Doses Of Nitrogen Fertilizer Research Articles

Produtividade do milho associado a inoculação com Azospirillum brasilense e diferentes doses de adubação nitrogenada

Embora a adubação química nitrogenada seja responsável pelo aumento da produtividade da cultura do milho, sua aplicação também e responsável pelo aumento do custo de produção e por promover uma serie de riscos ambientais. Uma alternativa para esse problema e a fixação biológica de nitrogênio. Este trabalho tem como objetivo a avalição da eficiência da inoculação com Azospirillum brasilense na cultura do milho associada a diferentes doses de adubação nitrogenada em cobertura. O experimento foi realizado na área experimental da UniEvangélica, com os tratamentos: testemunha com 100% da cobertura; inoculação + 85% da cobertura; inoculação + 85% de cobertura e aplicação em cobertura de A. brasilense; inoculação + 100% da cobertura. Foram avaliados parâmetros morfológicos e a produtividade. Os resultados foram submetidos à análise de variância, e quando ocorreram diferenças significativas, aplicou o teste de médias de Tukey (5% de probabilidade). A inoculação com A. brasilense e redução de 15% da adubação nitrogenada em cobertura, apresentou eficiência como promotora de crescimento e desenvolvimento vegetativo, efeito significativo sobre a altura de plantas e na massa verde e seca da inflorescência. A inoculação com A. brasilense não apresentou resultados significativos na manutenção da produtividade frente a redução da adubação nitrogenada, com redução de 21% na produtividade.

Cyanobacterial amendment boosts plant growth and flower quality in Chrysanthemum through improved nutrient availability

Cultivation of ornamentals requires heavy inputs of chemicals, which can be provided in an environment-friendly manner through cyanobacterial inoculation, facilitating better availability of key macro/micronutrients from the surrounding environment to the host plant and stimulate plant growth. Therefore, the objective of the present investigation was to compare a nursery of Chrysanthemum variety Pusa Aditya grown using potting medium amended with a diazotrophic cyanobacterial strain Anabaena torulosa, with the routine nursery potting medium, for their potential towards improving flower traits, soil fertility and crop productivity. In order to demonstrate the nitrogen savings, the plantlets from such primed nurseries were transplanted into pots, receiving two different doses of nitrogenous fertilizer (full N and 75% N), along with full doses of recommended P and K fertilizers. An increment of 1.8-fold in terms of nitrogen availability in soil was recorded in treatments receiving 75% N along with full doses of recommended P and K fertilizers and cyanobacterium-primed nursery, as compared to all other treatments. An average increase of 35% in the fresh weight of flowers, flower pigmentation as well as early appearance of flower buds was recorded. A significant stimulation of antioxidant and defense enzyme activities in plants, due to cyanobacterium amendment at nursery stage was also recorded. Correlation analyses illustrated a positive association of soil biological attributes (root biofilm formation, soil polysaccharides, glomalin related soil proteins) with most parameters related to plant growth, particularly, reproductive development and flower quality aspects. Principal component analysis illustrated the greater association of these parameters with the treatments involving Anabaena torulosa amended nurseries. It can be concluded that cyanobacterium-amended nurseries can be a useful intervention for deriving robust planting units and leading to beneficial influences on soil nutrient availability, flower quality traits and yield.

Продуктивность лофанта тибетского (Agastache rugosa) в зависимости от агротехнических приемов возделывания в условиях интродукции на Среднем Урале

