Beginning Of Tillering Research Articles

Soil and Foliar Zinc Biofortification of Triticale (x Triticosecale) under Mediterranean Conditions: Effects on Forage Yield and Quality.

Zinc (Zn) deficiency represents a significant global concern, affecting both plant and human health, particularly in regions with Zn-depleted soils. Agronomic biofortification strategies, such as the application of Zn fertilizers, offer a cost-effective approach to increase Zn levels in crops. This study aimed to assess the efficacy of soil and foliar Zn biofortification, applied as an aqueous solution of 0.5% zinc sulphate (ZnSO4·7H2O), on triticale (x Triticosecale) grown under Mediterranean conditions. The study was conducted over two growing seasons (2017/18 and 2018/19) in southern Spain, evaluating the effects on biomass yield; forage quality, including crude protein, Van Soest detergent fiber, organic matter digestibility, and relative forage value; and nutrient accumulation. Soil treatment consisted in the application of 50 kg of ZnSO4·7H2O ha-1 solely at the beginning of the first campaign to assess the residual effect on the second year. In contrast, the foliar treatment consisted of two applications of 4 kg of ZnSO4·7H2O ha-1 per campaign, one at the beginning of tillering and the other at the appearance of the first node. The foliar application increased the Zn content of the forage to adequate levels, while the soil application resulted in a 33% increase in biomass production, which is particularly beneficial for farmers. Overall quality was favored by the combined soil + foliar application, and no adverse antagonistic effects on other nutrients were detected. Instead, a synergistic interaction between Se and Zn was observed, which improved the efficacy of this important micronutrient for livestock and human wellbeing.

THE EFFECT OF DIVIDED TOP-DRESSING APPLICATIONS OF DIFFERENT NITROGEN FERTILIZERS ON GRAIN YIELD AND QUALITY TRAITS IN BREAD WHEAT (Triticum aestivum L.)

This study was carried out to determine the effect of different divided top-dressing applications of different nitrogen fertilizers on grain yield and quality traits of four bread wheat varieties (Selimiye, Esperia, Gelibolu and Rumeli). The experiment was conducted in a randomized split-plot design with 3 replicates during the 2017 and 2018 seasons. In the experiment, varieties were allotted as main plots and top-dressing applications were allotted as subplots. Five different pure nitrogen (N) top-dressing applications were done in the form of urea and calcium ammonium nitrate (CAN) at the beginning of tillering, the end of tillering, the beginning of stem elongation and the end of stem elongation stages. Grain yield, thousand kernel weight, test weight, protein content, wet gluten content, gluten index, Zeleny sedimentation value and delayed sedimentation value were investigated in the study. Gelibolu variety for grain yield, Rumeli and Esperia varieties for grain quality were prominent. The considering the ease of application for grain yield and quality, 2nd application (80 kg ha-1 pure N in the form of urea at the beginning of tillering, 40 kg ha-1 pure N in the form of urea at the beginning of stem elongation) can be proposed in the years when April and May rainfalls are sufficient, and 3rd application ( 40 kg ha-1 pure N in the form of urea at the beginning of tillering, 40 kg ha-1 pure N in the form of urea at the end of tillering, 40 kg ha-1 pure N in the form of CAN at the beginning of stem elongation) can be proposed in the years when April and May rainfalls are insufficient.

NITROGEN FERTILIZERS ROLE IN GRAIN CROPS PRODUCTIVITY IN SOUTH-EAST KAZAKHSTAN

Seeking to improve the efficiency of nitrogen fertilizers for grain crops led to conducting this study on developing methods using 15N in 2015–2017 at the Kazakh Research Institute of Agriculture, Almalybak Village, Almaty Region, Southeastern Kazakhstan. Nitrogen use efficiency using the stable isotope 15N in microfield experiments revealed that the assimilation of nitrogen fertilizers by grain crops largely depends on the norms, timing, fertilization method, and varietal parameters of the concerned crop. Based on morphophysiological methods of monitoring plant development conditions, the nitrogen fertilizers’ role based on the development has been affirmative, with the optimal timing of their application also determined. Results show that grain crops use nitrogen productively with partial application at the beginning of tillering and tubing, respectively, and stages III and V of organogenesis. With the use of nitrogen fertilizers, the significant varietal differences were evident. The help of an isotope label established the accurate nitrogen utilization coefficients of fertilizers based on the options ranging from 14.7% to 32.2%. Using the isotope method provides an opportunity for further development of practicing the most efficient techniques of applying fertilizers, which is an imperative method for determining the effectiveness of nitrogen fertilizers.

