The winter hardiness of Festuca rubra, Holcus lanatus and Agrostis spp. in comparison with Lolium perenne

Preliminary experiments were conducted to assess the winter hardiness of representative cultivars or populations of Festuca rubra, Holcus lanatus and Agrostis spp. in comparison with a hardy (Premo) and a susceptible (Grasslands Ruanui) cultivar of Lolium perenne. Two controlled-environment tests and a field experiment including two cutting and two fertilizer managements are reported.
Grasslands Ruanui and H lanatus suffered most damage in all tests. In the controlled-environment experiments, Premo was at least as hardy as the F. rubra and Agrostis cultivars but in the field Premo was more susceptible. Spring growth of Premo was affected more by the cutting and fertilizer managements applied the previous summer and autumn than was spring growth of F. rubra or Agrostis spp.
It was concluded that, whereas use off. F. rubra or Agrostis spp. should not be limited by fears of winter damage, poor winter hardiness may limit the value of H. lanatus for hill and upland reseeding.     

Hill Shape Effect on Yield,Quality, Stolon Length and Tuber Orientation of Two Potato Cultivars

Potato (Solanum tuberosum L.) cultivars are mostly planted using similar seed piece planting depths and hill shapes even though cultivars have unique tuber and stolon characteristics. A hill-shape study was conducted at Aberdeen, Idaho to determine the effects of hill shape on yield and field-green tuber yields and quality along with stolon length and tuber spatial orientation for two potato cultivars, 'Defender' and 'Summit Russet.' Plots were planted in late April to early May. Prior to emergence four hill shapes were formed: 1) plant-and-drag, 2) broad, 3) normal, and 4) peaked. Defender had higher total yield with the broad hill, but there were no differences among the remaining three hill shapes. For Defender, U.S. No. 1 yield was lower with the plant-and-drag hill shape, and the normal and peaked hills produced lower field-green tuber yield. Hill shape had no effect on total, U.S. No. 1, or field-green tuber yields of Summit Russet. The peaked hill resulted in a deeper uppermost tuber for Defender, while the uppermost tuber was deeper in the normal and peaked hills for Summit Russet. The broad hill resulted in a larger average tuber size for Defender, but hill shape had no effect on tuber size for Summit Russet. Total number of tubers per plant, stolon length and tuber spatial orientation were not affected by hill shape for either cultivar. Hill shape and height are important considerations in maximizing yield of saleable tubers, so needs to be customized according to cultivar-dependent stolon length and tuber orientation characteristics.     

THE EFFECT OF CUTTING TIMOTHY (PHLEUM PRATENSE L.) GROWN FOR PRODUCTION OF SEED

An experiment is described in which timothy, grown for production of seed, was cut once annually on dates ranging from 23 October to 24 May. New tillers in selected plants were labelled at monthly intervals during autumn and winter for 2 years, to determine the pattern of production of tillers and to assess the reproductive development of categories of tillers. The majority of tillers were produced in autumn, but production was continuous throughout the winter. There was a big increase from the first to the second year in the total number of tillers produced, but neither the pattern nor amount of tiller production was affected by cutting. The % of fertile tillers was highest in the oldest tillers, and was affected little by the increase in the number of tillers from the first to the second year; cutting had little effect on the % fertility except where floral primordia were removed by the cut on 24 May. In all treatments at least 90% of the ears at harvest were produced by tillers initiated the previous autumn. The penetration of light to the base of the plants was increased considerably by cutting, but it is concluded that interception of light by the whole plant is more beneficial than an increase in the penetration of light into the plant and a concomitant reduction in the total interception of light by the plant.     

THE EFFECT OF CUTTING COCKSFOOT (DACTYLIS GLOMERATA L.) GROWN FOR PRODUCTION OF SEED

An experiment is described in which cocksfoot, grown for production of seed, was cut annually for 3 years in either autumn, winter or spring. No significant increases in yield of seed/ac were obtained from any treatment compared with an uncut control, and a cut in late April in one year seriously reduced the yield of seed. Additional N applied after a defoliation in October did not increase the yield of seed compared with that from plots which were cut at the same time but not fertilized. The production of tillers was not affected by cutting on any date. The percentage fertility of tillers was increased by cutting in the first year, when the number of tillers was smallest; the fertility was less consistently affected in the second year, and was generally unaffected in the third year. The weight of seed produced per ear was usually reduced by the cutting treatments. In the third year of the experiment it was shown that the penetration of light to the base of the shoots was increased substantially by defoliation, but it is deduced that maximum interception of light by the whole plant is more important for the production of seed than increasing by cutting that proportion which penetrates to the base of the plant.     

