Useful variation in in vitro digestibility within perennial ryegrass

In vitro dry matter digestibility (DMD) and dry matter yield (DMY) of herbage from plots sown with three selected perennial ryegrass varieties with similar heading dates (Ba11778, Talbot and Gator) under a range of harvesting frequencies (2, 3, 4 and 5-weekly harvests) were compared over two harvest years (1994 and 1995). Varieties varied in mean percentage DMD over all harvests and harvesting frequencies by 3.4 and 3.5 units in 1994 and 1995 respectively. Varietal ranking in mean DMD over all harvests was the same under each harvesting frequency in both years: Ba11778 being the highest, Gator the lowest and Talbot intermediate. In 1995, Gator had a higher proportion of unsown species in the herbage than both Ba11778 and Talbot but this was only a minor factor contributing to the differences among the varieties in mean DMD over all harvests. Although varieties consistently ranked in the same order of mean DMD over all harvesting frequencies during 13 5-week periods, the range among varieties varied from less than 1 unit to 8.6 units. This range was greatest in mid-season of each year when mean DMD over all varieties was lowest. The minimum mean DMD over all harvesting frequencies during both years was 75.5%, 70.9% and 66.8% for Ba11778, Talbot and Gator respectively. The most digestible variety Ba11778 also had higher annual DMY than the other two varieties in both harvest years and under all four harvesting frequencies. These results indicate that there is sufficient useful genetic variation for DMD within perennial ryegrass to justify breeding for the trait and its routine assessment in official variety trials.     

Genetic variation in leaf epidermal cell size and shape in Lolium perenne

Summary Six diploid perennial ryegrass populations, two diploid F₁ hybrid families and the autotetraploid cv. Tove were grown in a glasshouse and the mean length and mean width of epidermal cells on the abaxial leaf surface of young fully expanded leaves compared. The diploids varied in cell length by 26%, in cell width by 9% and in length: width ratio by 39%. The cells of cv. Tove were 25% longer and 12% wider than those of the highest ranking diploid and the length: width ratio 9% higher. The DNA contents per telophase root-tip cell nucleus of a large-celled and a small-celled diploid population were similar, suggesting that the variation in epidermal cell size among diploids was due to the action of specific genes and not to differences in genome size. The mean epidermal cell dimensions of four of the above populations growing as plots in a field trial employing three levels of fertiliser nitrogen and four harvesting frequencies were measured on three occasions. Varietal ranking in cell dimensions was consistent over the different managements and dates, and agreed well with the glasshouse results. The results indicate that measurements of leaf epidermal cell length and width can be useful aids both in breeding for herbage yield and in distinguishing varieties with similar flowering dates.     

Management of Italian and Perennial Ryegrasses for Seed and Forage Production in Crop Rotations

Italian ryegrass (Lolium multiflorum Lam.) and perennial ryegrass (L. perenne L.) can be grown for seed and forage in cold winter regions provided the stand persists well over winter. Seed yield and plant characteristics during primary growth, and forage yield during regrowth, were determined for two Italian and one perennial ryegrass cultivars in Atlantic Canada. Establishment methods and dates included sowing ryegrass in cultivated soil alone or with barley in mid‐May and, after harvesting the barley crop, by sowing ryegrass following conventional or reduced cultivation and by no‐till drilling into barley stubble in mid‐August and early September. Despite some winterkill, particularly in Italian ryegrass, seed and forage yields were adequate in post‐establishment growing seasons. Seed yield for Italian ryegrass was greatest (1270 kg ha^?1) when it was sown into cultivated soil in mid‐August and least (890 kg ha^?1) when sown alone in May. Italian ryegrass yielded 15–17 % more seed when plots were established in mid‐August rather than in mid‐May or early September. Italian ryegrass cv. Lemtal had a greater density of fertile tillers (1030 m^?2) in the sward than cv. Ajax (860 m^?2) and its tiller density was greater when seeded into cultivated soil in September than in mid‐August. There were fewer spikelets per seed head for sowing Italian ryegrass with barley in May than for the other methods of establishment. Forage yield in regrowth was greater for Italian ryegrass cv. Ajax (2770 kg ha^?1) than for cv. Lemtal (2480 kg ha^?1). Seed yield of perennial ryegrass was greater when seeded in mid‐May than in mid‐August or early September. The seed yield of perennial ryegrass was greater when it was sown with barley in May and harvested for grain, than when it was sown alone or with barley harvested at late milk stage. The establishment methods for mid‐August and early September sowing had little effect on seed yield. However, the no‐till and reduced tillage methods resulted in a greater tiller density than sowing into the cultivated seedbed. Fertile tillers tended to be denser under reduced cultivation for sowing in August. Forage yield of perennial ryegrass regrowth was not influenced by the sowing method and timing. In conclusion, Italian and perennial ryegrasses produce adequate seed and forage regrowth under different establishment methods and timing. However, the poor persistence of Italian ryegrass may limit commercial production after the establishment year in Atlantic Canada.     