Response of Some Improved Upland Rice Varieties to Different Sources and Rates of Nitrogen Fertilizer in A Humid Rain Forest Region

ABSTRACT
 Nitrogen (N) is a major lacking nutrient element for the growth and yield of cereal crops Calabar, it is necessary to determine the response different sources and rates of N in four varieties of upland rice. Treatments comprised factorial combinations of the four rice varieties (NERICA 1, NERICA 2, FARO 45, FARO 48), three straight inorganic N sources (urea, Calcium ammonium nitrate, ammonium sulphate) and four levels of N (0, 30, 60, 90 kg N ha-1) laid in randomized complete block design. The N was split applied twice; one-third at the beginning of tillering and the remainder at panicle initiation. The results showed that the source of fertilizer N did not affect significantly the growth and yield of the rice crop (p=0.05). Considering that soils in Calabar are acid sands it will not be advisable to consistently apply such acidifying fertilizers as ammonium sulphate or urea except with soil liming which will undoubtedly increase the cost of production and probably make it unprofitable to cultivate rice in the area. The fertilized crop grew taller and produced more biomass compared with the control. It also produced significantly more tillers hill-1, panicles m-2, grains panicle-1, weight of 1,000 grains and grain yield. However, whereas NERICA 1, NERICA 2 and FARO 45 were more responsive to lower N levels, the grain yield of FARO 48 was significantly higher when the crop received 90 kg N ha-1 compared with other varieties, probably because of its longer growth duration in the field. The responsiveness of these varieties to low N application was the result of their higher grain yield resulting from enhanced N use efficiency. Genotypes that were most responsive to low N input levels were early maturing with high N-use efficiencies. On the basis of grain yield, it is recommended that for high yield in the humid region of Cross River State, N should be applied at the rate of 60 kg ha-1 for early- and 90 kg ha-1 or above for the medium-maturing upland rice varieties.
 Keywords: Rice, Varieties, Growth and Yield

Interference of post-emergent herbicides with wheat (Triticum aestivum L.) productivity parameters/ Interferência de herbicidas pós-emergentes sobre parâmetros produtivos do trigo (Triticum aestivum L.)

Wheat is the most important income-generating crop in southern Brazil during the cold season. It also contributes to the crop rotation system and increases the yield of successive crops. During its growth cycle, herbicides are used to control weeds, which are the main factor limiting wheat productivity. Further, high costs of weed control directly affect crop economic returns. The objective of this study was to evaluate the effect of the application of two herbicides, namely, 2,4-D and iodosulfuron-methyl, on the productivity of two wheat cultivars during the nine different stages of crop development. The most suitable crop stage for herbicide application, as described in the corresponding label on the package, is at the beginning of tillering. 2,4-D had a significant impact on productivity parameters, reducing the number of tillers, the number of ears, and the number of tillers without grains, while increasing the number of tillers without ears and ears without grains, indicating greater phytotoxicity and, ultimately, reducing crop productivity. Conversely, iodosulfuron-methyl showed greater selectivity to the wheat cultivars tested and caused a much lesser impact on the productivity parameters measured.

Nitrogen (N) and sulphate (S) fertilization in wheat crop: effect on the vigor of seeds produced

