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The appropriate fire return interval of prescribed burns is critical in many fire-driven systems. I use a mediterranean-type ecosystem – Cape fynbos, South Africa – to test guidelines for fire return intervals. Guidelines state that at least 50% of a population of the slowest-maturing obligate seeder Protea species must have flowered for three successive seasons, or that 90% of individuals from the slowest-maturing Protea species must have flowered at least once before a fire occurrence. Whether these ‘rules of thumb’ will lead to similar fire return intervals for prescribed burns is unknown. I address this by assessing two obligate seeding Protea species for length of juvenile period and age at three times flowering at 17 sites across a conservation area. For the slowest maturing species, when 50% of the fastest-maturing population had flowered three times (at 11 years), no individuals had flowered three times (happens at 14 years) in the slowest-maturing population. Using the 90% rule, this was reached at 9 years in the fastest-maturing P. neriifolia population and 11 years in the slowest-maturing. The 50% rule is more conservative than the 90% rule and is preferred. I highlight the importance of testing guidelines for fire return intervals to ensure effective biodiversity conservation.

A field study was carried out to assess the performance of power tiller operated seeder (PTOS) and to compare the yield, quality, maturity and economic traits of onion under different planting methods at Spices Research Sub-Centre (SRSC), Bangladesh Agricultural Research Institute (BARI), Faridpur, Bangladesh with four planting methods as four treatments: T1) ploughing the main field with high speed rotary tiller (HSRT) + direct seeding with power tiller operated seeder (PTOS), T2) ploughing the main field with HSRT + transplanting of seedlings, T3) ploughing the main field with HSRT + direct seeding in line and T4) ploughing the main field with HSRT + direct seeding as broadcasting. Under the study the treatments were arranged in a randomized complete block design with three replications. The outcome of the study revealed that the treatments had a significant influence on the characteristics studied accept yield of onion. Different economic traits of onion were varied among the planting methods. The bulbs under direct seeding with the PTOS matured earlier (133.66days) as compared to the transplant (155.54days). All direct seeding methods showed insignificantly higher yields than that of transplants. The maximum yield (15.05t/ha) was recorded from broadcasting method. The yield performance under direct seeding with the PTOS and transplants were 15.08 and 14.92t/ha, respectively. The broadcasting method had very heterogeneous and under-sized bulbs due to uneven spacing and maximum plant population per unit area. In case of economic performance, transplanting method incurred the highest total cost of production. Maximum net return and benefit-cost ratio (2.95) were calculated from direct seeding with PTOS. So, it is concluded that in Bangladesh, direct seeding method with the PTOS may be a good option for getting early crop and maximum economic benefit.

One of the most important stages of growing small-seeded crops in breeding is the sowing of seeds. Sowing should provide the most favorable conditions for seed germination and further plant development, which increases field germination and yield of breeding crops. One of such conditions is the uniformity of seed distribution in a row, which should be for breeding crops - 99.9%. According to the results of the analysis of the constructions of the existing sowing machines, their classification on the basis of the principle of operation of the machines and design features of the sowing mechanisms has been supplemented. As a result of patent information analysis, it was found that electromechanical sowing machines are the most effective during selective sowing of small-seeded crops, as they provide a sufficiently high seeding accuracy and have promising opportunities to change varieties directly during sowing in different areas. The analysis of the work of the sowing system "Maple" allowed to form the main ways of its improvement: it is necessary to improve the working body of the sowing machine to ensure the accuracy of sowing of small-seeded crops at the level of 99.9%; for sowing in areas of pre-seed production it is necessary to provide automatic loading of seeds of different varieties into the sowing machine; needs to improve the sowing system in areas of pre-seed production, taking into account GPS-tracking; the elements of the seeding system must be block for easy replacement in case of failure. To solve the set problems, the constructive-technological scheme of the sowing apparatus of the selection seeder of small-seeded crops is substantiated, which allows to fully automate the sowing process on the plots of pre-seed production almost without the breeder's participation with high seeding accuracy.

Rice residue management (RRM) has been the key component of systems’ sustainability. The paper reports the effect of different RRM and wheat (Triticum aestivum L.) establishment methods on productivity and yield contributing attributes through farmer participatory mode in south-western Punjab. Different RRM technologies including rice residue removal, residue incorporation and residue retention on soil as surface mulch were evaluated. Wheat grain yield was significantly (p

Highlights Soil type, operational speed, machinery weight, and power size affected corn seeding rate and seeding efficiency Corn growth and yield was affected by seeder type, so utilization of appropriate machinery is very important Having cover crop residue on the land can maintain soil moisture for a longer time than tilled land Abstract.Conservation agriculture (CA) is gaining popularity in Cambodia to sustain soil fertility, productivity, and profits. However, the adoption remains slow due to the low engagement so far of local services into CA machinery and technology. Therefore, this paper aimed to compare different no-till seeders and residue retention methods for corn (Zea mays L.) sowing and to determine their effects on growth and yield. The experiment was conducted in Rattanak Mondul District, Battambang Province, in the wet season of 2019. Sunn hemp (Crotalaria juncea L.) was grown as a cover crop for 74 days prior to corn. Each main plot was 14 × 34 m and was subdivided lengthwise with 4.0-m buffers for operations of two different seeders, namely one-row Morrison seeder mounted on 14 kW Oggun tractor and four-row Brazilian seeder mounted on 56 kW John Deere tractor. The results show that using Brazilian seeder saved around 50% of seed and 80% of time, when compared with Morrison seeder. Plant population, plant diameter, and kernel characteristics were also significantly greater with Brazilian seeder, when compared to the Morrison seeder. A combination of the Brazilian seeder and Cambodia made crimper plots had larger ear size and weight. Volumetric Moisture Content (VMC) was significantly affected by residue retention with higher VMC for rolled and crimped residue compared to disked/incorporated residue. The study demonstrates that using no-till equipment such as roller crimpers and no-till planters is feasible in Cambodia’s small farming systems although more research is needed to study long-term effects on crop yields and soil health. Keywords: Battambang Province, Conservation agriculture, Green manure, Soil improvements

Aim. The aim of the article is to describe lentil seeds as an essential source of nutrition for the population of our planet; substantiate the need to introduce this crop to rotation in arid conditions of the steppe zone of Ukraine. Methods. Field research was conducted in the central area of Odesa region, which is characterized by high air temperatures and a significant deficit of soil moisture. Accessions were sewn by hand in two-meter rows, the control nursery – by a breeding seeder „Klen-1.5C”. During the growing season, the dates of emergence, the beginning and end of flowering, full ripening, resistance to disease and lodging were noted. In the laboratory, the estimated plants' height, the number of the first and second-order branches, the number of beans and seeds per plant, and the mass of seeds per plant were evaluated in the collected cultivars. Results. Based on a three-year study, significant genetic variability in the duration of the growing season and its phases, elements of productivity, resistance to lodging and disease were identified. The most effective forms that come from different countries had been described. Attention is paid to the Canadian gene pool of lentil, which was distinguished by high seed productivity, drought resistance, increased attachment of the lower beans from the soil surface. The results of competitive variety testing of the best forms are given, which testify to the significant prospect of lentil in the steppe zone. Conclusions. Among the 290 foreign accessions of lentil, sources with a set of economically valuable traits were identified. We recommend to use them as parental forms for creating a new breeding material.

