Oat Cultivation Research Articles

Oat – production status and efficiency, new varieties and opportunities

Results and discussions. Biological peculiarities and trends of usage of common oat are described. Dynamics of crop areas, yield capacity and gross collections of this important forage and food agricultural plant. Economic analysis of the efficiency of oat grain production was performed. Recently there has been a downward tendency in the production of oat grain in Ukraine – for example, in 2008 gross collection was 944.400 tons, and in 2013 – 467.200 tons with the yield of 2.17 t/ha and 1.86 t / ha, respectively. The main cause for the decrease in gross collection of oat grain is a reduction of areas sown to oat from 445.600 ha to 241.300 ha, respectively. Oat cultivation allows simple reproduction provided that the yield capacity is not less than 2.0-2.5 t/ha. Based on the average of oat yields in Ukraine (1.42-2.17 t/ha), its profit is on the limit of positive balance, but more often it is determined by negative financial results. Conclusions. The new oat varieties Spurt, Busol, Iren, Sterno with the potential grain yield of 4.0-6.0 t/ha, capable of providing producers with positive financial results, were characterized.

Эффективность выращивания голозерного овса в северной лесостепи Украины

Приведены результаты эффективности выращивания овса при различных дозах удобрения и защиты посевов. Показано, что наиболее экономически целесообразным сочетанием элементов технологии выращивания овса — внесение до посева N30P60K60 на фоне заделки побочной продукции предшественника, подкормки N30 на IV этапе органогенеза и применения комплексной химической защиты посевов. При такой технологии выращивания урожайность овса составила 3,58 т/га при урожайности в контрольном варианте 1,47 т/га. Прибыль от выращивания овса по данной технологии составила 2696 грн/га при общих расходах 5896 грн/га и себестоимости 1647 грн за 1 т.

Erosão hídrica influenciada por uma aplicação de dejeto líquido de suínos no solo cultivado em semeadura direta

A suinocultura em Santa Catarina é responsável por geração de emprego no meio rural e, por isso, apresenta grande importância social e econômica. Este trabalho foi realizado entre março e setembro de 2012 para avaliar a influência de uma aplicação de dejeto líquido de suínos na erosão hídrica, em um Nitossolo Bruno aluminoférrico húmico, nos tratamentos constituídos pelas doses: 0; 50; 100; e 200 m³ ha-1 do dejeto aplicado na superfície do solo uma única vez, 30 dias após a germinação da aveia-preta. As parcelas tinham 11 × 3,5 m e declividade média de 14,4 %. Ao longo do ciclo da aveia, foram realizados quatro testes de chuva simulada, cada um com quatro chuvas com intensidade planejada de 65 mm h-1 e duração de 75 min, com simulador de chuva tipo Swanson. As perdas totais de solo e água por erosão hídrica não foram influenciadas pela dose de dejeto líquido de suínos aplicado sobre o solo cultivado com aveia, evidenciando, no entanto, influência do teor de água no solo antecedente às chuvas simuladas aplicadas. Os teores de P e K solúveis na água da enxurrada diminuíram após a aplicação de dejeto líquido de suínos no solo cultivado com aveia, por certo tempo; quando o cultivo foi submetido à chuva simulada, os teores reduziram nas chuvas do teste 1 para as do teste 3 e aumentaram nas do teste 4. Os teores de P e K solúveis na água da enxurrada diminuíram com a dose de 100 m³ ha-1 de dejeto líquido de suínos aplicado sobre o solo para a dose zero m³ ha-1, nas chuvas simuladas dos testes 1 e 2. As perdas totais de P e K solúveis na água da enxurrada não foram influenciadas pela dose de dejeto líquido de suínos aplicado sobre o solo no cultivo da aveia; no entanto, apresentaram tendência de diminuir nas chuvas do teste 1 para as do teste 3 e de aumentar naquelas do teste 4. Os teores de P e K solúvel na água da enxurrada reduziram exponencialmente com a elevação do número de teste de chuva simulada realizada em solo cultivado com aveia, cujos dados do modelo exponencial y = y0 + ae-bx ajustou-se significativamente; o modelo não se adaptou aos dados da dose zero de dejeto em relação ao K.

