RELАTIONSHIP BETWEEN PОPULATION DENSITIES OF Globodera rostochiensis AND YIELD OF PОTATO CULTIVARS UNDER FIELD CONDITIONS IN BULGARIA

In 2010–2011, in field conditions (Smolyan potato growing region) microplots experiment have been carried out to determine the effect of population densities of Globodera rostochiensis pathotyp 3 (Ro3) on the growth and yield of two new Bulgarian potato (Solanium tuberosum L.) varieties Evridika and Orfei. Microplots were 25 cm-diam, 30 cm-deep, filled with 10 L of soil infested with G. rostochiensis in a geometric series of nematode densities between 0 and 64 eggs/mL of soil. Eight weeks after planting in infested soil, the relative plant height of varieties Evridika and Orfei was reduced at Pi ≥ 1 and 32 eggs/mL soil, respectively. In both potato varieties the minimum possible relative values for plant height were 0,51 and 1,0, respectively, at Pi = 64 eggs/mL soil. The tolerance limits of potato yield of Evri-dika and Orfei were 2 and 16 eggs/mL soil, respectively. The minimum possible relative values for yield of Evridika and Orfei were 0,325 kg/plant and 0,659 kg/plant, respec-tively, at Pi = 64 eggs/mL soil. A mathematical model describing the influence of Pi of G. rostochiensis and yield of both varieties can be used in expert advisory systems when accounting for the environmental factors.In 2010–2011, in field conditions (Smolyan potato growing region) microplots experiment have been carried out to determine the effect of population densities of Globodera rostochiensis pathotyp 3 (Ro3) on the growth and yield of two new Bulgarian potato (Solanium tuberosum L.) varieties Evridika and Orfei. Microplots were 25 cm-diam, 30 cm-deep, filled with 10 L of soil infested with G. rostochiensis in a geometric series of nematode densities between 0 and 64 eggs/mL of soil. Eight weeks after planting in infested soil, the relative plant height of varieties Evridika and Orfei was reduced at Pi ≥ 1 and 32 eggs/mL soil, respectively. In both potato varieties the minimum possible relative values for plant height were 0,51 and 1,0, respectively, at Pi = 64 eggs/mL soil. The tolerance limits of potato yield of Evri-dika and Orfei were 2 and 16 eggs/mL soil, respectively. The minimum possible relative values for yield of Evridika and Orfei were 0,325 kg/plant and 0,659 kg/plant, respec-tively, at Pi = 64 eggs/mL soil. A mathematical model describing the influence of Pi of G. rostochiensis and yield of both varieties can be used in expert advisory systems when accounting for the environmental factors

Применение экстрактов растений для контроля за галловой нематодой Meloidogyne hapla, паразитирующей на растениях земляники

The activity of alcohol extracts from 6 plant species was investigated with respect to the root-knot nematode-strawberry system. An evaluation was made of the nematostatic and nematicidal activity of the extracts. In production conditions, the most active was the extract Tanacetum vulgare at concentration 0.6%. It had the lowest M. hapla population density, with gall index and root/soil population densities not different than the oxamil treated plants and there were no stastically proved difference between T. vulgare and non-infested control.Было изучено действие спиртовых экстрактов из 6 видов растений на систему галловых нематод, паразитирующих на растениях земляники. Была сделана оценка нематостатического и нематоцидного действия этих экстрактов. По результатам исследований, проведенных в производственных условиях было установлено, что наибольшую активность показал 0.6% экстракт Tanacetum vulgare. Благодаря его применению, была достигнута минимальная плотность M. Hapla. При обработке растений Tanacetum vulgare и оксамилом не было установлено разницы в значениях индекса обилия и численности нематод в корневой системе и почве. Не выявлено никакого статистически достоверного различия между группой растений, обработанной T. Vulgare и незараженной контрольной группой

RELАTIONSHIP BETWEEN PОPULATION DENSITIES OF Globodera rostochiensis AND YIELD OF PОTATO CULTIVARS UNDER FIELD CONDITIONS IN BULGARIA

In 2010–2011, in field conditions (Smolyan potato growing region) microplots experiment have been carried out to determine the effect of population densities of Globodera rostochiensis pathotyp 3 (Ro3) on the growth and yield of two new Bulgarian potato (Solanium tuberosum L.) varieties Evridika and Orfei. Microplots were 25 cm-diam, 30 cm-deep, filled with 10 L of soil infested with G. rostochiensis in a geometric series of nematode densities between 0 and 64 eggs/mL of soil. Eight weeks after planting in infested soil, the relative plant height of varieties Evridika and Orfei was reduced at Pi ≥ 1 and 32 eggs/mL soil, respectively. In both potato varieties the minimum possible relative values for plant height were 0,51 and 1,0, respectively, at Pi = 64 eggs/mL soil. The tolerance limits of potato yield of Evri-dika and Orfei were 2 and 16 eggs/mL soil, respectively. The minimum possible relative values for yield of Evridika and Orfei were 0,325 kg/plant and 0,659 kg/plant, respec-tively, at Pi = 64 eggs/mL soil. A mathematical model describing the influence of Pi of G. rostochiensis and yield of both varieties can be used in expert advisory systems when accounting for the environmental factors

