Showing papers on "Sowing published in 2014"

The role of the testa during development and in establishment of dormancy of the legume seed

Abstract: Timing of seed germination is one of the key steps in plant life cycles. It determines the beginning of plant growth in natural or agricultural ecosystems. In the wild, many seeds exhibit dormancy and will only germinate after exposure to certain environmental conditions. In contrast, crop seeds germinate as soon as they are imbibed usually at planting time. These domestication-triggered changes represent adaptations to cultivation and human harvesting. Germination is one of the common sets of traits recorded in different crops and termed the “domestication syndrome”. Moreover, legume seed imbibition has a crucial role in cooking properties. Different seed dormancy classes exist among plant species. Physical dormancy (often called hardseededness), as found in legumes, involves the development of a water-impermeable seed coat, caused by the presence of phenolics- and suberin-impregnated layers of palisade cells. The dormancy release mechanism primarily involves seed responses to temperature changes in the habitat, resulting in testa permeability to water. The underlying genetic controls in legumes have not been identified yet. However, positive correlation was shown between phenolics content (e.g., pigmentation), the requirement for oxidation and the activity of catechol oxidase in relation to pea seed dormancy, while epicatechin levels showed a significant positive correlation with soybean hardseededness. MYB transcription factors, WD40 proteins and enzymes of the anthocyanin biosynthesis pathway were involved in seed testa colour in soybean, pea and Medicago, but were not tested directly in relation to seed dormancy. These phenolic compounds play important roles in defence against pathogens, as well as affecting the nutritional quality of products, and because of their health benefits, they are of industrial and medicinal interest. In this review, we discuss the role of the testa in mediating legume seed germination, with a focus on structural and chemical aspects.

Individual and combined effects of transient drought and heat stress on carbon assimilation and seed filling in chickpea.

Abstract: High temperatures and decreased rainfall are detrimental to yield in chickpea (Cicer arietinum L.), particularly during grain filling. This study aimed to (i) assess the individual and combined effects of drought and heat stress on biochemical seed-filling processes, (ii) determine genotypic differences in heat and drought tolerance, and (iii) determine any cross-tolerance. Plants were grown outdoors in the normal growing season when temperatures during seed filling were 32-20°C; heat stress). Half of the pots were kept adequately watered throughout, but water was withheld from the others from the initiation of seed filling until the relative leaf water content reached 50% of the irrigated plants (drought stress); all plants were rewatered thereafter until seed maturit. Water was withheld for 13 days (normal sowing) and 7 days (late sowing), so soil moisture decreased by 54-57%. Tests on leaves and seeds were performed after the stress. Individual and combined stress damaged membranes, and decreased cellular oxidising ability, stomatal conductance, PSII function and leaf chlorophyll content; damage was greater under combined stress. Leaf Rubisco activity increased with heat stress, decreased with drought stress and decreased severely with combined stress. Sucrose and starch concentrations decreased in all seeds through reductions in biosynthetic enzymes; reductions were greater under combined stress. These effects were more severe in heat- and drought-sensitive genotypes compared with drought-tolerant genotypes. Drought stress had a greater effect than heat stress on yield and the biochemical seed-filling mechanisms. Drought- and heat-tolerant genotypes showed partial cross-tolerance.

Identifying the critical period for waterlogging on yield and its components in wheat and barley

Abstract: Crop tolerance to waterlogging depends on factors such as species sensitivity and the stage of development that waterlogging occurs. The aim of this study was to identify the critical period for waterlogging on grain yield and its components, when applied during different stages of crop development in wheat and barley. Two experiments were carried out (E1: early sowing date, under greenhouse; E2: late sowing date, under natural conditions). Waterlogging was imposed during 15–20 days in 5 consecutive periods during the crop cycle (from Leaf 1 emergence to maturity). The greatest yield penalties occurred when waterlogging was applied from Leaf 7 appearance on the main stem to anthesis (from 34 to 92 % of losses in wheat, and from 40 to 79 % in barley for E1 and E2 respectively). Waterlogging during grain filling reduced yield to a lesser degree. In wheat, reductions in grain number were mostly explained by reduced grain number per spike while in barley, by variations in the number of spikes per plant. The time around anthesis was identified as the most susceptible period to waterlogging in wheat and barley. Exposing the crop to more stressful conditions, e.g. delaying sowing date, magnified the negative responses to waterlogging, although the most sensitive stage (around anthesis) remained unchanged.