Maize is one of the most growing crops in Bangladesh. Sowing of maize seed is a time consuming, labor oriented and tedious operation. To overcome the problems in maize cultivation, a power operated maize seeder was designed and fabricated in the Department of Farm Power and Machinery in Bangladesh Agricultural University. A 24 volt DC motor worked as power unit. The speed of the seeder was fixed with an accelerator governing by a motor controller unit. Power transmission system was chain and sprocket for drive wheel and gear pinion system to operate the seed 12-cell plate type seed metering device at a revolution ratio of 1:1.3. The machine possesses an effective field capacity of 0.119 ha/h, field efficiency of 85.86%, average distance of dropping seed 21.29 cm and an average missing rate of 2.78%, respectively. Fabrication cost of the seeder excluding battery was USD 142.85. Financial analysis of the seeder revealed that business by this machine is profitable as the BCR and IRR was found to be 1.54 and 230% with a payback period of 0.43 years if bank interest rate is 12%. Results also revealed that the machine would be profitable if it can sow in more than 4.95 ha of land per year. The effectiveness of sowing and financial analysis predict that the machine can be a better option for marginal farmers in sowing maize with less labor orientation and ease of operation securing production cost. [J Bangladesh Agril Univ 2020; 18(4.000): 1065-1072]

The current paper has presented the study results of correlation between productivity and morphobiological traits of the collection peas samples. The study was carried out at the FSBSI “AgriculturalResearchCenter“Donskoy”, located in the southern part of theRostovregion. The purpose of the study was to analyze the correlation between the quantitative traits of collection peas samples and their productivity. The study of the pea collection was conducted in the collection nursery of pea in 2017–2019, in accordance with the IPI methodology for the study of legumes (1975), the methodology of the State Commission for Variety Testing of Agricultural Crops (2019) and the methodology of a fi trial (2012). The objects of the study were 100 samples of pea of domestic and foreign breeding taken from the world collection of VIGR named after N. I. Vavilov. The variety “Aksaysky Usaty5”was used as a standard variety. The forecrop was winter wheat. The sowing of the collection samples was carried out in the third decade of March with the SSFK-7 seeder, with a seeding rate of million germinating seeds per1 ha, with a row width of15 cm. The plots contained seven rows. The plot area was5 m2 with a single repetition. The registration plot was0.25 m2. There has been identifi that in 2017-2019 the average productivity ranged from 1.12 t/ha (“Omega”,Moldova) to 2.82 t/ha (“Kazanets”, Rossiya) with average 2.13 t/ha in the collection. The most productive samples were plants with a plant height of 45–55 cm, an average number of beans 2.7–3.3 pcs/plant, 1000 seed weight of 210–270 g, a vegetation period of 69–73 days, and seed weight per plant of 3.3–4.3 g, an average number of seeds 13–19 pcs/plant. The study results of correlation between productivity and morphobiological traits of the collection peas samples are going to be used as an initial material in further breeding work.

Background. Spring bread wheat is the main export crop in Kazakhstan. Unfortunately, wheat varieties cultivated for large-scale production do not fully meet the requirements of agricultural producers. The world diversity of wheat genetic resources should be widely used in breeding programs in order to develop new wheat cultivars with stable yields and with resistance to adverse environmental factors.Materials and methods. One hundred collection accessions of spring bread wheat were studied in 2015–2017 at the A.I. Barayev Science and Production Center of Grain Farming, Ltd. Seeds were sown at an optimum time (May 20–25), using an SSFC-7 seeder. Harvesting was conducted with a Wintersteiger combine. The study of the collection material was carried out in accordance with the guidelines developed by the N.I. Vavilov Institute of Plant Genetic Resources (VIR). The protein content was measured in line with State Standard 10846-91. The method of sodium dodecyl sulfate (SDS) sedimentation, modified by V. M. Bebyakin and M. V. Buntina, was used to measure the level of sedimentation.Results and conclusion. During the three-year study of spring bread wheat accessions in Northern Kazakhstan, only the cultivars ‘Shortandinskaya 2012’ and ‘Astana 2’ exceeded the reference ‘Astana’ in yield. The accessions ‘BW 252’, ‘Neepawa’ (Canada), ‘MANITUOU LR 13’ (CIMMYT, Mexico) and ‘Novosibirskaya 29’ (Russia) ripened 1–2 days earlier than the reference, while their average yield for 3 years was almost on the same level with the reference. The cultivars ‘Astana’ (the reference, Kazakhstan), ‘WA007824 WA7824’ (USA), ‘Novosibirskaya 29’, ‘Novosibirskaya 15’ (Russia), ‘OPATA85 LR10’ and ‘LR27+LR31,LR34’ (CIMMYT, Mexico) were distinguished for grain quality due to their high protein content and the level of sedimentation.

Field testing against pod borer and pod fly of 30 genotypes and cultivars revealed that RPS 2008-5, RPS 2008-4, and RPS 2007-109 were less infested by pod borer complexes and pod fly and produced higher grain yields. There was no significant relationship noticed between plant height, growth habit, pod length, pod breadth & days to maturity and borer complex and pod fly infestation, whereas, highly negative correlation was observed between morphological characters viz. pod wall thickness, calyx trichome length, calyx trichome density and pod trichome density against pod borer and pod fly infestation.

It is necessary to use new technologies to mitigate water scarcity in the semi-arid region. As such, the aim of this study was to evaluate the operational and energy performance of a ridge planter and fertiliser, as well as the deposition depth of maize seeds and fertiliser as a function of the sowing system, and the use of different furrowing mechanisms (disc and shank) for depositing fertilisers. The experimental design was of randomised blocks, in a 6 x 2 factorial scheme with four replications, including six sowing systems: (S1 - intercropped ridge-sown maize; S2 – monocropped ridge-sown maize; S3 - intercropped furrow-sown maize; S4 – monocropped furrow-sown maize; S5 - conventional intercropping system; S6 - conventional monocropped system) and two mechanisms for depositing the fertiliser (offset double disc and shank furrower). The statistical analysis was carried out using the SISVAR software at 5% significance. It was concluded that, irrespective of the sowing system (ridge or furrow) and mechanism employed, there is no difference in the initial plant population or in the depth of the maize seeds. However, greater attention must be paid to the depth of both the fertiliser and forage seeds when these are deposited at the same time. Sowing systems that turn the soil (furrow and ridge) consume more energy, as does the shank mechanism. Sowing system S5 affords better operating performance when used together with the disk mechanism. RESUMO A escassez hídrica na região semiárida deve ser mitigada com novas tecnologias. Diante disto, objetivou-se com o presente trabalho, avaliar o desempenho operacional e energético de uma semeadora adubadora camalhoeira, bem como a profundidade de deposição de semente de milho e fertilizante em função do sistema de semeadura e do uso de mecanismos sulcadores para deposição de fertilizantes (Disco e haste). Foi utilizado delineamento experimental em blocos casualizados, em esquema fatorial 6 x 2 com 4 repetições, com seis sistemas de semeadura: (S1 - semeadura do milho em consórcio em cima do camalhão; S2 - semeadura do milho em camalhão sem consórcio; S3 - semeadura do milho em consórcio dentro do sulco; S4 - semeadura do milho dentro do sulco sem consórcio; S5 - semeadura convencional em consórcio; S6 - semeadura convencional sem consórcio) e dois mecanismos para deposição de fertilizantes (disco duplo desencontrado e haste sulcadora). A análise estatística foi realizada utilizando o programa SISVAR a 5% de significância. Foi possível concluir que independente do sistema de semeadura (camalhão ou sulco) e mecanismo usado, não haverá diferença na população inicial de plantas e profundidade da semente de milho. No entanto, é necessário maior atenção na profundidade do fertilizante e semente de forrageira quando depositados juntos de maneira momentânea. Os sistemas de semeadura que mobilizam o solo (sulco e camalhão) apresenta maior consumo energético, assim como o mecanismo haste. O sistema de semeadura S5 apresenta melhor desempenho operacional, juntamente com o mecanismo disco.