Abstract. Research on the introduction of lofant (Agastache rugosa) has been conducted by the Department of Crop Production and Breeding of the Ural State Agrarian University since 2013. Studied by sowing seeds in open ground, especially the growth and development of lofant Tibetan background on the various types of mineral fertilizers, the effect of physiologically active substances comparative assessment of the types and varieties of lofant. The research was carried out in the Uralets agricultural farm, located in the Beloyarskiy district of the Sverdlovsk region. Methods. Phenological and biometric observations of plant growth and development were carried out. The method for laying the experience is generally accepted according to B. A. Dospekhov. This article presents the results of the introduction work on the study of the seedling method of cultivation and application of increasing doses of nitrogen fertilizers, which had the most pronounced effect on productivity, as well as on the structural composition of aboveground biomass – the most important indicator of quality in the preparation of medicinal raw materials. Purpose of research. To identify the features of the formation of productivity of aboveground biomass of the Agastache rugosa in the natural and climatic conditions of the Middle Urals. The task was to study the influence of seedling cultivation method, as well as the introduction of increasing doses of nitrogen fertilizers on the productivity and structural composition of aboveground biomass of Agastache rugosa. Results. The study revealed a clear dependence of the productivity of Agastache rugosa on the time of sowing seeds for seedlings: the earlier the sowing period, the higher the productivity. The maximum yield of medicinal raw materials per unit area was obtained in the I variant (seeding on seedlings – March 10) – 25.2 t/ha, the minimum productivity was formed in the IV variant (seeding on seedlings – April 10), it was 16.2 t/ha, which is 35.7 % lower than in the I variant (on average for 2013–2015). It is established that the higher the level of nitrogen nutrition, the greater the biological productivity. The maximum productivity (on average for 2018–2020) was 29.5 t/ha (IV variant – N60 kg/ha). Scientific novelty. For the first time, in the conditions of the Middle Urals, the features of the formation of productivity of Agastache rugosa with the seedling method of cultivation and different levels of nitrogen fertilizers were determined. Established: the optimal time for sowing seeds for seedlings and the dose of nitrogen fertilizers, in which Agastache rugosa provides high productivity with an optimal structure of medicinal raw materials.

Net assimilation rate, growth and yield of rice (Oryza sativa L cv Inpago Unsoed 1) with the application of PGPR in different rate of nitrogen

The aims of this research was to study the net assimilation rate, growth and yield of rice with the application of PGPR in different rate of nitrogen fertilizer. The experimental was conducted in experimental farm of Agriculture Faculty of UNSOED Purwokerto. The research was arranged in Randomized Block Design with three replications. The first factor is PGPR consortium, and the second factor is dosage of nitrogen fertilizer. The observed variables were plant height, number of tillers, plant biomass, leaf greenness, plant biomass, net assimilation rate, relative growth rate and yield. Data were analyzed using ANOVA followed with DMRT test for mean comparison between group. The results showed that PGPR consortium inoculation and nitrogen fertilization have effect on root growth, leaf greenness, and plant biomass. The PGPR consortium R08 isolate + R11 isolate and nitrogen fertilizer at dose of 1.36 g plant−1 gave highest net assimilation rate of 5.87 g dm−2 week−1. The highest grain yield was achieved at nitrogen fertilizer dose of 2.72 g plant−1 at 36.17 g per hill.

Growth and yield of shallots (Allium ascalonicum L.) Lokananta in various doses of nitrogen fertilizers and number of plant per hole in coastal sandy land

This research aimed to determine the effect of N fertilizer dose, number of plant/hole, and their interaction on the growth and yield of shallots. The research used a Randomized Complete Block Design (RCBD) with two factors: various doses of N fertilizer (P) (P1=90, P2=180, and P3=270 N kg/ha) and number of plant/hole (T) (T1=1, T2=2, T3=3, and T4=4). The observed variables were plant height, number of leaves, leaf area, chlorophyll content, stomata opening width, stomata density, weight of fresh and dry leaf, root and tuber, fresh and askip tuber yield, root length, number of roots, number of tubers, and tuber diameter. Obtained data were analyzed using F test then followed by Duncan Multiple Range Test (DMRT) of 5% level if diversity occur. The results showed that N fertilizer of 180 kg/ha produced higher plant height (25.78 cm), density of morning and evening stomata (71.86/mm2 67.03/mm2, respectively) with fresh tubers yield of 8.48 t/ha. One plant/hole showed higher yield of tuber diameter (4.68 cm), two plants/hole showed higher height (25.67 cm), and four plants/hole showed higher number of leaves (9.38 strands), roots (73.56 strands), and tubers (4 pieces). There was no interaction between both factors to the observed variables.

Effect of cultivation system on quality changes in durum wheat grain and flour produced in North-Eastern Europe.

