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Estimating Field Losses of Rice in Asia, Using Small Quadrat Samples
Author(s) -
Bell Mark A.,
McLaren Christopher G.,
Patena George F.,
Mendoza Dionisio C.
Publication year - 1997
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1997.00021962008900020022x
Subject(s) - quadrat , mathematics , statistics , paddy field , sampling (signal processing) , sample (material) , range (aeronautics) , agronomy , environmental science , oryza sativa , biology , ecology , physics , engineering , shrub , biochemistry , optics , detector , gene , aerospace engineering , thermodynamics
Field losses of rice ( Oryza sativa L.) in small fields of Asia are rarely quantified. In developed countries, loss is often measured using devices attached to large combines. Such harvesting equipment is rarely used in Asia, so quadrat counts are more applicable. We estimated field losses of rice using a 10‐ by 10‐cm rigid quadrat in commercial fields on Luzon in the Philippines. Losses ranged from 66 to 503 kg ha −1 . Due to the rapidity of the quadrat counts, sample variability throughout the field was easily assessed. By counting the number of seeds and multiplying by 22 to 25 (typical range for 1000‐kerneI weight), field loss (kg ha −1 ) was estimated directly. To estimate field losses within ±50 kg ha −1 , a rule of thumb of three is suggested (i.e., the total number of samples required is approximately three tunes the average number of grains being counted in the sample). A sequential sampling procedure is presented for efficiently determining whether grain losses are below a specified tolerance. The quadrat method is an option for rapid assessment of losses, especially by farmers, where more sophisticated methods are not available.