Comparative Biomass Production of Six Oat Varieties in a Saline Soil Ecology

Oat is widely used as a food source in human and animal diets. In China, supplementary cultivation of oat has recently been extended into marginal saline soils, due to its extensive use. The goal of the present study was to explore and compare the agronomic characteristics, biomass production, and distribution of oat in coastal saline soil. A single-factor randomized block design experiment with six naked and husked oat varieties [Bayou-1 (BU-1), Baiyan-2 (BY-2), Baiyan-7 (BY-7), Huawan-6 (HW-6), Huazao-2 (HZ-2), and Pin-16 (P-16)] as treatments was conducted in the Hebei Province of China. The growth period (77 to 88 days) of the six oat varieties were shorter in saline soil than their original breeding region. Moreover, the plant was shorter, with a lower grain number per plant and seed setting. Grain weight increased and no change was observed in the floret number in coastal saline soil relative to the original habitats. The BY-7 variety produced the highest biomass value of 7.0 t ha−1 compared to the other five varieties. Compared with two active growth points, most varieties in the present study showed just one growth activity point between elongation and heading. Two fast growth periods for the six oat varieties were due to the high total leaf biomass growth rate (BGR) from elongation to heading and panicle BGR from heading to maturity. The biomass growth ratio (BGO) during elongation to heading was the largest among the four growth stages of the oat varieties. The number of kernels per spike decreased at the research site, but grain weight increased. Substantial differences were observed for growth periods, biomass, BGR, BGO, and other agronomic characters in the coastal saline soil of North China, but the BY-7 variety was the most suitable variety for the study site.

Copper availability assessment of Cu-contaminated vineyard soils using black oat cultivation and chemical extractants.

Grapevines grown on acid soils with low fertility in southern Brazil are treated with intense foliar applications of copper (Cu) fungicides, resulting in an increased level of Cu in the soil and increased toxicity. The present study evaluated the accumulation and bioavailability of Cu, and soils with varying levels of Cu from the main producing regions of southern Brazil were collected. The forms of Cu present in the soil were assessed using chemical extractants; additionally, oat cultivation was performed, reflecting the use of the plant as an indicator of Cu bioavailability. Cu accumulated in the topsoil, mainly in bioavailable forms, and there was also an increase of Cu up to a depth of 0.4m. Cu was primarily found in the mineral fraction, with apparent saturation of the soil organic matter functional groups. Inceptisol and Alfisol soils with a long history of cupric fungicide application were found to have levels of Cu toxic to oat plants. Furthermore, accumulated copper in Alfisol soil from the Campanha Gaúcha region of the state of Rio Grande do Sul had higher bioavailability compared to Cu accumulated in Inceptisol soil from the Serra Gaúcha region. In addition, the copper concentration in roots was found to serve as an indicator of Cu bioavailability in soil, but not of copper phytotoxicity in plants.

Occurrence of antagonistic fungi in the soil after cover crops cultivation

The purpose of the studies was to determine the species composition of fungi and their antagonistic effect towards soil-borne plant pathogens after the cultivation of oats, spring vetch and tansy phacelia as intercrop cover plants. The total population of fungi in the soil after the cultivation of oats was twice as low as after the cultivation of tansy phacelia. A little smaller fungi population was obtained as a result of mulching the soil with spring vetch in comparison to that after the cultivation of tansy phacelia. The proportion of Fusarium spp., Alternaria alternata, Pythium irregulare and Thanatephorus cucumeris isolated from the soil after the cultivation of oats was the lowest one, while being a little higher after the cultivation of spring vetch, and the highest after tansy phacelia. The greatest number of antagonistic fungi occurred in the soil after ploughing in the mulch of oats. Antagonistic fungi isolated from the soil mulched with oats were the most effective in limiting the growth and development of A. alternata, Fusarium culmorum, F. oxysporum, Haematonectria haematococca, P. irregulare and T. cucumeris since the value of their antagonistic effect was the largest. The lowest antagonistic activity of fungi was found out after using tancy phacelia.

