Autumn Growth Research Articles

Nitrogen Uptake Efficiency, Mediated by Fine Root Growth, Early Determines Temporal and Genotypic Variations in Nitrogen Use Efficiency of Winter Oilseed Rape.

Maintaining seed yield under low N inputs is a major issue for breeding, which requires thoroughly exploiting the genetic diversity of processes related to Nitrogen Use Efficiency (NUE). However, dynamic analysis of processes underlying genotypic variations in NUE in response to N availability from sowing to harvest are scarce, particularly at the whole-plant scale. This study aimed to dynamically decipher the contributions of Nitrogen Uptake Efficiency (NUpE) and Nitrogen Utilization Efficiency (NUtE) to NUE and to identify traits underlying NUpE genetic variability throughout the growth cycle of rapeseed. Three experiments were conducted under field-like conditions to evaluate seven genotypes under two N conditions. We developed NUE_DM (ratio of total plant biomass to the amount of N available) as a new proxy of NUE at harvest, valid to discriminate genotypes from the end of inflorescence emergence, and N conditions as early as the beginning of stem elongation. During autumn growth, NUpE explained up to 100% of variations in NUE_DM, validating the major role of NUpE in NUE shaping. During this period, under low N conditions, up to 53% of the plant nitrogen was absorbed and NUpE genetic variability resulted not from differences in Specific N Uptake but in fine-root growth. NUtE mainly contributed to NUE_DM genotypic variation during the reproductive phase under high-N conditions, but NUpE contribution still accounted for 50–75% after flowering. Our study highlights for the first time NUpE and fine-root growth as important processes to optimize NUE, which opens new prospects for breeding.

Temperature-based prediction of harvest date in winter and spring cereals as a basis for assessing viability for growing cover crops

• The growth and viability of cover crops depends on autumn growth duration. • The viability of growing cover crops was assessed with a phenology model. • The phenology model predicts harvest time of spring and winter cereals. • The harvest time varies more spatially across Denmark than between years. • Simulations show that cover crops can be reliably established in southern Denmark. Cover crops are an important component of sustainable cereal cropping systems by providing nutrient retention and improving soil quality. However, the successful establishment and growth of cover crops depend on a timely harvest of the preceding annual crops. To assess the viability of growing cover crops in Denmark, a phenology model was developed, calibrated, cross-validated and applied to predict the harvest date of spring barley and winter wheat in Denmark using data from field experiments in Denmark during 1991 to 2018. A simple phenology model was used for the period from sowing to maturity, and this was extended to simulate the duration from maturity to harvest. This extended model was used to predict the harvest date in the ongoing season, and it provides the capability for assessing the performance of cover crops as a basis for improved cover crop management. The model uses temperature sums and day length to calculate the developmental rate of spring barley from sowing to harvest and for winter wheat from 1st January to harvest. The standard deviation of the estimated harvest date based on the uncertainty of the model parameters was 10-14 days and 1-4 days for spring barley and winter wheat, respectively. The model was evaluated using historically recorded temperature data (20 years, 1999–2018) to simulate harvest date, which was within the range of observed harvest dates. The interannual range of estimated harvest dates is 7–10 days for spring barley and 5–10 days for winter wheat. This interannual variation of harvest date was lower than the spatial variation across the country. The model can be used for forecasting cereal harvest time and thus readiness for autumn field operations, including the establishment of cover crops. Simulations of growing degree days from date of harvest to 1 November shows that cover crops can be reliably established in southern parts of Denmark to ensure low nitrate leaching. Advancing the harvest date to the date of physiological maturity of the cereals would allow the establishment of efficient cover crops in all years in the entire country.

Maternal control of early life history traits affects overwinter survival and seedling phenotypes in sunflower (Helianthus annuus L.).