环境因子对水稻品质形成的影响

通过对水稻不同生育时期的光温因子与产量构成因素及产量性状和品质性状的分析结果,发现在温光因子中,移栽期-始穗期日照、始穗期-成熟期积温对水稻的产量性状和品质性状的影响较大;在产量性状中,每穴穗数和结实率是受环境影响较大的性状;在品质性状中,蛋白质含量、垩白粒率、长宽比是受环境影响较大的性状。同时,灌浆结实期高温导致水稻结实率明显下降、千粒重略有提高;蛋白质含量、垩白粒率、长宽比受环境影响最大。     

Breeding perennial ryegrass ( Lolium perenne L.) for turf usage: an assessment of genetic improvements in cultivars released in Europe, 1974–2004

An assessment of genetic improvement in turf‐type perennial ryegrass was performed at a network of six locations. A comparison was made of the turf performances of five natural populations, five forage‐type cultivars used for turf seeding until the 1980s and 31 turf‐type cultivars released from 1974 to 2004. Populations and cultivars were also compared in two spaced‐plant experiments and in two seed‐yield trials. Trait regressions on registration year of turf‐type cultivars showed that breeding had been highly successful in improving the turf aesthetic merit (from +8·8 to +12·5% per decade according to seasons), wear tolerance (+5·4% per decade) and crown‐rust resistance (+8·9% per decade) and in lessening the turf height increase rate (?0·43 mm day^?1 per decade). Turf winter greenness had been marginally improved, whereas summer greenness and seed yield had not been significantly changed. A multivariate analysis provided evidence that turf density and fineness played a major role in the visual assessment of turf aesthetic merit and that wear tolerance was closely associated with turf density. Conflicting trait associations may have precluded improvements in turf ground‐cover 3 months after sowing, turf winter greenness and turf persistency.     

Hill to hill variations in tuber yield of potatoes in Alberta

The hill to hill variation in tuber yield and mainstem number was studied on 18 potato farms. There were up to 14-fold differences in the tuber yield per hill among plants of Norland, Russet Burbank, Norchip, Carlton and Alaska Red. The mainstem number was more variable than tuber weight per hill in Norland, Russet Burbank and Alaska Red. However, the opposite was true in Norchip and Carlton. In nearly all comparisons, the number of tubers per hill was less variable than tuber weight and mainstem number per hill. The total variation in tuber weight found in about 50% of the samples could be explained by the variance of hills within rows. Even in samples where an added variance component due to differences among rows was present, relatively more variation occurred within than among rows. The correlation coefficients between the number of mainstems and tuber weight per hill were positive but significant (P&< 0.05) only in Norland and Norchip. The correlation coefficients between the number of mainstems and number of tubers per hill were also positive but slightly higher and significant (P<0.01) in all 5 cultivars. The coefficient of determination values indicated that variation in cut seed piece weight explained only about 10% of the total variation in tuber weight harvested per hill. At a spacing of 30 cm within the row, a major proportion of hill to hill variation in tuber yield had to be explained by factors other than the seed piece weight.     

THE PRODUCTION OF WINTER GRASS FROM A ROW CROP OF COCKSFOOT AND LUCERNE

A crop of cocksfoot and lucerne in alternate rows was subjected to various autumn treatments for winter pasture. The yield of grass in winter, and the effect of autumn and winter treatments upon yield and composition in the following spring, are reported and discussed.
Maximum yield of winter grass was achieved by resting from an early date and applying nitrogenous fertilizer. The response to fertilizer applied in August and mid-September for winter grass production was as good as that obtained on ordinary swards at other times of the year. To ensure an adequate yield in any year the crop would need to be rested from early August and to receive about 70 lb N per acre.
The spring growth of cocksfoot was distinctly retarded by cutting twice in winter, i.e. in November and February. Cutting once only had no such adverse effect.
Both cocksfoot and lucerne persisted satisfactorily. The use of nitrogenous fertilizer to promote autumn growth of grass did not greatly reduce the overall productivity of the lucerne.
The two species were complementary in the sense that, in combination, they maintained a high aggregate yield of herbage under a range of weather conditions in midsummer and in winter.     