The objective of this work was to evaluate the influence of nitrogen in association with sulfur applied in the field and the influence of this fertilization on the vigor of wheat seeds produced and later evaluated in the laboratory. Field experiments were carried out in the municipalities of Caibaté-RS and Pelotas-RS using the TBIO Sinuelo cultivar adapted to all the regions of Rio Grande do Sul. The experimental design was a randomized block design with a 2x5x2 trifractory scheme (cultivation environments x doses of nitrogen x sulfur management) with 4 replicates. The treatments consisted of the combination of two cultivation environments [Caibaté-RS and Pelotas-RS], five nitrogen doses Urea 45%, [0; 22.5; 45; 67.5 and 90 kg ha-1] applied at the beginning of tillering and sulfur, Sulfuric 90% sulfur, [0 and 60 kg ha-1] applied before sowing, about 7 days. After reaching physiological maturity, the seeds were harvested manually and taken to the seed laboratory. The seeds were dried in a forced ventilation oven at 41ºC until the moisture content stabilized at 12% (wet bulb). We evaluated the first germination count (FGC), accelerated aging (AA), field emergence (FE), shoot length (RL) and seedling root length (SL). The seeds produced in Caibaté-RS have greater vigor in relation to Pelotas-RS. Nitrogen fertilization favors the production of seeds with greater vigor, while sulfur can influence the vigor according to the environment in which the plants are cultivated

Effects of Foliar Application of Potassium Silicate and Nanoparticles (silicon + zinc) in Different Stages of Growth and Development on Quantitative Yield and Grain Enrichment of Rice (Oryza sativa L.)

Introduction: Rice (Oryza sativa L.) is one of the three major food crops worldwide. Approximately 50% of the world’s population uses rice as a staple food. Silica and zinc among nutrients play a key role in improving plant nutrition and increasing rice growth, so that a lack of these elements reduces growth and consequently reduces yield. Also fortifying rice with silicon and zinc can correct deficiencies of these elements in humans who consume rice. Materials and Methods: This experiment was conducted as factorial based on a randomized complete block design with three replications at the private farm located in Babol (North of Iran) during the years 2017-18 and 2018-19. Measured values of electrical conductivity, soil acidity, organic carbon, total nitrogen, available phosphorus, available potassium, zinc content and soil texture for the first and second years were 2.33 dS m-1 and 1.27 dS m-1, 7.48 and 7.26, 3.27 % and 2.16 %, 0.32 % and 0.21 %, 11 mg kg-1 and 6 mg kg-1, 320 mg kg-1 and 238 mg kg-1, 0.96 mg kg-1 and 0.89 mg kg-1, Clay and Clay, respectively. The treatment included three levels of foliar application (Potassium silicate, Silicon nanoxide, and Zinc nanoxide) as the first factor and five levels of developmental stages (T1: beginning of tillering + middle of tillering + late of tillering + end of panicle emergence, T2: middle of tillering + late of tillering + end of panicle emergence, T3: late of tillering + end of panicle emergence, T4: late of tillering and T5: end of panicle emergence) as the second factor. Results and Discussion: The results showed that none of the studied traits were affected by the year. Maximum grain yield was obtained by foliar application silicon nanoxide (7733 kg ha-1) and zinc nanoxide (7498 kg ha-1), which was, respectively, due to increasing the total number of spikelets and the percentage of filled spikelets (1420.0 spikelets and 95.53%, respectively) and increasing the total number of tillers and 1000-grain weight (19.73 tillers and 26.80 g, respectively). The highest grain yield (7716, 7700 and 7492 kg.ha-1) and the percentage of filled spikelets (94.83, 94.72 and 93.89%) were obtained under T1, T2 and T3 treatments, respectively. By foliar application of silicon nanoxide and zinc nanoxide, the highest biological yield (19213 and 18986 kg ha-1, respectively) and, the highest grain silica concentration (3.13%) and grain zinc concentration (15.97 mg kg-1) were recorded. The minimum 1000-grain weight (24.11 and 24.00 g), the maximum total number of spikelets per panicle (143.1 and 143.2 spikelets) and the highest concentration of grain silica (3.00 and 2.97%) were obtained under T1 and T2 treatments, respectively. However, the highest total number of tillers per hill and the highest number of grain were obtained under T1 and T2 treatments, respectively. The interaction between treatments showed that the maximum total number of spikelets per panicle was obtained by foliar application of potassium silicate under T1 treatment (151.5 spikelets) and foliar application of silicon nanoxide under T2 treatment (153.3 spikelets). Also, the highest concentrations of silica and zinc in grain were obtained by foliar application of silicon nanoxide under T1 treatment (3.97%) and zinc nanoxide under T2 treatment (21.67 mg kg-1), respectively. Conclusions: According to the results of this study, we found that grain yield increases with the application of nanoparticles as well as foliar application during crop growth and development. In order to enrich rice grains, foliar application of nanoparticles in the middle of tillering, late of tillering and end of panicle emergence is also necessary.