When cultivated and wild plants hybridize, hybrids often show intermediate phenotypic traits relative to their parents, which makes them unfit in natural environments. However, maternal genetic effects may affect the outcome of hybridization by controlling expression of the earliest life history traits. Here, using wild, cultivated and reciprocal crop-wild sunflower (Helianthus annuus L.) hybrids, we evaluated the maternal effects on emergence timing and seedling establishment in the field and on seedling traits under controlled conditions. In the field, we evaluated reciprocal crop-wild hybrids between two wild populations with contrasting dormancy (the high dormant BAR and the low dormant DIA) and one cultivar (CROP) with low dormancy. Under controlled conditions, we evaluated reciprocal crop-wild hybrids between two wild populations (BAR and RCU) and one CROP under three contrasting temperature treatments. In the field, BAR overwintered as dormant seeds whereas DIA and CROP showed high autumn emergence (~50% of planted seeds), resulting in differential overwinter survival and seedling establishment in the spring. Reciprocal crop-wild hybrids resembled their female parents in emergence timing and success of seedling establishment. Under controlled conditions, we observed large maternal effects on most seedling traits across temperatures. Cotyledon size explained most of the variation in seedling traits, suggesting that the maternal effects on seed size have cascading effects on seedling traits. Maternal effects on early life history traits affect early plant survival and phenotypic variation of crop-wild hybrids, thus, they should be addressed in hybridization studies, especially those involving highly divergent parents, such as cultivated species and their wild ancestors.

Seed dormancy and germination of Asarum sieboldii, a disjunct relict species in East Asia.

Disjunct species in the same genus are a common feature of the flora in the temperate forests of East Asia and eastern North America. This study aimed to evaluate whether the kind of seed dormancy was maintained after species in the genus Asarum (Aristolochiaceae) were separated from their common ancestor. We classified the seed dormancy of Asarum sieboldii, an East Asian species, based on a phenology study and experiments in controlled temperature conditions, and then compared it to that of the previously studied A. canadense, an eastern North American species. The underdeveloped embryo of A. sieboldii grew and germinated (radicle emergence) in autumn but shoot emergence did not occur until the following spring. The seeds of A. sieboldii had deep simple epicotyl morphophysiological dormancy because the seeds with emerged radicle required a relatively long period of cold stratification to break epicotyl dormancy and produce a shoot. Although the seed of A. sieboldii had weaker radicle dormancy and stronger epicotyl dormancy compared to A. canadense, the kind of seed dormancy was the same for the two species. The trait of seed dormancy was inherited from a shared common ancestor and maintained in populations well after the two species (or their ancestors) separated. However, quantitative differences in temperature requirements for radicle and shoot emergence suggest the possibility of adaptation to the environment.

Does manipulating harvest regime of single‐cut 'Fahl' berseem clover compensate for reduced seeding rate?

AbstractProviding precise information about the variations in yield and quality of single‐cut 'Fahl' berseem clover (Trifolium alexandrinum L.) in relation to crop's harvest regime and seeding rate would support its optimal utilization in rotation with other crops grown in the Mediterranean environment. Current study investigated the variations in fodder yield and nutritive value of 'Fahl' berseem clover when cut at three harvesting regimes, adjusted in terms of three phenological stages: bud stage (60 days after sowing—DAS), early flowering (75 DAS) and full flowering (90 DAS) under elevated seeding rates (25%, 50%, 75% and 100% of the recommended). When 'Fahl' berseem clover was harvested at bud stage, the use of increased seeding rates was essential for higher fodder yield, while delaying harvesting to early or full flowering provided a good compensation to the reduced seeding rates. The optimal fresh fodder yield was achieved when the crop was cut at early flowering (75 DAS) with 55% seeding rate. Seeding rate had minimal effect on the studied fodder quality parameters, which were significantly variable according to the harvest regime. Late harvests were characterized by higher dry yield, dry matter accumulation, fiber and non‐fiber carbohydrates contents, yet lower crude protein. The highest significant crude protein content was a character of the crop harvested at early flowering (75 DAS) with around 60% seeding rate. In a similar Mediterranean context, 'Fahl' berseem clover can provide reasonable amount of forage of good quality throughout the autumn growth period when harvesting is done at early flowering and seeding rate is reduced to 60% of the recommended.

Assessment of the Biological Control Potential of Common Carabid Beetle Species for Autumn- and Winter-Active Pests (Gastropoda, Lepidoptera, Diptera: Tipulidae) in Annual Ryegrass in Western Oregon.

