Showing papers on "Sowing published in 2015"

Seed treatments for sustainable agriculture-A review

Abstract: Seed treatment refers to the application of certain agents physical, chemical or biological to the seed prior to sowing in order to suppress, control or repel pathogens, insects and other pests that attack seeds, seedlings or plants and it ranges from a basic dressing to coating and pelleting. Introduction and ban of arsenic (used from 1740 until 1808) is the key milestones in the history of modern seed treatment till then a continuous research and advancement in this technology is going on. The technological advancement prepared a roadmap for refiningexisting seed treatment technologies and future work on technologies like fluid drilling as a way to sow germinated seeds where gel can also serve as a delivery system for other materials, seed priming advances the early phase of germination without redicle emergence. Another advanced technology, solid matrix priming (SMP) has been evaluated as a means to advances the germination of seeds and serve as a carrier for useful material too. Physical and biological seed treatments alone an alternative to chemicals or in combination with a chemical treatment are being used worldwide because of their environmental safety and socioeconomic aspects. Biological seed treatments are expected to be one of the fastest growing seed treatment sectors in the near future, in part because they are easier to register at Environment Protection Agency (EPA). Lack of awareness to seed treatments at farmer’s level is one of the limiting factors in disease management and hence, efforts should be made at farmer’s level to adopt the technology. Keeping the all above facts in mind, selected seed treatment technologies with their improvement and significance will be discussed in this review.

Seed dispersal limitations shift over time in tropical forest restoration

Abstract: Past studies have shown that tropical forest regeneration on degraded farmlands is initially limited by lack of seed dispersal, but few studies have tracked changes in abundance and composition of seed rain past the first few years after land abandonment. We measured seed rain for 12 months in 10 6-9-year-old restoration sites and five mature, reference forests in southern Costa Rica in order to learn (1) if seed rain limitation persists past the first few years of regeneration; (2) how restoration treatments influence seed community structure and composition; and (3) whether seed rain limitation is contingent on landscape context. Each restoration site contained three 0.25-ha treatment plots: (1) a naturally regenerating control, (2) tree islands, and (3) a mixed-species tree plantation. Sites spanned a deforestation gradient with 9-89% forest area within 500 m around the treatment plots. Contrary to previous studies, we found that tree seeds were abundant and ubiquitous across all treatment plots (585.1 ± 142.0 seeds · m(-2) · yr(-1) [mean ± SE]), indicating that lack of seed rain ceased to limit forest regeneration within the first decade of recovery. Pioneer trees and shrubs comprised the vast majority of seeds, but compositional differences between restoration sites and reference forests were driven by rarer, large-seeded species. Large, animal-dispersed tree seeds were more abundant in tree islands (4.6 ± 2.9 seeds · m(-2) · yr(-1)) and plantations (5.8 ± 3.0 seeds · m(-2) · yr(-1)) than control plots (0.2 ± 0.1 seeds · m(-2) · yr(-1)), contributing to greater tree species richness in actively restored plots. Planted tree species accounted for < 1% of seeds. We found little evidence for landscape forest cover effects on seed rain, consistent with previous studies. We conclude that seed rain limitation shifted from an initial, complete lack of tree seeds to a specific limitation on large-seeded, mature forest species over the first decade. Although total seed abundance was equal among restoration treatments, tree plantations and tree islands continued to diversify seed rain communities compared to naturally regenerating controls. Compositional differences between regenerating plots and mature forests suggest that large-seeded tree species are appropriate candidates for enrichment planting.

Agricultural practices altered soybean seed protein, oil, fatty acids, sugars, and minerals in the Midsouth USA.