Antagonistic bacteria in the soil after cover crops cultivation

The purpose of the studies was to establish the quantitative composition of bacteria Bacillus spp. and Pseudomonas spp. and their antagonistic effect towards soil-borne fungi after the cultivation of oats, spring vetch and tansy phacelia as intercrop cover plants. The total population of bacteria in 1 g dry weight of the soil from the experimental combination where mulch of oats was used was larger than in the combination with spring vetch or tansy phacelia. Totally, approximately three times as much Bacillus spp. was obtained from soil samples as compared to Pseudomonas spp. Tests showed that the most isolates of antagonistic bacteria out of the enumerated genera occurred in the soil after oats cultivation, and the least in the soil after the cultivation of tansy phacelia. Antagonistic Bacillus spp. and Pseudomonas spp. inhibited the growth and development of Fusarium oxysporum, Haematonectria haematococca and Thanatephorus cucumeris in the most effective way. The greatest total antagonistic effect of Bacillus spp. and Pseudomonas spp. towards Altenaria alternata, F. culmorum, F. oxysporum, H. haematococca, P. irregulare and T. cucumeris was found out after managing the mulch of oats. The smallest total antagonistic effect of bacteria was observed after managing the mulch of tansy phacelia.

Wpływ zróżnicowanych dawek herbicydów na poziom plonowania i jakość ziarna dwóch odmian owsa

The aim of the study executed with the perpendicular strip method with three replications, conducted at the Experimental Department of Variety Evaluation in Krościna Mała in the years 2010–2012, was to determine how varieties of oat seeds would respond to the recommended and half of the recommended dose of herbicides for weed reduction, the size of grain yields, its structure and grain quality. Two varieties of oat were tested: Arden and Haker, which were sprayed during tillering with following herbicides: Starane 250 EC at doses of 0.4 and 0.8 l/ha and Chwastox Turbo 340 SL at doses of 1.0 and 2.0 l/ha. The listed herbicides, regardless of the dose, had a positive effect on the reduction of weed infestation, resulting in the increase of grain yield in relation to the controlled objects where no herbicides were used. The analysis of the structure of crops has shown that grain yields on combinations protected by herbicides resulted from increased stocking panicles per unit area, while the 1,000 grain weight and the number of grains per panicle followed a similar pattern as in the control plots. Herbicides used in the cultivation of oat increased the total protein content in grain and the share of grain yield with a diameter above 2.5 mm. Celem doświadczeń, które założono metodą pasów prostopadłych w 3 powtórzeniach, w Zakładzie Doświadczalnym Oceny Odmian w Krościnie Małej, w latach 2010–2012, była ocena wpływu pełnych i ograniczonych o połowę dawek wybranych herbicydów na redukcję zachwaszczenia oraz wysokość plonu, jego strukturę i cechy jakościowe ziarna dwóch odmian owsa. Badano różniące się pod względem morfologicznym, dwie odmiany owsa: Arden i Haker, które w fazie krzewienia opryskiwano herbicydami: Starane 250 EC w dawkach 0,4 i 0,8 l/ha oraz Chwastox Turbo 340 SL w dawkach 1,0 i 2,0 l/ha. Wymienione herbicydy, niezależnie od zastosowanej dawki, miały korzystny wpływ na redukcję zachwaszczenia, co skutkowało przyrostem plonów ziarna w stosunku do obiektów kontrolnych, nieopryskiwanych środkami chwastobójczymi. Analiza plonów dowiodła, że plony ziarna na kombinacjach chronionych herbicydami wynikały ze zwiększonej obsady wiech na jednostce powierzchni, natomiast masa 1000 ziaren i liczba ziaren w wiechach kształtowała się podobnie, jak na poletkach kontrolnych. Zastosowane w uprawie owsa herbicydy wpłynęły na zwiększenie zawartości białka ogólnego w ziarnie oraz zwiększenie udziału ziarna w plonie o średnicy powyżej 2,5 mm.