Simple SummaryMany studies have shown that ground beetles feed on different agricultural pests, but little is known about their species communities from US cropping systems. We assessed the biological control potential of the most common carabid beetle species in Oregon annual ryegrass grown for seed by investigating spatial and temporal overlap of the most common species with those of the most damaging autumn- and winter-active pests (slugs, caterpillars and cranefly larvae) and determined the number of field-collected specimens that had fed on the respective pests using molecular gut content analysis. Only the non-native Nebria brevicollis was abundant during pest emergence and tested positive for all three pest groups. While the other common carabid beetle species—Agonum muelleri, Calosoma cancellatum and Poecilus laetulus—were also found to have consumed pests, they were active only during spring and summer, when crop damage by pests is less critical. We also show that disk tilling did not affect any of the four common carabid beetle species and that only N. brevicollis was significantly associated with a vegetated field margin. This study contributes to expanding our knowledge on conservation biological control in a system where chemical pesticides are still the mainstay of control against invertebrate pests.While carabid beetles have been shown to feed on a variety of crop pests, little is known about their species assemblages in US annual ryegrass crops, where invertebrate pests, particularly slugs, lepidopteran larvae and craneflies, incur major financial costs. This study assesses the biological control potential of carabid beetles for autumn- and winter-active pests in annual ryegrass grown for seed by: (a) investigating the spatial and temporal overlap of carabids with key pests; and (b) molecular gut content analysis using qPCR. Introduced Nebria brevicollis was the only common carabid that was active during pest emergence in autumn, with 18.6% and 8.3% of N. brevicollis collected between September and October testing positive for lepidopteran and cranefly DNA, respectively, but only 1.7% testing positive for slug DNA. While pest DNA was also detected in the guts of the other common carabid species—Agonum muelleri, Calosoma cancellatum and Poecilus laetulus—these were active only during spring and summer, when crop damage by pests is less critical. None of the four carabid species was affected by disk tilling and only N. brevicollis was significantly associated with a vegetated field margin. However, as its impact on native ecosystems is unknown, we do not recommend managing for this species.

Drought tolerance of <i>Liriope graminifolia</i> (L.) Baker and <i>Ophiopogon japonicus</i> (Thunb.) Ker Gawl. – promising lawn-forming plants for the subtropical zone of the Black Sea coast of Russia

The lawn coverings creation in the humid subtropics zone of Russia is one of the topical areas of ornamental horticulture. This is due to the high requirements for year-round decorative plantings, the peculiarities of natural and climatic conditions and the general lack of issue knowledge. This direction is of particular importance in plantations located in shaded areas under the canopy of tree crowns, where, in addition to common for the region unfavourable factors of the hydrothermal regime, insufficient illumination is added, which together limits the possibility of traditional cereal grasses cultivating. Evergreen grass-like ground cover plants can be a complete substitute for lawn grasses in shaded areas. The aim of the research was to determine the degree of drought resistance of Liriope graminifolia (L.) Baker and Ophiopogon japonicus (Thunb.) Ker Gawl. and the ability to maintain decorativeness during the period of unfavourable hydrothermal conditions in the summer in the humid subtropics of Russia. The studies were carried out in 2013-2018 on the Black Sea coast of the Caucasus in the Sochi region, in plantations (on test plots with an area of 5-10 m2) and in conditions of vegetation experiments (in containers with a volume of 2 liters) on the territory of the Kuban Subtropical Botanical Garden (settlement Uch-Dere), according to generally accepted methods adapted to the studied taxa. It was found that an important mechanism of adaptation of the studied plants to drought is the ability to accumulate and redistribute moisture between vegetative organs, providing a high water content in the leaves. The decorativeness of O. japonicus and L. graminifolia in open ground in the atmospheric moisture absence lasts up to 12-14 days, in a vegetation experiment (container culture) – up to 14-16 days. O. japonicus and L. graminifolia retained the ability to self-regenerate up to 35-37 days of the experiment, and then the plants died. The consequences of summer drought in the studied plants were compensated by active autumn growth. Unlike classic lawns, which require daily watering, lawns from O. japonicus and L. graminifolia should be irrigated with a long (more than 12-14 days) absence of precipitation in the summer months.

Science-based approach to using growth rate to assess coral performance and restoration outcomes.

One response to the coral reef crisis has been human intervention to enhance selection on the fittest corals through cultivation. This requires genotypes to be identified for intervention, with a primary basis for this choice being growth: corals that quickly grow on contemporary reefs might be future winners. To test for temporal stability of growth as a predictor of future performance, genotypes of the coral Porites spp. were grown in common gardens in Mo'orea, French Polynesia. Growth was measured every two to four months throughout 2018, and each period was used as a predictor of growth over the subsequent period. Area-normalized growth explained less than 29% of the variance in subsequent growth, but for biomass-normalized growth this increased to 45-60%, and was highest when summer growth was used to predict autumn growth. The capacity of initial growth to predict future performance is dependent on the units of measurement and the time of year in which it is measured. The final choice of traits to quantify performance must be informed through consideration of the species and the normalization that best capture the information inherent in the biological processes mediating variation in traits values.