Grain of the highest hardness was produced from durum wheat grown without the use of growth regulator, at the lowest sowing density (350 seeds m-2) and nitrogen fertilization dose of 80 kg ha-1. The highest values L* and b* were determined in the grain of wheat cultivated without additional agrotechnical measures (growth regulator and nitrogen fertilization). Study results, supported by correlation analysis, indicated that high-quality grain with desired flour quality parameters (level of: FER ≈ 64%; FPS ≈ 98%; L* ≈ 92) can be produced from spring durum wheat grown without the growth regulator and at 80 kg·ha-1 nitrogen fertilization. Additionally, this variant of applied cultivation system can reduce costs of durum wheat production and contamination of the natural environment.

Effect of nitrogen fertilizers on the grain productivity of vetch and wheat mixture

Relevance and Methods. The effect of three doses of nitrogen fertilizers (N30, N60, and N90) on the formation of a crop of vetch seeds mixed with spring wheat was studied in a field experiment in sod-podzolic sandy loam soil.Results. In average for the study years, the yield of vetch seeds under the influence of nitrogen fertilizers decreased at the dose of mineral nitrogen 30 kg/ha by 12,7% at a dose of 60 kg/ha by 26,4% at a dose of 90 kg/ha by 36,4%, and grain yield of spring wheat increased, respectively, 1,8; 2,5 and 2,9 times. A significant decrease in the yield of vetch was observed at doses of mineral nitrogen N60 and N90, the yield of wheat grain significantly increased at all doses of mineral nitrogen. Nitrogen fertilizers were most effective in drought conditions, when the symbiotic fixation of air nitrogen in the crop area was weakened. Under conditions of increased moisture, nitrogen fertilizers did not provide an increase in the grain yield of the mixture, but increased the resistance of the crop to lodging, which made the mixture more technologically adapted to harvesting.

Indigenous Plant Growth Promoting Rhizobacteria and Chemical Fertilizers: Impact on Soil Health and Productivity of Capsicum (Capsicum Annuum L.) in North Western Himalayan Region

ABSTRACT At present, no commercial indigenous plant growth-promoting rhizobacteria (PGPR) is available for Capsicum crop in North-Western Himalayan Region. Therefore, PGPR were isolated from rhizosphere and root samples of capsicum collected from 28 locations of agro-climatic zones I, II and III of Himachal Pradesh. Thirty-four morphological distinct isolates were screened for multifarious plant growth-promoting traits. Four best PGPR isolates (MAT8, KAN11, JHA6 and ROH14) exhibiting maximum increase in capsicum seed germination were further screened at 80, 60 and 40% of recommended chemical doses of nitrogen (75 Kg ha−1) and phosphorus (70 Kg ha−1) fertilizer (RDNP) for capsicum growth and yield under net-house conditions. Two isolates, ROH14 (Bacillus amyloliquefaciens, Accession number KX447671) and JHA6 (Pseudomonas aeruginosa, Accession number KX447673), alone and in consortia along with 60 and 80% RDNP were further selected for two-year field experimentation. The conjoint application of PGPR isolate (JHA6 and ROH14) along with 80% RDNP brought a significant increase in yield (25.9%), plant height (8.2%), biomass (9.4%), nitrogen (47.1%) and phosphorus uptake (34.0%) over 100% of recommended doses of chemical fertilizers. In addition, the treatment also resulted in enhanced soil properties in terms of available contents of nitrogen and phosphorus, enzymatic activities (dehydrogenase, phosphatase and phytase), microbial population and microbial biomass-carbon besides providing net return of Rs 4484170. The study, therefore, indicates the potential of Bacillus amyloliquefaciens (ROH14) and Pseudomonas aeruginosa (JHA6) in partial replacement of nitrogen and phosphorus (~20%) applied through chemical fertilizers, providing Benefit/Cost ratio 2.73 along with sustainable crop production.