Effects of conventional tillage and no tillage permutations on extracellular soil enzyme activities and microbial biomass under rice cultivation

Abstract: Extracellular soil enzymes hold a cardinal position in nutrient dynamics by regulating bioavailability of elements, and hence are linked with soil health. The present study aimed to analyze the responses of extracellular enzymes involved in mineralization of carbon (β-d-glucosidase (BG), cellobiohydrolase (CBH), polyphenol oxidase (PPO)), nitrogen (urease (UR), glycine-amino peptidase (GAP)) and phosphorous (alkaline phosphatase (ALP)) under four permutations of conventional tillage and no tillage under rice–wheat system in eastern Indo-gangetic plains during rice cultivation period. The permutations were: tillage before sowing/transplantation of each crop (RCT–WCT), tillage before transplantation of rice and no tillage before sowing of wheat (RCT–WNT), tillage before sowing wheat and no tillage before sowing of rice (RNT–WCT) and no tillage before sowing of each crop (RNT–WNT). Microbial biomass carbon and nitrogen and activities of BG, CBH, ALP and UR increased with reduction in tillage frequency, becoming the highest under RNT–WNT and the lowest under RCT–WCT. Principal component analyses (PCA) condensed the variables in to two components, apparently described by soil temperature and moisture content under all the tillage permutations. Most of the enzymes and soil properties identified to be associated under PCA followed linear relationships. Under RCT–WCT, CBH, UR and ALP were related with BG. Different orders of residue incorporation and tillage under RCT–WNT, RNT–WCT and RNT–WNT masked these relations. Results indicated that reduction in tillage frequency made the soil healthier. Relationship of BG with other enzymes appeared as a probable indicator to reflect deviations from the conventional cultivation practice in the study region.

Responses of Seed Germination, Seedling Growth, and Seed Yield Traits to Seed Pretreatment in Maize (Zea mays L.)

Abstract: A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits inmaize (Zeamays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P < 0.05). The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method.

Plot size matters: interference from intergenotypic competition in plant phenotyping studies

Abstract: Genetic and physiological studies often comprise genotypes diverse in vigour, size and flowering time. This can make the phenotyping of complex traits challenging, particularly those associated with canopy development, biomass and yield, as the environment of one genotype can be influenced by a neighbouring genotype. Limited seed and space may encourage field assessment in single, spaced rows or in small, unbordered plots, whereas the convenience of a controlled environment or greenhouse makes pot studies tempting. However, the relevance of such growing conditions to commercial field-grown crops is unclear and often doubtful. Competition for water, light and nutrients necessary for canopy growth will be variable where immediate neighbours are genetically different, particularly under stress conditions, where competition for resources and influence on productivity is greatest. Small hills and rod-rows maximise the potential for intergenotypic competition that is not relevant to a crop’s performance in monocultures. Response to resource availability will typically vary among diverse genotypes to alter genotype ranking and reduce heritability for all growth-related traits, with the possible exception of harvest index. Validation of pot experiments to performance in canopies in the field is essential, whereas the planting of multirow plots and the simple exclusion of plot borders at harvest will increase experimental precision and confidence in genotype performance in target environments.

Priority effects of time of arrival of plant functional groups override sowing interval or density effects: a grassland experiment.

Abstract: Priority effects occur when species that arrive first in a habitat significantly affect the establishment, growth, or reproduction of species arriving later and thus affect functioning of communities. However, we know little about how the timing of arrival of functionally different species may alter structure and function during assembly. Even less is known about how plant density might interact with initial assembly. In a greenhouse experiment legumes, grasses or forbs were sown a number of weeks before the other two plant functional types were sown (PFT) in combination with a sowing density treatment. Legumes, grasses or non-legume forbs were sown first at three different density levels followed by sowing of the remaining PFTs after three or six-weeks. We found that the order of arrival of different plant functional types had a much stronger influence on aboveground productivity than sowing density or interval between the sowing events. The sowing of legumes before the other PFTs produced the highest aboveground biomass. The larger sowing interval led to higher asymmetric competition, with highest dominance of the PFT sown first. It seems that legumes were better able to get a head-start and be productive before the later groups arrived, but that their traits allowed for better subsequent establishment of non-legume PFTs. Our study indicates that the manipulation of the order of arrival can create priority effects which favour functional groups of plants differently and thus induce different assembly routes and affect community composition and functioning.