Establishment of switchgrass (Panicum virgatum L.) is challenging, and failure in establishment may expose growers to considerable economic risk. The objectives of this research were to (i) evaluate whether management practices are variety-specific for the establishment of switchgrass and (ii) assess the effectiveness of cover crops as preceding crops on ‘Shawnee’ switchgrass establishment. Therefore, two studies were conducted at the University of Massachusetts Agricultural Experiment Station in Deerfield, MA, USA, in the 2011–2012 and 2012–2013 growing seasons. In Experiment 1, cover crop treatments (fallow, oat (Avena sativa L.) and rye (Secale cereale L.)) were the main plots, the two seeding methods (no-till drill and a cultipacker seeder (Brillion)) were the sub-plots, and the two varieties (‘Cave-in-Rock’ (CIR) and Shawnee)) were the sub-sub-plots. The second study was conducted using Shawnee switchgrass and involved the three cover crop treatments used in Experiment 1 using a cultipacker seeder with seed firming prior to planting but not afterwards (consistent in both experiments). The results indicated that a combination of oat and no-till resulted in higher tiller density (493%), lower weed biomass (77%), increased switchgrass biomass (SGB) (283%) and SGB to weed biomass (WB) ratio. Compared with Shawnee, CIR planted into a winter-killed oat residue had higher tiller density (93%), lower weed biomass (18%), higher switchgrass yield (128%) and thus a greater SGB:WB ratio (507%). Trends of switchgrass response to management practices, however, were similar between the two varieties, indicating that seed quality rather than management practices could influence switchgrass’s response to management practices. In Experiment 2, Shawnee tiller density was suppressed by rye as the preceding crop, possibly due to late termination of rye. Shawnee switchgrass yields were below 1000 kg ha−1 under all management practices, thus, harvesting should happen in the year following establishment. Future research should focus on comparing no-till drilling with cultipacker seeder with rolling not only before but after seeding to increase seed–soil contact.

Coniothyrium Minitans is a kind of biological fungicide with high control effect against Sclerotinia sclerotiorum. There is a potential and simplification method to deliver a mixture of compound fertilizer and Coniothyrium Minitans powder into seedbed simultaneously with rape seed by using combined seeder.For this purpose, the special slow-releas fertilizer, common compound fertilizer and Coniothyrium Minitans powder were taken as the research objects and the triaxial size, hygroscopicity, friction coefficient and caking property of the fertilizers and the mixture of the fertilizer and the powder were measured by the determinator for agricultural materials. The results showed that the natural repose angle of special slow-release compound fertilizer, common compound fertilizer and Coniothyrium Minitans powder was 30.45 °, 32.20 ° and 44.88 ° respectively. The static friction coefficient with iron plate was 0.35, 0.41 and 0.70, which was similar with the acrylic plate that was 0.45, 0.57 and 0.70. The moisture absorption ratio of special slow-release compound fertilizer, common compound fertilizer and Coniothyrium Minitans was 0.213%, 0.287% and 0.267% respectively in ten to twenty minutes. While later twenty minutes the ratio beginning to change, the average increment of moisture absorption ratio was 0.006% 、 0.287% and 0.015%, respectively. The natural repose angle and static friction coefficient of the mixture increased with the increase of the addition of Coniothyrium Minitans. Although the moisture absorption of the mixture increased gradually with growth over time, it was significantly lower than the bare fertilizer in the first twenty minutes, which indicated that Coniothyrium Minitans could be effectively inhibited the moisture absorption of fertilizer. This study provided a reference for using the fertilizer and powder mixture by employed a combined seeder for rapeseed.

Purpose and objectives - to determine the breeding value of spring barley cultivars and lines.Materials and methods: Twenty-two cultivars and 3 lines of spring barley were taken as the test material. The field experiments were carried out in the competitive variety trial nursery in compliance with the method of state variety trials. The forecrop was grain pea. The plot area was 10 m2; the experiments were carried out in 4 replications. Barley was sown with a breeding seeder SSFK-7. The yield, growing period length, lodging resistance, performance and its structural elements were determined. Calculus of variations analysis of variance were performed in STATISTICA 10 and EXCEL as BA Dospekhov described.Results and discussion: The peculiarities of 22 cultivars and 3 lines of spring barley were described by expression levels of the following quantitative traits: morpho-biological (performance, total and productive tillering capacity, spikelet and grain number per spike, spike length, grain weight from the main ear and lateral stalks) and economic (yield, growing period length, lodging resistance) ones.The variability of quantitative traits of the accessions under investigation was determined. In particular, the plant height variability was low (9.5%), the spike length and grain weight from the main spike variabilities were medium (15.6 and 19.5%, respectively), and the variability of other traits were high.The analysis distinguished intensive high-yielding cultivars Margret, Grace, Avhur, Datcha, Khors, and Troian and the line 14-561 (5.07–4.84 t/ha); lodging-resistant cultivars Amil, Troian (Lider), Datcha, and Grace and line 15-139; and high performance cultivars Amil, Khors, Hatunok, Akhiles, and Krasen.Conclusions. As a result of determining the characteristics of the spring barley accessions with high levels of expression of quantitative morpho-biological and economic traits, the breeding value of cultivars and lines suitable for combination breeding was evaluated.

Rice (Oryza sativa L.) production in South Asia is increasingly threatened by the erratic nature of onset of monsoon rain and climate change. Wide variance in rainfall pattern affects the timing of nursery raising and transplanting later in the main field. Existing rice cultivation practices such as direct seeded rice using drum seeder (DSR), system of rice intensification (SRI) and conventional transplanting (CT) are not able to address the production problems adequately. Therefore, we developed a package of practices - Climate Change-Resilient Rice Production Technology (CRRPT) - which allows keeping rice seedlings in the seedbed for an extended period to synchronize with the onset of monsoon rain. On-station trials during 2015-2016 comparing CRRPT with DSR, SRI and CT demonstrated that in CRRPT the seedlings can be maintained successfully in the seedbed for up to 55 days while achieving the equivalent yield of CT (30 days seedling) because of improved plant vigour. The CRRPT seedlings of 25 d and 35 d gave 22% and 11% more yield compared to CT (30 d seedling). Total water requirement in CRRPT was reduced by 20%, 14% and 13% in case of 55d, 45d and 35 d seedling, respectively, compared to that for CT (30 d seedling). In an on-farm study with 120 farmers’ fields in West Bengal during 2017-2018, average yield increased by 32% and net profit increased by 96%. Thus, CRRPT is remunerative, water efficient, climate change-resilient and can be easily adopted in the farmers’ fields. Results demonstrate that there is wide scope for its adoption for sustainable rice production in West Bengal and South Asia.

