Ryegrass Varieties Research Articles

Glutathione S-Transferases of Italian Ryegrass (Lolium multiflorum): Activity toward Some Chemicals, Safener Modulation and Persistence of Atrazine and Fluorodifen in the Shoots

Many varieties of Italian ryegrass (Lolium multiflorum) show resistance to herbicides; while this ability was frequently attributed to alterations in the target sites of the herbicide's action of the plant or to an efficient oxidative metabolism, little attention has been paid to glutathione S-transferases (GSTs), which are a family of detoxifying enzymes involved in the inactivation of many toxic compounds. To investigate the role of GSTs, seedlings of Italian ryegrass were treated with four herbicides (atrazine, fenoxaprop-ethyl, fluorodifen, metolachlor) and a safener (fenchlorazol-ethyl). All the treatments were well tolerated by the plant, with very low decreases in terms of fresh weight and length of shoots. Regarding GST activity, the chemicals generally determined significant increases in the above enzyme activity toward the model-substrate CDNB. Therefore, the herbicides most GST inducing and the safener were tested themselves as enzyme substrates: constitutive GST activities toward atrazine, fluorodifen and fenchlorazol-ethyl were found, and, in addition, these activities were significantly induced by the safener. Following these results, a HPLC procedure was standardized in order to investigate the persistence of atrazine and fluorodifen in the seedlings of Italian ryegrass and the effect on this of the safener. It was found that the residual amounts of the two herbicides in the shoots were significantly reduced following the safener treatments.

Studies regarding the performance of some bluegrass and ryegrass varieties used in lawns under the climatic conditions in the forrest steppe of North - East Romania

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Registration of ‘Nelson’ Annual Ryegrass

‘Nelson’ ryegrass is a newly released variety of annual ryegrass that will be used as a forage crop for grazing livestock in the southern USA. Nelson (Reg. No. CV‐257, PI 658137) Italian ryegrass (Lolium multiflorum Lam.) was developed by the Texas Agricultural Experiment Station—now Texas AgriLife Research—as a forage‐type annual ryegrass. Plant breeding of Nelson was conducted at what is now the Texas AgriLife Research and Extension Center at Overton, Texas. Nelson is a tetraploid where 2n = 4x = 28 chromosomes. Nelson is an open‐pollinated three‐way cross from ryegrass breeding lines TXR2000‐T2, TXR2002‐T17, and the cultivar ‘Jumbo’. Both TX breeding lines were from ‘TAM 90’ germplasm that had its chromosome numbers doubled from 14 to 28. Adjacent rows, which were replicated, were grown in an isolation block and allowed to cross‐pollinate and produce seed. Subsequent generations were grown and selected for high forage‐yield potential and crown rust (caused by Puccinia coronate Corda) resistance at Beaumont, Texas. Seed from these populations was increased in Oregon and was later tested for forage yield across the southern USA. Nelson has high forage‐yield potential, good crown rust resistance, and good cold tolerance for the southeastern USA. Nelson is improved for forage yield potential compared with most commercial cultivars in East Texas. The predominant use is projected to be in overseeding warm‐season pastures for winter production of forage for grazing animals. Seed production of Nelson will be in Oregon. Nelson was tested as TXR2006‐T22 and released in 2009.

내한성 이탈리안 라이그라스 품종별 파종량이 종자생산에 미치는 영향

ABSTRACTThis experiment was carried out to investigate the effect of seeding rate of newly developed Italian ryegrass varieties, “Kogreen” and “Hwasan 101”, on those seed production in Cheonan for three years (2005 to 2007). Two Italian ryegrass varieties were seeded at experimental fields of Grassland and Forage Division, National Institute of Animal Science on late September, and harvested at seed shattering stage. The experiment was arranged in randomized complete block design with three replications by each variety. The treatments was consisted of five seeding rates(5, 10, 20, 30, 40kg/ha). The average heading date of “Kogreen” was 9 May and “Hwasan 101” was 25 May. The harvesting date of “Kogreen” was on 16 June when the rainy season should not set in. In the case of “Hwasan 101”, the harvesting date of seed production was 3 July, because of rainy season. The number of ear per square meter, ear length, spikelet number, seed yield per ha and ripening rate of “Hwasan 101” were 471, 28.5cm, 24.8, 1,631kg and 71%, respectively. and those of “Kogreen” were 633, 24.0cm, 20.8, 2,676kg and 82.1%, respectively. The shattering property rate of “Hwasan 101” 40.3% was higher than that of “Kogreen” 2.6%. The germination rate of harvested “Hwasan 101” seed was 81.8% and that of “Kogreen” was 79.4%, respectively. In conclusion, the optimum seeding rate of Italian ryegrass for seed production are recommended 20kg/ha in both “Hwasan 101” and “Kogreen”.(Key words: Hwasan 101, Kogreen, Seed yield, Germination, Seed amount)

