Showing papers on "Sowing published in 2016"
TL;DR: In this article, the delivery of chitosan nanoparticles loaded with nitrogen, phosphorus and potassium (NPK) for wheat plants by foliar uptake was investigated by transmission electron microscopy.
Abstract: Nanofertilizers have become a pioneer approach in agriculture research nowadays. In this paper we investigate the delivery of chitosan nanoparticles loaded with nitrogen, phosphorus and potassium (NPK) for wheat plants by foliar uptake. Chiotsan-NPK nanoparticles were easily applied to leaf surfaces and entered the stomata via gas uptake, avoiding direct interaction with soil systems. The uptake and translocation of nanoparticles inside wheat plants was investigated by transmission electron microscopy. The results revealed that nano particles were taken up and transported through phloem tissues. Treatment of wheat plants grown on sandy soil with nano chitosan-NPK fertilizer induced significant increases in harvest index, crop index and mobilization index of the determined wheat yield variables, as compared with control yield variables of wheat plants treated with normal non-fertilized and normal fertilized NPK. The life cycle of the nano-fertilized wheat plants was shorter than normal-fertilized wheat plants with the ratio of 23.5% (130 days compared with 170 days for yield production from date of sowing). Thus, accelerating plant growth and productivity by application of nanofertilizers can open new perspectives in agricultural practice. However, the response of plants to nanofertilizers varies with the type of plant species, their growth stages and nature of nanomaterials.
237 citations
TL;DR: Alternative methods of inoculation that were as effective as the standard seed inoculation are identified that may represent an important strategy to avoid the incompatibility between inoculant bacteria and pesticides employed for seed treatment.
Abstract: The utilization of inoculants containing Azospirillum is becoming more popular due to increasing reports of expressive gains in grain yields. However, incompatibility with pesticides used in seed treatments represents a main limitation for a successful inoculation. Therefore, in this study we searched for alternatives methods for seed inoculation of maize and wheat, aiming to avoid the direct contact of bacteria with pesticides. Different doses of inoculants containing Azospirillum brasilense were employed to perform inoculation in-furrow, via soil spray at sowing and via leaf spray after seedlings had emerged, in comparison to seed inoculation. Experiments were conducted first under greenhouse controlled conditions and then confirmed in the field at different locations in Brazil. In the greenhouse, most parameters measured responded positively to the largest inoculant dose used in foliar sprays, but benefits could also be observed from both in-furrow and soil spray inoculation. However, our results present evidence that field inoculation with plant-growth promoting bacteria must consider inoculant doses, and point to the need of fine adjustments to avoid crossing the threshold of growth stimulation and inhibition. All inoculation techniques increased the abundance of diazotrophic bacteria in plant tissues, and foliar spray improved colonization of leaves, while soil inoculations favored root and rhizosphere colonization. In field experiments, inoculation with A. brasilense allowed for a 25 % reduction in the need for N fertilizers. Our results have identified alternative methods of inoculation that were as effective as the standard seed inoculation that may represent an important strategy to avoid the incompatibility between inoculant bacteria and pesticides employed for seed treatment.
172 citations
TL;DR: In this paper, the effects of a fertilizer mixture (polymer coating of sulfur-coated urea, polymer coated urea and normal urea with N ratios of 3: 3: 4, respectively, during the wheat growing season, and 3.5:3: 4 during the maize season) on crop yields and nutrients uptake were investigated in a field using a wheat (Triticum aestivum L.) and maize rotation system.
153 citations
TL;DR: Main characteristics imparting weed-competitiveness to rice include selection of cultivars, seedling vigour, early and faster establishment of seedlings, root-shoot characteristics, and self-supportive allelopathy.
147 citations
TL;DR: It's clear that booting and grain filling are the most sensitive GS that are severely affected by both drought and delay in planting and the correlation between crop growth indices and grain yield depicted the highest value.