Оптимізація живлення сільськогосподарських культур за фізико-хімічної деградації кислих ґрунтів

Goal. To study and to identify features of optimization of crop nutrition during physicochemical degradation of acid soils. Methods. Field, laboratory, computational, mathematical, and statistical. Results. Results are given of researches in the influence of agrochemical load on gray forest soil with increasing doses of fertilizers (in combination with measures of radical chemical reclamation and without them) received during 2016–2019. It is established that the use of intensive fertilizer systems without radical chemical reclamation leads to the deterioration of the physicochemical properties of gray forest soil. On the background of reducing the aftereffects of radical chemical reclamation for 10–13 years, the annual application of a dose of alkaline earth elements, taking into account the physiological characteristics of the culture (average 11.4 and 4.6 kg/ha of calcium and magnesium, respectively) ensures for 10–12 years close to neutral reaction, and on the 13th year of application — the slightly acidic reaction of the soil solution. Besides, the content of exchangeable Ca and Mg in GVK increases slightly, it increases to 6.71–7.00 mg·eq/100 g of soil. Conclusions. The use of a dose of mineral fertilizers on gray forest soil, which is calculated according to the species genotypic ratio (SGR) of elements in the biomass of the culture on the background of application of lime, optimizes crop nutrition, physicochemical properties of the soil, reduces the dose of phosphorus and potassium and toxic action of H+ and Al3+. The optimal combination of N, P, K, Ca and Mg (216 kg/ha in the ratio of 1:0.4:0.5:0.3:0.1) in combination with seed inoculation with nitrogen-fixing and phosphorus-mobilizing bacteria provides an increase of productivity of the grain crop rotation to 5.45 t/ha g.p., and payback of 1 kg act. mat. of fertilizer applied to 15.6 kg g.p. Physicochemical degradation of acid soils at the application of high doses of nitrogen fertilizers can be partially prevented by saturation of the soil absorption complex with exchange cations of alkaline earth metals, supplementing the fertilization system with small doses of Ca and Mg, which are calculated according to the recommended dose of nitrogen, limited on acidic soils.

Effects of nitrogen fertilization on growth and yield of diterpene glycosides in stevia (Stevia rebaudiana Bertoni)

The effects of different nitrogen doses on dry weight yield, stevioside and rebaudioside A contents, and yields were evaluated in stevia (Stevia rebaudiana Bertoni). This study was carried out at the Instituto Federal Catarinense, Rio do Sul (SC), Brazil, under decreasing photoperiods. A randomized complete block design with four blocks and five treatments (0, 65, 135, 200 and 270 kg ha-1 N) was used. Variables related to dry weight yield (total dry weight, leaf dry weight, stem dry weight, number of secondary branches and tertiary branches, and main stem length), growth rates (total leaf area, leaf area index, specific leaf area, leaf area ratio, leaf weight ratio), and stevioside and rebaudioside A contents and yields were evaluated. The doses of nitrogen fertilization did not affect the variables related to dry weight yield, stevioside and rebaudioside A contents and yields, or rebaudioside A:stevioside ratio in stevia genotype 8 (G8), grown under decreasing photoperiods.

Physical and chemical properties of rice grain of variety Rapan at different seeding rates and does of nitrogen fertilizers

The paper presents the results of evaluating the rice variety Rapan grown in 2018, 2019 at different seeding rates and doses of nitrogen fertilizers, according to the main amylographic characteristics of starch dispersion and fracturing. In 2018 and 2019, when growing variety Rapan with seeding rates of 4, 6 and 8 million viable seeds, the highest values were noted for the “fracturing” trait at a nitrogen dose of 92 kg/ha of active ingredient. In 2018, they amounted to 31, 35 and 41%, respectively, in 2019 - 13, 12 and 12%, respectively. The following tendency in the change of rice quality traits was noted: in the samples grown without the use of nitrogen, low fracturing was revealed, while in the N92 variants the value of the trait was maximum, with N184 - the minimum. Indicators for the “maximum viscosity” at a nitrogen dose of 92 kg / ha of active ingredient had the lowest values at all three seeding rates and amounted to 484, 500 and 485 Br.units in 2018, respectively. In 2019 - 471, 440 and 480 Br. units. The opposite pattern was observed when determining the viscosity indices: at the minimum values of fracturing, the viscosity indices were maximum and decreased at high values of this trait.

