Sex pheromone traps were used to monitor the seasonal periodicity of the fall armyworm, Spodoptera frugiperda (J. E. Smith), moth over a 2-year period at eight locations from French Guiana northward to Canada. Results indicated a seasonal progression of movement by fall armyworm from the southern most locations in the United States into Canada. Although the fall armyworm survives throughout the year in the Caribbean Basin, analysis of moth capture and meteorological data for the region provided no direct evidence that this reservoir of continuous populations contributed significantly to the influx of this pest into the temperate regions of North America where it normally does not survive the winter. Weather disturbances along the Atlantic seaboard of the northeastern U.S. and Canada in October 1984 and an associated precipitous decline in moth captures in pheromone traps supports a previous hypothesis of a return (southward) migration by fall armyworm.

No abstract

The integration of tropical maize (Zea mays L.) germplasm into template breeding programs has been difficult and slow. More information on performance of temperate ✕ tropical populations and their heterotic combinations is needed. This study was conducted to compare heterotic patterns among four populations. Two, a Caribbean flint and a Caribbean dent, are useful in the tropics and have potential for temperate areas; the other two are temperate ✕ tropical populations adapted to the tropics. The four populations, their diallel crosses and reciprocals, and a commercial hybrid check were grown in two locations in Puerto Rico during two winter‐season environments. The best heterotic combination among the four populations was between the Caribbean flint and dent. The best‐yielding population per se was the temperate ✕ tropical population of Reid (Group B) heterotic pattern. The Caribbean flint population had highly significant negative maternal effects for yield. Both reciprocal crosses of the temperate ✕ tropical populations were low yielding. The results indicated that, for temperature breeding programs, both Caribbean populations should be useful for improving Corn Belt maize.

No abstract

Two experiments were conducted to determine time for full establishment of rhizoma perennial peanut (RPP) under irrigation. Experiment one (E1) and experiment two (E2) were conducted, respectively, at the Lajas and Fortuna Substations of the Agricultural Experiment Station of the University of Puerto Rico. At Lajas, rhizomes of accessions USDA-ARS no. 17033, 17050, 17052, 17097 (PI no. 276233, 262826, 262833, 262839, respectively) and cultivars Florigraze and Arbrook, planted at 0.76 and 1.5 m apart in rows, were compared for rate of establishment at 60,120, 180 and 240 days postplanting. At Fortuna, rhizomes of accessions 17033 and 17097, and cv. Florigraze were compared at 80,160, and 240 days postplanting. In E2, plots were subjected to the following weed control methods: (1) manual, (2) mowing, and (3) chemical. Time to full establishment in E1 increased from about six months to eight with an increase in planting distance from 0.76 to 1.5 m. Accessions 17033 and 17097 and cv. Florigraze showed a tendency for faster lateral spread prior to 120 days postplanting than the other RPPs. However, peanut genotypes achieved fufl cover at about the same time. The use of herbicide in E2 was the most effective method for promoting faster cover of RPP plants. Establishment of the stand was achieved prior to 240 days in plots receiving weed control treatments 1 and 3, whereas those receiving treatment 2 achieved only 62.5% cover. Compared to a tropical grass, RPP exhibits a slower pattern of lateral spread and requires a longer time for full establishment when planted under similar conditions. However, reducing planting distance and using herbicides to control weeds are management strategies that can reduce time for full establishment of the RPP stand.