Abstract: This study evaluates the potential for adaptability and tolerance of wheat genotypes (G) to an arid environment. We examined the influence of drought stress (DS) (100, 75, and 50% field capacity), planting times (PT) (16-November, 01-December, 16-December and 01-January), and G (Yocoro Rojo, FKAU-10, Faisalabad-08, and Galaxy L-7096) on phenological development, growth indices, grain yield, and water use efficiency of drip-irrigated wheat. Development measured at five phenological growth stages (GS) (tillering, jointing, booting, heading, and maturity) and growth indices 30, 45, 60, and 75 days after sowing (DAS) were also correlated with final grain yield. Tillering occurred earlier in DS plots, to a maximum of 31 days. Days to complete 50% heading and physiological crop maturity were the most susceptible GS that denoted 31-72% reduction in number of days to complete these GS at severe DS. Wheat G grown with severe DS had the shortest grain filling duration. Genotype Fsd-08 presented greater adaptability to studied arid climate and recorded 31, 35, and 38% longer grain filling period as compared with rest of the G at 100-50% field capacity respectively. December sowing mitigated the drought and delayed planting effects by producing superior growth and yield (2162 kg ha(-1)) at severe DS. Genotypes Fsd-08 and L-7096 attained the minimum plant height (36 cm) and the shortest growth cycle (76 days) for January planting with 50% field capacity. At severe DS leaf area index, dry matter accumulation, crop growth rate and net assimilation rate were decreased by 67, 57, 34, and 38% as compared to non-stressed plots. Genotypes Fsd-08 and F-10 were the superior ones and secured 14-17% higher grain yield than genotype YR for severely stressed plots. The correlation between crop growth indices and grain yield depicted the highest value (0.58-0.71) at 60-75 DAS. So the major contribution of these growth indices toward grain yield was at the start of reproductive phase. It's clear that booting and grain filling are the most sensitive GS that are severely affected by both drought and delay in planting.
111 citations
TL;DR: How the performance of cereals and legumes in an intercrop is affected by sowing densities, relative sowing times, and nitrogen fertilizer is shown to enhance species complementarity, total productivity and economic profit.
107 citations
TL;DR: Crop growth during the grain filling period was limited by the sink strength in early sowing dates and by the photosynthetic source capacity in the late ones, indicating that source-sink relationships are relevant to optimize crop management practices and to develop breeding strategies.
98 citations
TL;DR: In this paper, four tillage approaches were tested from 2004 to 2012 in a randomized study performed in triplicate: one conventional tillage and three conservation tillage experiments with straw mulching.
97 citations
TL;DR: Better emergence and vigorous seedling growth of rice after seed priming was associated with enhanced α-amylase activity, higher soluble sugars contents, and greater respiration rate in primed rice seedlings under chilling stress.
Abstract: Double direct-seeding for double rice cropping is a simplified, labor saving, and efficient cropping system to improve multiple-crop index and total rice production in central China. However, poor crop establishment of direct-seeded early rice due to chilling stress is the main obstacle to wide spread of this system. A series of experiments were conducted to unravel the effects of pre-sowing seed treatments on emergence, seedling growth and associated metabolic events of direct-seeded early rice under chilling stress. Two seed priming treatments and two seed coating treatments were used in all the experiments. A non-treated control treatment was also maintained for comparison. In both the field and growth chamber studies, seed priming with selenium or salicylic acid significantly enhanced the emergence and seedling growth of rice compared with non-treated control. Nevertheless, such positive effects were not apparent for seed coating treatments. Better emergence and vigorous seedling growth of rice after seed priming was associated with enhanced α-amylase activity, higher soluble sugars contents, and greater respiration rate in primed rice seedlings under chilling stress. Taking together, these findings may provide new avenues for understanding and advancing priming-induced chilling tolerance in direct-seeded early rice in double rice cropping system.
84 citations
TL;DR: In this paper, a boundary function was derived for the relationship between soybean yield and water supply, and an attainable water productivity of 9.1 kg grain ha −¹ mm−¹ for non-water limited crops.
