Green Ground Cover Research Articles

Warsaw small and medium-sized public urban green spaces as a response to short-time leisure needs of local residents and passers-by

ABSTRACT The study investigates visitors’ activity patterns in small and medium-sized public urban green spaces (SAMPUGS) and the relationship between the green space features and their use through the field observation of 36 case areas in Warsaw districts – Śródmieście and Ursynów. They were analysed using the perceived sensory dimensions (PSDs) and the Environmental Assessment of Public Recreation Spaces (EAPRS) tool. The green spaces in Ursynów are greener and richer in species than those in Śródmieście, but they lack historical features. The most popular activities are: sitting on a bench, strolling, dog walking, chatting and eating/drinking. Sitting on a bench is encouraged by the presence of historical feature and view outside green space but not by the ‘green ground cover’ or high green coverage ratio. Strolling is promoted in the green spaces of the bigger size and with the developed path network, but also with presence of flowerbeds and those rich in species. Chatting is promoted by the presence of historical features but not by the presence of ‘green ground cover’ and richness in species. Eating/drinking is encouraged by the presence of many places to sit, higher PSD ‘culture’ score, especially in Śródmieście and higher PSD ‘space’ score, especially in Ursynów.

Variation for turfgrass performance in a set of Lolium perenne germplasm evaluated under limited irrigation

AbstractPerennial ryegrass (Lolium perenne L.) is a major turfgrass species in temperate regions around the world. Unfortunately, it lacks drought tolerance compared with other cool‐season turfgrass species and often requires substantial inputs of freshwater as supplemental irrigation to achieve high turfgrass quality. To address the need for more drought‐tolerant perennial ryegrass, we conducted an evaluation of perennial ryegrass germplasm from the U.S. National Plant Germplasm System under deficit irrigation conditions and two mowing heights at Kaysville and Logan, UT during 2017 and 2018. We characterized turfgrass dark green color, ground cover, density, and quality using digital photography to capture images that we then converted to trait values using the TurfAnalyzer software. The higher mowing height resulted in greater ground cover, density, and quality. The collection of 49 germplasm accessions and 11 cultivars exhibited substantial variation for turfgrass dark green color, ground cover, density, and quality. Cultivars included as checks generally had greater turfgrass color and density, but the germplasm accessions generally had greater turfgrass ground cover and quality. Selection among these germplasm accessions will provide elite germplasm with utility for improving these traits in applied perennial ryegrass turfgrass breeding programs.

Potential drivers of common brushtail possum (

Australia’s terrestrial mammalian fauna have experienced severe declines since European settlement. On the Murray–Darling floodplain in south-eastern Australia, common brushtail possums (Trichosurus vulpecula, ‘possums’), have contracted to riparian zones. Although an important possum refuge, little is known about possum population dynamics here. We examined possum population dynamics and potential drivers across two decades on the Murray River floodplain at Calperum Station. We related possum density to satellite derived fractional cover, (a measure of the proportion of green, non-green and bare ground cover), and contextualised these findings using tree condition and grazing pressure datasets. Possum surveys were conducted between 1998 and 2019 in riparian and non-riparian habitats and density was modelled in relation to fractional cover values of green, non-green, and bare ground. Possum density fluctuated between 1998 and 2008 but in 2018 and 2019, possums were undetectable. Possum density was negatively associated with bare ground and positively associated with non-green. Overgrazing by kangaroos likely reduced vegetation cover and diversity and contributed to possum decline, via a reduction in possum food resources and increased exposure to predation. Inconsistent monitoring meant that the population decline was not detected until after it had occurred, and management interventions were not triggered, highlighting the dilemma of allocating scarce monitoring resources.