Germination and emergence characteristics of prickly lettuce (Lactuca serriola L.)

Prickly lettuce (Lactuca serriola L.) has become an increasing problem in cereals and lucerne pastures in southern New South Wales, Australia. A better understanding of the biology is needed for improved control. Laboratory and field experiments were conducted to determine dormancy status among L. serriola populations, to evaluate environmental factors affecting seed germination and to determine field emergence patterns. Among 76 L. serriola seed samples collected between 2015 and 2018, more than 59% of the samples had little or no innate dormancy, with germination greater than 80%. However, a further tetrazolium test showed that 42 samples collected in the summer season of 2015-16 differed in their dormancy status, with high levels of initial dormancy up to 75.6% in some populations. Lactuca serriola germinated from 10 C to more than 35 C, with the optimum temperatures being 15–25 C. Light stimulated the germination of L. serriola, while the germination was completely suppressed at 80–110 mM of NaCl. Lactuca serriola germinated well under a range of acidic and alkaline conditions. L. serriola predominately emerged (40–52%) from the soil surface, however, limited emergence also occurred from beyond 5-cm burial depth (up to 1.5%). Emergence in a standing crop was 10 times less than that in a bare soil. L. serriola populations from high and low rainfall zones had similar seasonal emergence patterns in the field, with 69% emergence in late autumn and early winter, 22–26.8% in late winter, 1.4–2.4% in spring in the first year after sowing, little or limited emergence in the second and third year. These results suggest that L. serriola can colonise wide geographical areas. Controlling the autumn and winter cohorts is important to stop seed set. If the seed set is completely prevented, L. serriola can be managed over a minimum of two years due to the relatively short-lived seed life.

Emergence Patterns of Rare Arable Plants and Conservation Implications.

Knowledge on the emergence patterns of rare arable plants (RAP) is essential to design their conservation in Europe. This study hypothesizes that is possible to find functional groups with similar emergence patterns within RAP with the aim of establishing management strategies. Seeds of 30 different species were collected from Spanish arable fields and sown under two tillage treatments: (a) 1 cm depth without soil disturbance to simulate no-till, and (b) 1–10 cm depth with soil disturbance every autumn to simulate tillage to 10 cm depth. Two trials were established; the first trial being maintained for three seasons and the second for two seasons. Relative emergence in autumn, winter and spring was calculated each season. Afterwards, multivariate analysis was performed by K-means clustering and Principal Component Analysis to find groups of RAP species with similar emergence patterns. Four RAP groups were defined, and each was based on its main emergence season: autumn, winter, spring, or autumn-winter. Tillage treatment and the year of sowing had little effect on emergence patterns, which were mostly dependent on environmental factors, particularly temperature and rainfall. Therefore, conservation strategies could be designed for each of these RAP functional groups based on emergence patterns, rather than on a species-by-species basis.

Autumn growth of three perennial weeds at high latitude benefits from climate change.

In autumn, agricultural perennial weeds prepare for winter and can store reserves into creeping roots or rhizomes. Little is known about influence of climate change in this period. We tested the effect of simulated climate change in autumn on three widespread and noxious perennial weeds, Elymus repens (L.) Gould, Cirsium arvense (L.) Scop. and Sonchus arvensis L. We divided and combined simulated climate change components into elevated CO2 concentration (525ppm), elevated temperatures (+2-2.5°C), treatments in open-top chambers. In addition, a control in the open-top chamber without any increase in CO2 and temperature, and a field control outside the chambers were included. Two geographically different origins and three pre-growth periods prior to the exposure to climate change factors were included for each species. All species increased leaf area under elevated temperature, close to doubling in E. repens and quadrupling in the dicot species. E. repens kept leaves green later in autumn. C. arvense did not benefit in below-ground growth from more leaf area or leaf dry mass. S. arvensis had low levels of leaf area throughout the experiment and withered earlier than the two other species. Below-ground plant parts of S. arvensis were significantly increased by elevated temperature. Except for root:shoot ratio of C. arvense, the effects of pure elevated CO2 were not significant for any variables compared to the open-top chamber control. There was an additive, but no synergistic, effect of enhanced temperature and CO2 . The length of pre-growth periodwas highly important for autumn plant growth, while origin had minor effect. We conclude that the small transfer of enhanced above-ground growth into below-ground growth under climate change in autumn does not favour creeping perennial plants per se, but more leaf area may offer more plant biomass to be tackled by chemical or physical weed control.