稻茬小麦不同光效型群体的光合物质生产积累及转运差异分析

为给苏中地区稻茬小麦高光效群体构建和栽培措施调控提供理论依据,以‘扬麦23’为材料,结合聚类分析的方法,研究了不同光效型群体光合物质生产、积累和转运特征的差异。结果表明,不同小麦群体间产量、收获指数、光合势、花后干物质积累量和开花期高效叶面积率具有明显差异。高光效群体具有较高的产量、光合势、开花期高效叶面积率和干物质积累量;中等光效群体的收获指数显著低于高光效群体和低光效群体。在产量构成上,高光效群体具有较高的穗数和千粒重,同时,高光效群体及其剑叶在开花期的光合特性表现良好。在本试验播后及冬季多雨条件下,密度为225×10⁴株/hm²,施氮量为270 kg/hm²且氮肥运筹为7:1:2:0以及密度为300×10⁴株/hm²,施氮量为330 kg/hm²,氮肥运筹为5:1:2:2可作为产量达到8400 kg/hm²的苏中地区稻茬小麦高光效群体构建的密肥组合方式。     

Agronomic Potential of Three Vetches (Vicia spp.) Under Rainfed Conditions

The major limiting factor to livestock production in West Asia and North Africa is the inadequate feed supply. The introduction of leguminous forage species into fallow lands represents a means of increasing feed supplies for the rapidly growing livestock population.
Twenty five lines each of common vetch ( Vicia sativa L.) wooly-pod vetch ( Vicia villosa ssp. dasycarpa Ten.), and bitter vetch ( Vicia ervilia L.) were tested over three seasons with contrasting rainfalls and winter temperatures. For each species, seedling vigour, winter growth, cold effect, spring growth, leafiness, herbage yield at 100 % flowering, grain yield, harvest index and aspects of herbage quality were recorded. There were considerable variation among entries with the same species, entries of V. ervilia were the earlier in flowering and maturity, and V. villosa ssp. dasycarpa almost the latest by 45 days. V. sativa , was the most affected by frost whilst both V. villosa ssp. dasycarpa and V. ervilia proved to be cold tolerant.
Although V. villosa ssp. dasycarpa produced high herbage yield in springs its grain yield is low resulting in a low harvest index. Both V. ervilia and V. sativa produced high grain yield with high harvest index. Seed yield was negatively correlated (P < 0.01) with days to flowering and maturity indicating the need of earlier types.
Quality of the herbage in term of digestibility was far lower (46 % IVDMD) in V. villosa ssp. dasycarpa than the other two species (69 % and 72 %).
The possible niches and utilization of each species as animal feed in the prevailing farming systems are discussed.     