Factors contributing to the usage of pocket parks―A review of the evidence

This paper presents a summary of empirical evidence drawn from a literature review on the factors contributing to people using the pocket parks. Initial findings indicate that pocket parks play a significant role by providing access to nature for individuals living in urban areas. This paper provides an evidence-based approach to the usage and benefits of pocket parks by applying the SE-Model approach. This review includes 15 papers on pocket parks, obtained from electronic journal databases such as Scopus, Science Direct, Springer Link, SAGE Journals and Google Scholar sort by relevance containing key words such as pocket parks, vest-pocket parks, small public urban green space, small urban parks, use as well as usage of pocket parks. Selection was restricted to peer-reviewed publications related to pocket parks usage. The authors analysed these literatures for its sample characteristics, data collection, sampling method, data analysis and the main study finding. This review reveals an increase in research on the usage of pocket parks published in peer-reviewed journals in the recent years and a strong geographic bias. The selected studies have consistently reported on the importance of pocket parks for mental well-being, predominantly, followed by social benefits, however limited study approached the potential of pocket parks for physical activities. Physical components (green ground cover, bushes, trees, flower beds, water features) and Perceived Environment (preference for greener view; calm atmosphere; safety) are mostly reported to be highly associated with human health.

An online system for calculating and delivering long-term carrying capacity information for Queensland grazing properties. Part 2: modelling and outputs

A combination of field data and models have been used to estimate long-term carrying capacity (LTCC) of domestic livestock in Queensland grazing lands. These methods have been synthesised and coupled with recent developments in science and information technology to provide a fully-automated approach of modelling LTCC through the FORAGE online system. In this study, the GRASP model was used to simulate pasture growth with parameter sets and safe pasture utilisation rates defined for 225 land types across Queensland. Distance to water points was used to assess the accessibility of pastures to livestock. Spatial analysis classified the property into unique areas based on paddock, land type and distance to water points, which estimated pasture growth, pasture utilisation and accessibility at a sub-paddock scale. Thirteen foliage projective cover (FPC) classes were used in modelling the pasture system to deal with the non-linear relationship between tree and grass interactions. As ‘proof of concept’, remotely-sensed individual-date green ground cover data were used to optimise the GRASP model parameters to improve the model performance, and a Monte Carlo analysis provided uncertainty estimates for model outcomes. The framework provides an efficient and standardised method for estimating LTCC. To test the system, LTCCs from 43 ‘benchmark’ properties were compared with simulated LTCCs, and 65% of the modelled LTCCs were within ± 25% of the benchmark LTCCs. Due to uncertainties in model inputs at the property scale and in model simulation, the modelled LTCC should be used as a starting point for further refinement of actual property LTCC.

Assessment and modelling of vegetation biomass in a major bauxite mine of Eastern Ghats, India

Large-scale surface mining are the major causes for ecological disaster at the landscape level, but ecological restoration in post mining areas offers an opportunity to re-develop an ecosystem. The present research programme was undertaken in Panchapatmali Bauxite Mines in Koraput district of Odisha which is one of the biggest mines in Eastern Ghats ecoregion. The above ground biomass (AGB) and soil parameters inside and outside the mines (natural forest) were compared and their interrelationships were also tested at 1% level of significance. For the three dominant species Pinus insularis, Eucalyptus hybrid and Samenia saman, the regression coefficient (R2) values for AGB were significant with respect to DBH (R2 = 0.80–0.90), height (R2 = 0.35–0.76) and with basal area (R2 = 0.90–0.96). Species wise, maximum biomass was shown by Pinus insularis followed by Eucalyptus hybrid and Samenia saman which reveals that exotic species have overruled the indigenous species in the plantation areas. An accurate cokriging geospatial model with minimum errors predicted the AGB values to range from 45.6 to 416.4 t/ha compared to the observed biomass range 5.90–507.06 t/ha through the developed regression equation y = 1.003x + 0.24. The overall AGB of the reclaimed area was at par with the natural forest outside the mines. Increasing the pH level of soils, planting indigenous species and increasing green ground cover species will have lesser negative competition with the trees in the reclaimed zone that can restore the fragile ecosystem.

