Horticultura Brasileira (2012) 30, 673-680

Matheus Geraldo P. de M. Ribeiro, Miguel Michereff Filho, Ítalo M.R. Guedes, Ana Maria R. Junqueira and Ronaldo S. de Liz (2012)
Efeito da adubação química na infestação do ácaro rajado e na produção do morangueiro
[Effect of chemical fertilization on two-spotted-spider mite infestation and strawberry yield]
Horticultura Brasileira 30 (4), 673-680
Abstract: The effect of N:K relationship was evaluated when applied through fertigation, on two-spotted-spider mite, Tetranychus urticae, infestation and on the yield of two strawberry cultivars. Strawberry plants received weekly doses of N and K (g/plant) by drip irrigation: 0.27 and 0.13; 0.27 and 0.50; 0.27 and 0.76 and control (water+micronutrients). Fruits were collected twenty two times during crop cycle. Marketable, non-marketable fruits and other yield parameters were evaluated. Leaf nutrient content analysis was performed to determine the nutritional condition of the plants. Population density of T. urticae was evaluated weekly. A significant interaction between K doses and pest population was observed. Higher doses of the nutrient reduced the number of eggs and active forms of the pest population and the cultivar Diamante showed the smallest pest density. K and P showed negative correlation with both variables, but N showed a positive one. No effects were observed of fertilization on yield parameters due, probably, to the high mite infestation (>40 individuals per leaflet) in all treatments during most of the crop cycle. Solely the use of different N:K ratios on the strawberry fertilization management at this specific experimental condition, was not sufficient to control two-spotted spider mite nor to reduce losses caused by that pest.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Portuguese)
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Database assignments for author(s): Miguel Michereff Filho

Research topic(s) for pests/diseases/weeds:
environment - cropping system/rotation
damage/losses/economics

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Tetranychus urticae	Strawberry (Fragaria)	Brazil (south)