Philippines - Costs and Returns Survey of Onion Production 2006

The domain of the study was the province, with the last completed production cycle in 2006 as reference period. The lists of onion producing barangays by province prepared by the concerned BAS Provincial Operations Centers (POCs) served as the sampling frame for this study. The lists contained data on area devoted to onion production and number of onion farmers as of 2006. These data were obtained from the Municipal Agriculturist Offices, Agricultural Technicians, barangay officials and other key informants in the barangays and updated results of the Barangay Screening Survey (BSS).

A two-stage sampling design was employed with the barangay as the primary sampling unit and the onion farmer as the secondary and ultimate sampling unit. The barangays were drawn using systematic sampling from an ordered list of barangays with at least five onion farmers. Systematic sampling was used so that both large and small barangays in the province in terms of onion production would be represented in the sample. On the other hand, sample operators were identified using snowball approach during data collection. During the search for sample operators, a set of screening questions was applied to see to it that the samples satisfy the following criteria: 1) must be engaged in onion production, and 2) must have harvested onion in 2006


The total sample size was 100 onion growers per province and this was equally allocated to 20 sample barangays. The survey resulted in the following distribution of sample farmers by province.


PROVINCE MULTIPLIER RED CREOLE YELLOW GRANEX TOTAL SAMPLE
and SHALLOT
Ilocos Norte 95 5 100
Pangasinan 97 3 100
Nueva Ecija 7 89 4 100

TOTAL 102 191 7 300


Response rate of 100 percent


Weighting is not applicable