Small‐seeded species are an integral component of many natural systems. However, small‐seeded species are often omitted from restoration projects due to limited flow through seeders, low broadcast distance, and inconsistent seeding rates. To address these problems, we developed a novel technique within a rotary coater that allows for the conglomeration of small, low‐purity seeds using a combination of clay, compost, water, and a polymer binder. We used Wyoming big sagebrush (Artemisia tridentata ssp. wyomingensis), which has a seed size of approximately 1 mm or less, as a model species to evaluate the technology. We demonstrated improved flowability of conglomerates over untreated (control) seeds through measurements of the Hausner ratio (8% decrease), the angle of repose (21% decrease), and delivery through a broadcast seeder. Seeding rates of conglomerated seed were more consistent than control seed over rugged terrain. Conglomerates were also broadcast 2.2 times further than control seed, which may mitigate the overall cost of implementing this technology. Laboratory trials demonstrated that the final germination of conglomerated seed averaged 15% higher than control seed. Field trials at two sites demonstrated that seedling emergence was similar for control and conglomerated seed. With no deleterious effects observed from the conglomeration treatment, additional research is merited for using conglomerates as a platform to apply various additives, such as fungicides, plant growth hormones, fertilizers, and biologicals. The potential outcomes of these strategies may have a significant impact on future seeding attempts by improving seed delivery and increasing overall seeding success.

Goal. To develop on the basis of complex system of observations, estimation of agroclimatic indicators, patterns of growth and development of plants of the first and second years of life, adaptive technology of growing mother roots and seed bearers under the conditions of the Central Forest Steppe of Ukraine. Methods. Laboratory, field, statistical. Results. The biological potential of modern varieties and hybrids of fodder beet to some extent is realized by using high quality seeds, which is caused by a complex of ecological-biotic and anthropogenic factors. Important factors affecting seed quality have been identified: laboratory and field germination. Its level depends on the duration of emergence and completeness of the seedlings, the uniformity of plants in the row and, ultimately, their seed productivity. The calculations of the main indicators of adaptive technology of cultivation of mother roots and seed bearers are the following: the yield of mother roots increased by 2.7 times, the preservation in storage by 7.7%, seed yield by 0.4 t/ha, germination by 8%, weight of 1000 seed clusters by 1.2 g compared to conventional technology. Conclusions. The cultivation of mother roots and seed bearers of fodder beet varieties and hybrids should be carried out according to adaptive technology, which provides: 1) sowing of seeds in the summer (early-mid June) with SST-12B seeder with a device for simultaneous separation of the main seeds by specific weight, 15–20 seeds/m, with an interval of 22.5 cm; 2) storage of mother roots in storages and containers equipped with plastic film with holes; 3) using planter VPS-2,8A and seeding on the background of 50 t/ha of manure + and design 70 × 20–70 × 30 cm; 4) seed treatment during mass formation of the stem; 5) additional pollination during the mass flowering period.

In order to meet the demand for mechanized seeding of special vegetables such as sprout seedling vegetable, this paper designs a small sprout seedling vegetable planter based on the design experience of the existing suction seeder. the machine is mainly composed of a box, a seedling tray pushing device, a seed pushing device, a seeding device, and a control system. according to this design, the prototype of the small sprout seedling vegetable planter is made. the test results show that the machine can realize the mechanized seeding of sprout seedling vegetables, with reliable work and easy operation. at the same time, the machine also has the advantages of simple structure and easy maintenance. this machine fills the gap in the field of sprout seedling vegetable seeding, and has broad promotion value in the field of large-scale production of sprout seedling vegetables.

Horizontal transmission of opportunistic Escherichia coli during hatch can have detrimental effects on early performance, particularly as pioneer colonizers. Commercially, formaldehyde is often applied in the United States to combat the bacterial bloom that occurs inside of the hatching environment. The purpose of these experiments was to develop a replicable E. coli horizontal challenge model to evaluate alternatives to formaldehyde sanitation applied to the hatching environment. In experiment 1, two trials were conducted for 2 wild-type (WT) E. coli isolates (isolate 1 [I1] or isolate 2 [I2]) to determine the appropriate in ovo challenge dose and day of embryogenesis (DOE) for challenge administration. In experiment 1 trial 1, the most appropriate inoculation dose and time point were determined to be 102 cfu/embryo on DOE 19. Experiment 1 trial 2 evaluated whether placement of seeder (direct-challenged) embryos with contact (indirect-challenged) embryos during hatch affected contact hatchability. Trial 2 showed no differences in hatchability between groups. A 7-day experiment (experiment 1 trial 2) was conducted to evaluate the effects of I1 or I2 on horizontal transmission, gram-negative bacterial (GNB) recovery from the gastrointestinal tract (GIT), and impact on BW gain (BWG). Compared with the negative control, seeder, and contact chicks challenged with I1 or I2, we observed increased (P

The use of native grasses for both restoration and commercial purposes is becoming increasingly important globally. Many native grasses have limited success in seed‐based restoration (e.g. post‐mine rehabilitation) and commercial industries (e.g. agriculture) due to poor seed germination and handling. Seed‐enhancement technologies can assist in overcoming these barriers. This study aimed to use combinations of seed enhancements to overcome the germination and handling challenges in two dominant Australian native grass species with demand in restoration and commercial industries (Triodia wiseana C.A Gardner and Rytidosperma caespitosum [Gaudich.] Connor & Edgar). Selected enhancements included hydropriming (including inoculation with karrikinolide [KAR₁]), flash flaming, and seed coating. Combinations of these seed enhancements allowed improvements in both germination (by up to 55% and 18% for T. wiseana and R. caespitosum, respectively) and floret geometry (flowability, as measured through a mechanized seeder, improved by up to 6‐fold and 17‐fold for T. wiseana and R. caespitosum, respectively), with the order of enhancement application being important. The responses of each species to enhancements corresponded with key biological processes and ecological cues required for recruitment events in nature, such as fire and rainfall events. Triodia wiseana germination was driven by fire‐related cues (i.e. KAR₁, flaming), while R. caespitosum germination was highest in response to moisture‐related cues (i.e. hydro‐priming). Responses to seed enhancements (and combinations of) may have implications for the management and scaled use of the targeted species. This can assist in improving the restoration and commercial success of the study species, and potentially other grasses with germination and handling challenges, into the future.

Plant populations persist under recurrent fire via resprouting from surviving tissues (resprouters) or seedling recruitment (seeders). Woody species are inherently slow maturing, meaning that seeders are confined to infrequent fire regimes. However, for grasses, which mature faster, the relationships between persistence strategy and fire regime remain unknown. Globally, we analysed associations between fire regimes experienced by hundreds of grass species and their persistence strategy, within a phylogenetic context. We also tested whether persistence strategies are associated with morphological and physiological traits. Resprouters were associated with less frequent fire than seeders. Whilst modal fire frequencies were similar (fire return interval of 4–6 yr), seeders were restricted to regions with more frequent fire than resprouters, suggesting that greater competition with long‐lived resprouters restricts seeder recruitment and survival when fire is rare. Resprouting was associated with lower leaf N, higher C:N ratios and the presence of belowground buds, but was unrelated to photosynthetic pathway. Differences between the life histories of grasses and woody species led to a contrasting prevalence of seeders and resprouters in relation to fire frequency. Rapid sexual maturation in grasses means that seeder distributions, relative to fire regime, are determined by competitive ability and recruitment, rather than time to reproductive maturity.