Productivity of Bahiagrass Pastures in South-western Japan: Synthesis of Data from Grazing Trials

This study examined the rate of herbage production and herbage quality of bahiagrass (Paspalum notatum Flügge) using data from five grazing trials in the low‐altitude region of Kyushu, south‐western Japan, in an effort to (a) evaluate productivity of bahiagrass pastures, (b) analyse its relationship to meteorological, vegetational and managerial variables, and (c) obtain implications for better management of bahiagrass pastures. The rate of herbage production, ranging from ?56 to 213 kg DM ha^?1 day^?1, tended to increase from spring (April–May) to mid‐summer (July) and decrease thereafter. The rate was expressed by a multiple regression equation where nitrogen fertilizer rate, air temperature, rainfall and herbage mass had positive effects. Dry matter digestibility (DMD) and crude protein (CP) concentration of herbage were in the range of 471–727 and 84–161 g kg^?1 DM respectively. DMD was expressed by a regression equation where the day number from 1 April and herbage mass had negative effects, and the sampling height and nitrogen rate had positive effects. CP concentration was expressed by an equation showing a positive effect of nitrogen rate and a negative effect of herbage mass. The results indicate that management of bahiagrass pastures should aim at maintaining herbage mass closely above the critical level below which intake by grazing animals is restricted, in order to increase quality and ensure quantity. This is particularly important when nitrogen fertilizer is applied.     

Phenotypic and genotypic variation in seed production traits within a full-sib family of meadow fescue

Phenotypic and genotypic variation for seed yield and associated traits (heading date, plant height, number of fertile tillers, 1000‐seed weight, panicle length, seed weight per panicle, fertility, flag‐leaf length and flag‐leaf width) were studied in a full‐sib family of meadow fescue using replicated clonal trials at two locations in Norway. Genotypic variances were highly significant for all traits and genotype × location interactions were significant for heading date, number of fertile tillers and seed yield. Seed yield and other seed component traits exhibited the largest genotypic variations. Heading date showed large genotype × location interaction, probably because of the very diverse origin of the two parents of the full‐sib family. Path coefficient analysis showed that panicle fertility, measured as seed weight per unit length of panicles, was by far the most important component trait contributing to seed yield, followed by the number of fertile tillers, plant height and flag‐leaf width. Flag‐leaf width and plant height had sizeable indirect effects on seed yield via panicle fertility. This is the first time that the importance of the size of the flag leaf for seed yield in herbage grasses has been demonstrated.     

水稻甬优12超高产群体分蘖特性及其与群体生产力的关系

以籼粳交超级稻甬优12为试材,四叶一心期带蘖小苗移栽,通过栽培措施的调控,形成超高产( >13.0 t hm^-2)和高产( >12.0 t hm^-2)群体,以高产群体作为对照,对分蘖挂牌追踪,比较研究超高产群体分蘖发生成穗特点。结果表明,超高产群体分蘖产量及对总产量的贡献率分别为11.53 t hm^-2和87.77%,高产群体分别为10.59 t hm^-2和87.40%。超高产和高产群体的分蘖利用都以一次和二次分蘖为主,一次和二次分蘖的产量均以超高产高于高产群体,超高产群体一次分蘖产量的贡献率略低于高产群体,二次分蘖产量的贡献率高于高产群体。超高产群体一次分蘖发生在第1至第9叶位,第4至第7叶位是分蘖发生与成穗的优势叶位,二次分蘖以1/3、2/3、3/3、2/4、1/5蘖位优势较强。对于高产群体而言,一次分蘖以第4至第7叶位分蘖优势较强,二次分蘖以1/3、2/3、3/3优势较强,三次分蘖发生叶位数明显高于超高产群体,但成穗率较低。超高产群体成穗分蘖的穗长、单穗重、总粒数、着[1]粒密度的平均值高于高产群体,结实率却略低于高产群体。     

Italian ryegrass establishment by self-seeding in integrated crop–livestock systems: Effects of grazing management and crop rotation strategies