Crescimento de plântulas de aveia branca submetidas ao estresse salino

The cultivation of white oat in succession to irrigated rice is considered a viable alternative, mainly because of their added value and for their restorative characteristics of the soil, though their productive potential can be reduced considerably because of the soil salinization, being very important to determine salt concentration tolerated by different white oat cultivars.The objective is to evaluate, oat cultivars recommended for the state of Rio Grande do Sul under different salt concentrations in seed germination and early growth. The experimental design was completely randomized factorial 2X5, with four replications, (cultivars Barbarasul and Chiarasul, salt concentration and levels 0, 25, 50, 75 and 100 mM NaCl per liter of water). The physiological seed quality was evaluated in the laboratory by germination, first count of germination, length of shoot and root dry weight of shoot and root. Based on the results we can conclude that: germination and seedling growth of oat cultivars and Barbarasul Chiarasul are negatively affected with increasing salt concentration. In addition the response is more pronounced on the shoot than the root system. The concentration of 100 mM NaCl L-1 impossible to seed germination of both cultivars.

Crescimento de plântulas de aveia branca submetidas ao estresse salino

The cultivation of white oat in succession to irrigated rice is considered a viable alternative, mainly because of their added value and for their restorative characteristics of the soil, though their productive potential can be reduced considerably because of the soil salinization, being very important to determine salt concentration tolerated by different white oat cultivars.The objective is to evaluate, oat cultivars recommended for the state of Rio Grande do Sul under different salt concentrations in seed germination and early growth. The experimental design was completely randomized factorial 2X5, with four replications, (cultivars Barbarasul and Chiarasul, salt concentration and levels 0, 25, 50, 75 and 100 mM NaCl per liter of water). The physiological seed quality was evaluated in the laboratory by germination, first count of germination, length of shoot and root dry weight of shoot and root. Based on the results we can conclude that: germination and seedling growth of oat cultivars and Barbarasul Chiarasul are negatively affected with increasing salt concentration. In addition the response is more pronounced on the shoot than the root system. The concentration of 100 mM NaCl L-1 impossible to seed germination of both cultivars.

PRELIMINARY REPORT OF EPIPHYTIC AND ENDOPHYTIC COLONIZATION OF BLACK OAT (AVENA STRIGOSA) AND WHEAT (TRITICUM AESTIVUM) BY CURTOBACTERIUM FLACCUMFACIENS PV. FLACCUMFACIENS IN BRAZIL

Bacterial wilt, incited by Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff), is one of the major bacterial diseases for dry bean in Brazil, with a higher incidence under no-till- age system after black oat (Avena strigosa) cultivation. There are also reports of wheat (Triticum aestivum) colonization by Cff under controlled conditions (Silva Junior et al., 2012). In 2012, black oat and wheat plants grown in Ponta Grossa and Tibagi (Parana state) were collected 90 days after sowing in crop fields with historic incidence of bacterial wilt of bean, and Cff was isolated in MSCFF culture medium (Maringoni et al., 2006), with specific methodologies to verify the natural epiphytic and endophytic colonization of grasses. Bacterial isolates with yellow and orange colonies, rod-shaped and Gram-positive were obtained, tested for pathogenicity on bean cv. Perola, and identified as Cff by PCR with the spe- cific primers CffFOR2 and CffREV4. Bacterial isolates were pathogenic to bean. This is the first report of epiphytic and endophytic colonization of oat and wheat by Cff in Brazil, showing the importance of these grasses in the epidemiology of bean bacterial wilt in field conditions.

Reakcja odmian owsa na poziom ochrony w różnych systemach następstwa roślin

Summary In 6-year studies (2005–2010) carried out in static field experiment on lessive proper soil in the Balcyny Production and Experimental Company near Ostroda town, the reactions of two varieties of oat (Chwat and Cwal) to a chemical protection against weeds as well as weeds and diseases was evaluated. The comparison of reactions of oat was estimated in two following crop sequence systems: i.e. A) the cultivation of oat varieties in 6-field crop rotation: potato – oat – fibrous flax – rye – horse bean and winter triticale, and B) cultivations in 38–43-year monoculture. The oat cultivation without any protection was a control object in both systems. The studies demonstrated that the both crop sequence systems significantly differentiated the reaction of two oat varieties to applied levels of the protection. Generally, chemical protection applied in crop rotation, decreased yields of oat varieties, and in the case of the monoculture the yield of oat significantly increased with intensification of protection. Simultaneously, a significant higher yield growth took place in the case of the protection against diseases than against weeds. In both crop sequence systems, the Chwat variety of oat reacted better to protection levels. When it was cultivated in the 6-field crop rotation the grain yield was decreased despite herbicides and fungicides application while in the case of monoculture it significantly increased.