Removal of nutrients and veterinary antibiotics from swine wastewater by a constructed macrophyte floating bed system

The potential of three varieties of Italian ryegrass ( Lolium multiflorum Lam.), Dryan, Tachimasari and Waseyutaka, to improve the water quality of swine wastewater was evaluated using a constructed macrophyte floating bed system. With respect to reductions in levels of nutrients, chemical oxygen demand (COD), and sulfonamide antimicrobials (SAs, including sulfadiazine, sulfamethazine, and sulfamethoxazole), Dryan performed better than Tachimasari and Waseyutaka. For Dryan, total N was reduced by 84.0%, total P by 90.4%, COD by 83.4% and sulfonamide antimicrobials by 91.8–99.5%. Similar results were observed for Tachimasari and Waseyutaka. The results indicated that the treatment of swine wastewater using the constructed macrophyte floating bed system was effective in the removal of nutrients and veterinary antibiotics.

Effect of cultivation of clover based grassland on N losses to groundwater on a clay-loam soil

Herbage utilisation is of primary importance to grassland farmers due to its strong association with profit, yet it is not assessed in routine grass evaluations. On commercial grassland farms, grazing efficiency of varieties is believed to influence their level of herbage utilisation. To understand grazing efficiency the interaction between plant and animal is critical; mechanically simulated grazing protocols are limited in the information they provide. The objective of this paper was to further understand the grazing efficiency of perennial ryegrass varieties by identifying grazing traits which can be used as selection criteria by breeders striving to develop varieties with improved herbage utilisation. Fifty-five perennial ryegrass varieties, both diploid and tetraploid with intermediate and late heading dates, were sown in plots (3 m × 7 m; 21 m2) following a randomised block design with three replicates per variety. Swards were rotationally grazed by lactating dairy cows during the 2015 and 2016 grazing seasons. Sward structural, morphological, and chemical characteristics were measured and related to grazing efficiency, as measured by post-grazing sward height. These data were analysed using the PROC MIXED procedure to test the fixed effects of traits and the GLM procedure to test their relationships with grazing efficiency. Varieties were shown to differ in their level of grazing efficiency (p < 0.001). Tetraploid varieties had significantly (p < 0.001) greater grazing efficiency than diploids recording post-grazing sward heights of 3.8 and 4.1 cm, respectively. Increased free leaf lamina (p < 0.001), tiller mass (p < 0.05) and dry matter digestibility (p < 0.01) were shown to significantly improve grazing efficiency of varieties. This study has identified free leaf lamina, tiller mass and dry matter digestibility as key selection criteria for plant breeders to base their developments upon if grazing efficiency is imported into their breeding programmes.

Change in agronomic performance of Lolium perenne and Lolium multiflorum varieties in the past 40 years based on data from Belgian VCU trials

AbstractBy using data of Belgian trials for Value of Cultivation and Use (1963–2007) the change in agronomic performance of ryegrass varieties was quantified. Data included 144 Lolium perenne and 69 Lolium multiflorum candidate varieties, plus ‘Vigor’ and ‘Lemtal’, two varieties which were always included in the Value of Cultivation and Use (VCU) trials. As the genetics of ‘Vigor’ and ‘Lemtal’ have remained identical to those in 1963, these were used as constant standards to measure improvements of new varieties. Dry matter yield (DMY) of ‘Vigor’ and ‘Lemtal’ varied annually but did not show a progressive change, indicating that cultural changes in VCU trials of ryegrasses were small. By expressing DMY, persistency and rust resistance of the candidate varieties relative to Vigor and ‘Lemtal’, the change in agronomic performance due to breeding was determined. DMY increased with 0.3% of ‘Vigor’ and ‘Lemtal’ annually. Persistency showed an annual increase around 0.5% of the standard varieties. Before 1990, rust resistance of ryegrasses varied around 100% relative to ‘Vigor’ or ‘Lemtal’. After 1990, an annual increase of 3.6% against these standard varieties was found.