辽宁省水稻新品种产量及产量结构与环境效应的方差分析

以辽宁省2004～2005年中晚熟水稻区试参试品种为试材,分析了水稻品种在不同试点的产量和产量结构的差异,方差分析表明:水稻品种产量的变化主要受环境效应影响,年份×地点互作效应是影响产量的主要随机因素。每穴穗数、每穗总粒数、成粒率、千粒重都与产量有显著线性效应,每穴穗数和每穗总粒数对产量的直接作用较大,每穗总粒数通过每穴穗数对产量表现为显著负向作用。     

THE EFFECT OF AUTUMN MANAGEMENT ON WINTER DAMAGE AND SUBSEQUENT SPRING PRODUCTION OF SIX VARIETIES OF LOLIUM PERENNE GROWN AT CAMBRIDGE

Six perennial ryegrass varieties which were known to differ in winter hardiness were subjected to ten managements comprising two N rates and fire autumn cutting treatments. Autumn yields and soluble carbohydrate contents were measured, also the amount of winter damage in February and subsequent spring yields. The winter was mild, herbage damage was slight and no plant deaths were recorded, but significant differences were found between cutting treatments and varieties. The amount of winter damage increased with the length of the autumn rest period and with the degree of winter dormancy of individual varieties, indicating that natural senescence was a more important causative agent than frost action. Spring yields were affected by the amount of winter damage but there were considerable interactions between varieties and environments. The results are discussed in relation to autumn management practices, choice of variety for different locations and measurements of winter hardiness. The induction of winter dormancy by day length or low temperature reactions is considered in the breeding of varieties for maximum production in different parts of the country.     

Grain yield and yield components as affected by forage removal in winter and spring triticale

Two field experiments were carried out under irrigation and high fertility in northeastern Spain during 1992 and 1993. Ten triticale genotypes, five of spring growth habit and five winter types, were tested for their suitability for both forage and grain. Forage removal reduced grain yield per plant by about 17%, but did not have any significant effect on plant density, ear density or tiller number per plant. Tiller mortality was greater in winter types (65%) than in spring triticales (25%), but was not affected by cutting. Decreases in grain yield following cutting could be attributed to reductions in the number of grains per spike and kernel weight. Cutting decreased the number of grains per spike by about 9% by reducing the two components, spikelets per head and grains per spikelet. The average spike length was 10·6 cm in the uncut treatment and 10·1 cm in the dual-purpose plots. Cutting reduced thousand kernel weight by about 7% in winter triticales, and around 10% in spring types, both in main spike and in first tiller. The effect of a forage harvest on yield components was in general similar for both types of triticale. Cutting when jointing commenced induced changes in the relative importance of yield components influencing future grain yield. The yield components reduced by cutting were the most important contributors to grain yield after forage removal.     

The conservation management of mesotrophic (meadow) grassland in Northern England. 2. Effects of grazing, cutting date, fertilizer and seed application on the vegetation of an agriculturally improved sward

The plant species number and composition, iind yield of herbage biomass of an agriculturally improved hay meadow were assessed after 4 years under various combinations of grazing, fertilizer applicution. cutting date and seed addition treatments in a replicated split-plot design. Grazing treatments consisted of either autumn grazing with cattle and sheep, spring grazing with sheep or both regimes. Fertilizer application treatments consisted of either 25 kg ha^?1 N plus 12–5 kg ha^?1 P and K or no fertilizer. Cutting date treatments consisted of cuts on either 14 June, 2i July or 1 September. Seed addition treatments consisted of either no addition or sowing with a range of meadow species in the autumn. Data analysis was by correspondence analysis and analysis of variance. Species number decreased with fenilizer use and when the cutting date was 1 September. A range of species was affected by the main treatments and there were some first-order interactions, mainly between cutting date and fertilizer application. Rhinanthus minor was particularly favoured by the seed addition treatment. Species attnbutes in the regenerative and established phase were related to treatments and their effect on species composition. The National Vegetation Classification communities were associated with particular treatment regimes. The 21 July cutting date favoured ‘improved’ over ‘unimproved-traditional’ swards, with spring grazing favouring ‘unimproved-traditional’ swards. Lowest yields of herbage biomass were associated with autumn and spring grazing, the 14 June cutting date and no fenilizer treatments. The fenil-izer, 1 September cutting date and auiumn grazing treatments gave the highest yields. The implications of these results are discussed in terms of the conservation management required to return agriculturally improved mesotrophic grassland to a species composition similarto that of traditionally managed grassland.     