We evaluated the re-establishment of an Italian ryegrass pasture by self-seeding on a no-till integrated crop–livestock systems (ICLS) in the southern region of Brazil. This work is part of a long-term experimental protocol initiated in 2003. We tested the effects of various management practices, such as summer crop systems (soybean vs. maize–soybean rotation), stocking methods (continuous vs. rotational) and grazing intensities (low vs. moderate), on Italian ryegrass pasture establishment. In addition, we tested resilience of the system by testing pasture's ability to re-establish following a year without seed head production. The experiment consisted in the rotation, on the same area, of Italian ryegrass pasture grazed by sheep during the winter and up to the end of the grass production cycle, and soybean or soybean–maize grain crops rotation cultivated during the summer. The pasture established itself by self-seeding since 2005. Data were collected in 2011 and 2012 stocking season. The soybean summer crop, continuous stocking and low grazing intensity, all positively affected the production of reproductive tillers in 2011. Grazing intensity in 2011 strongly influenced early vegetative tiller densities (before crop harvest) in 2012. However, none of the grazing intensity or the stocking method treatments affected herbage mass at the end of pasture establishment in 2011 or 2012. On the other hand, the soybean summer crop positively affected pasture establishment, both in term of tiller densities and herbage mass at the end of pasture establishment. The removal of all seed heads in 2011 (preventing seed production) resulted in the total failure of pasture establishment in 2012. Overall, Italian ryegrass establishment by self-seeding relies on the annual replacement of the soil seed bank. This experiment demonstrated that under various stocking methods, moderate grazing intensity and maize or soybean summer crop, Italian ryegrass pasture establishment by self-seeding remains successful even when the stocking periods extended up to the end of the grass production cycle. Self-seeding with moderate grazing intensity ensures successful pasture establishment, reduces labour and costs and allows to increase the stocking period and so animal live weight gain over the grazing season.     

Italian ryegrass establishment by self-seeding in integrated crop-livestock systems: Effects of grazing management and crop rotation strategies

We evaluated the re-establishment of an Italian ryegrass pasture by self-seeding on a no-till integrated crop-livestock systems (ICLS) in the southern region of Brazil. This work is part of a long-term experimental protocol initiated in 2003. We tested the effects of various management practices, such as summer crop systems (soybean vs. maize–soybean rotation), stocking methods (continuous vs. rotational) and grazing intensities (low vs. moderate), on Italian ryegrass pasture establishment. In addition, we tested resilience of the system by testing pasture's ability to re-establish following a year without seed head production. The experiment consisted in the rotation, on the same area, of Italian ryegrass pasture grazed by sheep during the winter and up to the end of the grass production cycle, and soybean or soybean-maize grain crops rotation cultivated during the summer. The pasture established itself by self-seeding since 2005. Data were collected in 2011 and 2012 stocking season. The soybean summer crop, continuous stocking and low grazing intensity, all positively affected the production of reproductive tillers in 2011. Grazing intensity in 2011 strongly influenced early vegetative tiller densities (before crop harvest) in 2012. However, none of the grazing intensity or the stocking method treatments affected herbage mass at the end of pasture establishment in 2011 or 2012. On the other hand, the soybean summer crop positively affected pasture establishment, both in term of tiller densities and herbage mass at the end of pasture establishment. The removal of all seed heads in 2011 (preventing seed production) resulted in the total failure of pasture establishment in 2012. Overall, Italian ryegrass establishment by self-seeding relies on the annual replacement of the soil seed bank. This experiment demonstrated that under various stocking methods, moderate grazing intensity and maize or soybean summer crop, Italian ryegrass pasture establishment by self-seeding remains successful even when the stocking periods extended up to the end of the grass production cycle. Self-seeding with moderate grazing intensity ensures successful pasture establishment, reduces labour and costs and allows to increase the stocking period and so animal live weight gain over the grazing season.     

Variation in digestibility in nine populations of perennial ryegrass (Lolium perenne) and its genetic basis

Summary Thirty five individuals from each of nine perennial ryegrass populations were sampled from set-stocked and zero-grazed swards and from an old permanent pasture. The swards were 6, 18, 30 months and 11 years old when sampled. The permanent pasture was at least 40 years old.Dry matter digestibility (DMD) and organic matter digestibility (OMD) were determined for green leaf material harvested 4 days after ear emergence. Significant differences were found between the populations, but genotypic differences were found only for OMD. The largest proportion of the total variation was due to differences between blocks. In the zero-grazed populations, DMD and OMD declined significantly with increasing sward age. This was not found for the set-stocked swards. Two sets of pair crosses, from which mid-parent, progeny regressions could be determined, were carried out.The regressions of offspring on mid-parent for set-stocked and zero-grazed swards were used to assess the presence of additive genetic variation and to estimate narrow sense heritability of DMD. The coefficients of correlation, 0.122 and 0.226 respectively, were non-significant, indicating an absence of additive genetic variation.     