Susceptibility to Rust (Puccinia Sp.) in Cultivars of Italian and Perennial Ryegrass Grown in Two Locations of Italy

A large set of foreign varieties of Italian ryegrass (Lolium multiflorum) and perennial ryegrass (L. perenne) were evaluated for their response to natural rust infection in two Italian locations (Lodi in the north; Perugia in the centre of the country) at three-year intervals in 2001, 2004 and 2007, to acquire information on novel germplasm for Italy and verify any spatial and temporal variation in the varietal response to the disease. Crown rust (caused by Puccinia coronata) on Italian ryegrass and stem rust (caused by P. graminis) on perennial rygrass were consistently recorded in appreciable amount (average susceptibility score &gt; 2.0 on a 1-9 scale). Vice-versa, crown rust on perennial and stem rust on Italian ryegrass seldom affected appreciably the crop. Strong interactions of variety response (to the prevailing pathogen) with locations and years of evaluation were observed in both ryegrasses. Subsequently, the repeatability of results between locations, or between years within locations, as measured by rank correlations of variety scores, was sometimes only moderate or low. However, despite such interactions, a few promising varieties were identified in each species with consistently low susceptibility across evaluation environments, which deserve further investigation for a possible direct utilisation, or as donors of useful genes for breeding purposes.

Mineral Accumulation by Perennial Grasses in a High-Rainfall Environment

Mineral content affects the suitability of biomass for thermochemical conversion to bioenergy and represents macro- and micronutrients whose loss from the production system can impact subsequent regrowth and ecosystem services provided by perennial grasses. Genotypic differences in mineral content among cool-season grasses grown for seed are not well documented, and, consequently, the potential for genetic improvement of this trait is not known. This study compared the concentrations of carbon, nitrogen, potassium, phosphorus, chlorine, silicon, aluminum, boron, calcium, cobalt, iron, magnesium, manganese, sulfur, and zinc in leaves and stems from perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata), tall fescue (Schedonorus phoenix (Scop.) Holub), and Kentucky bluegrass (Poa pratensis L.) grown in the high-rainfall area of western Oregon. The concentration of C was similar in all grasses and in leaves and stems, but orchardgrass contained the greatest quantities of N, P, and K. The concentration of N was greater in leaf tissue, and similar among these grasses. There were differences in Cl, K, P, and Ca concentrations among these species and between leaf and stem tissues. Genotypic differences in the concentration of some of the minerals occurred among three varieties of tall fescue and among varieties of perennial ryegrass grown at two locations. Amounts of N, P, and K removed by harvest of 2.4 Mg ha − 1 of straw biomass of two perennial ryegrasses would range from 12 to 17, 3.4 to 3.8, and 40 to 47 kg ha −1 . Location had significant impact on mineral content, although plant mineral concentrations were not strictly correlated with soil composition.

내한 중생 이탈리안 라이그라스 신품종 '코윈마스터'

