------
 Table 1. Number of farms, pastures and ruminant livestock in the
 U.S. Virgin Islands, (U.S. Dept. Commerce, 1983).


Farms:
Farms with pastures:
Pastures (acres):
Sheep:
Goats:
Cattle:
Milk (quarts sold):


U.S.V.I.


 St. Croix

 219
 126
 14,732
 2,233
 3,044
 5,244
1,680,825


St. Thomas


St. John


 15,985
 2,889
 4,035
 5,672
1,858,145


1,058


* Information withheld to avoid disclosing data for individual farms