Change in the soils’ fertility level of tea agrocenoses in the transition to cultivation without mineral fertilizers in the humid-subtropical zone of Russia

Research was carried out on the basis of preserved field multifactor experiment on tea crop (Camellia sinensis (L.) Kuntze) in the conditions of the Sochi Black Sea coast. The application of NPK fertilizers in different doses and combinations according to the experimental scheme was carried out annually from 1986 to 2011. Since 2012, the use of fertilizers has been completely discontinued. The fertility indicators of long-fertilized brown forest acidic soils (in layers 0-20/20-40 cm) were compared with those after 7-8 years of fertilizer withdrawal. During the period of fertilizers’ application, the level of soils’ nitrogen supply significantly exceeded the control (by 30-75/30-56 mg/kg depending on the doses of nitrogen fertilizers). After the fertilizers’ discontinuity, nitrogen supply level equalization occurred in all experimental options. The content of labile phosphorus in soils previously fertilized with high phosphorus doses (120 kg P2O5 ha-1 year-1 and more), during the period of experiment’s conservation decreased by 450-500/350-450 mg/kg, but exceeded the control in 2-2.5 times; in soils previously fertilized by low doses, the indicators have not changed significantly. In soils highly supplied with labile potassium, the content of the element decreased by 70-140 mg/kg. The yield of tea in 2019-2020 was equally low (12-26 cwt/ha) on all options, 2.2-3 times lower than fertilized plantations. After the fertilizers’ withdrawal, there was a decrease in acidity (an average increase in pH by 0.18-0.24/0.12-0.20 units) of agrogenic-acidized soils and an increase in their oppressed respiratory activity (on average by 1.6 times). These changes reflect the tendency of soil self-restoration after the removal of the fertilizers’ load.

ВОПРОСЫ МИНЕРАЛЬНОГО ПИТАНИЯ ГОРОХА В РСО – АЛАНИЯ

The article considers the effect of various doses of nitrogen fertilizers on the formation and activity of the symbiotic apparatus of peas. It is revealed that application of fertilizers P60K40 normalized to growth of a harvest of dry biomass of plants of peas of a grade Phoenix on 0.52 t/hectare, and additional introduction of N30 nitrogen - on 0.66 t/hectare. The maximum yield of dry matter (9.22 tons/ha) was noted when using full mineral fertilizer - N60P60K40. Studies have found that the content of nutrients in the soil available to plants before laying the experience was quite low. By the phase of branching on the backgrounds using fertilizers, a noticeable increase in the content of mobile nitrogen was observed, especially on versions with N60P60K40, then it decreased (2.12-4.78 mg/kg of soil) and again increased only at the time of harvesting (9.03-12.14 mg/kg of soil). This is due to the fact that at the beginning of vegetation, the need of pea plants for nitrogen is minimal, then, as it grows and develops, nitrogen is absorbed in large sizes. It was revealed that the dynamics of ammonium were characterized by a high content of it to the butonization phase, and then a decrease by the beginning of grain filling. By the end of the growing season, the ammonium content increased again. The amount of phosphorus and potassium increases and reaches a maximum by the beginning of seed filling, then before harvesting there is a tendency to decrease their content, due to a significant increase in the consumption of these elements by plants.

ТЕХНОЛОГИИ ЗАКЛАДКИ И УХОДА ЗА ЧАЙНЫМИ ПЛАНТАЦИЯМИ

The use of fertilizers is one of the most eff ective methods for ensuring a steady increase in the yield of tea plantations and maintaining it at a high level. The author analyzed agrotechnical requirements for the establishment and maintenance of tea plantations, taking into account the specifi c natural production and physiological characteristics of tea plants. The paper considers the infl uence of agrotechnical methods for the care of tea plantations on their productivity, such as: fertilizing, pruning, and cultivating the soil in the inter-rows. It has been established that both mineral and organic fertilizers greatly infl uencence on the development and productivity of tea plants. The latter type in the form of manure or peat compost, when applied in 4 years one time at a rate of 50 t/ha, gives an excellent eff ect. First, organic fertilizers are used for plantations located on slopes or fl at areas with heavy soils. Doses of nitrogen fertilizers are set depending on the age and yield of the tea plantation. It is noted that plantations with closed rows and trellis trimming do not need deep tillage. On such plantations, it is recommended to carry out winter tillage every 3-4 years with the simultaneous intra-soil application of phosphorus and organic fertilizers. The timing of applying phosphorus fertilizers can be adjusted depending on their content in the soil. It is recommended to leave the trellis pruning material on the plantations as an organic fertilizer for plant nutrition. According to the current agrotechnical requirements, the optimal indicator of soil acidity, at which a tea plant shows maximum viability and can give the highest leaf yield, is PH = 4.0…6.5.