본 시험은 이탈리안 라이그라스 내한 중생 신품종을 육성하기 위하여 1999년부터 2006년까지 축산과학원 조사료자원과에서 수행되었다. 이탈리안 라이그라스 신품종 '코윈마스터'는 2배체 품종으로서 엽의 색은 담녹이며, 월동전 초형은 중간형, 봄의 초형은 반직립형이다. 코윈마스터는 5월 13일경에 출수하는 중생 품종이었다. 특히, 신품종 코윈마스터는 Florida 80 품종과 지엽의 폭은 비슷하나 지엽의 길이가 3 cm 정도 길며, 초장은 89 cm로 Florida 80 보다 6 cm 길었다. 줄기의 두께는 Florida 80과 같이 중간이었다. 코윈마스터의 내한성은 Florida 80 보다 월등히 강한 품종이었다. 코윈마스터의 건물수량은 9.521 kg/ha로서 Florida 80 보다 2% 많았다. 코윈마스터의 사료가치는 조단백질 함량이 12.1%, in vitro 소화율이 70.9%, ADF가 32.9%로 Florida 80과 비슷하였고, NDF는 56.0%로서 Florida 80 보다 1% 낮았다. 이상의 결과, 신품종 코윈마스터는 겨울이 추운 중부 북부지역에서 재배안정성이 높은 내한 중생 품종으로 사료된다. This experiment was carried out to breed a cold-tolerant variety of Italian ryegrass (Lolium multiflorum Lam.) in Grassland and Forage Crops Division, National Institute of Animal Science, RDA, Suwon from 1999 to 2006. ew variety, Kowinmaster as a diploid variety was light-green in leaf color and had medium and semi-erect growth habit in late autumn and early spring, respectively. Kowinmaster was 13th May in heading date as a medium-maturing variety. Especially, Kowinmaster was similar to Florida 80 in flag leaf width, longer 3cm in flag leaf length and longer 6cm in plant length than those of control variety, Florida 80, respectively. Stem width of Kowinmaster was similar to that of Florida 80. Cold tolerance of Kowinmaster was better than that of Florida 80. Dry matter yield (9,521 kg/ha) of Kowinmaster was 2% more than that of Florida 80. Feed value of Kowinmaster was 12.1% in crude protein, 70.9% in In vitro dry matter digestibility and 32.9% in acid detergent fiber that were similar to those of Florida 80, respectively, but in neutral detergent fiber, Kowimaster was 56.0% that was 1% lower than that of Florida 80.

Mapping of QTL for resistance to powdery mildew and resistance gene analogues in perennial ryegrass

AbstractThe objective of this study was to map resistance gene analogues (RGA) and quantitative trait loci (QTL) for powdery mildew resistance in perennial ryegrass (Lolium perenne L.). The mapping population consisted of 184 F2 genotypes produced from a cross between one genotype of a synthetic perennial ryegrass variety Veyo and one genotype from the perennial ryegrass ecotype Falster. The greenhouse infection was measured as number of sporulating colonies on a 10‐cm leaf area with the maximum possible number of colonies to be counted set to 50. The range of infection scores in the population was 0–50 and the heritability was 71.7%. In total, two QTL for powdery mildew resistance were identified, and mapped to linkage groups (LG) LG3 and LG7. Individually, these QTL explained between 7.5% and 22.1% of the total phenotypic variation. Six RGA and three laccases were mapped to LG2, LG3, LG4, LG5 and LG7, however, no close linkage between RGA and QTL was observed.

Effect of Water Soluble Carbohydrates on Fermentation Characteristics of Ensiled Perennial Ryegrass

Well-preserved silage is characterized by reduced pH, greater lactic acid concentration, and reduced ammonia (NH3) concentration compared with silage that did not ferment well. Water soluble carbohydrates (WSC) are the primary fermentation substrate. In temperate grass forages, glucose, fructose, sucrose, and fructans are the primary WSC. New varieties of ryegrass have been developed in the United Kingdom to express high levels of WSC.The objective of this trial was to determine differences in fermentation characteristics of grasses with different WSC levels cut and processed as silage. Four perennial ryegrasses, 3 cultivars with a relatively greater WSC concentration (AberAvon, AberDart, and Elgon) and 1 cultivar commonly grown in Oregon, the control WSC (Linn), were planted. Three replicates of each grass were ensiled after morning and afternoon harvests. Each sample was packed, vacuum sealed, and ensiled for 60 d at 10°C. Fresh grass samples were taken from each cutting and analyzed before ensiling. Fresh grass WSC was greater in the 3 high WSC grass cultivars vs. Linn. Final pH was less, total acids were greater, and lactic acid tended to be greater for the high WSC grass silages. Final pH, lactic acid, acetic acid, total acids, and NH3 were less for the afternoon vs. morning cutting. Ensiling was most efficient for high WSC grass varieties harvested at the afternoon cutting.

