Naslov
The use of different water rates in the Colorado potato beetle [Leptinotarsa decemlineata Say. (Coleoptera: Chrysomelidae)] control

Autori
Mešić, Aleksandar ; Barčić, Josip ; Igrc Barčić, Jasminka ; Bažok, Renata

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
International Conference: Enviromentally Friendly Spray Application Techniques / Holownicki, R. ; Doruchowski, G. ; Knopacki, P. - Varšava : Research Institute on Pomology and Floriculture, 2004, 131-131

Skup
Enviromentally Friendly Spray Application Techniques

Mjesto i datum
Varšava, Poljska, 04.10.2004. - 06.10.2004

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Spray application; CPB control; water rates

Sažetak
Potato is the third most important crop in Croatia. It is planted on the area of 65-70 000 ha. The main pests of potato in Croatia are Colorado potato beetle (Leptinotarsa decemlineata Say.) and Potato late bleach (Phytophtora infestans Mont. de Bary). The great number of insecticides is registered for the CPB control in Croatia. CPB could cause economically important damages if the 20% of potato leaves are destroyed. It is considered that economic threshold is 15 larvae on at least 15% of all potato plants. At early appearance of CPB on early-planted potato, economic threshold for all of potato plants. At early appearance of CPB on early-planted potato, economic threshold for use of insect growth regulators is even lower (10 larvae on 15% of all potato plants). In Croatia the infestation of 50 larvae per plant was registered. Damages on potato vine at the beginning of tuberisation are reducing potato yields more than later damages. Tuberisation in Croatia starts (depending of cultivar and weather conditions) approximately 40-45 days after planting of potato. For example, the delay of the control of 10 days is reducing the yield for 20-30%. So, precious timing of treatment is very important for CPB control. The control of CPB in Croatia is usually conducting during July. In that period several periods with a few rainy days in line are usual. After hard rains it is not possible to enter the field with a tractor to spray insecticides for CPB control. In those situations the use if knapsack mist blower is very usual because it can provide application of relatively large are in short period of time with small water rate. The trials were conducted during the 2001-2002 period. The spraying was in the first decade of June each year and the results were measured till the end of the first decade of June each year and the results were measured till the end of first decade of July. In the two-year-trials the efficacy of imidaclopride based insecticide in a dose of 0, 5 l/ha by using of tractor-mounted sprayer and knapsack mist blower were compared. With tractor-mounted sprayer potato were treated with spray volumes of 150 l/ha and 300 l/ha respectively. Water rates of 20 l/ha, 40 l/ha and 60 l/ha respectively were used by the knapsack mist-blower. In the years 2001 and 2002 statistically important difference between treatments with water rates of 60 l/ha, 150 l/ha and 300 l/ha were not registered. The efficacy in those three treatments was always over 95%. The same efficacy was achieved in 2001 with water rate of 40 l/ha, which was lower in 2002. The efficacy of treatment with water rate of 20 l/ha was less in both years (less then 80%), but still statistically better than untreated control. Although, this rate is not recommendable for the CPB control We expect that using of knapsack mist blower is also appropriate for use in control of Potato late bleach.

Izvorni jezik
Engleski

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