Quinoa in Morocco – Effect of Sowing Dates on Development and Yield

Abstract: Quinoa is a highly nutritious food product, being cultivated for several thousand years in South America, and it is recently introduced in Morocco and showed a high potential of adaptation in Morocco. A field study was carried out in the south of Morocco in order to investigate the effects of sowing date on quinoa performance in a series of experiments conducted for adaptation of quinoa. The experiment took place in Agadir, with a test of 10 sowing dates, each 15 days from 1st November to 15th March. Sowing dates affected the growth and productivity due to differences in temperature, precipitation and radiation over the year. Highest seed yield and dry matter yield were obtained when quinoa sown in November and early December. The growing season length has been affected by accumulated radiation. In addition to abiotic factors (temperature, radiation, rainfall) affecting quinoa growth, biotic factors such as downy mildew and weeds affected the yield. Early sowing in November to early December secured good plant development when low temperatures occurred in January and February and downy mildew appeared in March.

Effect of weed management and seed rate on crop growth under direct dry seeded rice systems in Bangladesh.

Abstract: Weeds are a major constraint to the success of dry-seeded rice (DSR). The main means of managing these in a DSR system is through chemical weed control using herbicides. However, the use of herbicides alone may not be sustainable in the long term. Approaches that aim for high crop competitiveness therefore need to be exploited. One such approach is the use of high rice seeding rates. Experiments were conducted in the aman (wet) seasons of 2012 and 2013 in Bangladesh to evaluate the effect of weed infestation level (partially-weedy and weed-free) and rice seeding rate (20, 40, 60, 80, and 100 kg ha−1) on weed and crop growth in DSR. Under weed-free conditions, higher crop yields (5.1 and 5.2 t ha−1 in the 2012 and 2013 seasons, respectively) were obtained at the seeding rate of 40 kg ha−1 and thereafter, yield decreased slightly beyond 40 kg seed ha−1. Under partially-weedy conditions, yield increased by 30 to 33% (2.0–2.2 and 2.9–3.2 t ha−1 in the 2012 and 2013 seasons, respectively) with increase in seeding rate from 20 to 100 kg ha−1. In the partially-weedy plots, weed biomass decreased by 41–60% and 54–56% at 35 days after sowing and at crop anthesis, respectively, when seeding rate increased from 20 to 100 kg ha−1. Results from our study suggest that increasing seeding rates in DSR can suppress weed growth and reduce grain yield losses from weed competition.

Effects of density and sowing pattern on weed suppression and grain yield in three varieties of maize under high weed pressure

Abstract: Summary We tested the hypothesis that improved weed suppression by maize can be achieved through increased crop density and spatial uniformity. Field experiments on three varieties of maize sown at three densities (5, 7 and 10.5 seeds m−2) and in two spatial patterns (grid pattern and rows) under very high weed pressure from Brachiaria brizantha were performed in 2012 and 2013. We measured weed biomass 1 month after sowing and at harvest, and grain yield at harvest. Density, variety and sowing pattern all had strong and significant effects on both weed biomass and yield. On average, weed biomass was reduced (by 72% in the first year and 58% in the second year), and grain yield was increased (by 48% and 44%) at the highest density in the grid pattern compared with standard sowing practices (medium density, row pattern). There was a significant density × variety interaction, which is evidence for genetic differences in the response of the varieties to density in characteristics that influence weed suppression. The variety that suppressed weeds best at high density had the lowest variation in the angle of insertion of the oldest living leaf at harvest (leaf 6), supporting the hypothesis that reduced phenotypic plasticity may be advantageous for weed suppression under high density and spatial uniformity. Increased density and uniformity can contribute to weed management in maize in many cases, potentially reducing the need for herbicides or mechanical weed control.

Phenological performance of groundnut varieties under sowing environments in hyper arid zone of Rajasthan, India

Abstract: An experimental trail was conducted on groundnut during kharif seasons of 2009 and 2010. The experimental soil was loamy sand in texture. The experiment was laid out in split-plot design with three replications, assigning 32 treatments consisting of four date of sowing (20 th April, 15 th May, 9 th June and 4 th July) and two varieties (HNG-10 and TG-37A) as main-plot treatments and four fertility levels of nitrogen and phosphorus application (0, 20 N-40 P 2O5, 30-60 P 2O5 and 40 N-80 P 2O5 kg/ha) as sub-plot treatments. The results showed that significantly higher plant stand was observed in 9 th June and 4 th July sowing date of the groundnut at harvest. 20 th April sowing had significantly higher dry matter accumulation, CGR of 30-60 and 60-90 DAS of HNG-10 variety. Further delays in sowing significantly reduce growth parameters. However, growth parameters viz. dry matter accumulation, CGR, RGR etc. in all the sowing dates in TG-37A was statistically at par with each other. All the fertility treatments produced significantly higher dry matter, CGR, RGR etc . Application of 30 kg N-60 kg P 2O5 / ha significantly enhanced the dry matter accumulation over 20 kgN-40 kg P 2O5 /ha but statistically at par with 40 kg N- 80 kg P 2O5/ ha.