When Termites’ Waste Products Highlight a Fundamental Law of Fertilization under Rainfed Rice Cultivation in West Cote d'Ivoire

Food security is a major development issue in Côte d’Ivoire that is experiencing population growth over 3% per year. Food crop production, however, is experiencing weak growth, most often linked to increase in area. In addition, low yields could be explained by the scarcity of rainfall in a context where farmers hardly use agronomic-based fertilizers without soil analysis although Cote d’Ivoire is agricultural based developing country. To be part of integrated production logic in rice production, a study is initiated in 2016 in Daloa in order to improve the yield of paddy rice by using a local amendment produced by termites kept in captivity on agricultural residues. Four (4) doses of this amendment made of termites’ waste products (TWP): 1.8%; 3.6% and 7.2% and 14.4% of one hectare soil weight were tested versus an unfertilized (control) and a NPK fertilized (100kg.ha)-. The experimental design consists of randomized complete blocks with three replicates. Plant growth parameters such as plant height at maturity, total number of tillers, number of leaves at the beginning of tillering, biomass at maturity and yield data were collected. The results showed that all agronomic parameters were improved with increasing dose up to an optimum dose that can be found between 7.2 % and 14.4 % of termites’ waste products. The highest yield (2484.3 kg.ha-1) was obtained with the 7.2 % dose. The results of the application of the TWP on rice showed important yield increases with efficacy varying from 30 to 72 % compared to common fertilizer application and 27.1 to 221.9 % if compared to non-fertilized plot.

Does nitrogen application timing and sources influence barley grain yield?

The suitable management of nitrogen (N) fertilization can increase barley grain yield, since it is the nutrient required in greater quantity. In this sense, the source and timing of nitrogen application are relevant factors. The objective was to evaluate the effects of N sources and splitting on the performance of barley. The experiment was carried out under a clayey Cambisol (550 g kg-1), in Curitibanos, Santa Catarina. Factorial randomized blocks were used: three mineral sources of N: urea (45% N); urea with urease inhibitor-NBPT (45% of N) and nitrate (30% of N), associated with two nitrogen splitting fertilization: i) split of the rate of N in two seasons: beginning of tillering and full tillering and ii) single application at full tillering. 100 kg ha-1 of N were applied. There was no interaction between the factors and there was no effect of treatments for plant height, ear length, grains per ear, ears per m² and mass of a thousand grains. Yield was influenced by the N source, where nitrate exceeded the yield from amidic sources by 16%. The splitting of N in two times did not present advantages over the single application. Urea with NBPT was not viable in relation to readily soluble forms of N, with the highest yield obtained with a nitric source.

Physiological and morphological responses of different spring barley genotypes to water deficit and associated QTLs.

Water deficit is one of the major limitations to food production worldwide and most climate change scenarios predict an aggravation of the situation. To face the expected increase in drought stress in the coming years, breeders are working to elucidate the genetic control of barley growth and productivity traits under water deficit. Barley is known as a relatively drought tolerant crop and genetic variability was observed for drought tolerance traits. The objectives of the present study were the quantification of morphological and physiological responses in a collection of 209 spring barley genotypes to drought stress, and the genetic analysis by genome-wide association study to find quantitative trait loci (QTL) and the allele contributions for each of the investigated traits. In six pot experiments, 209 spring barley genotypes were grown under a well-watered and water-limited regime. Stress phases were initiated individually for each genotype at the beginning of tillering and spiking for the vegetative- and the generative stage experiments, respectively, and terminated when the transpiration rates of stress treatments reached 10% of the well-watered control. After the stress phase, a total of 42 productivity related traits such as the dry matter of plant organs, tiller number, leaf length, leaf area, amount of water soluble carbohydrates in the stems, proline content in leaves and osmotic adjustment of corresponding well-watered and stressed plants were analysed, and QTL analyses were performed to find marker-trait associations. Significant water deficit effects were observed for almost all traits and significant genotype x treatment interactions (GxT) were observed for 37 phenotypic traits. Genome-wide association studies (GWAS) revealed 77 significant loci associated with 16 phenotypic traits during the vegetative stage experiment and a total of 85 significant loci associated with 13 phenotypic traits during the generative stage experiment for traits such as leaf area, number of green leaves, grain yield, harvest index and stem length. For traits with significant GxT interactions, genotypic differences for relative values were analysed using one way ANOVA. More than 110 loci for GxT interaction were found for 17 phenotypic traits explaining in many cases more than 50% of the genetic variance.