Physical properties and organic carbon content of a Typic Hapludult soil fertilised with pig slurry and pig litter in a no-tillage system

Applications of swine residues to the soil surface in a no-tillage system (NTS) may increase the organic carbon level and improve the physical properties of the soil. This study aimed to evaluate the effect of the continuous application of pig slurry (PS) and pig litter (PL) on the total organic carbon (TOC) content and physical properties of soil under NTS in Southern Brazil. In March 2010, after 8 years of cultivation of black oats (Avena strigosa)–maize (Zea mays), soil samples were collected in the 0–5, 5–10, 10–15, and 15–20 cm layers. The treatments consisted of a control plot (without manure application), plots with PS applications equivalent to one and two times the recommended rate of nitrogen (N) for maize and black oats (PS1X and PS2X, respectively), and plots with PL equivalent to one and two times the recommended rate of N for maize and black oats (PL1X and PL2X, respectively). The TOC, soil bulk density (BD), penetration resistance (PR), total porosity (TP), macro- and microporosity, distribution of pore diameters, and indices of aggregation and aggregate stability were evaluated. Differences were found between treatments for TOC, BD, macro- and microporosity, pore diameter, aggregation, and PR. Treatment with PL favoured the production of aggregates (diameter >4 mm) and increased the rates of aggregation and aggregate stability in the 10–15 and 15–20 cm layers and macroporosity in the 0–5 and 15–20 cm layers. Application of PL2X reduced PR by 34% and 20%, respectively, in the 5–10 and 10–15 cm layers. Eight years of adding PS to successive cultivations of black oats–maize soil managed under NTS produced no changes in the physical features or the TOC of the soil, whereas the application of PL produced improvements in physical attributes of the soil and increased soil TOC.

Effect of Buckwheat and Potato as Forecrops on Soil Microbial Properties in Crop Rotation

Field trials were carried out at the experimental cereal breeding fields in Stende (Latvia), an area characterized by a northern temperate climate. The soil had been under short-term organic or conventional crop management and was then subjected to crop rotation, using buckwheat (Fagopyrum esculentum Moench.) and potato (Solanum tuberosum L.) as the forecrops; wheat (Triticum aestivum L.) and oat (Avena sativa L.) as the following crops; and two fertilizer regimes under common organic and conventional practices. As the evaluation criteria of the soil quality, physico-chemical (pH value, organic matter, N, P, K) were tested. In addition, the following biological properties were estimated: plate counts of different physiological groups of microorganisms, soil microbial respiration, enzymatic activity (urease, dehydrogenase and fluoresceine diacetate hydrolysis) of soil microorganisms. Soil microbial respiration activity, FDA hydrolysis and urease activity showed a tendency to decrease in the soil after potato cultivation as the forecrop. The number of bacteria was higher in plots with wheat, and the actinomycete count was lower after oat cultivation. The number of bacteria, actinomycetes, fungi, as well as soil microbial respiration and enzymatic activity, fluctuated due to weather seasonality.

Desenvolvimento de plantas de cobertura e produtividade da soja conforme atributos físicos em solo compactado

Com a intensa utilização de tecnologias voltadas à mecanização das operações agrícolas, a compactação do solo é um fator que tem limitado a produtividade. Para atenuar este problema, o uso de plantas de cobertura do solo é frequentemente recomendado. Com o objetivo de avaliar o efeito da compactação nas propriedades físicas do solo, no desenvolvimento de plantas de cobertura e na produtividade da soja, conduziu-se um experimento no delineamento em blocos casualizados no esquema fatorial 2 x 5, sendo duas espécies de plantas de cobertura (aveia preta - Avena strigosa e nabo forrageiro - Raphanus sativus) e cinco níveis de compactação (0, 2, 4, 6 e 8 passadas de trator com 5,0 Mg na superfície do solo), com quatro repetições. Intensidades de tráfego superiores a 2 passadas de trator alteram a densidade do solo, a porosidade total e a resistência mecânica à penetração, na camada de 0-0,10 m, e reduzem, de forma linear, a altura e a produção de matéria seca da parte aérea das plantas de cobertura. O cultivo da aveia preta ou nabo forrageiro antecedendo a soja, associado ao uso de sulcadores na operação de semeadura da soja minimiza os efeitos da compactação do solo, possibilitando obter-se produtividades superiores a 3,5 t ha-1.

