Resumo

MIRANDA, Ileana et al. DENSITY LIMIT FOR THE CONTROL OF POLYPHAGOTARSONEMUS LATUS (BANKS) (Acari: tarsonemidae) IN PROTECTED CROP OF PEPPER (CAPSICUM ANNUUM L.). Rev. Protección Veg. [online]. 2009, vol.24, n.3, pp. 146-151. ISSN 2224-4697.

Changes of conditions in the ecosystems determine the behavior of their inhabitant populations and variations may take place in the thresholds of damages and growth parameters. The logistical growth of Polyphagotarsonemus latus was modeled to estimate the growth parameters, the maximum capacity of increment and the intrinsic ratio of this mite in protected crop systems during the applications of chemicals. To estimate the maximum density at which any type of control must be applied, a graph was made of the widespread relationship between the population in a sampling and that in the next one. Data used for this study came from population counts done on 100 randomly selected leaves in 16 serial samplings made weekly. The maximum capacity of increment of P. latus was up to 227,8 individuals per sampling with an intrinsic ratio of 0,36. It was demonstrated that density stability can in fact change to severe dynamic movements with balance points when the densities are higher, thus showing that in absence of an effective control the populations of P. latus can rise considerably. A control measure is suggested to be applied when the mite populations are higher than 56 individuals per each 100 leaf sample.

Palavras-chave : Polyphagotarsonemus latus; protected crop; peppers; Capsicum annum; logistical model; population widespread relationship.

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