The influence of cutting date and previous fertilizer treatment on the productivity and botanical composition of species-rich hay meadows on the Somerset Levels

The effects on productivity, botanical and chemical composition of cutting species-rich hay meadows in Somerset on four different dates between late May and early September in two consecutive years, were measured. Plots that had received 200 kg N ha⁻¹ year⁻¹ with low levels of P and K for the previous 5 years were compared with plots that had previously received no fertilizer.
Previous fertilizer treatment increased metabolizable energy (ME) production only with cutting in May. Dry-matter (DM) yield increased significantly with date of cutting until August, whereas ME value declined correspondingly. There was no difference in either yield or quality of herbage cut between August and September. ME output per hectare increased very significantly between May and July, but showed no further change between cutting dates.
Botanical diversity was reduced by cutting in May after 1 year and by cutting in either May or September after 2 years, and was greatest with cutting in August. The dominance of Holcus lanatus on previously fertilized plots increased after cutting in either May or September. The contribution to vegetation cover of species that regenerate primarily by seed, including annuals, was greatly influenced by cutting date in preceding years, whereas species that regenerate vegetatively were not affected.     

Lodging Resistance Related to Root Traits for Mechanized Wet-Seeding of Two Super Rice Cultivars

Mechanical hill wet-seeded rice machine is beneficial for establishing and growing uniform rows of seedlings.However,there is limited knowledge regarding the effects of the establishment of furrows on growth,lodging and yield,and their relationships with root traits.In this study,field experiments were conducted during 2012 and 2013 using two super rice varieties(hybrid rice Peizataifeng and inbred rice Yuxiangyouzhan)under three furrow establishment treatments(T1,both water and seed furrows were established by the machine;T2,only seed furrows were established by the machine;and T3,neither water nor seed furrows were established by the machine).Lodging index,lodging-related traits,grain yield,above-ground dry weight and root traits were measured.The results showed that the lodging index was significantly affected by the treatments with furrows(T1 and T2).The strongest lodging resistance was detected in the mechanical hill wet-seeded rice with furrow treatment(T1)in both 2012 and 2013.Lodging resistance was strongly related to the breaking resistance.No significant difference was found in grain yield or dry weight of the mechanical hill wet-seeded rice.Therefore,the mechanical hill wet-seeded rice with furrow treatment increased rice lodging resistance,which was related to root traits.     

茶园昆虫群落时空格局及多样性稳定性

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Species enrichment in an agriculturally improved grassland and its effects on botanical composition, yield and forage quality

In a field experiment, the effects of different management treatments on the botanical development and productivity of a previously species‐poor, intensively managed, lowland permanent grass sward were investigated over a 4‐year period. Fertilizer inputs were stopped and nine main treatments, based on three pre‐sowing and three post‐sowing cutting regimes, were applied. Half of each treatment plot was oversown with a mixture of forb (wildflower) species and half left unsown. The aims were: (1) to investigate the effect of cutting regimes on the establishment of introduced forb species, (2) to assess the development and dry‐matter (DM) yield potential of these introduced species, and (3) to compare the DM yield and forage quality of swards with and without introduced species. Seedling establishment was recorded until the end of the second year. From the third year onwards, a common twice‐yearly cutting regime was imposed on all treatments, and the development of the introduced species was recorded. The DM yield of the nine oversown sub‐treatments was compared with the sub‐treatments not oversown. Frequent cutting after oversowing resulted in the greatest number of established plants and three times greater harvested DM yield of introduced species, compared with infrequent cutting. Plantago lanceolata and Trifolium pratense were the best performing introduced species. By years 3 and 4, there was proportionately 0·15 and 0·23, respectively, additional herbage DM yield harvested from the oversown treatments compared with unsown treatments, and up to 0·60 more in some treatments. The introduction of forbs increased the crude protein concentration, but decreased the digestibility of the forage.     