Management of root-knot nematode Meloidogyne hapla on strawberry plant with some plant extracts

The activity of alcohol extracts from 6 plant species was investigated with respect to the root-knot nematode-strawberry system. An evaluation was made of the nematostatic and nematicidal activity of the extracts. In production conditions, the most active was the extract Tanacetum vulgare at concentration 0.6%. It had the lowest M. hapla population density, with gall index and root/soil population densities not different than the oxamil treated plants and there were no stastically proved difference between T. vulgare and non-infested control

THE EFFECT OF RADIATION ON DEVELOPMENT OF ROOT-KNOT NEMATODES

Root-knot nematodes (Meloidogyne spp.) are one of the most important plant parasitic nematodes of great economic importance which reduce the quantity and the quality of the yields of many cultivated and wild plants everywhere (in tropical, subtropical and temperate regions). The objectives of the study were to investigate the changes in the Meloidogyne arenaria and its host Tiny Tim tomato plant under radiation influence The influence of various doses of γ-irradiation (90, 700 and 1800 mGy) on cv. Tiny Tim tomato plants and developing eggs sacs of root-knot nematode Meloidogyne arenaria were investigated. Ionizing radiations of tomato seeds by low dose (90 mGy) stimulate development of plants. High doses of γ-irradiation (700 and 1800 mGy) suppress development (height, root and shoot weight) of tomato plants. High irradiation doses (700 and 1800 mGy) retarded the growth of nematodes. Metric characteristics of M. arenaria females, mainly body size, were smaller. The highest experimental dose (1800 mGy) prevented the development of females of M. arenaria (J4) to mature forms. A change of female to male ratio under the influence of γ- ionizing radiation has been observed, resulting in a decrease in males. These results show aspects for future research into the application of γ-irradiation in management of root-knot nematode

ДЕЙСТВИЕ РАДИАЦИИ НА РОСТ И РАЗВИТИЕ КОРНЕВЫХ НЕМАТОД

Root-knot nematodes (Meloidogyne spp.) are one of the most important plant parasitic nematodes of great economic importance which reduce the quantity and the quality of the yields of many cultivated and wild plants everywhere (in tropical, subtropical and temperate regions). The objectives of the study were to investigate the changes in the Meloidogyne arenaria and its host Tiny Tim tomato plant under radiation influence The influence of various doses of γ-irradiation (90, 700 and 1800 mGy) on cv. Tiny Tim tomato plants and developing eggs sacs of root-knot nematode Meloidogyne arenaria were investigated. Ionizing radiations of tomato seeds by low dose (90 mGy) stimulate development of plants. High doses of γ-irradiation (700 and 1800 mGy) suppress development (height, root and shoot weight) of tomato plants. High irradiation doses (700 and 1800 mGy) retarded the growth of nematodes. Metric characteristics of M. arenaria females, mainly body size, were smaller. The highest experimental dose (1800 mGy) prevented the development of females of M. arenaria (J4) to mature forms. A change of female to male ratio under the influence of γ- ionizing radiation has been observed, resulting in a decrease in males. These results show aspects for future research into the application of γ-irradiation in management of root-knot nematodesКорневые нематоды (Meloidogyne spp.) являются основными представителями класса нематод, паразитирующих на растениях. Нематоды наносят большой экономический ущерб, который выражается в снижении продуктивности и ухудшении качества урожаев сельскохозяйственных культур и дикорастущих растений, произрастающих во всех климатических зонах (тропических, субтропических, а также в регионах с умеренным климатом). Цель настоящего исследования состоит в изучении изменений, происходящих в галловой нематоде Meloidogyne arenaria и ее хозяине – растении томатов Tiny Tim («Крошка Тим») под воздействием радиации. Было изучено влияние различных доз гамма-излучения – 90, 700 и 1800 мГр на коэффициент изменчивости растений томатов Tiny Tim и развитие яиц галловой нематоды M. arenaria. Ионизирующее излучение в малых дозах (90 мГр) стимулирует рост и развитие растений, в то время как высокие дозы гамма-излучения (700 и 1800 мГр) подавляют развитие томатов, замедляя скорость роста побегов и корней. Использование ионизирующей радиации в высоких дозах (700 и 1800 мГр) способствует замедлению роста нематод. По метрическим данным, в основном это сказывается на уменьшении размеров тела самки M. аrenaria. Применение самой высокой экспериментальной дозы излучения (1800 мГр) препятствовало переходу самок M. arenaria (J4) ко взрослой стадии. Наблюдались изменения численного соотношения самцов и самок под влиянием гамма-излучения, приводящие к снижению числа самцов. Данные результаты открывают перспективы для дальнейших исследований воздействия гамма-излучения на развитие корневой нематоды