Ağır Bünyeli Toprakta Azot Magnezyum ve Demir Uygulamalarının Maydanoz Bitkisinin Klorofil, C Vitamini, Nitrat ve Nitrit İçeriğine Etkisi

To increase the yield and improve some quality parameters of vegetables, which have an important place in human nutrition, it is possible by feeding them in a balanced and sufficient level. As the quality parameters of vegetables, external quality parameters (such as shape, size, colour) and internal quality parameters (vitamins, protein, carbohydrates, nutrients, and NO3 and NO2 amounts) are emphasized. Internal quality parameters of vegetables are important not only for people's nutrition, but also for their health. The high amounts of nitrate accumulated by some vegetables (spinach, lettuce, purslane, arugula, cress, parsley, etc.) is very important for human health. This study was carried out to determine the effect of different doses of nitrogen, magnesium and ferrous fertilizer applications on the nutrition and quality of the parsley plant. The study was carried out as a pot experiment in the greenhouse and parsley plant was grown. Three different fertilizers were applied to parsley: Nitrogen (as ammonium nitrate, 33% N), Magnesium (as magnesium sulphate, 16% MgO) and Iron (as iron sulphate, 20% Fe). As control application, 15-15-15 compound fertilizer (10 kg / da N-P2O5 and K2O) was applied. Application doses of elements was 13-16-19-22-25-28 and 31 kg / da for N; 4-8-12-16-20-24 and 28 kg / da for Mg; and 0.8-1.6-2.4-3.2-4.0-4.8-5.6 kg / da for Fe. The study was carried out in 66 pots with 3 replications. The effect of increasing application doses of nitrogen fertilizer was significant at 1% level on the contents of NO3, NO2, chlorophyll a, chlorophyll b and total chlorophyll of the parsley plant and was significant at %5 level on vitamin C. The effect of increasing application doses of magnesium fertilizer was significant at 1% level on the contents of C vitamin, chlorophyll a and chlorophyll b and total chlorophyll of the parsley plant and was significant at %5 level on amounts of NO3, NO2. The effect of increasing application doses of iron fertilizer was significant at 1% level on the contents of chlorophyll a, chlorophyll b and total chlorophyll of the parsley plant and was significant at %5 level on NO3. The effect of these treatments on NO2 and C vitamin contents was not insignificant.

The Effects of Different Doses of Nitrogen Fertilizer on Yield, Yield Components and Fiber Quality Properties in Second Crop Cotton in Aydın Province, TURKEY

Bu çalışma, 2016 ve 2017 yıllarında, ikinci ürün pamuk üretim sezonunda, farklı azot dozlarının (0, 70, 140 ve 210 kg N/ha); verim, verim komponentleri ve lif kalite özellikleri üzerine etkisini saptamak amacıyla Nazilli Pamuk Araştırma Enstitüsü deneme arazisinde yürütülmüştür. Denemede materyal olarak 4 farklı pamuk çeşidi (Özbek 105, Gloria, Julia ve Lydia) kullanılmıştır. Çalışmada, azot dozu miktarındaki artışın, kütlü pamuk verimini belirli bir noktaya kadar arttırdığı belirlenmiştir. Yapılan istatistiksel analizler sonucunda, kütlü pamuk verimi bakımından en ekonomik azot dozunun, 150 kg N/ha olduğu belirlenmiştir. Azot dozu miktarındaki artış ile 100 tohum ağırlığı (g), bitki boyu (cm), koza sayısı (adet/bitki), lif inceliği (mic) ve lif uzunluğu (mm) değerlerinin arttığı; çırçır randımanının (%) ise azaldığı belirlenmiştir. Ayrıca, azot dozlarının, lif kopma dayanıklılığı (g/tex) ve üniformite indeksi (%) değerleri üzerinde ise istatistiksel açıdan önemli bir etkisinin olmadığı tespit edilmiştir.