THE AGRONOMIC EVALUATION OF SYN 1 TALL FESCUE IN THE WEST OF SCOTLAND

The agronomic value of Syn 1 tall fescue, a synthetic variety derived from North African parent material, was determined in three experiments. Herbage yield, sward purity and digestibility were measured under cutting treatments for incremental sward growth during autumn/winter, and for sward regrowths during autumn/winter, spring and a complete season. Similar data were obtained for sward regrowths during autumn/winter and spring under defoliation by grazing. Syn 1 was compared with several of the north-temperate region tall fescues, e.g. S170, Rozelle and Manade, also with S143 cocksfoot Syn 1 showed yield superiority in autumn/early winter when there were comparable populations of tall fescue. Under cutting management, Syn 1 swards thinned out rapidly because of lack of winter-hardiness and yields were depressed in the second season; the effects were worst under the winter foggage-type management. Under grazing, with probably less severe defoliation, Syn 1 swards maintained yields for an additional season, but thereafter failed to persist Syn 1 swards had low spring- and annual-yields. The yield advantage of Syn 1 in autumn/early winter was not sufficient to be of great agricultural value and with its shortcomings in winter-hardiness and annual yield, it was considered unsuitable for West of Scotiand conditions. The main value of plant material such as Syn 1 may lie in ccmferring autumn/winter growth potential to winter-hardy north-temperate tall fescues in a breeding programme.     

大麦茎、叶、穗对饲草产量及品质的影响

为探明大麦不同组织（茎、叶和穗）在不同刈割期对饲草产量及品质的影响,以安徽省两个主栽饲用大麦品种为材料,比较了两年度两个品种茎、叶和穗分别在齐穗期及其后14 d和28 d饲草产量及品质的差异。结果显示,不同组织、刈割期及组织×刈割期互作效应对饲草产量及品质均有显著影响(P<0.05),年度效应主要影响产量,其他互作效应因品种和性状不同而异。饲草产量随刈割期后移增加,对其贡献表现为茎﹥穗﹥叶,第2年度高于第1年度。饲草品质性状在组织间和刈割期间存在显著差异,而在年度间仅在单个品种若干性状上存在差异;粗蛋白含量表现为穗﹥叶﹥茎,且随刈割期后移下降;粗纤维、酸性洗涤纤维、中性洗涤纤维和酸性洗涤木质素含量均为茎﹥叶﹥穗,且随刈割期后移前3个性状先降后升,酸性洗涤木质素含量持续上升;粗脂肪含量为叶﹥穗﹥茎,且随刈割期后移上升。综上,在株高相当时,增加穗部比例可提高大麦饲草产量和品质;刈割期后移可提升饲草产量但降低品质。基于本研究,选育大穗、多叶型品种,适期刈割,有望同步提升大麦饲草产量和品质。     

A COMPARISON OF BROADCAST AND WIDE-ROW SPACED GRASSES WHEN MANAGED FOR FOGGAGE PRODUCTION

A small-plot trial comparing perennial ryegrass, cocksfoot, timothy and meadow fescue sown broadcast and also in 21 inch rows was conducted at Auchincruive from 1954 to 1957. The cutting treatments were arranged so that measurement could be made of both summer and winter production.
Of the four species, cocksfoot was the most suitable for foggage production. Perennial ryegrass suffered severely from winter killing. Timothy and meadow fescue, although persistent, did not yield as much as cocksfoot.
Total dry-matter production over three years was higher from the cocksfoot rows than from the broadcast stand. For ryegrass and meadow fescue, broadcasting gave higher yields than row sowing while timothy showed no significant difference between sowing methods.
During the winter, all species showed a loss of dry matter. Losses for ryegrass, cocksfoot, timothy and meadow fescue were respectively 34%, 17%, 18% and 24%. Broadcast stands averaged 11% greater loss than the rows.     

黑龙江杂交粳稻产量相关性状配合力及遗传参数分析

按照不完全双列杂交(NCII)设计,以6个恢复系为父本、3个不育系为母本共配制18个杂交粳稻组合,分析了产量相关性状的配合力及遗传参数.结果 表明,杂交组合的产量和结实率受母本的影响大于父本,每穗实粒数更多地依赖恢复系,穴穗数和千粒重则受双亲的共同影响.遗传分析表明,主要受基因加性效应影响的性状为穗实粒数,主要受非加性...