Tag Archives: overwintering

846-853 V. Obraztsov, D. Shchedrina and S. Kadyrov
Festulolium seed production dependence on fertilizer application system
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Festulolium seed production dependence on fertilizer application system

V. Obraztsov*, D. Shchedrina and S. Kadyrov

Voronezh State Agrarian University named after Emperor Peter the Great, Department of Crop Science, Forage Production and Agricultural Technologies, ul. Mitchurina 1, RU394087 Voronezh, Russia
*Correspondence: ovennn@mail.ru

Abstract:

Festulolium (× Festulolium F. Aschers. et Graebn.) is a new perennial grass Роасеае family. The benefits of this culture are good regrow capacity, increased sugars content and higher winter hardiness. It can be used as a green feed when creating cultivated hayfields and pastures. Widespread application of this new culture for forage production is constrained by the shortage of seeds, due to the imperfection of their production technologies. There are still very few of studies on the biology and technology of Festulolium cultivation in the forest-steppe of the Central Chernozem Region of Russia (CCR). The experiments involved the VIC-90 Festulolium variety with the first crop being the vetch-oat mixture harvested for green fodder. The soil in the experimental plots was leached medium thick medium loamy chernozem. The humus content in the arable horizon was 4.56%, pH was 4.9, degree of base saturation was 74‒86%, P2O5 content was 129 mg kg-1, K2O content was 115 mg kg-1 (according to Chirikov) and the hydrothermal index was 1.13. The experiment included the following variants: no fertilizer application (control) and application of mineral fertilizers (ammonium nitrate and ammonium nitrate phosphate fertilizer) at different doses. Soil preparation was conventional for seed swards of perennial grasses in the CCR. Festulolium was sown in broad drills by coverless sowing to the depth of 0.5–1.0 cm at the seeding rate of 6.0 kg ha-1. Experiments, records, observations and determination of economic and bioenergetic efficiency were carried out according to conventional procedures. It was found that the climatic conditions in the forest steppe of the CCR were favorable for Festulolium seed cultivation. Application of mineral nitrogen fertilizers in autumn at a dose of 60 kg ha-1 of active ingredient (AI) ensures the formation of high yielding erect seed-producing sward, and can increase harvest energy efficiency an average by 1.45‒1.82 times and obtain 591‒620 kg ha-1 of certified seeds. The greatest profitability of production (179%) and the highest notional farm net income (RUB 43,000 per hectare) are provided by a single application of ammonium nitrate fertilizer at a dose of 60 kg ha-1 of active ingredient in autumn (after vegetative mass topping).

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328-334 I. Kivimägi, A. Ploomi, L. Metspalu, E. Svilponis, K. Jõgar, K. Hiiesaar,A. Luik, I. Sibul and A. Kuusik
Physiology of a carabid beetle Platynus assimilis
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Physiology of a carabid beetle Platynus assimilis

I. Kivimägi¹, A. Ploomi¹, L. Metspalu¹, E. Svilponis¹, K. Jõgar¹, K. Hiiesaar¹,A. Luik¹, I. Sibul² and A. Kuusik¹

¹Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences,Kreutzwaldi 1, Tartu 51014, Estonia; e-mail: irja.kivimagi@emu.ee
²Institute of Forestry and Rural Engineering, Estonian University of Life Sciences,Kreutzwaldi 5, Tartu 51014, Estonia

Abstract:

Predacious carabid beetle Platynus assimilis Paykull (Coleoptera: Carabidae) is a fast-moving insect which should be considered as an important component of biological control in organic farming. In this study we tested some factors of potentially dangerous influence of pesticide Fastac (synthetic pyrethroid) on overwintering physiology of adult ground beetle under laboratory conditions. Cold-hardiness (measured by supercooling point SCP) was determined 2 weeks after exposure to pesticide treated-food. Pesticide had decreased cold-hardiness of the ground beetles. Weak supercooling capacity could be harmful to overwintering insects in cold winters without snow cover.

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21–30 K. Hiiesaar, L. Metspalu, J. Jõudu and K. Jõgar
Over-wintering of the Colorado potato beetle (Leptinotarsa decemlineata Say) in field conditions and factors affecting its population density in Estonia
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Over-wintering of the Colorado potato beetle (Leptinotarsa decemlineata Say) in field conditions and factors affecting its population density in Estonia

K. Hiiesaar, L. Metspalu, J. Jõudu and K. Jõgar

Estonian University of Life Sciences, Institute of Agricultural and Environmental Sciences, Kreutzwaldi St. 64, 51014 Tartu, Estonia; e-mail: kylli.hiiesaar@emu.ee

Abstract:

The adaptation of Colorado potato beetles (CPB) (Leptinotarsa decemlineata Say) to low temperatures has been the basis for the formation of a local permanent population in Estonia. The number of this pest fluctuates in different years on a large scale. The hibernation of the beetles in field conditions during the years 2000–2005 was observed and some factors influencing the beetles’ mortality was discussed in this study. Soil with a lighter texture – loamy sand proved better for the hibernation of CPB than clay loam soil with a heavier texture. 30 cm confirmed to be more suitable depth for hibernation than 50 cm, demonstrating lower mortality rate. Every autumn CPB populations were differently prepared for hibernation: part of the beetles burrowed themselves into the soil considered to be ready for over-wintering, and there were more survivals than among the beetles staying on the soil surface: that could not complete their maturation feeding. The temperature may become lethal for a majority of the hibernating population only during extreme winters when the temperature falls to -30oC for a longer period of time. During our observation period, it happened only once: in 2002/2003. In more mild winters there were no problems with over-wintering: about two third of the beetles survived in clay sand and about a half in loamy clay soil. It is difficult to predict the annual damage caused by CPB because the Estonian population consists of adapted over-wintered beetles and beetles migrated from southern regions. In some years we have had a great number of immigrant beetles and, in some years, no immigration has occurred.

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