Response of oat-triticale mixture to post-emergence weed harrowing

ABSTRACTIn experiments with weed harrowing crops are negatively affected by competing weeds but also by the destructive effect of used implement. This research was carried out to find growth stages during which mixture of oat (Avena sativa L.) and triticale (× Triticosecale Wittm.) was resistant to harrowing and was able to effectively recover from this physical disturbance. Plots were harrowed 1–3 times on the same day at six consecutive stages of mixture growth with spring-tine harrow. After the latest harrowing, all plots were sprayed with herbicide to exclude competitive effect of weeds on the mixture. Compared to non-harrowed plots plant density of mixture was significantly reduced after a single cultivation at 1- and 2-leaf stage (20% and 23% respectively), two cultivations at 3-leaf stage (22%) and three at the beginning of the tillering (21%). No yield penalty was noticed for the density reductions, thus showing high ability of mixture to recover from physical disturbance. We recommend plant emergence as an appropriate growth stage for single harrowing of oat-triticale mixture. Two cultivations on the same day should not be planned earlier than at the beginning of tillering.

Technological factors for the application of the Medax Top plant growth regulator in seed crops of Bromus inermis under conditions of the right-bank Forest-Steppe of

Purpose. To develop the element for regulating the formation of seed yield and the seeding properties of Bromus inermis through the application of Medax Top growth regulator from the time of tillering to the stem elongation of seed crops. To establish its effect on the growth of plants, their height, productive density, the number and mass of grains in inflorescences, the power of growth and seed germination. Methods. Field, visual, measuring, weight, quantitative, test sheaf method, laboratory, mathematical and statistical. Results. The results of scientific research aimed at creating favorable conditions for the formation of seed productivity of Bromus inermis and its seeding properties through the application of Medax Top plant growth regulator in the sixth-eighth period of organogenesis, i.e. from the beginning of tillering to the stem elongation of seed crops are presented. Its effect on increasing plant resistance to lodging, reducing plant height, increasing productive shoot formation, the number and mass of grains in inflorescence, improving seeding properties, in particular, the power of growth and seed germination, which contributed to the formation of seed yield of 343—354 kg/ha or 47—58 kg/ha more compared to the control without application of the plant growth regulator. Conclusions. Application of Medax Top plant growth regulator at the rate of 0.5—1.0 l/ha in the seed crops of Bromus inermis of Vseslav cultivar during the growing season is effective from the beginning of tillering to the stem formation, it contributes to an increase in its seed productivity by 5.0—21.2 % and provides conditional net profit of 5,179—5,288 UAH/ha.

Timing and growing conditions of nitrogen topdressing influence the grain yield and protein content of four wheat cultivars

ABSTRACT The application of an adequate rate and splitting of nitrogen is essential for wheat grain yield and protein content. The aim of this work was to adjust nitrogen management approaches regarding agronomic performance and protein content of wheat cultivars in various environments. Field experiments were conducted under no-tillage system on soybean mulch during the 2011 and 2012 growing seasons in Londrina and Pato Branco regions. The experimental design was a randomized block in split plot with four replicates. Four wheat cultivars (IPR Catuara TM, BRS Gaivota, Quartzo, CD 120) were tested with six nitrogen (N) management forms. Were evaluated: number of ears per unit area (NEA); plant height (PH); thousand-kernel weight (TKW); test weight (TW); grain yield (GY); and protein content (PC). The combined ANOVA (p ? 0.01) and Tukey’s test (p ? 0.01) were used. The interaction between cultivars and environments influence all yield components, GY and PC. The interaction management forms of N and environments affected the TKW, NEA, GY and PC. The results showed that in low-rainfall environments, nitrogen topdressing could be suppressed with no negative effects on GY or PC. Under ideal weather conditions, the GY of wheat cultivars was enhanced on application of 60 kg.ha–1 N of urea at the beginning of tillering as well 20 kg.ha–1 of N at booting. Matching the appropriate cultivars to the ideal growth environment is essential for achieving high GY values. The nitrogen forms on the topdressing do not influence the PC of cultivars in Pato Branco.