Abstract: The interactive influence of climate and management factors on soybean [Glycine max (L.) Merr.] yield potential has not been investigated in subtropical production environments. Such information can help fine tune current soybean management practices to increase yield and resource-use efficiency and to minimize risk. The objective of this study was to identify key biophysical and management factors governing variation in soybean yield potential in southern Brazil. To accomplish that objective, we used a large database on soybean yield and phenology collected from a combination of on-farm and research-station experiments conducted during four crop growing seasons (2011–2015) in Rio Grande do Sul (southern Brazil). The database portrayed a wide range of weather conditions, soil types, water regimes, sowing dates, and cultivar maturity groups (MGs). Water supply and photothermal quotient explained most of yield variation across site-years. A boundary function was derived for the relationship between soybean yield and water supply, and an attainable water productivity of 9.1 kg grain ha–¹ mm–¹. A seasonal water supply of ∼800 mm appeared sufficient to maximize seed yield, and most late-sown crops fell short of this value. Late-sown crops were also exposed to a lower photothermal quotient during reproductive stages, and this explained the yield penalty of 26 kg ha–¹ d–¹ of sowing delay after 4 November observed for non-water-limited crops. Sowing date, accompanied by proper selection of cultivar MG and determination of soil water status at sowing time, appear to be the most cost-effective management practices to ensure a high photothermal quotient and low risk of water deficit during reproductive stages and, therefore, a high yield potential in the subtropical environment of southern Brazil.
83 citations
TL;DR: In this paper, the authors investigated the possibility of using hyperspectral imaging (HSI) technique to discriminate viable and non-viable corn seeds, where a group of corn samples were heat treated by using microwave process while another group of seeds were kept as control group (untreated).
TL;DR: The use of direct seeding as a complementary technique to reduce restoration costs, particularly for species with large seeds and known high germination rates, is suggested, but the results do not support direct seeded as a substitute for seedling planting.
Abstract: Ecological restoration has become an important technique for mitigating the human impacts on natural vegetation. Planting seedlings is the most common approach to regain lost forest cover. However, these activities require a large economic investment. Direct seeding is considered a cheaper and easier alternative technique, in which tree seeds are introduced directly on the site rather than transplanting seedlings from nurseries. To evaluate the effectiveness of direct seeding, we conducted a comprehensive search of the literature using ‘restoration’, ‘direct seeding’ and ‘sowing’ as keywords, and we performed a meta-analysis using 30 papers and 89 species. We used two different measures of restoration success: seed germination probability and success probability (the chance that a seed germinates and survives until the end of the experiment). In general, restoration attempts using direct-seeding techniques were relatively unsuccessful. On average, seed germination and success probability were 0·239 and 0·114, respectively, and were not affected by climate, species successional group or the application of pre-germinative treatments. Germination and success probability increased with seed size, and the use of physical protections resulted in a nearly twofold increase in germination probability, but this effect faded by the end of the experiments. Because of the low rate of seedling success, we suggest the use of direct seeding as a complementary technique to reduce restoration costs, particularly for species with large seeds and known high germination rates, but our results do not support direct seeding as a substitute for seedling planting. Copyright © 2015 John Wiley & Sons, Ltd.
TL;DR: In this article, a 5-year-long, location-fixed field experiment was conducted to determine the effects of plastic mulch, straw retention, planting legume, and straw-legume on soil water and winter wheat grain yield.
TL;DR: In this article, the authors present data of two years field experimentation on yield and yield components of a wheat-maize intercrop system in different planting configurations in the Netherlands and show that there is a potential yield benefit for the wheat and maize intercropping system under Western European growing conditions.
TL;DR: Heat stress was extremely detrimental for all three lentil genotypes, with only minor differences among them, and controlled-environment studies validated the detrimental effects of heat stress on studied traits, similar to outdoor conditions.