UTILIZING LANDSAT AND SENTINEL-2 TO REMOTELY MONITOR AND EVALUATE THE PERFORMANCE OF WINTER COVER CROPS THROUGHOUT MARYLAND

Abstract. Winter cover crops have been shown to limit erosion and nutrient runoff from agricultural land. To promote their usage, the Maryland Department of Agriculture (MDA) subsidizes farmers who plant cover crops. Conventional verification of cover crop planting and analysis of subsequent crop performance requires on-the-ground fieldwork, which is costly and labor intensive. In partnership with the MDA, NASA's DEVELOP program utilized imagery from Landsat 5, Landsat 8, and the European Space Agency’s Sentinel-2 to create a decision support tool for satellite-based monitoring of cover crop performance throughout Maryland. Our teams created CCROP, an interactive graphical user interface, in Google Earth Engine which analyzes satellite imagery to calculate the normalized difference vegetation index (NDVI) of fields across the state. Linear regression models were applied to convert NDVI to estimates of crop biomass and percent green ground cover, with measure of fit (R2) values ranging from 0.4 to 0.7. These crop metrics were implemented into an interactive filtering tool within CCROP which allows users to examine cover crop performance based on a variety of growing parameters. CCROP also includes a time series analysis routine for examining the progression of NDVI throughout the spring to help determine farmer-induced termination dates of cover crops. With this decision support tool, the MDA can analyze the effectiveness of cover crops throughout the state with reduced need to manually spot-check enrolled production fields, and can identify variables influencing overall cover crop performance to optimize implementation of their winter cover crop program via adaptive management approaches.

Digital Image Analysis of Old World Bluestem Cover to Estimate Canopy Development

Core Ideas ImageJ and Canopeo agreed in accurately measuring vegetative ground cover of pasture. Light interception was linearly related to ground cover measurement with ImageJ and Canopeo. ImageJ and Canopeo reduced the time for estimating canopy development by 96%. ABSTRACTDigital image analysis (DIA) can potentially provide rapid, objective assessment of pasture canopy development. In pastures of ‘WW‐B.Dahl’ Old World bluestem [Bothriochloa bladhii (Retz) Blake], we compared the DIA programs ImageJ and Canopeo for ground cover estimates, their ability to estimate canopy functions, and their time savings for vegetation analysis relative to a manual method. The DIA procedure involved processing overhead canopy images into two color groupings corresponding to green ground cover and non‐green (dead) cover plus bare ground for ground cover calculation. ImageJ analysis of ground cover agreed with two types of Canopeo applications (r2 values of 0.97 and 0.98). The prediction regression for percentage photosynthetically active radiation interception (PARI) using ImageJ, y = 0.94x − 2.91 (r2 = 0.72), was not different from Canopeo. Predicted values of leaf area index (LAI) and biomass increased exponentially with ground cover, likely owing to overlapping leaf area in older canopies. Two‐dimensional ground cover had limited power of estimating LAI and biomass when ground cover exceeded 60%, LAI exceeded 1.8, and biomass exceeded 1500 kg DM ha−1. The time required for estimating PARI, LAI, and green biomass using ground cover from both DIA methods was reduced to 3.6% of manual methods. The use of DIA with ImageJ provided measurements of ground cover that are simple and conducive to large batch analyses. Regressions of ground cover were deemed useful for rapid estimations of PARI and LAI, but of lesser value for biomass, especially when canopies developed stems and seedheads.

Crop Ground Cover Fraction and Canopy Chlorophyll Content Mapping using RapidEye imagery

Abstract. Remote sensing is a suitable tool for estimating the spatial variability of crop canopy characteristics, such as canopy chlorophyll content (CCC) and green ground cover (GGC%), which are often used for crop productivity analysis and site-specific crop management. Empirical relationships exist between different vegetation indices (VI) and CCC and GGC% that allow spatial estimation of canopy characteristics from remote sensing imagery. However, the use of VIs is not suitable for an operational production of CCC and GGC% maps due to the limited transferability of derived empirical relationships to other regions. Thus, the operational value of crop status maps derived from remotely sensed data would be much higher if there was no need for reparametrization of the approach for different situations. This paper reports on the suitability of high-resolution RapidEye data for estimating crop development status of winter wheat over the growing season, and demonstrates two different approaches for mapping CCC and GGC%, which do not rely on empirical relationships. The final CCC map represents relative differences in CCC, which can be quickly calibrated to field specific conditions using SPAD chlorophyll meter readings at a few points. The prediction model is capable of predicting SPAD readings with an average accuracy of 77%. The GGC% map provides absolute values at any point in the field. A high R² value of 80% was obtained for the relationship between estimated and observed GGC%. The mean absolute error for each of the two acquisition dates was 5.3% and 8.7%, respectively.