Regulating Effect of Sowing Depth on Saline Land Oat Growth and K<sup>+</sup> and Na<sup>+</sup> Migration

Biological utilization of Saline soil is an effective way to improve land utilization and ecological environment. Oat is a unique crop of Inner Mongolia and has strong resistance to salt. This study setting five sowing depth of 3 cm, 5 cm, 7 cm, 9 cm and 11 cm on the morphological and physiological characteristics of two oat cultivars. The K+ /Na+ and selective absorption and migration, yield and nutrient quality, and soil salt content were measured from a field experiment. The highest yield of oat on saline land was obtained at sowing depth of 7 cm. The dry matter of stem and leaf accumulated more rapidly at 7 cm, membrane damage was less, leaf chlorophyll content was higher and kept higher photosynthetic capacity, K+ /Na+ and SK+, Na+ (migration) of stem and leaf were higher. So it showed stronger salinity adaptability and higher yield, and the yield was between 43.1% and 64.1% higher than conventional seed planting’s and it occupied between 37.2% and 42.7% of loam soil, and the crude fat content was higher. Sowing depth of 5 cm was the second choice, but sowing depth of 9 and 11 centimeter was not suitable to plant salt-enduring cultivar. The decrease sequence of oat yield and quality under salt stress was: grain yield > fresh yield > hay yield > crude fat > crude fiber. The grain yield and crude fat of salt-enduring cultivar Nei nong da you 1 were favorable for improving oat’s salinity adaptability and increasing the desalination in soil. The study can provide a theoretical basis to improve saline land utilization and high-yield cultivation of oat.

Values of Winter Fallow Crops on Soil Properties and Watermelon Productivity in Plastic Greenhouse

This study was performed to screen fallow crops during winter period for improvement of soil quality and utilizing as mulching material in watermelon cropping system during winter period. Five fallow crops, mainly, hairy vetch, barley, rye, oat and wheat, were sown in early November. They were mowed for covering the soil surface instead of polyethylene (PE) film before watermelon planting in early April the following year. The highest absorbed nutrients and dry matter yield were found in rye. Bulk density in plots with fallow crop was lower than control plot. There was observed no significant differences among the fallow crops. However, porosity was the lowest in control plot. Soil EC reduced to 12%, 13%, 14%, 16% and 22%, respectively, by cultivation of hairy vetch, oat, wheat, barley and rye. Microbial biomass carbon and dehydrogenase activities were higher in soil treated with gramineous crops, such as barley, rye and oat. The growth of watermelon was more affected by regeneration of fallow crop than the occurrence of weed, especially in plots treated with rye or oat. Also, the fruit damage by aphid was found severe in these treatment plots. The fruit yield in plots treated with hairy vetch and barley was increased 5.7% and 2.6%, respectively, compared to that of PE films. The present experiment findings implied that these fallow crops had significant beneficial effects on improvement of soil qualities and could be utilized for mulching materials in watermelon cropping system.

Statistical analysis of agronomical factors and weather conditions influencing deoxynivalenol levels in oats in Scandinavia

The relationship between weather data and agronomical factors and deoxynivalenol (DON) levels in oats was examined with the aim of developing a predictive model. Data were collected from a total of 674 fields during periods of up to 10 years in Finland, Norway and Sweden, and included DON levels in the harvested oats crop, agronomical factors and weather data. The results show that there was a large regional variation in DON levels, with higher levels in one region in Norway compared with other regions in Norway, Finland and Sweden. In this region the median DON level was 1000 ng g–1 and the regulatory limit for human consumption (1750 ng g–1) was exceeded in 28% of the samples. In other regions the median DON levels ranged from 75 to 270 ng g–1, and DON levels exceeded 1750 ng g–1 in 3–8% of the samples. Including more variables than region in a multiple regression model only increased the adjusted coefficient of determination from 0.17 to 0.24, indicating that very little of the variation in DON levels could be explained by weather data or agronomical factors. Thus, it was not possible to predict DON levels based on the variables included in this study. Further studies are needed to solve this problem. Apparently the infection and/or growth of DON producing Fusarium species are promoted in certain regions. One possibility may be to study the species distribution of fungal communities and their changes during the oats cultivation period in more detail.