Abstract: Information on the effects of management practices on soybean seed composition is scarce. Therefore, the objective of this research was to investigate the effects of planting date (PD) and seeding rate (SR) on seed composition (protein, oil, fatty acids, and sugars) and seed minerals (B, P, and Fe) in soybean grown in two row-types (RT) on the Mississippi Delta region of the Midsouth USA. Two field experiments were conducted in 2009 and 2010 on Sharkey clay and Beulah fine sandy loam soil at Stoneville, MS, under irrigated conditions. Soybean were grown in 102 cm single-rows and 25 cm twin-rows in 102 cm centers at seeding rates of 20, 30, 40, and 50 seeds m–2. The results showed that in May and June planting, protein, glucose, P, and B concentrations increased with increased SR, but at the highest seeding rates (40 and 50 seeds m–2), the concentrations remained constant or declined. Palmitic, stearic, and linoleic acid concentrations were the least responsive to SR increases. Early planting resulted in higher oil, oleic acid, sucrose, B, and P on both single and twin-rows. Late planting resulted in higher protein and linolenic acid, but lower oleic acid and oil concentrations. The changes in seed constituents could be due to changes in environmental factors (drought and temperature), and nutrient accumulation in seeds and leaves. The increase of stachyose sugar in 2010 may be due to a drier year and high temperature in 2010 compared to 2009; suggesting the possible role of stachyose as an environmental stress compound. Our research demonstrated that PD, SR, and RT altered some seed constituents, but the level of alteration in each year dependent on environmental factors such as drought and temperature. This information benefits growers and breeders for considering agronomic practices to select for soybean seed nutritional qualities under drought and high heat conditions.

Optimising grain yield and grazing potential of crops across Australia’s high-rainfall zone: a simulation analysis. 1. Wheat

Abstract: Interest is growing in the potential to expand cropping into Australia’s high-rainfall zone (HRZ). Dual-purpose crops are suited to the longer growing seasons in these environments to provide both early grazing for livestock and later regrow to produce grain. Grain yield and grazing potential of wheats of four different maturity types were simulated over 50 years at 13 locations across Australia’s HRZ, and sowing date, nitrogen (N) availability and crop density effects were explored. Potential grazing days on wheat were obtained by simulating sheep grazing crops to Zadoks growth stage Z30 at 25 dry sheep equivalents (DSE)/ha. Optimal sowing dates for each maturity type at each location were matched to the flowering window during which risk of frost and heat stress was lowest. Overall, we found significant national potential for dual-purpose use of winter wheat cultivars across Australia’s HRZ, with opportunities identified in all regions. Simulated mean wheat yields exceeded 6 t/ha at most locations, with highest mean grain yields (8–10 t/ha) in southern Victoria, and lower yields (5–7 t/ha) in the south-west of Western Australia (WA) and central and northern New South Wales (NSW). Highest grazing days were from winter cultivars sown early (March–mid-April), which could provide 1700–3000 DSE-days/ha of grazing across HRZ locations; this was 2–3 times higher than could be obtained from grazing spring cultivars (200–800 DSE-days/ha). Sowing date was critical to maximise both grazing and grain yield potential from winter cultivars; each 1-week delay in sowing after 8 March reduced grazing by 200–250 DSE-days/ha and grain yield by 0.45 t/ha. However, in Mediterranean climates, a lower frequency of early sowing opportunities before mid-April (<30% of years) is likely to limit the potential to use winter cultivars. Prospects to graze shorter season spring cultivars that fit later sowing windows require further examination in south-west WA, the slopes of NSW and southern Queensland.

Influence of Seeding Ratio, Planting Date, and Termination Date on Rye-Hairy Vetch Cover Crop Mixture Performance under Organic Management.