Identifying Features of Pocket Parks that May Be Related to Health Promoting Use

Urban green spaces have been shown to promote health and well-being and recent research indicates that the two primary potentially health promoting uses of pocket parks are ‘rest and restitution’ and ‘socialising’. The aim of this study is to identify features in pocket parks that may support these uses. The relationship between the two types of use and the shape, size, noise level, greenness, as well as ‘elements’ (paved and unpaved trails, café, historical feature, table, other seating than benches, flowerbeds, view outside park, playground) in nine pocket parks in Copenhagen were analysed. The results show that ‘green features’ do not seem to be of crucial importance for ‘socialising’ whereas, as expected, features promoting gathering should be prioritised. For ‘rest and restitution’, the main results show that ‘green ground cover’ and ‘enclosed green niches’ are important, while ‘disturbing features’ (playground, view outside park) should be avoided. The results add knowledge about the features which support the health promoting use of pocket parks to the existing body of research.

Minimizing Interspecific Competition in Soybean by Optimizing Cover Crop Self‐Seeding

Developing self‐seeding cover crop systems that minimize interspecific competition with soybean [Glycine max (L.) Merr.] are possible if cover crop growth is restricted to optimize cover crop seed production and dispersal. The objectives of this research were to quantify cover crop seed production, viability, and self‐seeding when growing concurrently with soybean. Winter wheat (Triticum aestivum L.), triticale (X Triticosecale Wittmack), and rye (Secale cereale L.) were seeded at two target rates (99 and 198 seeds m−2). Three seed dispersal methods (natural seed rain, simulated combine, and mechanical preharvest) were also tested to disperse mature cover crop seed. Wheat combined with mechanical seed dispersal before soybean harvest exhibited the greatest consistency in self‐seeding (171 and 123 plants m−2 in 2007 and 2008) regardless of establishment seeding rate. Additionally, wheat averaged 51 and 32% green groundcover in the fall of 2007 and 2008. Wheat seed viability (>82%) exceeded rye and triticale at soybean harvest, approximately 60 to 80 d after seed maturity. Cover crop species or establishment seeding rate did not affect soybean seed yield either year. Averaged across seeding rate and seed dispersal treatments, wheat self‐seeding systems exhibit the greatest potential for adoption, although soybean yield was 27% lower in 1 of 2 yr compared with a no cover crop control.

Bermudagrass and Buffalograss Drought Response and Recovery at Two Soil Depths

ABSTRACTDrought responsive turfgrass cultivars are becoming increasingly important in water conservation. Eight cultivars of bermudagrass [Cynodon dactylon (L.) Pers.], one cultivar of buffalograss [Buchloe dactyloides (Nutt.) Engelm.], and two root‐zone depths were evaluated for drought response and recovery during consecutive 60‐d drought and 60‐d recovery periods over 2 yr. Individual cultivar responses to drought and post‐drought recovery time were quantified through digital image analysis as the number of days to decrease to or increase to 50% green ground cover, respectively. No grass survived the 60‐d drought when planted on the restricted 10‐cm soil depth in 2006 or 2007, while all entries survived when planted on the unrestricted native soil depth. Both study years provided unique conditions for investigating drought response as the mean time to reach 50% green ground cover differed by 17 d between the 2 yr of study. Some cultivars lost 50% green ground cover in 20 d while other cultivars lasted the entire 60‐d drought period without losing 50% green ground cover. Post‐drought turfgrass recovery responses differed by as much as 45 d in achieving 50% green ground cover. Documenting individual cultivar responses to drought and recovery may provide perspective on individual grass cultivars that may initiate poor irrigation management behavior due to early leaf firing as well as refine consumer expectations following drought conditions.