The colonization of broilers with extended-spectrum β-lactamase- (ESBL-) and plasmid-mediated AmpC β-lactamase- (pAmpC-) producing Enterobacteriaceae has been extensively studied. However, only limited data on intervention strategies to reduce the colonization throughout the fattening period are available. To investigate practically relevant management measures for their potential to reduce colonization, a recently published seeder-bird colonization model was used. Groups of 90 broilers (breed Ross 308) were housed in pens under conventional conditions (stocking of 39 kg/m2, no enrichment, water and feed ad libitum). Tested measures were investigated in separate trials and included (I) an increased amount of litter in the pen, (II) the reduction of stocking density to 25 kg/m2, and (III) the use of an alternative broiler breed (Rowan x Ranger). One-fifth of ESBL- and pAmpC- negative broilers (n = 18) per group were orally co-inoculated with two E. coli strains on the third day of the trial (seeder). One CTX-M-15-positive E. coli strain (ST410) and one CMY-2 and mcr-1-positive E. coli strain (ST10) were simultaneously administered in a dosage of 102 cfu. Colonization of all seeders and 28 non-inoculated broilers (sentinel) was assessed via cloacal swabs during the trials and a final necropsy at a target weight of two kilograms (= d 36 (control, I-II), d 47 (III)). None of the applied intervention measures reduced the colonization of the broilers with both the ESBL- and the pAmpC- producing E. coli strains. A strain-dependent reduction of colonization for the ESBL- producing E. coli strain of ST410 by 2 log units was apparent by the reduction of stocking density to 25 kg/m2. Consequently, the tested management measures had a negligible effect on the ESBL- and pAmpC- colonization of broilers. Therefore, intervention strategies should focus on the prevention of ESBL- and pAmpC- colonization, rather than an attempt to reduce an already existing colonization.

Background Administration of a competitive exclusion culture (CE culture) has the potential to induce protective effects in very young chicks against caecal colonisation by EEC (= extended-spectrum β-lactamases [ESBL] and AmpC-type [AmpC] beta-lactamases producing Escherichia coli). The study aimed to verify the protective capacity of a CE culture in broilers using the seeder bird model against EEC exposure of the chicks. Results Introduction of infected seeder birds resulted in rapid and strong caecal colonisation of four different EEC challenge strains tested in untreated contact broilers. Compared to controls the broilers pre-treated with the CE culture showed a considerable decrease in caecal load of different EEC challenge strains from about 3.0–3.5 log10 units (P 10 units (P Conclusions Our findings suggest that CE cultures of undefined composition can be valuable to reduce the intestinal colonisation by EEC in newly hatched broilers.

In view of the uneven artificial sowing, low sowing, as well as the fact that the existing seeders cannot meet the sowing requirements of Pteris vittata, this paper designed an automatic plug seeder by using the method of spraying and sowing after mixing spores and water. In order to obtain the optimum working parameters of the seeder, response surface method (RSM) was employed to design the experiments and evaluate the results with the purpose of optimizing parameters for improving spraying uniformity. The parameters such as the distance between the nozzle and plug and the nozzle angle and transmission speed were selected, and then the regression equation of spraying uniformity was established. The results showed that the influence of various factors on spraying uniformity coefficient from high to low were nozzle angle, distance between the nozzle and plug and transmission speed. Through the experimental analysis, it can be concluded that when the distance between the nozzle and plug was 11.63 cm, the nozzle angle and the transmission speed were 79.23° and 0.21 m/s, respectively; the seeding uniformity coefficient was the largest, 83.43%. The verification test results indicated that the optimized result was reliable. This study can provide reference for the development of micro seed seeder.

Efficacy ofBovi-Shield GOLD® FP® 5 VL5 in heifers at five to seven months of gestation was evaluated following exposure to seeder calves persistently infected (Pl) with bovine viral diarrhea virus (BVDV) type 2., American Association of Bovine Practitioners Proceedings of the Annual Conference, 2006

Climate change is expected to alter disturbance regimes including fires in European beech (Fagus sylvatica L.) forests. Regarding the resilience of beech forests to fire it is questionable whether seeds of this non-serotinous obligate masting seeder find advantageous conditions in a post-fire environment. The probability of recruitment success has been shown to increase when fire coincides with a mast year. However, the fire-induced recruitment window is poorly defined, and it is unclear how other interacting factors influence its duration. We used a space-for-time approach to model the relationships between post-fire beech recruitment, timing of seed mast events, and interacting environmental conditions using a zero-inflated model. Our results show that recruitment peaks 5–12 years after a fire, and continues throughout three decades post-fire. Beech recruitment in the post-fire period is driven by mast intensity interacting with (i) canopy opening as a consequence of progressive post-fire tree mortality and (ii) coverages of competing ground vegetation. Spring-summer moisture showed a weak positive effect on beech recruitment. We conclude that fires increase light availability, which in coincidence with a mast event results in pulses of beech recruitment. The delayed post-fire mortality of beech creates a recruitment window lasting for up to three decades, resulting in a higher-than-expected resilience of beech to individual fire disturbances.

Hardseededness is a common trait in Mediterranean plant communities, although the origin of its selection is controversial. It may be a mechanism of persistence to fire temperatures, but could also form part of a gap-detecting mechanism to provide germination cues under arid conditions. To disentangle this, we studied the phylogenetic structure of plant communities against fire frequency and aridity gradients. The phylogenetic structure in Mediterranean Basin ecosystems was analysed for the hardseededness trait as a whole and was separated by the families composing this trait (Fabaceae and Cistaceae). This study focused on woody perennial species. The phylogenetic structure was also contrasted against soil classes. Hardseededness on the whole, and for the Fabaceae family alone, showed phylogenetic clustering as aridity increased. Cistaceae displayed the opposite pattern with phylogenetic clustering in most humid areas, together with a significant soil effect. Surprisingly, fire frequency had no influence in any case. This climate-driven phylogenetic clustering indicates that the hardseededness trait could confer some fitness advantage under dry conditions. For this reason, coexisting species were more closely related in the community with increasing aridity. This effect was especially evident for the Fabaceae family. These results shed some light on the evolutionary selection of this adaptive trait under Mediterranean conditions. Our results question the role of fire in the selection of the hardseededness trait in Mediterranean Basin ecosystems and indicates that climate is the most important factor. Therefore, we should be cautious in assigning to fire a preponderant role in the selection of some plant traits. This research was financed by the IMAGINA (PROMETEO/2019/110) project. VMS was supported by a “Beatriu de Pinós” fellowship (2014BP-B-00056) from the Generalitat de Catalunya. JGA was supported by a Ramón y Cajal fellowship (RYC-2016-20528). IA was supported by a Horizon 2020 research and innovation programme with Marie Sklodowska-Curie Cofund grant agreement No. 801596.

In order to design a seeder for direct sowing, a seed characterization study was conducted. The objective was to assess the physical, mechanical and kinetic properties of the most cultivated cereals and leguminous in Benin. Two varieties of Zea mays , four varieties of Vigna unguiculata , one variety of Arachis hypogea , one variety of Cajanus cajan and two varieties of Glycine maxwere studied. It was noticeda variation in physical parameters not only between species but also between varieties of the same species. All sphericity coefficients are greater than 0.7 with C. cajan which is more spherical (0.91±0.03) against the DMR ESR-W/QPM and 85 TZSR-W varieties of Z. mays which are the least spherical with 0.72±0.10 and 0.71±0.11 respectively. The rupture force generally increased from 14 to 720 N. Vigna TVX 32-36 is the most resistant with 633.3±75.72 N against 16.0±2.0 N for Arachis TS32-1 the least resistant. Overall, the falling speed decreased from 1.67 to 0 m/s on the rigid PVC, from 1.36 to 0 m/s on the black plate and from 1.67 to 0 m/s on the transparent hose when the angle of inclination increases from 20° to 70° relative to vertical. These parameters are essential for good sizing of the distribution system and the seed descent channels for a seeder. They can also be used for grains calibration and other use in agricultural engineering and food processing. Keywords: Seeds, physical properties, mechanical properties, kinetic properties, Benin

