Ranching in Panama'

242 McCORKLE the size of the plant, because plants sprayed at a hardinggrass, and orchardgrass at rates as high as similar size the following year did not show this 2 lb/acre to control herbaceous range weeds in tolerance. new seedings. Normally spraying would be done Harding-grass and Palestine orchardgrass were at 0.5 to 1.0 lb/acre when the weeds are small. Up not damaged at any of the combinations of rates to 0.5 lb/acre could also be used on rose clover and growth stages tested. There were no differ- grown for forage recognizing that moderate dam- ences in seedling height or other damage symp- age will result to the clover. Moderate damage in toms. The first two applications were followed by the seeding year is preferable to a seeding failure a very wet fog the following night which probably due to weed competition. resulted in some runoff from the sprayed plants to LITERATURE CITED the root zone. Still, no mortality was noted. The results of these trials indicate that 2,4-D KAY, BURGESS L. 1963. Effects of 4-(2,4-DB) and dalapon on three annual trifoliums. Weeds 11: 195-198. may have a much more prominent place in con- KAY, BURGESS L. 1964. Paraquat for selective control of trolling weeds in range seedings than had been range weeds. Weeds 12: 192-194. supposed earlier. The experiments by Williams KAY, BURGESS L. 1967. Bromoxynil on rose clover, sub- and Leonard (1959) showed severe damage to rose clover, hardinggrass and Palestine orchardgrass. Research clover by rates of 2,4-D amine as low as 0.75 lb/ progress report. Western Weed Control Conf., p. 14-15. acre. However, most of their applications were ORMROD, D. P., AND W. A. WILLIAMS. 1960a. Vegetative made at later growth stages to coincide with brush and reproductive growth response of three trifolium spe- control practices rather than control of herbaceous cies to 2,4-D. Agron. J. 52:229-234. weeds. Also the damage they measured using ORMROD, D. P., W. A. WILLIAMS, AND B. L. KAY. 1960b. amine in the 2-inch rosette stage would not pro- Growth responses of three annual clovers to treatments hibit the use of 2,4-D. Ormrod et al. (1960a, with 2,4-D. Parts I and II. California Agr. 14(7 and 8): 7-8, 6-7. 1960b) tested only the less selective ester formula- WILLIAMS, W. A., AND 0. A. LEONARD. 1959. Effect of tion and again sprayed at later growth stages than 2,4-D on growth, seed production, and seed viability of would be used for herbaceous weeds. an annual reseeding clover. Agron. J. 51:383-387. In view of the results reported here it seems safe YATES, W. E., AND F. M. ASHTON. 1966. Logarithmic dos- to use the alkanolamine salt of 2,4-D on subclover, age sprayer. Agr. Eng. 41:436-438, 442. pastoreo contienen una 6 mas especies de gramineas intro- Ranching in Panama’ ducidas. El combate de arbustivas, el control de las quemas, y el mejoramiento tanto de las plantas forrajeras coma de1 J. S. McCORKLE ganado son de 10s problemas mas importantes. Ecologist, Albuquerque, New Mexico. El ganado se cria y se engorda para el mercado en 10s potreros. Los bajos porcentajes de paricion, las enferme- dades y 10s parasites, el bajo valor nutritivo de 10s forrajes Highlight durante las epocas de sequia, y 10s animales de calidad in- ferior traen coma consecuencia, por lo general, una baja Grass and cattle are an important part of Panama agri- production por vaca. Mayores porcentajes de paricion y culture. Ninety percent of all grassland contains one or aumentos en el rendimiento de came podran lograrse me- more introduced grasses. Brush control, fire control, and diante practicas de pastoreo mejoradas y un manejo ade- improvement in grass and livestock management are major cuado de1 ganado. problems. Cattle are grown and finished for market on grass. Low calf crops, disease and parasites, poor dry sea- La ganaderia en Panama ofrece un buen potential para son feed conditions, and low-quality animals result in a establecer empresas remunerativas. generally low beef production per cow. Improved grazing practices and sound livestock management will result in Panama is best known as the narrow strip of higher calf crops and increased beef yields. Potential exists land which connects the two Americas, and as the for a sound and economically profitable ranching enter- location of the strategic Panama Canal which prise. makes events in this area of worldwide importance. La Ganaderia en Panama Panama is a small country some 400 miles long and 40 to 150 miles wide. It is bisected by a mountain Resumen chain only about 200 ft high at the lowest point, Los pastizales y el ganado son una parte muy importante rising to 11,000 ft at the high point near the Costa de la agricultura de Panama. El 90% de las tierras de Rica boundary. Temperatures are tropical except where elevations