南方粳型超级稻物质生产积累及超高产特征的研究

以超级粳稻品种武粳15、淮稻9号、徐稻3号和常优1号为材料,对高产(8.25~9.75 t hm^-2)、更高产(9.75~11.25 t hm^-2)和超高产(＞11.25 t hm^-2) 3个产量等级群体的物质生产与产量的关系、干物质积累、输出与转运等方面进行了系统的比较研究。结果表明,4个超级稻品种成熟期、抽穗至成熟期的干物质重与产量呈极显著正相关,抽穗期干物质重均与产量呈抛物线关系,拔节至抽穗期的干物质重与产量呈极显著正相关(高产—更高产、更高产—超高产以及将3个产量等级综合起来);从高产到更高产再到超高产,4个超级稻品种的生物学产量不断提高(差异显著),而超高产群体的经济系数则与更高产水平相当(0.5000以上),显著高于高产水平;较之更高产、高产群体,超高产群体在生育中期(拔节至抽穗期)干物质积累量大,抽穗期叶面积指数高、株型挺拔、群体质量优[有效叶面积率、高效叶面积率、总颖花量与颖花/叶(cm²)、基部节间粗、单茎茎鞘重均高],在生育后期(抽穗至成熟期),光合能力强(叶面积衰减率小,光合势、群体生长率、净同化率高)、干物质积累量高(占生物学产量的40.0%以上)、茎鞘物质的输出与转运协调[实粒/叶(cm²)、粒重(mg)/叶(cm²)均高]。     

温麦6号小麦9000kg/hm2若干群体质量指标研究补报

通过两年对温麦6号小麦的小区试验和高产攻关调查研究,提出温麦6号小麦9000kg/hm~2的几个群体质量指标,即最高叶面积系数为10.0左右,高效叶面积率70％以上,有效叶面积率95％以上,每公顷成穗在750×10~4左右,分蘖成穗率50％左右,抽穗期无效分蘖残存率在5％以下。同时对上三叶的叶面积和叶质量以及小麦生育后期的干物质积累特点也进行了分析。     

Inheritance of conditional dormancy in over-summering buds of Phalaris aquatica L.

Summary The relative ability of the underground buds of a Mediterranean perennial grass species to break dormancy in response to summer rain was compared between individual plants and between half-sib families in two experiments with broadly-based breeding populations under different environmental conditions. Significant genetic variation was found in summer regrowth activity in both experiments. The narrow-sense heritability of the ratio of new to old, dead tillers after summer rain under spaced plant conditions at a relatively cool site was 0.40±0.16. Under sward conditions at a warm site, the narrow-sense heritability of an index of summer regrowth potential on a half-sib family mean basis was 0.36±0.08. Summer regrowth activity was negatively but weakly correlated with flowering time (r_g=–0.22), and strongly positively correlated with early autumn herbage yield (r_g=0.79). Summer regrowth activity was not genetically correlated with seedling size or herbage yield in the second or third growing seasons. These correlations are different in sign or magnitude from those observed in collections of Mediterranean ecotypes from which the breeding populations were derived by crossing to Australian cultivars and recurrent selection for vigour and persistence. The correlations in Mediterranean populations therefore are not due to pleiotropic effects; they can be altered by recombination. Phenotypic variance relative to the population mean was considerable in both experiments, and hence the level of the responsiveness of dormant buds to summer rainfall should be manipulable readily by selection. The possible effects of altered responsiveness on long term survival and productivity in several different environments are discussed.     