Many important herbs [e.g., mint (Mentha sp.), thyme (Thymus sp.)], underused and nutritious vegetables [e.g., purslane (Portulaca oleracea), amaranth (Amaranthus tricolor)], and important biological control plants [e.g., sweet alyssum (Lobularia maritima)] have small seeds (≤ 1.5-mm long) that are difficult to plant with raw (i.e., nonpelleted) seed using existing seeders. A novel tool known as the slide hammer (SH) seeder was developed for the precise seeding of raw seeds of small-seeded plants. The SH seeder is a jab-type planter made primarily from electrical conduit tubing and other materials that are inexpensive and readily available in a hardware store or on the Internet. The interchangeable seed hopper is made from a plastic snap cap vial that has one or more holes of varying diameter depending on the desired seeding rate and seed size. Seed forms a “bridge” above the hole in the vial until they are dislodged from the force of the SH that discharges seeds to fall to the soil. Detailed plans are provided for how to make and use the SH seeder. The fabrication time is 2 to 4 hours with a material cost of ≈$32. I determined the seed vial hole specifications for the precise seeding of a variety of small-seeded plants, including chives (Allium schoenoprasum), chinese chives (Allium tuberosum), basil (Ocimum basilicum), grain amaranth (Amaranthus sp.), sweet alyssum, purslane, creeping thyme (Thymus serpyllum), and spearmint (Mentha spicata) that ranged in size from ≈200 to 11,000 seeds per gram. The diameter of the hole that was suitable for discharging the seed from the vial was always larger than the average seed length, and the ratio of hole diameter to seed length ranged from 1.07 to 1.62. Seeding rate uniformity evaluations were conducted for these species using vials with one vs. two holes and showed that the seeding rate was higher by an average of 58% to 173% from a vial with two holes compared with one hole. For most plant species evaluated, the SH seeder was able to dispense as few as one to three seeds consistently. Seed discharge increased somewhat with increasing SH weight for all species evaluated. The SH seeder can be useful for interplanting sweet alyssum as an insectary plant for aphid (Aphidoidea) control between existing plants of organic lettuce (Lactuca sativa), and for intercropping cultivars of purslane as a novel vegetable in between transplanted organic broccoli (Brassica oleracea Italica group) plants. This novel seeding tool has many potential uses for direct, hand seeding in vegetable and herb production systems and in weed research trials. The seeder could be automated and made with a variety of alternative materials.

To ensure a given rate of seed soybean seeding, a substantiation of the design parameters of the sowing disk is provided by the nesting method: the number of cells and the distance between the cells, depending on the diameter of the disc and the linear dimensions of the cell. An analytical relationship were obtained to determine the distance between the seeds in the nest and between the nests, depending on the central angles between the centers of the cells in the group and the groups of cells on the lateral surface on the sowing disk, taking into account the seeding rate and the number of cells. The necessary number of cells on the sowing disk its critical linear speed is justified taking into account the seeding machine speed at which the cells are guaranteed to be filled. As a result of the numerical experiment, the following data were obtained: for a given diameter of the sowing disk 0.21m with a cell diameter of 0.008 m and a cell depth of 0.005 m, the total number of cells on the side surface of the disk is 120 pieces, the central angle between the cells in the group is 20, and the central angle between groups of cells is 50. At these values of the design parameters of the sowing disk and the specified soybean seeding rate from 9 to 27 pieces/m., the distance between the seeds in the nest varies from 0.025 to 0.074 m, and between the nests from 0.062 to0.0 185 m. A seeding disc was designed and manufactured for laboratory testing of a sowing device for nesting soybean seeds.

Manual supplemental seeding in plug seedling production is a labor intensive and very tedious task. This paper studied and developed an automatic supplemental seeding device using machine vision technique for corrections of seeding errors of plug seeder, and replacement of the manual reseeding. The device includes five units: sweet corn seed detection, seed releasing, seed picking up, and plug tray conveying. A voting mechanism-based sweet corn seed detection method was proposed for detecting the missing seeds in a moving plug tray. The seed releasing cells and the suction nozzle for picking a seed up were fabricated using 3D printing technique. The proposed device was placed into the practical growing seedling pipeline to test its reseeding performance. The results showed that the sweet corn seed detection accuracy was about 99%, the empty cell rate decreased from 9.61% to 0.38% (after reseeding) on average, and the reseeding rate was about 221 trays per hour when the miss-seeding rate was under 5%. This proved that the proposed supplemental seeding device has great significance for increasing the seeding precision of sweet corn, and improving the efficiency of the practical seedling.

Despite Erica being the most diverse genus in the Cape Floristic Region, very few studies have focused on their breeding systems. The ability to self-fertilise autonomously and to tolerate self-pollen was assessed in three bird-pollinated obligate seeder ( E. densifolia , E. sessiliflora and E. discolor ) and three insect-pollinated obligate seeder ( E. penicilliformis , E. scabriscula and E. formosa ) Erica species in the southern coastal part of the Cape Floristic Region. None of the species successfully reproduced through autogamy and only the bird-pollinated E. sessiliflora produced a significant proportion of viable seeds per fruit when selfed. With the other five Erica species examined, cross-pollination yielded a significantly higher proportion of viable seeds per fruit compared to other treatments (autogamy and self-pollination). This suggests that the role of pollinators is essential for the reproductive success of Erica regardless of their pollination system (bird- versus insect-pollination) and that most are out-crossers.

A field experiment was conducted during rainy season 2014 and 2015 at Research Farm of the Punjab Agricultural University, Ludhiana, Punjab, India to study the effect of conservation agriculture practices (Happy Seeder sowing, Straw Chopper + Zero Tillage and Conventional tillage) and biofertilizers [Bradyrhizobium and plant growth promoting rhizobacteria (PGPR)] on growth, symbiotic parameters and productivity of soybean. The results showed that Happy Seeder sowing and Straw Chopper + Zero Tillage sowing improved the emergence count, leaf area index, photosynthetic active radiation interception, plant height of soybean and symbiotic traits (number and dry weight of nodules and leghaemoglobin content). Highest pods plant−1 and 100-seed weight were recorded in Happy Seeder sowing, followed by Straw Chopper + Zero Tillage sowing and conventional sowing. Based on the mean of two years, Happy Seeder sowing recorded 14.6 and 17.0% higher seed yield than Straw Chopper + Zero Tillage sowing and conventional sowing, respectively. Total nitrogen, phosphorus and potassium uptake were significantly higher in Happy Seeder sowing than the other planting methods. Single and dual inoculation of Bradyrhizobium and PGPR did not influence the growth parameters, symbiotic traits, yield attributes, biological, straw and seed yields, nutrient uptake and protein content of soybean significantly. Therefore, retention of crop residues with zero tillage (Happy Seeder sowing) proves to be the best planting method for sustainable productivity of soybean.

In rice-wheat cropping system of Punjab, Pakistan, seeding directly into the standing rice stubbles is gaining popularity. This study was conducted to develop the most favorable and economical no-till technique for wheat sowing in combine-harvested paddy fields with different residue conditions. The experiment was comprised of three no-till techniques viz. (1) turbo seeder, (2) happy seeder and (3) zone disk tiller. There were four heights of standing rice stubbles viz. (1) 15 cm, (2) 30 cm, (3) 45 cm, and (4) 60 cm. Different no-till techniques at various heights of standing rice stubbles significantly affected the stand establishment and yield related traits of wheat during both growing seasons. Turbo seeded plot showed 12-14% more total soil porosity in comparison with zone disk tiller sown field. Conversely, wheat plots sown by zone disk tiller exhibited 8% more soil bulk density than turbo seeder sown field. Better stand establishment and grain yield were observed in turbo seeded wheat in comparison with happy seeder and zone disk tiller sown wheat. Among the stubble heights, wheat crop sown in standing rice stubbles at 45 cm height performed the best with maximum germination, 1000 grain weight and grain yield. Furthermore, turbo seeder in standing rice stubbles at 45 cm height significantly produced 32-35% more benefit cost ratio than zone disk tiller at 15 cm stubble height during both years of experiment. In crux, direct drilling of wheat by turbo seeder in rice field combine harvested at 45 cm stubble height is the most viable technology for rice-wheat cropping system.

