https://jopr.mpob.gov.my Wed, 17 Nov 2021 07:14:30 +0000 en-US hourly 1 https://wordpress.org/?v=7.0 https://jopr.mpob.gov.my/dispersion-of-the-bagworms-pteroma-pendula-and-metisa-plana-in-oil-palm/ Sat, 13 Nov 2021 08:03:01 +0000 https://jopr.mpob.gov.my/V2/?p=9028 An attempt was made to determine optimum sampling unit of between-palm and within-palm distribution of bagworms and their interspecific association distribution in oil palm using aggregation indices or distribution models. The within-frond distribution of bagworms varied significantly within the oil palm crown. Peak bagworm density was recorded between frond numbers 9 and 19. Through polynomial regression, standardised residual and relative net precision analyses, frond number 17 was established as the representative sampling unit for experimental work, and frond numbers 10-19 should be used when a greater precision is required as in life-table construction. A lack of interspecific association suggested these sampling units to be applicable for single and mixed infestations. Evaluation of between-palm dispersion revealed that Taylor’s Power Law gave a more appropriate fit with highly significant r² values for all categories of assessment. The bagworms were regularly dispersed in oil palm with a general mean-variance relationship of log (s²) = 1.780 + 0.821 log (x¯).

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