act to moderate the heat. Precipi- 1 Information compiled by the author while employed by International Engineering Co., San Francisco, California, tation is from 1,000 to 5,000 mm annually, with a servicing the Agrarian Reform Project in Panama. dry season of 100 to 130 days. Rainfall is adequate PANAMA 243 tree, Curatella americaru?, is the best example, prefer open sun and are resistant to fire, grazing, and other acts of man. These are now apparent dominants in localities where such plants would not occur in the natural vegetation. Precipitation of about 2,500 mm produces tropical forest with a dry season of 100 to 120 days. There appears to be adequate basis for accept- ing Savannah as the natural vegetation on upland soils in the 1,000 to 2,500 mm zone of precipitation where the dry season is severe. The deep alluvial soils have a forest climax in the most arid climate found in Panama. The Savannah vegetation is typical tropical savannah. CurateZla americana is probably the most common scrub tree, often called sandpaper tree because of the large rough leaves, but is called Anacardium occident& or Ca- to abundant in the wet season and drooth is fre- chumico locally. quently severe in the dry season. Precipitation is shew nut, Brysonima cramfolia or name, and a higher on the Atlantic slopes but this discussion is number of other xerophytic species are common. limited to the populated areas along the Pacific Xerophytes are represented in grasses and sedges slopes and the vicinity of the Canal. by one or more species of such genera as Trachy- Muhlenber,qia, Aristida, Andropogon, Pas- Cattle in Panama are grown and finished on grass fiogon, with little or no supplemental feed. Grass is a ma- p&m, Scleria, Bulbostylis, and many others. jor land use but a considerable percentage of it is Seeding of exotics, brush control, and other derived from tropical Savannah and from clearing treatments are applied on grassland regardless of tropical forest. Much of the land is not suited to original plant cover, and most grassland has scrub crops and cultivation but is maintained in satisfac- brush in the cover. Consequently the boundary tory condition in either forest or grass when sup- between true forest and Savannah is essentially of ported by correct practices (Fig. 1). academic interest except as a question of competi- Cattle and grassland not only provide a sound tion of land use arises. The land suitable for culti- land use but also provide employment and subsist- vation is limited, the relative competitive position ence for comparatively large numbers of people, of cropland and other uses is not to be explored as well as an important contribution to the na- here but obviously cultivation is a high priority tional economy. use when soil and topoFaphy are suitable. An ex- The Pacific coast has always been the principal tensive area of Savannah and scrub forest is more area of habitation. The alternating wet and dry useful and productive in grass than in trees except seasons offer a much more pleasant and healthful under intensive treatment not found in current climate and well-adapted to production and har- tree culture practice in Panama. Both forest and vesting of crops. <grassland use are suitable uses for resource conser- vation when supported by correct treatment. ECOlOgy Native Grazing Plants Considerable variation occurs in rainfall and temperature and there is a corresponding variation Some of the native grasses are excellent forage in soil and vegetation. Space does not permit a but many of the dominants are coarse harsh bunch- complete treatment of the area ecology but it is grasses of low palatability. Representative domi- evident that the natural or climax vegetation is nants on good upland sites are Andropogon bi- determined by the length and severity of the dry cornis, A. angustatzrs, Paspalurn uirgatum, P&cum season as well as by the amount ol precipitation. g’ande, Manzsuris aurita, Setaria tenax. The domi- Tropical forest is the most extensive plant forma- nants on shallow arid sites include Truchypogorl tion with variations from a low but dense scrub, to ,secundus, Andropog-on leucostnchys, Axonopus a tall four-story rain forest, although the rain for- amem, Muhlenbergrs emersleyii, Paspalum hum- est is outside the area of this discussion for the boldtianum, Aristida tin&a. Wet land dominants most part. There is no question that plant cover include Pmpalum uirgatum and numerous sedges has been greatly influenced by man in the inhab- ited sections and many plants now found are India ? Identiiication of grasses and forbs principally by Florida State lJnivrrsity, with a limited number by the author caters of man’s treatment rather than an index 01 after Swallen (1943).

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