高寒草原针茅牧草花期物候变化特征及其影响因子分析

利用三江源区兴海县气象局观测的1999—2021年高寒草原西北针茅牧草开花期物候资料及同期气象资料,对牧草开花期变化趋势进行分析,寻找出影响花期的主要气象因子,并构建花期预测模型。结果表明：（1）1999—2021年三江源区兴海县高寒草原西北针茅牧草开花期的平均气温较平稳,而降水量呈显著增多趋势。（2）1999—2021年三江源区兴海县高寒草原西北针茅开花期呈不显著推迟趋势。牧草开花期年际变化较大,最早与最晚相差26天。（3）相关分析表明,4月上旬和下旬的平均气温、平均最高气温与牧草开花期呈显著负相关;5月上旬平均最高气温、日照时数与牧草开花期呈显著正相关;4月下旬的平均最低气温与牧草开花期呈极显著负相关。（4）回归方程显示,4月下旬平均最低气温每升高（或降低）1.0℃,牧草开花期则相应提前（或推迟）2.1天。     

Accumulation of Secondary Metabolites Formed by Field Fungi in Autumn-Saved Herbage

Taking into consideration the fact that in recent years weather conditions were sufficient to feed cattle on pasture until late autumn or early winter, an experiment was carried out during the years 2000 and 2003 on a low input pasture to show the effect of the pre‐utilization date (June, July, August) and the harvest date in the autumn/winter period (November, December, January) on the accumulation of the following secondary metabolites formed by fungi: ergosterol (ERG), ochratoxin A (OA) and zearalenone (ZEA) in the autumn‐saved herbage. The highest levels of concentration of these metabolites were 470.3, 1.63 and 34.9 ng g^?1 respectively. Lower ERG levels were influenced by later pre‐utilization, which is a logical consequence of the shorter period of time for field toxigenic fungi development. Pre‐utilization in August is strongly recommended as the concentration of ochratoxin A (OA) in the autumn‐saved herbage in January was the lowest (not much changed in comparison with earlier harvest). Later harvest was also affected by higher ZEA concentrations in the analysed samples, which indicates that, under conditions of prolonged pasture utilization, field toxigenic fungi (producing ZEA) increased their population and had proper weather conditions stimulating the biosynthesis of the toxin. The later suggests that the final harvest of autumn‐saved herbage should be made rather in December than in January. Higher levels of humidity influenced higher concentrations of ERG and ZEA in the autumn‐saved herbage.     

Changes induced by defoliation in the yield and digestibility of leaves and stems of perennial ryegrass (Lolium perenne L.) during reproductive development

Ten identical perennial ryegrass plots (cv. Frances) were sequentially harvested for first cut silage at 7 day intervals, with second cuts after 6 weeks regrowth and further cuts until the growing season ended. Total herbage dry matter and digestible organic matter yields increased and digestibility decreased with delayed cutting, as was expected. The opposite and counterbalancing response occurred at the second cut. This pattern of yield change was mirrored by changes in the amount of stem tissue, whereas leaf yield did not change significantly at the first harvest but declined at the second, in response to delayed cutting. Furthermore, stem digestibility declined at the first cycle of harvests from ca. 75 to 62–64% in the most delayed cutting treatments. In contrast, leaf digestibility remained high (ca. 70%) until after seed-head emergence but then decreased rapidly to ca. 56%. This decline may have been associated with accelerated leaf senescence and redistribution of assimilates, though this needs to be examined. It was concluded that although manipulating first harvest date determined the proportioning of yield and digestibility in the first and second cuts, the observation that the combined yield and digestibility in these two harvests did not vary substantially is an important result for farming practice.     

Effects of Population Density on the Vegetative Growth of Leafy Reduced-stature Maize in Short-season Areas

Maize hybrids which produce more leaves above the ear, with leaf area indices similar to conventional hybrids, which require fewer corn heat units to flowering and maturity, and tolerate higher population densities, should be better adapted for production in short season areas than currently available hybrids. Leafy reduced-stature maize hybrids, which have only recently been developed, have traits which address these criteria. The objective of this study was to evaluate the effects of different population densities (50 000, 100 000, 150 000, and 200 000 plants.ha⁻¹) on the vegetative growth of one leafy reduced-stature (LRS), one non-leafy reduced-stature (NLRS), and two conventional control hybrids (Pioneer 3979, < 2500 CHU, and Pioneer 3902, 2600–2700 CHU) at two locations. There were no differences among population densities for leaf number above the ear; however leaf area index increased as population density increased for all hybrids. The LRS hybrid had a greater average leaf number above the ear (2.7 and 2.0 more leaves than NLRS and the control hybrids, respectively). As a result the leaf area index value of LRS was much greater than the NLRS and similar to the conventional hybrids, but LRS matured substantially before the conventional hybrids. The LRS hybrid required fewer corn heat units to reach flowering and maturity and had more time for grain filling than the conventional hybrids. Therefore, LRS hybrids show promise for production in short season areas where maize cultivation is not economical due to shortness of growing season.     