Summary Understanding how drought affects seeder and resprouter plants during post-fire regeneration is important for the anticipation of Mediterranean vegetation vulnerability in a context of increasing drought and fire caused by climate change. A Mediterranean shrubland was subjected to various drought treatments (including 45% rainfall reduction, 7 months drought yr−1), before and after experimental burning, by means of a rainout–shelter system with an irrigation facility. Predawn shoot water potential (Ψpd), relative growth rate (RGR), specific leaf area (SLA) and bulk leaf carbon isotopic composition (δ13C) were monitored in the main woody species during the first 3 yr after fire. Cistus ladanifer seedlings showed higher Ψpd, RGR and SLA, and lower δ13C, than unburned plants during the first two post-fire years. Seedlings under drought maintained relatively high Ψpd, but suffered a decrease in Ψpd and RGR, and an increase in δ13C, relative to control treatments. Erica arborea, E. scoparia and Phillyrea angustifolia resprouts had higher Ψpd and RGR than unburned plants during the first post-fire year. Resprouters were largely unaffected by drought. Overall, despite marked differences between the two functional groups, post-fire environments were favourable for plant functioning of both seeder and resprouter shrubs, even under the most severe drought conditions implemented.

Before starting a study with many birds, it helps to know the method of chick inoculation. The objective was to compare 3 methods of Salmonella challenge (oral gavage [OR], intracloacal inoculation [IC], and seeder bird [SB]). Day-old broiler chicks (n = 100) were inoculated with 106 colony forming units (CFU) per chick of a marker strain of Salmonella Heidelberg (SH) with each route of inoculation. Chicks (n = 25) inoculated by each route were placed in floor pens on fresh pine shavings litter. For the seeder batch, 5 colonized chicks, each orally gavaged with 106 CFUs, were placed with 20 pen mates. Two weeks after inoculation, 10 birds from each pen and the 5 inoculated seeder birds were euthanized, the ceca were aseptically removed and macerated with a rubber mallet and weighed, and 3 times (w/v) buffered peptone was added and stomached for 60 s. Serial dilutions were made and plated onto Brilliant Green Sulfa plates containing 200 ppm nalidixic acid. Plates were incubated along with the stomached ceca for 24 h at 37°C. If no colonies appeared on the plates, an additional plate was streaked from the preenriched bag and incubated for 24 h at 37°C. In addition to all seeder birds being positive, the number of SH-positive birds out of 20 sampled in each group was 13, 17, and 7 for OR, IC, and SB, respectively. The level of SH per g of ceca and cecal contents was log (SE) 3.0 (0.7), 2.0 (0.4), and 2.6 (0.4) for OR, IC, and SB, respectively. After enrichment, the number of colonized birds out of 20 was 18, 20, and 10 for OR, IC, and SB, respectively. In conclusion, this study suggests that IC is the method to use to ensure most of the challenged birds are colonized. However, if you prefer to have a smaller percentage of the birds colonized with higher levels, then OR might be better.

erotiny degree may hypothetically depend on mother plant age and fire severity, and fire severity can strongly affect the regeneration of Pinus pinaster Aiton, which is an obligate seeder species with aerial seed banks stocked in cones showing a certain degree of serotiny. The main objective of this study was to evaluate the effect of serotiny and mother plant age on seed germination of P. pinaster in relation to fire severity. For this purpose, cones were collected in two stands from mother trees of different ages. Serotinous cones were opened in oven at increasing temperatures to determine the number of seeds released. The length of cones and the number and weight of seeds were measured. Seeds from both classes of mother plant age were subjected to 34 different treatments simulating different fire severity levels, and their germination was recorded. The results showed that serotiny was significantly higher in cones from young mother trees. Seed germination in the control groups from serotinous cones was always higher than that from non-serotinous cones without thermal shock. Fire severity decreased seed germination as fire severity increases in both mother age classes. Mother plant age was related to the serotiny level, which was higher in young than in old trees, suggesting a strong selection in the population due to a recent fire. This work is part of the research projects AGL2013-48189-C2-2-R (Ministerio de Economía y Competividad, Madrid, Spain, and ERDF founding), AGL2017-86075-C2-2-R (Ministerio de Ciencia, Educación y Universidades, Madrid, Spain, and ERDF founding), LE001P17 (Junta de Castilla y León, Valladolid, Spain), ED431C2019/07 and ED431E 2018/09 (Xunta de Galicia, Santiago de Compostela, Spain) SI

The ability to reliably and efficiently restore degraded ecosystems at scale is a major challenge. Restoration on a mine site typically consists of either the planting of cultivated nursery stock or the direct seeding of seed onto site to reinstate native plants and ecosystems. At scale, planting seedlings can be extremely costly and time consuming and therefore, restoration practitioners have moved towards mechanical direct seeding methods. In many circumstances, however, mechanical direct seeding is unreliable and most mechanisms lack the versatility needed to plant a variety of native species in a range of sowing environments. Results of a global survey of restoration practitioners uncovered that seeding depth precision and accuracy is extremely important when distributing many native seeds. In order to guide improvements to the design of native seeders that are used in the Pilbara region of Western Australia, we studied the maximum and optimal emergence depth of a species crucial to restoration in the region, Triodia pungens (soft spinifex). Results showed that the current practice of broadcasting seeds on the soil surface may be inadequate to facilitate germination, and that covering seeds to 5 mm yields optimal emergence. Seedling emergence dropped off considerably at 10 mm with almost no emergence occurring once seeds were sown to 30 mm. Most mechanical seeders currently in operation are unable to control depth to this level of precision, particularly on the rocky and uneven terrain associated with mine waste dumps. Future designs should focus on improving depth control in such conditions.

Arsenic can cause heavy metal pollution of the soil, while Pteris vittata L. can enrich arsenic. It is currently being applied to the field of soil remediation, owing to Pteris vittata L. can absorbs up to 22630 p.p.m. of arsenic from the soil which has the arsenic content of 1500 p.p.m.. Since the diameter of Pteris vittata L. spores is small, only about 48 microns, it is not suitable for seeding with a conventional seeder.Currently, its seeding procedure has been performed manually, which is a laborious and time-consuming procedure with poor evenness and not conducive to factory-cultivated seedlings. An automatic seeder for Pteris vittata L. with fast and even characteristics has been developed. The seeder mixes spores and water in a certain proportion, stirs to form a mixture by a stirring mechanism.Then it uniformly sprays the spore-water mixture onto the seed tray by a pressure spraying device. The seeder can realize automatic feeding, automatic substrates placement, automatic seeding and automatic detection. This seeder is effectively improving seeding quality and efficiency. The maximum seeding speed can reach 800 seed tray per hour.