Abstract: Cover crop benefits include nitrogen accumulation and retention, weed suppression, organic matter maintenance, and reduced erosion. Organic farmers need region-specific information on winter cover crop performance to effectively integrate cover crops into their crop rotations. Our research objective was to compare cover crop seeding mixtures, planting dates, and termination dates on performance of rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) monocultures and mixtures in the maritime Pacific Northwest USA. The study included four seed mixtures (100% hairy vetch, 25% rye-75% hairy vetch, 50% rye-50% hairy vetch, and 100% rye by seed weight), two planting dates, and two termination dates, using a split-split plot design with four replications over six years. Measurements included winter ground cover; stand composition; cover crop biomass, N concentration, and N uptake; and June soil NO3--N. Rye planted in mid-September and terminated in late April averaged 5.1 Mg ha-1 biomass, whereas mixtures averaged 4.1 Mg ha-1 and hairy vetch 2.3 Mg ha-1. Delaying planting by 2.5 weeks reduced average winter ground cover by 65%, biomass by 50%, and cover crop N accumulation by 40%. Similar reductions in biomass and N accumulation occurred for late March termination, compared with late April termination. Mixtures had less annual biomass variability than rye. Mixtures accumulated 103 kg ha-1 N and had mean C:N ratio <17:1 when planted in mid-September and terminated in late April. June soil NO3--N (0 to 30 cm depth) averaged 62 kg ha-1 for rye, 97 kg ha-1 for the mixtures, and 119 kg ha-1 for hairy vetch. Weeds comprised less of the mixtures biomass (20% weeds by weight at termination) compared with the monocultures (29%). Cover crop mixtures provided a balance between biomass accumulation and N concentration, more consistent biomass over the six-year study, and were more effective at reducing winter weeds compared with monocultures.

Coating seeds with endophytic fungi enhances growth, nutrient uptake, yield and grain quality of winter wheat

Abstract: The aim of this study was to assess whether seed coating with microbial consortium based on the arbuscular mycorrhizal (AM) fungus Glomus intraradices BEG72, Glomus mossae and Trichoderma atroviride MUCL 45632 could improve seedling establishment, yield and grain quality (protein content and mineral composition) of wheat (Triticum durum Desf.). As a first step, a laboratory experiment was conducted in a growth chamber to verify the capability of seed coating with endophytic fungi to promote emergence and plant growth of wheat seedlings. Two additional experiments were carried out under open field conditions, to evaluate the effects of coating with beneficial fungi on SPAD index, chlorophyll fluorescence, yield, grain quality and mineral composition of winter wheat. In the growth chamber experiment, 17 days after sowing, the SPAD index, the number of leaves, shoot and root dry biomass of seedlings were significantly higher by 10.0%, 28.6%, 23.1% and 64.2%, in coated as compared to uncoated wheat seeds. In the open field trials, use of the uncoated seeds led to a significant reduction in grain yield by 24.3% and 7.7%, during the first and second growing season, respectively, compared to the coated seeds. Grain quality of wheat, in particular protein content, K, P, Fe and Zn concentrations were improved by AM fungi and Trichoderma inoculation. Uncoated wheat plants exhibited a strong variation of yield between the two growing cycles (2.8 and 3.6 t ha -1 for 2011-12 and 2012-13, respectively) in comparison to coated seeds (3.7 and 3.9 t ha -1 for 2011-12 and 2012-13, respectively). The increase in grain yield and yield stability

Seed priming techniques in field crops-A review

Abstract: Germination and seedling emergence are the critical stages in the plant life cycle. Insufficient seedling emergence and inappropriate stand establishment are the main constraints in the production of crops which receiving less rainfall. Farmers do not have sufficient resources to meet the requirement of seedbed preparation for sowing and they are at more risk as compared to progressive farmers. On the other hand good establishment increases competitiveness against weeds, increases tolerance to drought period, increase yield and avoids the time consuming need for re-sowing that is costly too. It is well accepted fact that priming improves germination, reduces seedling emergence time and improves stand establishment. A method to improve the rate and uniformity of germination is the priming or physiological advancement of the seed lot. The general purpose of seed priming is to partially hydrate the seed to a point where germination processes are begun, but they would exhibit rapid germination when re-imbibed under normal or stress conditions. A lot of work has been done on seed priming and results of these studies indicate well the importance of priming to get a good crop stand in many crops of tropical region such as rice, maize, sorghum and pigeon pea.