Vegetables and Grass Winter Covers in Rotation

ABSTRACT It may be that rotation of dispirit crops can allow for extended usage of cropland. Early and later maturing ryegrass varieties ‘Shiwasuaoba’ and ‘Gulf’ were planted as over-wintering covers. Controls consisted of a fall planted wheat species and bare soil. In the following spring the ryegrasses were clipped and the stubble left in place. The wheat was turned under. Biomass of the covers was determined. Sweet corn was planted using no-till techniques. Following harvest of sweet corn the stalks were tilled under and raised beds prepared. Bell pepper from transplants or cucumbers from seed were established. Harvests of the second vegetable crops occurred well before frost and the land was replanted to the ryegrasses or wheat or left bare. Yields from all crops were determined. Year affected results–yields of covers were higher in 2004 than 2005 with wheat producing the most biomass. Sweet corn yield was not affected by treatment, bell pepper had higher yields in 2004, and cucumber had higher yields in 2005. Total combined yields of all components (covers, sweet corn and bell pepper or cucumber) were generally better on land with covers than on land without a cover. Three crops could be produced on the same land in a year. The ryegrass ‘Shiwasuaoba’ matures earlier than does ‘Gulf’ and can be used for forage or a seed harvest. The system allows for diversity of production and for maximization of land usage.

내한 조숙성 이탈리안 라이그라스 신품종 '코스피드'

This experiment was carried out to breed the cold-tolerant variety of Italian ryegrass (Lolium multiflorum Lam.) in Grassland and Forage Crops Division, National Institute of Animal Science, RDA, Cheonan from 1999 to 2005. New variety, `Kospeed` is a diploid variety with green in leaf color, and has semi-erect and erect growth habit in late autumn and early spring, respectively. `Kospeed` was on 1 May in heading date as a early-maturing variety. Also `Kospeed` was wider by 0.2mm in flag leaf width, longer by 1cm in flag leaf length and shorter by 1cm in plant length than those of `Florida 80`, respectively. Stem width of `Kospeed` was similar to that of `Florida 80` and `Hwasan 101`. Cold tolerance of `Kospeed` was better than that of `Florida 80`. Dry matter (DM) yield (13,257kg/ha) of `Kospeed` was similar to that of `Florida 80`. In vitro dry matter digestibility (IVDMD) and total digestible nutrient (TDN) of `Kospeed` were 73.2% and 65.3% which are 2.1% and 1.7% higher than those of `Florida 80`, respectively. Acid detergent fiber(ADF) and neutral detergent fiber (NDF) of `Kospeed` were 29.1% and 53.1% which are 2.1% and 2.3% lower than those of `Florida 80`, respectively.

Linkage disequilibrium in synthetic varieties of perennial ryegrass

Synthetic varieties obtained after three to four panmictic generations are variable, not structured and so can be used for association studies. The pattern of linkage disequilibrium (LD) decay determines whether a genome scan or a candidate gene approach can be used for an association study between genotype and phenotype. Our goal was to evaluate the effect of the number of parents used to build the synthetic varieties on the pattern of LD decay. LD was investigated in the gibberelic acid insensitive gene (GAI) region in three synthetic varieties of perennial ryegrass (Lolium perenne L.) chosen for their contrasted number of parents in the initial polycrosses. Results were compared with those obtained from a core collection. STS and SSR markers were used to evaluate variation, structuration and LD in each variety. As expected, the varieties variability increased with the number of parents almost up to the core collection variability. No structuration was observed in the varieties. Significant LDs were observed up to 1.6 Mb in a variety originated from six related parents and not above 174 kb in a variety originated from 336 parents. These results suggest that a candidate gene approach can be used when varieties have a large number of parents and a genome scan approach can be envisaged in specific regions when varieties have a low number of parents. Nevertheless, we strongly recommend to estimate the pattern of LD decay in the population and in the genomic region studied before performing an association study.