The consequent influence of crop rotation and six-year-long spring barley monoculture on yields and weed infestation of white mustard and oats

The present study was conducted in the years 2007- 2008, after 6-year-long experiments in the cultivation of spring barley in a crop rotation system and in monoculture. The other experimental factor was the spring barley protection method. Intensive protection involved comprehensive treatment of barley (in-crop harrowing, seed dressing, application of herbicides, fungicides, a retardant and an insecticide). Extensive protection consisted only in in-crop harrowing, without the application of crop protection agents, except for seed dressing. The above mentioned factors formed the background for the study on the cultivation of white mustard and oats, as phytosanitary species, in successive years. In the test plants, no mineral fertilization and crop protection were applied. Such agricultural method enabled an objective assessment of the consequent effect of monoculture, crop rotation and crop treatments. A hypothesis was made that the cultivation of the phytosanitary plants in the stand after 6-year-long barley monoculture would allow obtaining the level of yields and weed infestation similar to those of the crop rotation treatments. It was also assumed that the cultivation of white mustard and oats would eliminate differences in plant productivity caused by the negative influence of extensive protection. It was proved that the cultivation of the phytosanitary plants eliminated the negative influence of monoculture on the level of their yields and weed infestation. However, the test plants did not compensate negative consequences of extensive protection. In spite of this, white mustard and oats effectively competed with weeds, and the number and weight of weeds in a crop canopy did not cause a dramatic decline in yields. In the test plant canopy, the following short-lived weeds were predominant: <i>Chenopodium album</i>, <i>Galinsoga parviflora</i>, <i>Echinochloa crus-galli</i>. The absence of herbicide application resulted in the compensation of perennial species: <i>Elymus repens</i> and <i>Cirsium arvense</i>.

Suppression of Common Scab of Potato Caused by Streptomyces turgidiscabies Using Lopsided Oat Green Manure.

Field experiments were conducted to determine the effect of green manure as fallow on common scab of potato caused by Streptomyces turgidiscabies. Significantly fewer diseased tubers were harvested from soil incorporated with lopsided oat or woolly pod vetch compared with those from oat and continuous potato cultivation in a planter experiment. Each field experiment consisted of lopsided oat cultivated during the spring and summer prior to the potato planting. Comparisons were also made with several other treatments, including cultivation of woolly pod vetch, oat, soybean, sugar beet, and potato ('Yukirasya', which is resistant to potato common potato scab) and soil application of Ferosand (Fe, mainly FeSO4, to decrease the soil pH). In field experiments conducted during 1999-2000, treatment with lopsided oat followed by lopsided oat or woolly pod vetch was significantly more effective at suppressing the disease severity than oat and continuous potato cultivation (P < 0.001). An increase in the marketable tuber ratio was also more significant than for oat and continuous potato cultivation (P < 0.001). In field experiments conducted during 2000-01, lopsided oat cultivation alone and with the application of Ferosand (1.8 t/ha) or resistant potato cultivar treatment were significantly more effective at suppressing the disease severity and incidence than sugar beet cultivation (P < 0.001), even under high disease intensity in the field. However, potato yield had a tendency to reduce after lopsided oat treatment with an application of Ferosand (1.8 t/ha) compared with lopsided oat alone or the application of Ferosand at 600 kg/ha, due to low pH conditions. In field experiments conducted during 2001-02, the lowest severity and incidence of common scab of potato were observed in soil treated with lopsided oat than with other treatments (P < 0.05 and P < 0.001, respectively). These findings suggest that lopsided oat used as fallow green manure can reduce the severity of common scab and increase potato yield.