Abstract: Rising temperatures or global warming will be detrimental for various crops. Moreover, because of increasing demand for lentil (Lens culinaris L.) grains, there is a need to broaden the adaptation of this crop into warmer climes. Hence, a study was conducted to evaluate the effects of high temperatures (>32/20oC) during reproductive growth on performance of lentil and to probe the mechanisms associated with reproductive failures. Three lentil genotypes, viz., LL699, LL931, and LL1122, were grown in pots at two sowing dates: (1) the normal sowing time (NS) in November so that day/night temperatures during the reproductive stage were below 32/20°C; and (2) late-sown (LS) in February so that temperatures during the reproductive stage were above 32/20°C. The plants were fully irrigated during both the sowing situations. In LS plants, the phenology was accelerated, leading to substantial reduction in biomass, flowers, and pods, accompanied by marked shortening of flowering period and podding duration, ...
TL;DR: A few promising heat-tolerant lines have been identified, which would not only serve as useful donor/s for breeding programs, also act suitable base plant source to gain more insights on heat stress induced effects in cell metabolism.
TL;DR: If clothianidin and thiamethoxam were used annually as a seed treatment in a typical crop rotation of maize, soybean, and winter wheat over several years, residues would plateau rather than continue to accumulate.
Abstract: Neonicotinoid insecticides, especially as seed treatments, have raised concerns about environmental loading and impacts on pollinators, biodiversity, and ecosystems. The authors measured concentrations of neonicotinoid residues in the top 5 cm of soil before planting of maize (corn) in 18 commercial fields with a history of neonicotinoid seed treatment use in southwestern Ontario in 2013 and 2014 using liquid chromatography-tandem mass spectrometry with electrospray ionization. A simple calculator based on first-order kinetics, incorporating crop rotation, planting date, and seed treatment history from the subject fields, was used to estimate dissipation rate from the seed zone. The estimated half-life (the time taken for 50% of the insecticide to have dissipated by all mechanisms) based on 8 yr of crop history was 0.64 (range, 0.25-1.59) yr and 0.57 (range, 0.24-2.12) yr for 2013 and 2014, respectively. In fields where neonicotinoid residues were measured in both years, the estimated mean half-life between 2013 and 2014 was 0.4 (range, 0.27-0.6) yr. If clothianidin and thiamethoxam were used annually as a seed treatment in a typical crop rotation of maize, soybean, and winter wheat over several years, residues would plateau rather than continue to accumulate. Residues of neonicotinoid insecticides after 3 yr to 4 yr of repeated annual use tend to plateau to a mean concentration of less than 6 ng/g in agricultural soils in southwestern Ontario.
TL;DR: Interaction between different tillage practices and cropping systems had significant effect on density and dry biomass of total, broadleaved and grass weeds, agronomic and yield-related traits, and grain yield of bread wheat.
TL;DR: Differing functional groups that group species with the same germination ability may help in choosing the most adapted cover crop species to sow based on climatic conditions in order to favor plant establishment and the services provided by cover crops during fallow periods are developed.
Abstract: A wide range of species can be sown as cover crops during fallow periods to provide various ecosystem services. Plant establishment is a key stage, especially when sowing occurs in summer with high soil temperatures and low water availability. The aim of this study was to determine the response of germination to temperature and water potential for diverse cover crop species. Based on these characteristics, we developed contrasting functional groups that group species with the same germination ability, which may be useful to adapt species choice to climatic sowing conditions. Germination of 36 different species from six botanical families was measured in the laboratory at eight temperatures ranging from 4.5-43°C and at four water potentials. Final germination percentages, germination rate, cardinal temperatures, base temperature and base water potential were calculated for each species. Optimal temperatures varied from 21.3-37.2°C, maximum temperatures at which the species could germinate varied from 27.7-43.0°C and base water potentials varied from -0.1 to -2.6 MPa. Most cover crops were adapted to summer sowing with a relatively high mean optimal temperature for germination, but some Fabaceae species were more sensitive to high temperatures. Species mainly from Poaceae and Brassicaceae were the most resistant to water deficit and germinated under a low base water potential. Species were classified, independent of family, according to their ability to germinate under a range of temperatures and according to their base water potential in order to group species by functional germination groups. These groups may help in choosing the most adapted cover crop species to sow based on climatic conditions in order to favor plant establishment and the services provided by cover crops during fallow periods. Our data can also be useful as germination parameters in crop models to simulate the emergence of cover crops under different pedoclimatic conditions and crop management practices.