Water-saving fertilizer-saving method for crop rotation of winter wheat and summer maize

Abstract: The invention discloses a water-saving fertilizer-saving method for crop rotation of winter wheat and summer maize and belongs to the technical field of agriculture. The water-saving fertilizer-saving method comprises a wheat planting method and a maize planting method, wherein the wheat planting method and the maize planting method both comprise steps of seeding, fertilizing, irrigating, field management, chemical weeding, pest control, harvesting and the like, and all the wheat and maize straws are returned to the fields. By means of the water-saving fertilizer-saving method, the effect of water saving, fertilizer saving and high yield is improved, the fertilizer utilization rate is increased, and fertilizing labor intensity and cost are reduced.

Method for planting tomatoes

Abstract: The invention discloses a method for planting tomatoes The method includes the steps of variety selection, strong seedling breeding, land preparation, fertilization, field planting, field management, harvesting and the like The method for planting the tomatoes has the advantages that operation is easy and convenient to conduct, management is convenient to conduct, cost is low, benefits are good, the method is easy to popularize, the disease incidence is low in the planting process, using of chemical pesticide can be reduced or avoided, the yield of the tomatoes is increased, the quality of the tomatoes is improved, the tomatoes planted through the method are safe and free of pollution, edible safety of customers is guaranteed, and environmental pollution is reduced

A crop model-based approach for sunflower yields

Abstract: Pushed by the Brazilian biodiesel policy, sunflower (Helianthus annuus L) production is becoming increasingly regarded as an option to boost farmers' income, particularly under semi-arid conditions Biodiesel related opportunities increase the demand for decision-making information at different levels, which could be met by simulation models This study aimed to evaluate the performance of the crop model OILCROP-SUN to simulate sunflower development and growth under Brazilian conditions and to explore sunflower water- and nitrogen-limited, water-limited and potential yield and yield variability over an array of sowing dates in the northern region of the state of Minas Gerais, Brazil For model calibration, an experiment was conducted in which two sunflower genotypes (H358 and E122) were cultivated in a clayey soil Growth components (leaf area index, above ground biomass, grain yield) and development stages (crop phenology) were measured A database composed of 27 sunflower experiments from five Brazilian regions was used for model evaluation The spatial yield distribution of sunflower was mapped using ordinary kriging in ArcGIS The model simulated sunflower grain productivity satisfactorily (Root Mean Square Error ≈ 13 %) Simulated yields were relatively high (1,750 to 4,250 kg ha-1) and the sowing window was fairly wide (Oct to Feb) for northwestern locations, where sunflower could be cultivated as a second crop (double cropping) at the end of the rainy season The hybrid H358 had higher yields for all simulated sowing dates, growth conditions and selected locations

Multiple agricultural product application method and systems

Abstract: A method and system for planting one of a plurality of seed types, hybrids and/or varieties is provided. A planter is provided with a plurality of row units. The row units include metering systems, which can include multiple seed meters at a particular row unit, as well as a queuing system. The metering systems including more than one seed meters are configured such that the seed meters will plant a different seed types or varieties. The operation of one or more of the seed meters at a time will provide for the planting of a particular seed variety. The invention provides for on-the-go changing of a seed being planted by changing the operation of one or more of the seed meters at each of the row units and provides for almost infinite variation among the row units for planting particular seed varieties or not planting at all.

Pepper planting method

Abstract: The invention discloses a pepper planting method. The pepper planting method includes the following steps of seed selection and pretreatment, seedling growing, soil preparation, fixed planting, field management, harvesting and the like. According to the pepper planting technology, the acre yield of peppers can reach 2000-3000 kilograms. Compared with a traditional planting technology, the yield can be improved by 30-50 percent, meanwhile, the planted peppers are good in quality, green, friendly to the environment, low in planting cost, convenient to manage and suitable for large-scale popularization and has obvious social benefits, economic benefits and ecological benefits.

Method for growing watermelons

Abstract: The invention discloses a method for growing watermelons. The method includes the steps of processing seeds and accelerating germination, sowing and raising seedlings, applying base fertilizer on the whole land, transplanting the seedlings, performing field management, harvesting and the like. The method for growing watermelons is easy to operate, convenient to manage, good in growth vigor of watermelons, high in disease resistance, uniform in result nature and high in yield, the yield per mu can reach 4000 kg to 5000 kg, the watermelons are large, good in quality, high in sugar content, bright in flesh color, delicate in flesh and high in water content and commodity value, and therefore the method has great significance for increasing income of melon farmers.