Wachstumsanalytische Untersuchungen an Knaulgras (Dactylis glomerata L.) unter besonderer Berücksichtigung des phänologischen Entwicklungsstadiums bei der Nutzung im ersten Aufwuchs

Regrowth characteristics of a cocksfoot (Dactylis glomerata L.) sward after initial defoliation at different stages of development Over 2 two-year period (1984-1985) the productivity of Dactylis glomerata (cv. Baraula) swards as influenced by variations in time of the initial defoliation was studied. The stages at which the initial cuts were taken were: (a) before stem apices were raised to defoliation level (5 cm), (b) about two weeks later, when the reproductive tillers reached ear emergence, (c) about 4 weeks after (a), when the reproductive tillers reached flowering stages. Subsequent production was measured by weekly harvesting of representative sward samples over a 6-7 weeks lastening growth period. Furtheron patterns of growth in a second regrowth in August and a third regrowth in September/October were studied. The growth behaviour in the investigation was described by calculations of curves concerning mainly the development of dry matter yield (DM), leaf area index (LAI), crop growth rate (C), relative growth rate (R) and net assimilation rate (E) during the growth period. The leaf area ratio (F) and leaf weight ratio (LWR) were derived from fitted curves. The highest dry matter yield and the highest growth rate (more than 20 g m^?2day^?1) was estimated in the spring growth and in the earliest regrowth (a). About 30 % of the tillers in these swards became reproductive. The main difference between regrowths of primary defoliations at successively later dates was between the earliest, after cutting on 8.-13. May, on the one hand, and, on the other hand, the two later regrowths after primary cuts from 31. May to 12. June. The two latter and the second regrowth in August were in most respects very similar: no reproductive development; herbage yield of about 400-500 g m^?2; highest C of about 15-20 g m^?2day^?1; maximum LAI- values from 8-9. In respect to the E there were some differences between the stands. The E was at the time when C was highest somewhat higher in the reproduction stands (spring growth and first regrowth) compared with the vegetative regrowths. The relationship between C and LAI could in all stands be described by an relatively optimum curve, which means that C did not differ much within a wide range of LAI.     

Growth Analysis, Herbage and Seed Yield of Certain Forage Legume Species Under Rainfed Conditions

The need to increase forage production for the growing livestock population in the Mediterranean region necessitates the evaluation of various promising forage species with respect to maximum herbage yield, optimum time for harvest and seed yield. Seven forage legumes, woolly pod vetch ( Vicia villosa subsp. dasycarpa accession 683), narbon vetch (V. narbonensis accession 67), common vetch ( V. sativa selections 2541, 2037, 2020), common chickling ( Lathyrus sativus selection 439) and ochrus chickling ( L. ochrus selection 104) were compared over two years with contrasting rainfall. In both years the entries were sown in November and their primary growths sampled periodically during growth. For each sample, phenology, total dry matter, leaf area index (LAI) and, at maturity, total dry matter, seed yield and harvest index, were recorded.
In both seasons, narbon vetch attained the highest dry matter and seed yields, and there was very limited variability in the maximum dry matter yield of the other entries. In general, the maximum dry matter occurred at 20–50 % podding in woolly pod vetch, 100 % podding in common vetch selection 2541 (local), narbon vetch and common chickling and at maturity in common vetch selection 2037, selection 2020 and ochrus chickling.
Throughout the vegetative to early flowering stages, woolly pod vetch had the highest dry matter yield and LAI. Possible uses of each species as animal feed are discussed.