Enumerative Sampling Plans Research Articles

SamplingPhenacoccus manihoti incassava fields in Nigeria

Abstract Between 1982 and 1985, Nigerian cassava fields were periodically sampled through three crop growing seasons to analyze the within and between‐plant distribution of CM as affected by weather (dry and rainy season) using the mean crowding statistics and Taylor's power law. Enumerative and binomial sampling plans were developed which take into consideration the seasonal changes in the spatial distribution patterns of CM. The costs of the two procedures were compared to select the most cost‐efficient sampling plan.

Sampling egg batches ofMaliarpha separatellaRAG. (Lep., Pyralidae) in Madagascan rice fields

Abstract Sampling with quadrats of 0.25 m2 in Madagascan rice fields reveals that egg batches of the African White Stem Borer, Maliarpha separatella RAG. are distributed at random. The physical size of the sampling unit is selected because of practical rather than ecological considerations. According to the enumerative sampling plan at least 40 quadrats should be taken per field to satisfy precision requirements. Sequential binomial sampling with constant error rates is more cost efficient and decision making with respect to an action threshold is possible with 12 quadrats or more at a critical time. For regional estimates a stratified random sampling procedure is proposed.