Impact of waterlogging and temperature on autumn growth, hardening and freezing tolerance of timothy (Phleum pratense)

AbstractPrecipitation has generally increased in Norway during the last century, and climate projections indicate a further increase. The growing season has also become longer with higher temperatures, particularly in autumn. Previous studies have shown negative effects of high temperatures and, depending upon temperature conditions, contrasting effects of waterlogging on hardening capacity of timothy. We studied effects of waterlogging on seedlings of timothy (Phleum pratense, cv. Noreng) under three pre‐acclimation temperatures: 3°C, 7°C, 12°C, and in autumn natural light in a phytotron at Holt, Tromsø (69°N). After temperature treatments, all plants were cold acclimated at 2°C for three weeks under continued waterlogging treatments. Freezing tolerance was determined by intact plants being frozen in pots at incremental temperature decreases in a programmable freezer. Waterlogging resulted in a higher probability of death after freezing, and a significantly reduced regrowth after three weeks at 18°C, 24 hrs light in a greenhouse. Increasing pre‐acclimation temperatures also had a clear negative effect on freezing tolerance, but there was no interaction between temperatures and waterlogging. The results indicate that waterlogging may have negative implications for hardening of timothy and may contribute to reduced winter survival under the projected increase in autumn temperatures and precipitation.

Удосконалення агротехніки вирощування садивного матеріалу горіха чорного (Juglans nigra L.) у лісовому розсаднику Державного підприємства «Лисянське лісове господарство»

Anthropogenic impact on the environment leads in most cases to forest systems degradation; therefore there is a need for the forest science development towards a balance finding between forest’s ecological functions and economic effect from stands. Introduced species are of great importance in this respect, especially if they are dominated by native tree species. Feasibility of diverse use of black walnut fruits and wood, the urgency of searching for tree species, which are resistant to negative impacts associated with climate change, the issue of increasing pests and diseases resistance encourages scientists to an in-depth study of the questions on the possibilities of black walnut cultivation in the Right Bank Forest-Steppe of Ukraine. Taking into account the previous experience of black walnut growing in this region and its prospects, we have decided to study more thoroughly the first stage of high-yielding stands restoration, which involves forest stands development. The study included several stages, in particular: studying of black walnut growing experience, seeds quality inspection, sites selection according to forestry scientists recommendations for this species conditions, test plots establishment using plant growth regulators with the definition of the most effective ones and identification of optimal doses of their application. To study the influence of plant growth regulators on the growth and development of black walnut plants we used preparations of N-oxide pyridine derivatives and their compositions with the biological preparation of Ecostim-1. Bleached were the seeds of black nuts, which had a tight germ of milk-white or cream color. The quality of samples was 99 %. The best results in the first year of autumn growth were obtained using growth regulators of group 1. In the group 1 percent of liveliness varied from 73 % to 93 % in June and from 77 % to 90 % in October. On the control site the survivability is 69 %. Comparing the height of black walnut tree seedlings, determined in spring and autumn, it should be emphasized that the increase of seedlings height of black walnut was proportional – the highest plants of the spring period remained the same in the autumn period. In autumn the seedlings grown using growth regulators D5S, D11S, D13S, D16S, D20S, D21S, DGK6, DGUR had the height of more than 90 cm. In the control area the height of the black walnut plants in the spring period was 20 cm, and in the autumn it was 76 cm. Having determined the average diameter of the plants at the height of the root collar, we obtained the best results using D5S, but there are no significant fluctuations on this indicator.