TL;DR: In this paper, the authors compared a fallow-winter wheat (Triticum aestivum L.) rotation to several cover crop-Winter wheat rotations under rainfed and irrigated conditions in the semi-arid US High Plains.
TL;DR: It was demonstrated that increasing the rate of soil applied K up to 90 kg P ha−1 in two equal splits (50% each at sowing and knee height) improve growth and maize productivity under semiarid climates.
Abstract: Potassium (K) fertilizer management is beneficial for improving growth, yield and yield components of field crops under moisture stress condition in semiarid climates. Field experiments were conducted to study the response of maize (Zea mays L., cv. Azam) to foliar and soil applied K during summer 2013 and 2014. The experiments were carried out at the Agronomy Research Farm of The University of Agriculture Peshawar, Northwest Pakistan under limited irrigation (moisture stress) condition. It was concluded from the results that application of foliar K at the rate of 1–3% and foliar Zn at the rate of 0.1–0.2% was more beneficial in terms of better growth, higher yield and yield components of maize under moisture stress condition. Early spray (vegetative stage) resulted in better growth and higher yield than late spray (reproductive stage). Soil K treated plots (rest) plots performed better than control (K not applied) in terms of improved growth, higher yield and yield components of maize crop. The results further demonstrated that increasing the rate of soil applied K up to 90 kg P ha−1 in two equal splits (50% each at sowing and knee height) improve growth and maize productivity under semiarid climates.
TL;DR: Late October to early November sowings gave maximum yield and irrigation WP of both mulched and non-mulched wheat in NW India, and maximum WPET occurred with scheduling at 40–60% and 70% SWD on the sandy loam and clay loam, respectively.
TL;DR: It is found that change in sowing/transplanting date did not significantly affect rice and wheat yield in RWRS, although alleviated the negative impact of climate change to some extent.
Abstract: Using the detailed field experiment data from 1981 to 2009 at four representative agro-meteorological experiment stations in China, along with the Agricultural Production System Simulator (APSIM) rice-wheat model, we evaluated the impact of sowing/transplanting date on phenology and yield of rice-wheat rotation system (RWRS). We also disentangled the contributions of climate change, modern cultivars, sowing/transplanting density and fertilization management, as well as changes in each climate variables, to yield change in RWRS, in the past three decades. We found that change in sowing/transplanting date did not significantly affect rice and wheat yield in RWRS, although alleviated the negative impact of climate change to some extent. From 1981 to 2009, climate change jointly caused rice and wheat yield change by −17.4 to 1.5 %, of which increase in temperature reduced yield by 0.0–5.8 % and decrease in solar radiation reduced it by 1.5–8.7 %. Cultivars renewal, modern sowing/transplanting density and fertilization management contributed to yield change by 14.4–27.2, −4.7– −0.1 and 2.3–22.2 %, respectively. Our findings highlight that modern cultivars and agronomic management compensated the negative impacts of climate change and played key roles in yield increase in the past three decades.
TL;DR: An experiment was conducted during kharif season of 2014 to investigate suitable sowing environment and bio-regulator and its effect on clusterbean, and significantly higher plant height, number of branches per plant, leaf area index, seed yield and harvest index were recorded in foliar spray of thiourea.