Drought Response and Recovery Characteristics of St. Augustinegrass Cultivars

ABSTRACTAs water resources become restricted for use on amenity turfgrass systems, the inability for consumers to delineate incremental drought stress relating to plant health can result in the misuse of water resources during drought conditions. Seven cultivars of St. Augustinegrass (SA) [Stenotaphrum secundatum (Walt.) Kuntze] and two root zone depths were evaluated for drought response and recovery during consecutive 60‐d drought and 60‐d recovery periods over 2 yr. Using digital image analysis, drought response and recovery were quantified as the number of days to decrease or increase to 50% green ground cover, respectively. Both study years provided unique conditions for investigating drought response as the mean time to reach 50% green ground cover differed by 24 d between the 2 yr of study. Some SA cultivars lost 50% green ground cover in 23 d while other cultivars lasted the entire 60 d drought period without losing 50% green ground cover. Floratam provided the most consistent drought response and recovery compared to other SA cultivars. Once water was no longer limited, cultivars demonstrated up to a 52 d difference in attaining 50% green ground cover. Results could significantly impact home consumer irrigation behaviors and influence consumer expectations of turfgrass following drought conditions.

Establishment and Growth of Self‐Seeded Winter Cereal Cover Crops in a Soybean–Corn Rotation

Perpetuating cereal cover crops through self‐seeding may increase adoption by reducing risk and cost. Winter rye (Secale cereale L.), wheat (Triticum aestivum L.), and triticale (× Triticosecale Wittmack) were used to develop self‐seeding cover crop systems in a soybean [Glycine max (L.) Merr.]–corn (Zea mays L.) rotation. Cereals were planted and managed chemically and mechanically in varying configurations. The objectives were to (i) quantify temporal establishment patterns after one cycle of self‐seeding, (ii) quantify shoot biomass, N uptake, and seed production growing concurrently with corn, and (iii) quantify cover crop establishment after two cycles of self‐seeding. Final plant densities for most species by treatment combinations were fully established within 1 wk after soybean (Cycle 1) harvest. Fall green ground cover after soybean was consistently higher with wheat and ranged from 16 to 61%. Straw biomass the following July ranged from 50.4 to 79.1 g m−2 in wheat, 20.1 to 39.3 g m−2 in triticale, and 0.0 to 52.7 g m−2 in rye. Combined spring and maturity maximum N uptake was 20.7, 21.2, and 35.0 kg ha−1 for triticale, wheat, and rye. Cycle two cover crop seed production was greatest in wheat and ranged from 559 to 1280 seeds m−2. Wheat also consistently had greater self‐seeding plant establishment after two cycles than rye and triticale, which ranged from 5 to 21% of the original plant densities and 19 to 64% of the cycle one plant densities. Future research on self‐seeding cereal cover crops should focus on efficient technologies for seed dispersal.

Establishment and Growth of Self-Seeded Winter Cereal Cover Crops in a Soybean–Corn Rotation

Perpetuating cereal cover crops through self-seeding may increase adoption by reducing risk and cost. Winter rye (Secale cereale L.), wheat (Triticum aestivum L.), and triticale (× Triticosecale Wittmack) were used to develop self-seeding cover crop systems in a soybean [Glycine max (L.) Merr.]–corn (Zea mays L.) rotation. Cereals were planted and managed chemically and mechanically in varying configurations. The objectives were to (i) quantify temporal establishment patterns after one cycle of self-seeding, (ii) quantify shoot biomass, N uptake, and seed production growing concurrently with corn, and (iii) quantify cover crop establishment after two cycles of self-seeding. Final plant densities for most species by treatment combinations were fully established within 1 wk after soybean (Cycle 1) harvest. Fall green ground cover after soybean was consistently higher with wheat and ranged from 16 to 61%. Straw biomass the following July ranged from 50.4 to 79.1 g m−2 in wheat, 20.1 to 39.3 g m−2 in triticale, and 0.0 to 52.7 g m−2 in rye. Combined spring and maturity maximum N uptake was 20.7, 21.2, and 35.0 kg ha−1 for triticale, wheat, and rye. Cycle two cover crop seed production was greatest in wheat and ranged from 559 to 1280 seeds m−2. Wheat also consistently had greater self-seeding plant establishment after two cycles than rye and triticale, which ranged from 5 to 21% of the original plant densities and 19 to 64% of the cycle one plant densities. Future research on self-seeding cereal cover crops should focus on efficient technologies for seed dispersal.