Bed planting of wheat (Triticum aestivum L.) improves nitrogen use efficiency and grain yield compared to flat planting

Abstract: Conventional flat planting is commonly used for growing wheat in Pakistan and the crop is irrigated by flood irrigation, but it leads to ineffective use of applied nitrogen owing to poor aeration and leaching and volatilization losses. The practice also results in greater crop lodging, lower water use efficiency, and crusting of the soil surface. In contrast, bed planting of wheat not only saves water but improves fertilizer use efficiency and grain yield. Three years of pooled data from the present study showed that wheat planting on beds and nitrogen application at 120 kg ha− 1 produced 15.06% higher grain yield than flat planting at the same nitrogen rate. Similarly, 25.04%, 15.02%, 14.59%, and 29.83% higher nitrogen uptake, nitrogen use, and agronomic and recovery efficiencies, respectively, were recorded for bed compared to flat planting. Wheat planting on beds with a nitrogen application of 80 kg ha− 1 gave a yield similar to that of flat planting with 120 kg ha− 1 nitrogen. However, the economic return was 29% higher in bed planting as compared to flat planting, when nitrogen was applied at 120 kg ha− 1.

Seeding machine with seed delivery system

Abstract: A seed delivery system for use in a seeding or planting machine that removes the seed from a seed meter by capturing the seed therefrom. The delivery system then moves the seed down to a lower discharge point and accelerates the seed horizontally rearward to a speed approximately equal to the forward travel speed of the seeding machine such that the seed, when discharged has a low or zero horizontal velocity relative to the ground. Rolling of the seed in the trench is thus reduced. Furthermore, as the seed only has a short drop from the outlet to the bottom of the seed trench, the seed has little vertical speed to induce bounce. The delivery system uses a brush belt to capture, move and accelerate the seed. By capturing the seed and moving it from the meter to the discharge, the seed is held in place relative to other seeds and the planter row unit. As a result, the seeds are isolated from row unit dynamics thereby maintaining seed spacing.

Spatial and temporal variations of, and the impact of climate change on, the dry season crop irrigation requirements in Bangladesh

Abstract: Sustaining irrigation is vital for ensuring future food security in the face of population growth and a changing climate in Bangladesh. In this study, a daily soil water balance simulation model was used to estimate the net irrigation requirements of nine crops including Boro rice for the historical period of 1985–2010 and for future climate scenarios of 2030 and 2050 dry and average conditions using the A1B emission scenario. The average net irrigation requirement of Boro rice, the main crop, is 676 mm with temporally averaged spatial variation of 644–779 mm and spatially averaged temporal variation of 570–755 mm for base case planting on clay loam soil. The variations are due to the variation in crop evapotranspiration and rainfall during the cropping period. Changing planting or sowing date affects the net irrigation requirement which for Boro rice is lower in early (October–November) or late planting (January–February). The net irrigation requirement of Boro rice is about twice that required by wheat, maize, potato, tomato and sunflower, three times that of pulses and 5–6 times that required by oilseeds. The impact of climate change on irrigation requirements of Boro rice is small. The average irrigation requirement is projected to increase by a maximum of 3 % for the 2050 dry scenario. For other crops this is projected to increase by 1–5 % depending on the crop and the time of sowing/planting.

Response of Spring Wheat (Triticum aestivum L.) Quality Traits and Yield to Sowing Date

Abstract: The unpredictability and large fluctuation of the climatic conditions in rainfed regions do affect spring wheat yield and grain quality. These variations offer the opportunity for the production of better quality wheat. The effect of variable years, locations and sowing managements on wheat grain yield and quality was studied through field experiments using three genotypes, three locations for two years under rainfed conditions. The two studied years as contrasting years at three locations and sowing dates depicted variability in temperature and water stress during grain filling which resulted considerable change in grain yield and quality. Delayed sowing, years (2009–10) and location (Talagang) with high temperature and water stress resulted increased proline, and grain quality traits i.e. grain protein (GP) and grain ash (GA) than optimum conditions (during 2008–09, at Islamabad and early sowing). However, opposite trend was observed for dry gluten (DG), sodium dodecyl sulphate (SDS), SPAD content and grain yield irrespective of genotypes. The influence of variable climatic conditions was dominant in determining the quality traits and inverse relationship was observed among some quality traits and grain yield. It may be concluded that by selecting suitable locations and different sowing managements for subjecting the crop to desirable environmental conditions (temperature and water) quality traits of wheat crop could be modified.