A review of forage grass and clover seed use in Northern Ireland, UK between 1980 and 2004

AbstractThe total amount and the composition of varieties of all forage grass and clover seed delivered for farm use in Northern Ireland was monitored over the 25‐year period of 1980–2004. Total seed use in Northern Ireland declined from the 1980s to the 1990s but then stabilized despite isolated drops in sales associated with outbreaks of animal diseases. This profile was mirrored by similar declines in the rest of the UK. The survey revealed the annual volatility of the market and its sensitivity to changes in government financial support, to changes in farm practice and farm incomes. Examination of the data on the grassland area under 5 years old showed them to be poor indicators of actual seed use. Levels of species use were very stable over the 25 years of the survey but reseeding of varieties of perennial ryegrass differing in maturity and ploidy type changed dramatically. When sufficient seed was available, selection of varieties complied with the contemporary recommended list ratings of agronomic value but in a few cases selection of varieties was determined by price. The current survey of seed sales provides a benchmark against which responses by farmers following the latest changes in the Common Agricultural Policy of the European Union can be measured.

Effects of continuous or rotational grazing of two perennial ryegrass varieties on the chemical composition of the herbage and the performance of finishing lambs

AbstractPlant breeding has developed perennial ryegrass varieties with increased concentrations of water‐soluble carbohydrates (WSCs) compared with conventional varieties. Water‐soluble carbohydrates are major metabolic and storage components in ryegrass. Therefore, if perennial ryegrass herbage is allowed to grow to greater heights it should contain higher water‐soluble carbohydrates concentrations, for example as under rotational grazing rather than continuous grazing by livestock. This study investigated this hypothesis and measured the performance of lambs grazed rotationally and continuously. Replicated plots of the variety AberDart (bred to express high WSC concentrations) or the variety Fennema were grazed by a core group of ten male Cheviot lambs for 10 weeks. Lambs were weighed and replicate forage samples were taken every 7 d. Concentrations of WSC in AberDart herbage were significantly (P &lt; 0·05), but not substantially, higher than those in Fennema herbage. Rotational grazing did not increase the differential in WSC concentration between the AberDart and Fennema varieties. However, there was a tendency (P = 0·07) for lambs rotationally grazing the AberDart swards to have a higher final live weight than lambs grazing the Fennema swards. Overall, lamb performance was increased when either perennial ryegrass variety was rotationally rather than continuously grazed (P &lt; 0·001).

내한 다수성 이탈리안 라이그라스 신품종 '코위너'

본 연구는 이탈리안 라이그라스 내한성 품종 을 육성하기 위하여 1987년부터 2005년까지 농촌진흥청 축산연구소 조사료자원과에서 수행되었다. 신품종 '코위너'는 4배체 품종으로서 엽의 색은 농녹, 월동전 초형은 반포복형, 봄의 초형은 중간형이었다. '코위너'는 5월 19일경에 출수하는 중만생 품종으로 지엽의 길이가 29cm 로서 '화산 101호'와 같았으며 최장간장은 70cm로 '화산 101호' 보다 3cm 길었으며, 초장 은 97cm로 '화산 101호' 보다 3cm 길었다. 또한 '코위너'는 줄기 두께가 '화산 101호' 보다 두터웠으며, 1차 수확 후 재생이 양호하였다. '코위너' 품종의 내한성은 '화산 101호' 보다 다소 약하고 'Florida 80' 보다는 다소 강하였다. '코위너'의 건물수량은 14,345kg/ha로서 '화산 101호' 보다 8% 많았다. '코위너'의 사료가치는 in vitro 건물소화율(IVDMD)이 76.2%, 가소화양분총량(TDN)이 63.3%로서 '화산 101호' 보다 각각 1.6, 0.4% 낮았다. This experiment was carried out to breed the cold-tolerant variety of Italian ryegrass(Lolium multiflorum Lam.) in Grassland and Forages Division, National Livestock Research Institute, RDA, Suwon from 1987 to 2005. New variety, Kowinner as a tetraploid variety was dark green in leaf color and growth habit in autumn and early spring was semi-prostrate and medium, respectively Kowinner as a medium or late-heading variety was 19th May in heading date. Flag leaf length of Kowinner was 29 cm that was the same as control variety, Hwasan 101. Length of longest stem and plant length of Kowinner were 70 cm and 97 cm that was longer 3 cm than those of Hwasan 101, respectively. Stem width of Kowinner was thicker than that of Hwasan 101. Expecially, Kowinner was very good in regrowth. Cold tolerance of Kowinner was slightly weaker than that of Hwasan 101 and slightly stronger than that of Florida 80. Dry matter(DM) yield(12,884 kg/ha) of Kowinner was 8% more than that of Hwasan 101. In vitro dry matter digestibility and total digestible nutrient(TDN) of Kowinner were 76.2 and 63.3% that was 1.6 and 0.4% lower than those of Hwasan 101, respectively.