Autumn growth and condition of anchovy larvae in the Argentine-Uruguayan Common Fishing Zone

Autumn growth and condition of anchovy larvae in the Argentine-Uruguayan Common Fishing Zone

Temporal dynamics of seedling emergence among four fire ephemerals: the interplay of after-ripening and embryo growth with smoke

AbstractThe flora of Mediterranean ecosystems contains families with species having fully and under-developed embryos in their seeds. After-ripening for physiological dormancy release and smoke influence germination in many species. We investigated how after-ripening and embryo growth interact with smoke to influence the temporal dynamics of seedling emergence among fire ephemerals. Seeds were placed in the field and under standardized (50% relative humidity, 30°C) laboratory conditions to test the effects of summer conditions on physiological dormancy loss. Germination was tested with water or smoke compounds (smoke water, KAR1) at a simulated autumn/winter temperature (18/7°C). The timing and amount of seedling emergence with smoke was observed for seeds exposed to near-natural conditions. During summer, physiological dormancy was broken in all species, enabling germination at autumn/winter but not summer temperatures; no embryo growth occurred in seeds with under-developed embryos. At the start of the wet season, seedling emergence from seeds with fully developed embryos occurred earlier than from seeds with under-developed embryos. In a non-consistent manner among our study species, smoke and smoke compounds influenced the rate of embryo growth and amount of germination. Effects of smoke were noticeable in terms of number of emergents in the first emergence season. Among ecologically similar species, we have shown (1) that both thermal and embryo traits exclude germination in the summer, (2) how embryo size influences the timing of seedling emergence in autumn–winter, and (3) a reduced requirement for smoke in the second emergence season after a fire with a shift to reliance on seasonal cues for emergence.

Measuring viability selection from prospective cohort mortality studies: A case study in maritime pine.

By changing the genetic background available for selection at subsequent life stages, stage‐specific selection can define adaptive potential across the life cycle. We propose and evaluate here a neutrality test and a Bayesian method to infer stage‐specific viability selection coefficients using sequential random genotypic samples drawn from a longitudinal cohort mortality study, within a generation. The approach is suitable for investigating selective mortality in large natural or experimental cohorts of any organism in which individual tagging and tracking are unfeasible. Numerical simulation results indicate that the method can discriminate loci under strong viability selection, and provided samples are large, yield accurate estimates of the corresponding selection coefficients. Genotypic frequency changes are largely driven by sampling noise under weak selection, however, compromising inference in that case. We apply the proposed methods to analyze viability selection operating at early recruitment stages in a natural maritime pine (Pinus pinaster Ait.) population. We measured temporal genotypic frequency changes at 384 candidate‐gene SNP loci among seedlings sampled from the time of emergence in autumn until the summer of the following year, a period with high elimination rates. We detected five loci undergoing allele frequency changes larger than expected from stochastic mortality and sampling, with putative functions that could influence survival at early seedling stages. Our results illustrate how new statistical and sampling schemes can be used to conduct genomic scans of contemporary selection on specific life stages.

Ongoing seasonally uneven climate warming leads to earlier autumn growth cessation in deciduous trees.

Ongoing global warming is causing phenological shifts that affect photosynthesis and growth rates in temperate woody species. However, the effects of seasonally uneven climate warming-as is occurring in much of Europe, where the winter/spring months are warming twice as fast than the summer/autumn months-on autumn growth cessation (completion of overwintering buds) and leaf senescence, and possible carry-over effects between phenophases, remain under-investigated. We conducted experiments in which we exposed saplings of canopy and understory species to 4°C warming in winter/spring, summer/autumn, or all year to disentangle how the timing of bud break, bud set completion, and leaf senescence is affected by seasonally uneven warming. All-year warming led to significantly delayed leaf senescence, but advanced bud set completion; summer/autumn warming only delayed leaf senescence; and winter/spring warming advanced both bud set and senescence. The non-parallel effects of warming on bud completion and leaf senescence show that leaf senescence alone is an inadequate proxy for autumn growth cessation in trees and counterintuitively suggest that continued uneven seasonal warming will advance cessation of primary growth in autumn, even when leaf senescence is delayed. Phenological responses to warming treatments (earlier spring onset, later autumn senescence) were more than twice as high in understory species than in canopy species, which can partly be explained by the absence of carry-over effects among phenophases in the former group. This underscores the need to consider differences among plant functional types when forecasting the future behaviour of ecosystems.