Effect Of Pre-Sowing Seed Treatments With Silicon Nanoparticles On Germinability Of Sunflower (Helianthus Annuus)

Abstract: Abstract Silicon is one of the most widespread macro elements that have beneficial effects on plant growth. Although its positive effects on plant growth and development have been widely considered, little information is available about possibility of nano-silicon utilization in seed invigoration treatments. Enhanced seed germination may lead to improved stand establishment and it can play important role in successful crop production. Partial hydration of the seeds followed by dehydration in a controlled environment often results in rapid seed germination and more uniform seedling emergence compared to untreated seeds. In the present study, the effect of seed soaking in different concentration nano-silicon solutions (0, 0.2, 0.4, 0.6, 0.8, 1 and 1.2 mM for 8 h) on germination characteristics of sunflower was investigated. Seed soaking in low concentration nano-silicon solutions (0.2 and 0.4 mM) significantly reduced days to 50% germination and mean germination time and improved root length, mean daily germination, seedling vigour index and final germination percentage. These results suggest that the incorporation of nano-silicon in priming solution, in an appropriate concentration, remarkably enhances germination performance and causes an effective invigoration of the seedling. These results underline the importance of pre-sowing seed soaking in diluted nano-silicon solutions for improving the germinability of sunflower.

Yield and Profitability of Groundnut ( Arachis hypogaea L.) as Influenced by Sowing Dates and Nutrient Levels with Different Varieties

Abstract: A field study was conducted to evaluate the date of sowing of groundnut (Arachis hypogaea L.) during kharif 2009 and 2010. Experiment was laid out in split-plot design by assigned dates of sowing (20 April, 15 May, 9 June and 4 July) and varieties (‘HNG 10’ and ‘TG 37A’ ) in main plots and four fertility levels (without fertilizers, 20 N + 40 P2O5, 30 N + 60 P2O5 and 40 N + 80 P2O5 kg /ha) in sub-plots. Yield components of semi-spreading variety ‘HNG 10’ were statistically at par with each other at different dates of sowing from 20 April to 9 June. Harvest index in both the varieties was observed significantly higher in 4 July sowing. The results of the study showed that significantly higher crop stand at harvest was observed in 9 June and 4 July sowing than all other sowing dates and variety ‘TG 37A’ flowered significantly earlier than ‘HNG10’. Significantly higher yields were recorded in 30 kg N+60 kg P2O5 /ha which was statistically at par with 40 kg N+80 kg P2O5 /ha. On the basis of economics, variety ‘HNG 10’ of groundnut recorded significantly higher net return (61843/ha) when sown on 9 June.

Glyphosate-Resistant Palmer Amaranth (Amaranthus palmeri) Morphology, Growth, and Seed Production in Georgia