The Effects of Different Doses of Nitrogen Fertilizer on Population Dynamics of Pests and Natural Enemies in Second Crop Cotton of Aydın Province, TURKEY

Bu çalışma, 2015-2017 yılları arasında, ikinci ürün pamuk üretim sezonunda, Aydın İli Nazilli Pamuk Araştırma Enstitüsü Müdürlüğü deneme arazisinde yürütülmüştür. Çalışmada, farklı azot dozlarının (0, 70, 140 ve 210 kg N ha-1), sokucu-emiciler ve doğal düşmanlar üzerine etkilerinin belirlenmesi amaçlanmıştır. Çalışmada, Özbek 105, Gloria, Julia ve Lydia pamuk çeşitleri kullanılmıştır. Haftalık periyotlarla yapılan zararlı gözlemleri sonucunda; Aphis gossypii Glover (Hemiptera: Aphididae), Empoasca decipiens Paoli + Asymmetrasca decedens (Paoli) (Hemiptera: Cicadellidae), Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), Thrips tabaci Lindeman (Thysanoptera: Thripidae) ve Tetranychus urticae Koch (Acarina: Tetranychidae) türlerinin farklı azot dozlarına ve pamuk çeşitlerine göre popülasyon değişimleri tespit edilmiştir. Uygulanan azot dozu miktarındaki artış, tüm pamuk çeşitlerinde, zararlıların popülasyon yoğunluğunun artmasına neden olmuştur. Predatör türler olarak; Aeolothrips spp. (Thysanoptera: Aeolothripidae), Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), Campylomma diversicornis Reuter (Hemiptera: Miridae), Nabis spp. (Hemiptera: Nabidae), Orius spp. (Hemiptera: Anthocoridae), Adonia variegata (Goeze) (Coleoptera: Coccinellidae), Coccinella septempunctata Linnaeus (Coleoptera: Coccinellidae), Coccinella undecimpunctata Linnaeus (Col.: Coccinellidae) ve Scymnus spp. (Coleoptera: Coccinellidae) tespit edilmiştir. Çalışmadan elde edilen veriler ışığında, gübrelemenin zararlılar ile mücadelede önemi ortaya konulmuştur. Ayrıca, azot dozlarının, önerilen dozlarda (150 kg N ha-1) uygulanması ile zararlı türlerinin popülasyon yoğunluğunun düştüğü ve bu durumun, ekonomik ve ekolojik pamuk üretimine yardımcı olabileceği belirlenmiştir.

Stover biogas potential of corn crops grown under contrasting water availability and nitrogen supply

Corn stover is a biogas feedstock capable of enhancing agriculture bioenergy potential. Although the influence of growing conditions on biogas yield of corn stover has been reported, the joint effects of water and nitrogen on biogas production potential have not been addressed. A two year experiment (Exp. 1 and Exp. 2) was conducted in Balcarce, Argentina to assess nitrogen supply effects on stover composition and potential methane yield of corn crops grown under contrasting water regimes. Treatments were a combination of two nitrogen fertilization doses (0 and 120 kg ha−1) and two water regimes (irrigated and rainfed). Biomass composition (mass closure procedure) was determined, a BMP test was carried out and first-order kinetic parameters were obtained. Interactive effects of nitrogen and water on stover composition were found. BMP tests showed that the biogas production rate (k) decreased upon irrigation while its response to nitrogen depended on water availability. Nitrogen supply decreased specific biogas potential (Bmax) independently of water availability. Methane yield increased with nitrogen fertilization under irrigation, while it decreased under rainfed conditions. The observed water and nitrogen supply interactive effects on stover yield, methane yield and biomass conversion efficiency highlights the importance of considering the joint effects of multiple factors when trying to assess the effects of the environment on biomass quality for bioenergy purposes.