Cool-season turf grass species adaptability in Mediterranean environments and quality traits of varieties

Public and private sport turfgrass fields in areas with a Mediterranean climate are largely based on cool-season grasses. The widespread use of these turfgrasses in such environments has been ascribed to their availability on the seed market. The large number of cool-season cultivars of all turf species are generally released in northern Europe, Canada and the USA. Thus, the appropriate use of turf for implanting lawns requires field evaluation of the genotypes in sites with a Mediterranean climate to assess the behaviour of cultivars during the growing period. Our study aimed to evaluate the adaptability and quality of the most popular varieties of cool-season turfgrass species in a Mediterranean site in southern Italy. Forty varieties of perennial ryegrass ( Lolium perenne L.), 20 Kentucky bluegrass ( Poa pratensis L.) and tall fescue ( Festuca arundinacea Schreb.) and 10 cultivars for each species of creeping red ( Festuca rubra spp. rubra L.), chewing red ( Festuca rubra spp. commutata Gaud.) and slender creeping red fescue ( Festuca rubra spp. tricophylla Gaud. (Richter), were evaluated for 5 years in a replicated experimental block group design. On the varieties of each species turf quality, colour and cover were determined by using a visual score (1–9), assessed monthly from January to December, from 1999 to 2003. Kentucky bluegrass achieved lower scores in turf quality, colour and cover in winter, spring and autumn, and red fescue subspecies in spring and summer, than perennial ryegrass and tall fescue. Perennial ryegrass and tall fescue genotypes were better able than those of Kentucky bluegrass to cope with the climatic condition. The establishment of the varieties to the environment is determined by cluster analysis which identified for each trait of all turfgrass species, a group of varieties with superior performance and adaptability to cope in Mediterranean environmental conditions.

Pumpkin Yield and Weed Populations Following Annual Ryegrass

ABSTRACT Sustainable production can sometimes be achieved with diversification of cropping patterns and by the use of disparate crops in rotation. Following a forage grass harvest for feed it may be possible to produce a cucurbit crop before it is time to reseed an overwintering grass cover crop. Pumpkins may be a crop that can be grown in rotation with grasses. Five annual Italian ryegrass varieties of varying maturity [“Shiwasuaoba” (early); “Miniamioba” and “Waseyutaka” (medium); “Marshall” and “Zorro” (late)] were established in the fall. In early summer of the following year the grasses were harvested, their yield determined, and the stubble left in place. The control was composed of winter wheat which was harvested in the spring and the stubble turned under and the soil maintained without cover. Seed of pumpkin, cv. ProGold 300, were sown into strips tilled in the ryegrass stubble or bare soil. Number and weight of pumpkins were determined. Weed cover in plots following pumpkin harvest was determined. Plots were seeded with the ryegrasses or wheat, with the procedures repeated over two years. Marketable number and yield of pumpkin were not affected by cover or year of planting and averaged 1,755 fruit/ha and 5.9 Mg·ha−1, respectively, over both years. The percent of pumpkin fruit of the expected size for this cultivar, >7.25 kg, was 41% in the first year and 26% in the second year. Approximately 68% of fruit from plants on bare soil, and 27% from plants on soil covered with ryegrass stubble, were >7.25 kg. Total weed cover was not different on bare soil between years (avg. 86%), and dicot weeds were greater in 2002 than 2003. Total weed cover in ryegrass plots averaged about 36% in 2002 and 93% in 2003. Dicot weed cover in ryegrass stubble plots were not different between years or ryegrass variety and averaged 32%. Monocot weed cover was significantly lower in 2002, 5%, than in 2003, 57%, regardless of cover. There is a need for additional studies in ryegrass-pumpkin rotation before recommendations can be made for its implementation in southeastern Oklahoma.