Abstract: Herbicide-resistant Palmer amaranth has become the most economically detrimental weed of cotton in the southeast United States. With the continual marginalization of potential herbicide tools, research has expanded to include alternative means of affecting future Palmer amaranth populations by altering safe sites and reducing inputs to the seedbank population. The influence of delayed Palmer amaranth establishment on seed production potential has not been investigated in the southeast United States. Studies were conducted to evaluate the influence of time of Palmer amaranth establishment on morphology, growth, and seed production. The experiment was a factorial, with five levels of Palmer amaranth transplanting (0 to 12 wk after cotton planting) and two levels of crop type (cotton and noncrop). In the absence of crop competition, the first cohort of Palmer amaranth produced 446,000 seeds per plant. This potential seed production was reduced 50% when Palmer amaranth plants were established nearly 6 wk later. In contrast, the first Palmer amaranth cohort growing in competition with cotton produced 312,000 seeds, 30% less than was produced in the absence of competition. Interference from cotton shifted time to 50% seed production to nearly 4 wk earlier in the growing season, relative to plants without crop competition. Delayed establishment of Palmer amaranth simulates premature loss of herbicide efficacy and alters the competitive balance between cotton and Palmer amaranth. Although the planting time that resulted in 50% reduction in Palmer amaranth plant height at the end of the season was not affected by the presence of cotton, 50% reduction in plant width and biomass occurred within the first 3.8 wk of the growing season when growing with cotton, more than 4 wk earlier than Palmer amaranth growing without a crop. This suggests that early season weed control programs will have a large effect on Palmer amaranth potential growth and seed production, as well as crop yield. To implement soil seedbank reduction strategies effectively, information on mechanisms that regulate Palmer amaranth persistence in the soil seedbank is needed.

Interference and economic threshold level of little seed canary grass in wheat under different sowing times.

Abstract: Little seed canary grass (LCG) is a pernicious weed of wheat crop causing enormous yield losses. Information on the interference and economic threshold (ET) level of LCG is of prime significance to rationalize the use of herbicide for its effective management in wheat fields. The present study was conducted to quantify interference and ET density of LCG in mid-sown (20 November) and late-sown (10 December) wheat. Experiment was triplicated in randomized split-plot design with sowing dates as the main plots and LCG densities (10, 20, 30, and 40 plants m(-2)) as the subplots. Plots with two natural infestations of weeds including and excluding LCG were maintained for comparing its interference in pure stands with designated densities. A season-long weed-free treatment was also run. Results indicated that composite stand of weeds, including LCG, and density of 40 LCG plants m(-2) were more competitive with wheat, especially when crop was sown late in season. Maximum weed dry biomass was attained by composite stand of weeds including LCG followed by 40 LCG plants m(-2) under both sowing dates. Significant variations in wheat growth and yield were observed under the influence of different LCG densities as well as sowing dates. Presence of 40 LCG plants m(-2) reduced wheat yield by 28 and 34% in mid- and late-sown wheat crop, respectively. These losses were much greater than those for infestation of all weeds, excluding LCG. Linear regression model was effective in simulating wheat yield losses over a wide range of LCG densities, and the regression equations showed good fit to observed data. The ET levels of LCG were 6-7 and 2.2-3.3 plants m(-2) in mid- and late-sown wheat crop, respectively. Herbicide should be applied in cases when LCG density exceeds these levels under respective sowing dates.

Physiological Strategies to Improve the Performance of Spring Maize (Zea mays L.) Planted under Early and Optimum Sowing Conditions.

Abstract: Low temperature at stand establishment and high temperature at reproductive stage are involved in reduction of grain yield of spring maize. A field study was therefore conducted to evaluate different physiological strategies for improving performance of spring maize under temperature extremes. Seed priming and foliar spray with 3% moringa leaf extract (MLE) and 100 mg L-1 kinetin solution alone or in all possible combinations with each other at three growth stages (knee height, tasseling and grain filling stage) and hydropriming was compared with control. Seed priming plus foliar spray of MLE and kinetin significantly improved stand establishment especially under early sown crop as indicated by reduced mean emergence time (MET), improved emergence index (EI) and final emergence percentage (FEP). Similarly increased chlorophyll contents, crop growth rate, leaf area index, photosynthetic rate, transpiration rate, relative water content and decreased membrane permeability were recorded in both early and optimum sowing conditions in MLE priming plus foliar spray treatment. All these improvements were harvested in the form of increased yield and harvest index compared with control treatment. Overall crop sown at optimum time performed best but exogenous application of MLE through seed priming and foliar spray maximally improved the performance of early sown maize crop which is attributed more likely due to improved stand establishment, chlorophyll and phenolic contents, increased leaf area duration and grain filling period. It can be concluded that seed priming with MLE along with its foliar spray could increase production of maize under temperature extremes.