Effect of Nitrogen Fertilizer Levels on the Incidence of Insect Pests in Four Rice Cultivars

Aim: To determine the effect of local rice cultivars and inorganic nitrogen fertilizer on the incidence of stem borer, Scirpophaga incertulas (Walker); leaffolder, Cnephalocrocis medinalis (Guenee); and gall midge, Orseolia oryzae (Wood Mason) and on grain yield of rice.
 Study Design: A field experiment for two consecutive years was carried out in a split-plot arrangement in randomized block design with three replications.
 Place and duration of the study: Department of Entomology, Agricultural Research Station, Nellore, Andhra Pradesh, India during Kharif, 2013 and 2014.
 Methodology: The rice cultivars (NLR 20104, NLR 20106, NLR 3135 and NLR 33892) were attributed to experimental main plots and nitrogen levels (40, 80, 120, 160 and 200 kg ha-1) to the sub plots. Observations on incidence of stem borer, gall midge and leaf folder was recorded in randomly selected 10 hills per subplot in replication and percent incidence was calculated.
 Results: The pest incidence for the treatments with high N rate as 160 and 200 kg/ha was higher (31.43 & 43.86% stem borer, 9.23 & 13.59% leaffolder and 2.75 & 3.00% gall midge, respectively) than that for lower N rate i.e. 40 and 80 kg ha-1 (19.24 & 20.04% stem borer, 7.37 & 7.95% leaffolder and 1.42 & 1.93% gall midge, respectively). Different rice cultivars significantly influenced the leaffolder incidence but not the stem borer and gall midge incidence. The Highest leaffolder incidence (13.44%) was noticed in NLR 20104 cultivar which was followed by NLR 3135 cultivar with 9.64% leaffolder incidence. Gall midge and leaffolder incidence was not significantly influenced by the combined effect of rice cultivar and nitrogen levels; in contrast, interaction effect has a significant influence on stem borer incidence. Significantly lowest stem borer incidence (18.21%) was noticed with NLR 3135 rice cultivar treated with 40 N ha-1, which was statistically on par with the NLR 20106 rice cultivar treated with 40 kg N ha-1 (18.23%) and NLR 20104 rice cultivar treated with 40 kg N ha-1 (19.76%). Among the different cultivarscultivar, NLR 33892 cultivarhad produced significantly highest grain yield (5955 kg ha-1) may be for having higher physiological indices. The highest/optimum grain yield (5726 kg ha-1) produced by plots that received 120 kg N ha-1. Further increase in nitrogen level beyond 120 kg ha-1 did not significantly improve the grain yield. Optimal N rate was revealed to be 120 kg ha-1 for four rice cultivars for reducing the stem borer/leaffolder/gall midge incidence so as to minimize the cost of inputs for pest control measures and for achieving high grain yield.
 Conclusions: The incremental doses of nitrogen fertilizer significantly enhanced stem borer, leaffolder and gall midge infestation on rice, which further affects the grain yields.

Effects of Plant Growth Regulators and N Rate on the Morphological Traits of Generative Tillers and Seed Yields of Chewings and Strong Creeping Red Fescue

Plant growth regulators (PGRs) are used as a management tool to minimize plant height and subsequent stem lodging in grass seed crops. Their efficacy is influenced not only by the method of application, but also by the management and genetic variations within and between species. This aim of the study was to evaluate the effect of PGRs on morphological traits of generative tillers and seed yield of Festuca rubra L ssp. rubra (strong creeping red fescue) and F. r. L ssp. commutata (Chewings red fescue) under low and medium doses of spring nitrogen fertilization (40 and 70 kg N ha−1). PGRs were applied as: chlormequat chloride (CCC) at BBCH 30–31; CCC at BBCH 30–31 + ethephon (ET) at BBCH 37–39; CCC at BBCH 30–31 + trinexapac-ethyl (TE) at BBCH 37–39. All the application methods of PGRs resulted in the shortening of the second internode, and the sequential application of CCC with ET or TE also resulted in the shortening of the third internode. In each PGR treatment, the lodging index in the plant (canopy height to tiller length ratio) was higher than that of the control. PGRs had a beneficial effect on the seed yield. The greatest increase in the seed yield was recorded after the application of CCC+TE. No interaction between PGRs and spring N fertilization rates on the seed yield of red fescue. The increase in the dose of spring nitrogen fertilizer from 40 to 70 kg N ha−1 resulted in a significant increase in yield. Seed yield of chewing red fescue cv. Dorosa was 29% higher than strong creeping red fescue cv. Nista, mainly due to an increase in the number of generative tillers.