Spectral vegetation indices for benchmarking water productivity of irrigated cotton and sugarbeet crops

Irrigation performance and water productivity can be benchmarked if estimates of spatially distributed yield and crop water use are available. A commonly used method to estimate crop evapotranspiration in irrigated areas is to multiply reference evapotranspiration values by appropriate crop coefficients. This study evaluated convenient ways to derive such coefficients using multispectral vegetation indices obtained by remote sensing. Detailed ground radiometric measurements were taken in small plots perpendicular to the crop rows to obtain canopy reflectance values. Ancillary measurements of green ground cover, plant height, leaf area index and biomass were taken in the cropped strip covered by the radiometer field-of-view. The results were up-scaled using 10 Landsat-5 and 1 Landsat-7 images. Crop measurements and ground radiometry were made at the time of Landsat overpass on two commercial fields, one grown with sugarbeet and the other with cotton. Crop height and ground cover were determined weekly in these two fields, three additional sugarbeet fields and one additional cotton field. The ground and satellite observations of canopy reflectance yielded similar results. Two vegetation indices, the normalized difference vegetation index (NDVI) and the soil adjusted vegetation index (SAVI) were evaluated. Both indices described the crop growth well, but SAVI was used in further evaluations because it could be conveniently related to both ground cover and the basal crop coefficient using a simple model. Based on these findings, crop water use variability was analyzed in a large sample of sugarbeet and cotton fields, within a homogeneous irrigation scheme in Southern Spain. The yield versus evapotranspiration data points were highly scattered for both cotton and sugarbeet. The yield values obtained from the sugarbeet fields and cotton fields were substantially lower than values predicted by a linear yield function, and close to a curvilinear yield function, respectively. Evapotranspired water productivity varied in the cotton fields from 0.3 to 0.78 kg m −3, and in the sugarbeet fields from 7.15 to 14.8 kg m −3.

Oferta de forragem de capim-elefante anão 'Mott' e a dinâmica da pastagem

Esta pesquisa foi conduzida durante as estações de crescimento de 1994/95 e 1995/96 (out./abr.), na Estação Experimental de Ituporanga/EPAGRI - SC, objetivando avaliar a dinâmica de uma pastagem de capim-elefante anão `Mott' (CEAM) submetida a níveis de oferta de forragem (OF). Os níveis reais de OF foram 3,8; 7,5; 10,2 e 14,0 kg de MS de lâminas verdes/100 kg de PV/dia, em pastejo contínuo, por meio da técnica "put-and-take", usando terneiros de 8 a 10 meses, em um delineamento em blocos completos casualizados com duas repetições. As OF determinaram resíduos médios de MS de lâminas verdes (RMSLV) de 722, 1537, 2332 e 2542 kg/ha, respectivamente. A taxa de acúmulo de matéria seca de lâminas verdes, a cobertura do solo, o diâmetro de touceiras, o peso de afilhos, a altura de plantas e o comprimento de entrenós aumentaram com as maiores OF. Já as menores provocaram aumento da densidade aparente, bem como redução da porosidade total do solo e do sistema radicular, com incremento pronunciado de espécies anuais na pastagem de CEAM. OF de 10 a 11 kg de MS de lâminas verdes/100 kg de PV/dia (equivalentes a RMSLV de 2000 a 2300 kg/ha) asseguram condição de sustentabilidade à pastagem de CEAM, em pastejo contínuo.