Study the effect of different methods of applying salicylic acid on quantitative, qualitative and biochemical parameters of wheat (Triticum aestivum L.) in drained and not drained lands

با توجه به اهمیت گیاه گندم در تغذیه انسان و همچنین تأثیر تنش شوری در اراضی زهکشی نشده، بررسی اثر تنش شوری و نقش اسید سالیسیلیک در تعدیل اثرات آن در کشت گندم حائز اهمیت است. لذا این پژوهش با هدف بررسی و مقایسه اثر روش‌های مختلف کاربرد هورمون اسید سالیسیلیک بر ویژگی‌های کمی، کیفی و بیوشیمیایی گندم در زمین‌های زهکشی شده و زهکشی نشده به‌صورت تجزیه مرکب در قالب طرح بلوک‌های کامل تصادفی در سه تکرار اجرا شد. تیمارها شامل زمین‌های زراعی زهکشی شده (آزمایش اول) و زهکشی نشده (آزمایش دوم) و عامل دوم شامل روش‌های کاربرد اسید سالیسیلیک به‌صورت (1) عدم محلول‌پاشی (شاهد)، (2) تلقیح بذر با اسید سالیسیلیک، (3) محلول‌پاشی در ابتدای پنجه‌دهی، (4) تلقیح بذر با اسید سالیسیلیک + محلول‌پاشی در ابتدای پنجه‌دهی، (5) محلول‌پاشی در مرحله انتهای پنجه‌دهی، (6) تلقیح بذر با اسید سالیسیلیک + محلول‌پاشی در مرحله انتهای پنجه‌دهی. نتایج نشان داد که تأثیر نوع اراضی مورد کشت بر تعداد سنبله در متر‌مربع، تعداد دانه در سنبله، تعداد سنبلچه در سنبله، وزن هزار دانه، عملکرد دانه، شاخص کلروفیل، پرولین و درصد پروتئین دانه در سطح احتمال یک درصد معنی‌دار بود. تأثیر سطوح اسید سالیسیلیک در تمامی صفات اندازه‌گیری در سطح احتمال یک درصد معنی‌دار بود. اثر متقابل نوع زمین و روش کاربرد سالیسیلیک ازنظر درصد پروتئین در سطح احتمال پنج درصد و ازنظر تعداد سنبله در متر‌مربع، تعداد سنبلچه در سنبله، وزن هزار دانه، شاخص کلروفیل و مقدار پرولین در سطح احتمال یک درصد معنی‌دار بود. بیشترین و کمترین عملکرد دانه در اراضی زهکشی شده و زهکشی نشده به ترتیب با 3308 و 2017 کیلوگرم در هکتار مشاهده شد و در بین روش‌های مختلف کاربرد اسید سالیسیلیک، بیشترین و کمترین عملکرد دانه در روش تلقیح بذر با اسید سالیسیلیک + محلول‌پاشی در ابتدای پنجه‌دهی و بدون کاربرد اسید سالیسیلیک به ترتیب با 3636 و 1759 کیلوگرم در هکتار حاصل شد. نتایج کلی آزمایش نشان داد که تأثیر اسید سالیسیلیک در اراضی زهکشی شده با افزایش مؤلفه‌های تولیدی و در اراضی زهکشی نشده با کم کردن اثرات تنش شوری و بهبود آسیب‌های ناشی از آن توانست در جهت افزایش عملکرد کمی مؤثر واقع شود. این در حالی است که در این شرایط کمترین عملکرد ازلحاظ کیفی حاصل شد.

