sodininkystė ir daržininkystė 25(4)

Plot size at least 12m 2 , the trial was repeated 4 times at random plot distribution.
Sprayer Hardi 4110-12 was used for spraying, water volume – 1 000 l ha -1 . Weather
conditions at 91 growth stage according BBCH scale (Meier, 1997) during application
presented in Table 2.
Assessments in 2005 and 2006 were made as follows: before application (VI.27
and VII.20), 3–4 (VII.02 and VII.24), 7 (VII.06 and VII.27) and 21 days (VII.20
and VIII.10) after application. Assessments were made on 20 leaflets for assessment
the number of strawberry mites per leaf in each plot. Meteorological data (air
temperature and amount of precipitation) were recorded using scab warning equipment
Metos D (Table 3).
Mortality of mites was calculated: x = 100 (1–Ab/Ba) (x – mortality, %, A –
number of mites, before spraying in untreated plot, B – number of mites, before
spraying in treated plot, a – number of mites, after spraying in untreated plot, b –
number of mites, after spraying in treated plot).
We applied quantitative toxicity categories those employed by the International
Organization for Biological Control for assessment of pesticide toxicity to predatory
and phytophagous mites in field trials: non-toxic (< 25% mortality), slightly toxic
(25–50%), moderately toxic (51–75%), very toxic (> 75%) (Hassan et al., 1985).
The number of strawberry mites was compared among treatments in this study
with a single factor analysis of variance (ANOVA). Differences were identified with
Duncan’s multiple range test.
Month
Mënuo
Table 3. Meteorological conditions in 2005–2006
3 lentelë. Meteorologinës sàlygos 2005–2006 m.
Air temperature
Precipitation
Oro temperatûra, °C
2005 m. 2006 m.
average of
1924–2000
1924–2000 m.
vidurkis
Results. There were found on average 9.25, 10.5 and 5.75 strawberry mites
per leaflet in unsprayed plots 3, 7 and 21 days after treatment in 2005 (Table 4).
Abamectin 18 g l -1 , 21.6 g AI ha -1 reduced to 2.25, 2.75 and 3.25 the number of mites
per leaf 3, 7 and 21 days after treatment, respectively. Abamectin 18 g l -1 , 21.6 g AI
ha -1 was very toxic (mortality - 77.8 and 76.1%) to strawberry mite 3 and 7 days and
slightly toxic (mortality – 48.4%) 21 days after treatment, respectively (Table 5).
Abamectin 18 g l -1 , 18.0 g AI ha -1 was moderately toxic (mortality – 56.9 and 52.0%)
3 and 7 days and slightly toxic (mortality – 41.6%) 21 days after treatment. The
lowest rate 9.0 g AI ha -1 of Abamectin 18 g l -1 was slightly toxic 3 and 7 days and
non-toxic 21 after treatment. The mortality ranged from 16.3 to 45.6%. The toxicity
of Abamectin was compared with the toxicity of Lambdacihalotrin and Spirodiclofen
to strawberry mite. There were found any statistical differences of number of
155
Krituliai, mm
2005 m. 2006 m.
average of
1924–2000
1924–2000 m.
vidurkis
June / Birželis 14.8 16.3 16.6 66,6 13.8 50.4
July / Liepa 19.4 19.3 17.6 3,8 30.2 71.8
August / Rugpjûtis 14.7 17.5 16.3 109.4 173.4 75.8