sodininkystė ir daržininkystė 25(4)

Table 2. Weather conditions at application in 2005-2006
2 lentelë. Oro sàlygos purðkimo metu 2005–2006 m.
Date of application
Purškimo data
2005-07-13 2006-07-12
Temperature on the date of application
23.0 19.0
Temperatûra, °C
Wind speed on the date of application
2.0 1.5
Vëjo greitis, m/s
Relative air humidity on the date of application 65 70
Santykinë oro drëgmë, %
Rainless period, hours
Laikotarpis po purškimo iki lietaus, val.
66 136
Table 3. Meteorological conditions in 2005–2006
3 lentelë. Meteorologinës sàlygos 2005–2006 m.
Air temperature
Oro temperatûra, °C
Precipitation
Krituliai, mm
Month
average of
average of
Mënuo
2005 m. 2006 m. 1924-2000 2005 m. 2006 m. 1924-2000
1924–2000 m.
1924–2000 m.
vidurkis
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
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 fruit tree red spider mites was compared among treatments in
this study with a single factor analysis of variance (ANOVA). Specific differences
were identified with Duncan’s multiple range test.
Results. Tables 4 to 7 describe the effect and toxicity of Abamectin 18 g l -1 to
fruit tree red spider mite in apple trees. Abamectin 18 g l -1 , 27 g AI ha -1 reduced to
0.12, 0.22 and 0.3 the mean number of mites per leaf 5, 7 and 31 days after treatment,
respectively. Meanwhile the number of mites reached on the average 12.0,
11.7 and 2.5 per leaf in unsprayed plots 5, 7 and 31 days after treatment in 2005
(Table 4). Mite mortality in 5 and 7 and 31 days after treatment with Abamectin 18
g l -1 , 27 g AI ha -1 was 99.1, 98.4 and 89.7%, respectively, what indicates it to be very
toxic to fruit tree red spider mite (Table 5). Similar results showed lower rate (18 g
AI ha - 1) of Abamectin 18 g l -1 . There were not found any statistical differences of
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