Effects of foliar spraying with new zinc sources on rice seed enrichment, nutrition, and productivity

ABSTRACTNew Zn sources have emerged recently, which may boost the beneficial effects of leaf sprays on rice cropping. Thus, this study aimed to compare the effects of foliar sprays using Zn chelate against those with new Zn sources such as sorbitol-stabilised Zn nitrate and Zn oxide nanoparticles on rice seed enrichment and production. Treatments were arranged in a completely randomised design, comprising of three Zn sources and four Zn concentrations with four replicates. Rice plants were sprayed three times: at the beginning of tillering, maximum tillering, and booting stage. Experimental unity consisted of 7-dm³ pots filled with 5-dm³ medium textured sand. Each pot had 10 plants, of which 6 randomly harvested at the flowering stage and the remaining at the maturity stage. Plant dry matter, content and accumulation of Zn in the shoot, seed Zn content, and seed production at the grain-filling stage were also estimated. Seed production and Zn accumulation showed a quadratic behaviour with the use of novel sources. Overall the new Zn sources were more effective than the traditional EDTA chelated Zn in terms of rice seed production and quality, especially the sorbitol-stabilised Zn nitrate.

Localization of Chromosome Regions Controlling High Photosynthetic Potential in Russian Rice Cultivars

Breeding practice defined the main ways to increase crop yield: morphotype change, exploitation of heterosis, and increase in photosynthesis effectiveness. We identified donors and sources of high photosynthetic potential genetic system and polymorphic loci controlling photosynthetic efficiency in Russian rice cultivars. Thirty-two Russian rice cultivars were used as material. The content of chlorophyll a and b and carotenoids was measured at the beginning of tillering, heading, and flowering stages by a Genesys 8 spectrophotometer. Twenty plants of each cultivar in two replications were used for measurement. SSR markers were used. DNA was extracted by the STAB method. Polymerase chain reaction (PCR) and visualization of amplification products were performed under the International Rice Research Institute (IRRI) protocol. Donors of high contents of each pigment were found. A high level of polymorphism for the loci connected with photosynthesis effectiveness in Russian rice cultivars will allow us to create new cultivars with improved characters by hybridization. Six markers significantly divided cultivar groups with different photosynthetic rate, three of them (RM154, RM600, RM5508) were related to the content of carotenoids, two markers (RM347, RM240) were related to specific leaf weight (SLW) control, and two others (RM154, RM509) were related to the chlorophyll a content.

Topdressing nitrogen recommendation in wheat after applying organic manures: the use of field diagnostic tools

Nitrogen is the largest input used by farmers, but they often apply excessive quantities of N fertilizer, causing nitrogen losses. In recent years, the management of large quantities of manure and slurry compounds has become a challenge. The aim of this study was to assess the usefulness of the proxy tools Yara N-tester™ and RapidScan CS-45 for diagnosing the N nutritional status of wheat crops when farmyard manures were applied. Our second objective was to start designing a N fertilization strategy based on these measurements. To achieve these objectives, two field trials were established with three factors: growing season, three kinds of initial fertilizers [dairy slurry (40 t ha−1), sheep manure (40 t ha−1) and conventional (no organic fertilizer on basal dressing and 40 kg N ha−1 at tillering)] and five N mineral fertilization dose applied at stem elongation. The proxy tools for diagnosing the N nutritional status were used at stem elongation before applying the mineral N. Proxy tool readings as indicators of the nitrogen nutritional status of the field were as good as soil mineral nitrogen (Nmin) or Nitrogen Nutrition Index (NNI). When the readings were approximately 65% (as compared to an overfertilized control), the optimal N rate applied at stem elongation was slightly higher (10–20 kg N ha−1) than the readings at 88%. The first N topdressing at the beginning of tillering could be avoided when manure was applied before sowing, unfolding new possibilities for a later application that might improve the protein content with lower likely fertilization costs.

Eficácia e seletividade do iodossulfurão-metilo-sódio +mesossulfurão-metilo na cevada dística (Hordeum distichum L.)