Effect of stubble height and irrigation management on the growth, botanical composition and persistence of perennial ryegrass, tall fescue and chicory swards in cool-temperate Tasmania

The profitability of dairying in south-eastern Australia can be improved by increasing pasture production during summer–autumn, when growth rates for the existing perennial ryegrass (Lolium perenne L.) feedbase are low. A study undertaken in cool-temperate north-west Tasmania examined the effect of stubble height and irrigation management on swards of perennial ryegrass, continental (summer-active) tall fescue (Festuca arundinacea Schreb.) and chicory (Cichorium intybus L.). Irrigation treatments included full irrigation (~20mm applied at every 20mm precipitation deficit), deficit irrigation (~20mm applied at alternate full-irrigation events) and rainfed (no irrigation). All species achieved greater summer–autumn yields when repeatedly defoliated to stubble heights of 35 or 55mm than when defoliated to 115mm, irrespective of irrigation treatment. Swards were managed under a common defoliation schedule of nine defoliation events in 12 months. Under full irrigation, second-year tall fescue achieved a greater summer–autumn yield than perennial ryegrass (by 10%, or 0.7 t DM ha–1), highlighting the potential role of tall fescue in north-west Tasmania. This was further demonstrated by the high marginal irrigation water-use index values (1.6–2.7 t DM ML–1) of tall fescue. By contrast, summer–autumn growth achieved by chicory was less than or equal to perennial ryegrass.

Growth characteristics and Productivity of Italian Ryegrass (<i>Lolium multiflorum</i> Lam.) New Variety, ‘Green Call’

This experiment was conducted to breed a very early maturing variety of Italian ryegrass (Lolium multiflorum Lam.) in Grassland and Forage Crops Division, National Institute of Animal Science, RDA, Cheonan 2015-2017. The new variety of Italian ryegrass, ‘Green call 2ho’ is a diploid variety with green in leaf color and has semi-erect growth habit in late autumn and erect growth habit in early spring, ‘Green call 2ho’ was in heading date as a early-maturing variety April 24. Also ‘Green call 2ho’ was narrower by 2 mm in flag leaf width, longer by 2.5 cm in flag leaf length and shorter by 3 cm in plant height than those of the control variety, ‘Florida 80’, respectively. ‘Green call 2ho’ was also thicker by 0.33 mm in stem thickness and strong in winter hardness. Dry matter (DM) yield (11,688 kg/ha) of ‘Green call 2ho’ was 7% higher than that of ‘Florida 80’. Total digestible nutrient (TDN), crude protein (CP) and relative feed value (RFV) of ‘Green call 2ho’ were 61.3 %, 9.8 % and 98.2, respectively which are 2.6, 0.6, and 8.4 % higher, respectively than those of ‘Florida 80’, respectively. Acid detergent fiber (ADF) and neutral detergent fiber (NDF) of ‘Green call 2ho’ were 34.9 and 58.5 % which are 3.3 and 2.7 % lower than those of ‘Florida 80’, respectively.

Micro‐Granulated Starter Fertilizer Effects on Growth and Productivity of Winter Oilseed Rape

Core Ideas Micro‐granulated starter fertilizer enhances crop growth in autumn. Micro‐granulated starter fertilizer increases the yield of autumn biomass. Micro‐granulated starter fertilizer increases overwintering success. Micro‐granulated starter fertilizer increases nutrient uptake. Micro‐granulated starter fertilizer increases seed and straw yields. The effectiveness of starter or band application of fertilizers may improve the response to in‐season fertilizer application. This technique reduces fertilizer costs and minimizes environmental risks through decreased nutrient stratification, reduced nutrient emissions to surface water, ground water, and the atmosphere. This paper presents the results of a 3‐yr study investigating the effects of a micro‐granulated starter fertilizer (MSF) applied in the seed zone on the autumn growth, overwintering success, and biomass yield of winter oilseed rape (Brassica napus L.). The study was performed at the Agricultural Experiment Station in Bałcyny (northeastern Poland) from 2012 to 2015. The MSF did not compromise seedling emergence, it increased the dry matter (DM) content of rosette leaves by 15 to 24% (without influencing taproot length or weight) in autumn, and contributed to a 6% increase in the overwintering success of oilseed rape. The MSF increased seed yield (by 0.26–0.44 Mg ha−1), lowered the harvest index (from 0.401 to 0.380) and decreased root biomass yield (by 0.51–0.69 Mg ha−1). The use of the MSF reduced or even eliminated the need for conventional pre‐sowing NPK fertilizer without exerting adverse effects on the overwintering success or the yield of winter oilseed rape. The application of the MSF during sowing reduces fertilization costs and minimizes environmental hazards.