Abstract: An experiment was conducted during kharif season of 2014, aims of the experiment were to investigate suitable sowing environment and bio-regulator and its effect on clusterbean (Cyamopsis tetragonoloba (L.) Taub.), experimental treatments were applied foliar spray of thiourea (500, 1000 ppm) and salicylic acid (50, 100 ppm) at 45 and 60 days after sowing under normal (15 July) and late (30 July) sowing environments. Normal sowing performed well as compared to late sowing, in respect to all morphology and yield parameters. Amongst foliar spray, significantly higher plant height (100.17 cm), number of branches per plant (7.99), leaf area index (4.85), seed yield (9.19 q/ha) and harvest index (29.39) were recorded in foliar spray of thiourea 500 ppm as compared to all other bio-regulators spray level. Similarly, salicylic acid 100 ppm found statistically at par with thiourea 500 ppm foliar spray at 45 and 60 DAS. Impacts of climate change have significant reflections on clusterbean productivity. Sowing dates plays a vital role to determining the productivity of clusterbean with bio-regulators spray by controlling the environmental factors.
TL;DR: The results suggest that the prophylactic use of pesticide-coated seeds should be avoided, with the approval of this treatment considered on a case-by-case basis and accompanied with specific measures to minimize risks of adverse effects on avian communities.
Abstract: Summary
Due to reductions in winter food resources, newly sown cereal seeds have become a key component of many bird species' diets, but these seeds are often treated with pesticides that may cause toxic effects. To complete an appropriate risk assessment, data on treated seed toxicity need to be combined with information about the risk of exposure of birds in the field and the factors that modulate such exposure.
We studied the abundance of pesticide-treated seeds available for birds in the field, the pesticides and their concentrations in treated seeds, and the bird species observed in the field that were feeding on these pesticide-treated seeds. The exposure of red-legged partridge to treated winter cereal seeds was characterized through the analysis of crop and gizzard contents of hunted individuals (n = 189). Moreover, we measured the contribution of cereal seeds in the autumn–winter diet of partridges in order to assess the potential risk of exposure to pesticide-treated seeds.
Density of treated seeds on the soil surface after sowing (11·3 ± 1·2 seeds m−2 in the centre of field and 43·4 ± 5·5 seeds m−2 in the headlands) was enough to provide, in an area between 6 and 50 m2, doses of six active ingredients above those indicating acute (i.e. a dose capable of killing 50% of individuals of a sensitive species) and / or chronic (no observed effect level) toxicity.
Up to 30 bird species were observed consuming treated cereal seeds in recently sown fields. Corn bunting was identified as an appropriate focal passerine species for the risk assessment of pesticide-treated seeds.
We found that treated seeds were an important route of pesticide ingestion for red-legged partridge; pesticide residues (six fungicides and two insecticides) were found in 32·3% of crops and gizzards. Cereal seeds represented more than half (53·4 ± 4·3%) of total biomass consumed by partridges from October to February.
Synthesis and applications. The field exposure data combined with previous studies about the toxicity to partridges of using pesticide-treated seeds point to an unacceptable risk of this practice to farmland birds. Our results suggest that the prophylactic use of pesticide-coated seeds should be avoided, with the approval of this treatment considered on a case-by-case basis and accompanied with specific measures to minimize risks of adverse effects on avian communities.
TL;DR: In this article, an 11-year field experiment (2003-2013) with the same maize cultivar and two short-term experiments including different sowing dates and plant densities were conducted at Luancheng Agro-ecological Experimental Station in the North China Plain (NCP).
TL;DR: Throughout the growth period, the dry matter production and leaf area index of maize increased as the plant density increased irrespective of whether it was grown as a sole crop or as an intercrop, however, the effect of increasing cropping density was less obvious for soybean.
TL;DR: The response of durum Wheat and maize grain yield to N was remarkable, while sunflower grain yield was not significantly influenced by N rate, and durum wheat and sunflower performed better under both CT and MT and with N2 rates.
TL;DR: The results suggest that dry seeding of boro rice in mid November is risky because of low temperature in December–January, and boro varieties with greater cold tolerance during the vegetative stage are needed to enable the switch from PTR to November-sown dry-seeded boro Rice in the High Ganges River Floodplain of western Bangladesh.
TL;DR: In this paper, the authors used a social-ecological framework and multinomial logit model to analyze seed systems and factors influencing farmers' decisions about seed use, particularly in response to climate-induced stress.