During the vegetation periods 2012/13 and 2013/14 four field trials were carried out (two per year) on the Experimental Farm of Almocreva (Beja), with the objective to study the efficacy and selectivity of the herbicide iodosulfuron-methyl-sodium (50 g L-1) + mesosulfuron-methyl (7.5 g L-1) in malt barley. In both trials three application rates were applied (5.0 + 0.75, 7.5 + 1.125 e 10.0 + 1.5 g a.i ha-1) at two different development stages of both weeds and the barley crop. In the year 2012/2013, the herbicide was applied when the weeds were in the development stage of three to four pairs of leaves, and the crop, at the beginning of tillering that corresponded the stage 20 of Zadoks scale (first application timing). The second application timing was when the weeds were at the development stage of six to seven pairs of leaves, and the crop at the complete tillering (29 Zadoks` stage). In the year 2013/2014, the first application timing was when the weeds were in the development stage of five to six pairs of leaves, and the crop at the main culm (24 Zadoks` stage). The second application timing was when the weeds were at the development stage of seven to eight pairs of leaves, and the crop at the third visible node (33 Zadoks` stage). The results show that the first application date at earlier weed and crop development stages did not lead to an increase in efficacy when compared to the later application timing, and for application rates. Using the recommended application rates (7.5 + 1.125 e 10.0 + 1.5 g a.i ha-1) an increase in efficacy could be observed in both years and application dates when compared to the lowest application rate (5.0 + 0.75 g a.i ha-1), but no significant interaction between application rates and dates was obtained. In contrast to 2013/14, a significant reduction in crop yield was observed in 2012/13 when anticipating the application date. This effect is attributed to phytotoxicity caused by the herbicide when applied at an early tillering stage.

Effect of different doses of post-emergence-applied iodosulfuron on weed control and grain yield of malt barley (Hordeum distichum L.), under Mediterranean conditions

AbstractA study was carried out over a two year period (2009/2010 and 2012/2013) on an experimental farm in the Alentejo region (Beja), in southern Portugal where rainfed malt barley (Hordeum distichum L.) is sown at the end of autumn or beginning of winter (November- December). The aim of this experiment was to study the efficiency of the herbicide iodosulfuron-methyl-sodium to control post-emergence broadleaved weeds in this cereal crop. The malt barley crop was established using no-till farming. This technology provides the necessary machine bearing capacity of the soil to assure the post-emergence application of herbicides at two different weed development stages. The herbicide iodosulfuron-methyl-sodium was applied at three doses (5.0, 7.5, and 10.0 g a. i. · ha-1) and at two different broadleaved weed development stages (3 to 4 and 6 to 7 pairs of leaves), that also corresponded to two different crop development stages (beginning of tillering and complete tillering). The results indicated that early herbicide application timing provided a significantly higher efficiency for all the applied herbicide doses, but this better weed control was not reflected in a higher crop grain yield. The lack of a higher crop grain yield was probably due to a crop phytotoxicity of the herbicide, when used at an early application timing.

Waterlogging Affects Leaf and Tillering Dynamics in Wheat and Barley

AbstractThe aim of this study was to analyse (i) the crop attributes that determine flowering time (i.e. final leaf number, FLN; and phyllochron, Phy), (ii) the dynamics of tiller appearance and (iii) the synchrony between leaf and tiller appearance in wheat and barley plants exposed to waterlogging. Two experiments were carried out in pots, in which wheat and barley cultivars were exposed to five waterlogging treatments, during different periods throughout the crop cycle, from emergence to maturity. The appearance of leaves and tillers on the main stem was measured twice a week in labelled plants. Waterlogging from emergence to flag leaf appearance significantly delayed time to flowering. The delay was greater when waterlogging occurred at the beginning of tillering, lengthening the period from emergence to flowering 24 % (13–15 days) in barley and 10–15 % (6–10 days) in wheat, as compared to control. Phy was the main attribute explaining the delay in flowering, as FLN was not altered. Waterlogging during the early stages of development reduced tiller appearance rate (TAR) in both species, but this effect was partially counterbalanced by a lengthening of the tillering phase, so the effect on final tiller number at maturity was limited. In conclusion, the exposure of wheat and barley to waterlogging during early stages of development delayed time to flowering and reduce TAR in both species. Waterlogging during more advanced crop stages produced slight effects on tillering dynamics, which would indicate that waterlogging affected structure generation more than mortality.