A sampling protocol to detect latent infections in potato tubers stored in bins, based on the preparation of standard samples of 200 tubers, was described and tested for reliability. Bins of tubers were manually distributed in windrows and 1% of tubers was replaced with painted tubers, simulating tubers with latent infections. They were distributed in windrows with clustered, regular and random allocation. Tubers were harvested and transferred in bins. Layers, 15 cm-depth, were considered in each bin and 20 tubers were collected along the X-shaped path of the bin layer. A simulated sampling approach was applied to obtain 10 bulk samples (200 tubers) for each kind of tuber allocation. The number of marked tubers, the mean percentage and the standard deviation of the bulk samples of each group was computed. The analysis of results confirmed that the sampling design adopted in this study allowed to prepare representative bulk samples. In fact, marked tubers were effectively detected; the mean percentages of marked tubers reached acceptable values, even if an overestimate of the true percentage was generally obtained. The percentage of marked tubers was underestimated in 50% of cases when considering the regular allocation of marked tubers; on the contrary, it was never underestimated when considering the clustered allocation, the most representative situation of tubers with laten
A sampling protocol to detect latent infection in potato tubers
SANGUINETI, MARIA CORINNA;MAZZUCCHI, UMBERTO
2005
Abstract
A sampling protocol to detect latent infections in potato tubers stored in bins, based on the preparation of standard samples of 200 tubers, was described and tested for reliability. Bins of tubers were manually distributed in windrows and 1% of tubers was replaced with painted tubers, simulating tubers with latent infections. They were distributed in windrows with clustered, regular and random allocation. Tubers were harvested and transferred in bins. Layers, 15 cm-depth, were considered in each bin and 20 tubers were collected along the X-shaped path of the bin layer. A simulated sampling approach was applied to obtain 10 bulk samples (200 tubers) for each kind of tuber allocation. The number of marked tubers, the mean percentage and the standard deviation of the bulk samples of each group was computed. The analysis of results confirmed that the sampling design adopted in this study allowed to prepare representative bulk samples. In fact, marked tubers were effectively detected; the mean percentages of marked tubers reached acceptable values, even if an overestimate of the true percentage was generally obtained. The percentage of marked tubers was underestimated in 50% of cases when considering the regular allocation of marked tubers; on the contrary, it was never underestimated when considering the clustered allocation, the most representative situation of tubers with latenI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.