Question: The study of temporal variation of plant–plant interactions has received little attention despite its importance in community dynamics. Successional processes triggered by disturbances such as fire may be determined by changes in key interactions between dominant woody plants. Taking advantage of a 95-yr-old post-fire natural experiment we assessed temporal shifts in post-fire interactions between woody resprouters and the obligate seeder tree Austrocedrus chilensis. We hypothesized that during the initial post-fire period, resprouters may facilitate A. chilensis trees' growth, while at advanced time since fire the interaction between A. chilensis trees and resprouters may turn to competition. Location: Northwestern Río Negro province, Patagonia, Argentina. Methods: We selected pairs of A. chilensis trees and woody resprouters growing 80 cm apart (growing in association) and both A. chilensis trees and resprouters growing at more than 3 m apart from any individual (controls). We cored all individuals, measured ring widths and calculated basal area increment (BAI) and the relative interaction index (RII). Results: During mid-early stages of post-fire succession, A. chilensis trees' BAI was suppressed for at least 15 yr when growing in association with resprouters, and accordingly displayed a negative RII. Strikingly, during the same period, resprouters associated with A. chilensis trees showed higher BAI than control resprouters, and a positive RII. At advanced time since fire, RII showed a neutral interaction, and according to model estimations, the BAI of A. chilensis trees in association may eventually exceed control BAI whereas resprouters' BAI in association may decline earlier than that of the controls. Interestingly, A. chilensis trees and resprouters' growth was less correlated with climate when growing in association than when growing in isolation. Conclusions: Competition of resprouters over A. chilensis treess' growth during intermediate post-fire stages may be slowing the successional process. However, the association appears to be at the same time mutually beneficial as it buffers against adverse climatic conditions. Studying how plant growth varies along the succession is essential to understand community functioning and to predict possible alterations associated with changes in disturbance regimes due to climate change. Fil: Landesmann, Jennifer Brenda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Gowda, Juan Janakiram Haridas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina Fil: Kitzberger, Thomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; Argentina

Forests that regenerate exclusively from seed following high-severity fire are particularly vulnerable to local extinction if fire frequency leaves insufficient time for regenerating plants to reach sexual maturity. We evaluate the relative importance of extrinsic (such as fire weather and climate cycles) and intrinsic (such as proneness to fire due to stand age and structural development) factors in driving the decline of obligate seeder forests. We illustrate this using obligate seeding alpine ash (Eucalyptus delegatensis) forests in the montane regions of Victoria, Australia, that were burnt by megafires in 2003 (142,256 ha) or 2007 (79,902 ha), including some twice-burnt areas (11,599 ha). Geospatial analyses showed only a small effect of stand age on the remote sensing estimates of crown defoliation, but a substantial effect of forest fire weather, as measured by forest fire danger index (FFDI). Analysis of meteorological data over the last century showed that 5-year increases in FFDI precede cycle major fires in the E. delegatensis forests. Such strong extrinsic climate/weather driving of high-severity fires is consistent with the ‘interval squeeze model’ that postulates the vulnerability of obligate seeder forests to landscape-scale demographic collapse in response to worsening fire weather under climate change.

In order to realize large-scale cultivation of the cyperus esculentus, reduce its labor input and meet precision sowing requirement, a precision pneumatic cyperus esculentus filming seeder was to be developed. Physical characteristics of the cyperus esculentus seeds was to be calculated and analyed for optimization design seeder structure. Through field test, the variation coefficient of each row and space between the plants of seeder meets agronomic requirements. Qualified rate of sowing depth is 90%.

A higher frequency of natural selection is expected in populations of organisms with shorter generation times. In fire-prone ecosystems, populations of seeder plants behave as functionally semelparous populations, with short generation times compared to populations of resprouter plants, which are truly iteroparous. Therefore, a stronger signature of natural selection should be detected in seeder populations, favoured by their shorter generation times and higher rates of population turnover. Here we test this idea in Erica coccinea from the Cape Floristic Region, which is dimorphic for post-fire regeneration mode. We measured three floral traits supposedly subject to natural selection in seeder and resprouter populations. We then compared phenotypic trait variation with neutral genetic variation in each group of populations using PST–FST comparisons to detect signatures of natural selection in seeders and resprouters. We found a strong signature of selection in seeder populations, but not in resprouters. Furthermore, anthers of seeders were more exserted (and larger) than those of resprouters. These differences were maintained at sites where seeders and resprouters co-occurred, suggesting that phenotypic plasticity or adaptation to different growth environments are unlikely explanations for trait variation. These results provide empirical support for the hypothesis that the genetic signature of natural selection is certainly more intense in seeder than in resprouter populations, favoured by their comparatively faster generation turnovers. Increased frequency of natural selection would increase differentiation among populations, thus promoting speciation in pyrophytic seeder lineages of the Cape flora., J.G.S.-M. was supported by a ‘Ramón y Cajal’ postdoctoral contract from MICINN

Germination and emergence are often the most precarious stage in a plant's lifecycle: plants are particularly vulnerable to environmental stress at this time. Despite these constraints, plants colonize much of the planet including extreme environments. We argue that for many species, establishment in extreme situations is not because seed is adapted to germinate in extreme environments but because it falls into, and is spatially and temporally nurtured within, more benign “recruitment niches.” This principle has importance for revegetation in extreme environments such as the world's drylands. Using examples from ground-breaking experiments conducted by CV Malcolm and colleagues between 1976 and 1982 on saltland revegetation with halophytes, we show that recruitment niches can be constructed based on an understanding of the key requirements that seeds need in their immediate environment to establish. As part of their studies, Malcolm's team developed a “niche seeder” capable of distributing and precisely placing fruits of Atriplex species in an elevated “V”-shaped mound (to decrease waterlogging), covering the fruits with vermiculite (to decrease capillarity and therefore salinity at the soil surface), and spraying the placements with black paint (to increase soil temperatures). Subsequent studies in arid environments showed that the establishment of woody plants was also improved using stones on the soil surface to develop appropriate recruitment niches. Malcolm's identification of the “recruitment niche” is an important principle of broader relevance to the revegetation of degraded landscapes in extreme environments. In addition, the development of the niche seeder is an important case study in ecological restoration.

Reproductive output and seed traits can be altered by water availability during seed formation and maturation, which could affect the population recovery after fire of seeders (i.e., species regenerating from seeds). This is important for species in fire-prone, dry areas that are projected to encounter reduced total precipitation and longer annual drought with climate change. Here we determine the sensitivity of several reproductive processes to drought in Cistus ladanifer , a plant widely distributed in the shrublands of the western part of the Mediterranean Basin. Three levels of annual drought were simulated in a shrubland by means of a rainout shelter and an irrigation system in 6 × 6 m plots. Fruits and seeds from drought-exposed mother plants were collected, and reproductive output, seed size and anatomy studied. Seeds non-exposed/exposed to fire cues (heat plus smoke) were germinated at five levels of water stress (Ψ s = 0.0 to −0.50 MPa). Hydrotime modeling was applied to germination under water stress. Plant growth was sensitive to drought, but reproductive output, seed size, dormancy and viability were not. Drought significantly affected seed anatomy, increasing the palisade layer at the micropyle. Drought in the maternal plants, in interaction with seed exposure to fire cues, significantly reduced final germination. Water stress during germination decreased final germination, independent of maternal plant drought, and interacted with fire cues to decrease germination when exposed. Hydrotime modeling confirmed that fire cues made seeds highly sensitive to water stress (Ψ b (50) = −0.25 MPa). Post-germination viability was reduced in seeds from drought-treated maternal plants that were exposed to fire cues and germinated under water stress. Reproductive output showed low plasticity in response to drought. However, the effects of drought in the mother plant affected seed anatomy and germination in interaction with fire cues. The conclusion is that exposing C . ladanifer maternal plants to drought arguably increases seed sensitivity to water limitations during germination after fire.