Corrigenda - Growth, development and light interception of old and modern wheat cultivars in a Mediterranean-type environment

A field experiment was conducted at Merredin in the eastern wheat belt of Western Australia, comparing 10 wheat cultivars representing old and modern wheats. The aim of the study was to identify any morphological and physiological characters associated with higher grain yield of modern wheat cultivars.The modern cultivars reached double ridge, terminal spikelet, anthesis and maturity earlier than the old cultivars, but modern cultivars had a longer duration between double ridge and terminal spikelet stage. The number of leaves on the main stem generally decreased from old, Purple Straw (14) to modern cultivars like Kulin (8). The modern cultivars had a shorter phyllochron interval than the old cultivars. The old cultivars also produced more tillers per plant (7.3) and had a lower percentage (35%) of ear bearing tillers, as compared with 3.9 and 51% for modern cultivars.The green area index and ground cover was higher in old than modern cultivars. However, the efficiency of conversion of photosynthetically active radiation to dry matter was slightly greater for modern cultivars. Although dry matter at final harvest was similar between cultivars, there was a trend for higher dry matter production with modern cultivars. The post-anthesis green area duration was longer with modern cultivars and grain yield increased with increase in post-anthesis green area duration.Grain yield and HI increased consistently from old to modern cultivars. The most recent cultivar Kulin had the highest yield and second highest harvest index, which were 63% and 48% respectively higher than the oldest cultivar, Purple Straw. Increases in grain yield in the modern cultivars were associated with increased grains spikelet-1 and grains ear-1. Mean grain weight showed a slight reduction with modern cultivars. The results are discussed in relation to future improvement in yield.

Growth, development and light interception of old and modern wheat cultivars in a Mediterranean-type environment

A field experiment was conducted at Merredin in the eastern wheat belt of Western Australia, comparing 10 wheat cultivars representing old and modern wheats. The aim of the study was to identify any morphological and physiological characters associated with higher grain yield of modern wheat cultivars.The modern cultivars reached double ridge, terminal spikelet, anthesis and maturity earlier than the old cultivars, but modern cultivars had a longer duration between double ridge and terminal spikelet stage. The number of leaves on the main stem generally decreased from old, Purple Straw (14) to modern cultivars like Kulin (8). The modern cultivars had a shorter phyllochron interval than the old cultivars. The old cultivars also produced more tillers per plant (7.3) and had a lower percentage (35%) of ear bearing tillers, as compared with 3.9 and 51% for modern cultivars.The green area index and ground cover was higher in old than modern cultivars. However, the efficiency of conversion of photosynthetically active radiation to dry matter was slightly greater for modern cultivars. Although dry matter at final harvest was similar between cultivars, there was a trend for higher dry matter production with modern cultivars. The post-anthesis green area duration was longer with modern cultivars and grain yield increased with increase in post-anthesis green area duration.Grain yield and HI increased consistently from old to modern cultivars. The most recent cultivar Kulin had the highest yield and second highest harvest index, which were 63% and 48% respectively higher than the oldest cultivar, Purple Straw. Increases in grain yield in the modern cultivars were associated with increased grains spikelet-1 and grains ear-1. Mean grain weight showed a slight reduction with modern cultivars. The results are discussed in relation to future improvement in yield.

Winter wheat vegetation indices calculated from combinations of seven spectral bands

Spectral reflectance data were obtained for winter wheat over a full growing season. Four irrigation treatments, applied to six genotypes, provided a variety of crop growth conditions. Leaf area index, green ground cover, total wet and total dry phytomass, and leaf phytomass measurements were taken monthly during the winter and biweekly during the spring. Reflectance measurements were made with a radiometer having three visible, two near-IR and two mid-IR bands. Vegetation indices, calculated from various band combinations, were linearly related to the five plant parameters. Of the 1240 vegetation indices formed, ratio indices had the higher (0.79–0.86) coefficients of determination ( r 2) than N-space greenness (0.61–0.81) when related to the plant parameters. The commonly used IR/red ratio produced considerably lower r 2 values than many of the other ratio indices. The mid-IR bands appeared more frequently in the ratio indices than in the greenness indices. The results show the relative merits of the seven bands, when combined into vegetation indices, to estimate various plant parameters.