PERENNIAL RYE-GRASS STRAIN INVESTIGATION.

New Zealand Journal of Agriculture, Volume XL, Issue 6, 20 June 1930, Page 363

PERENNIAL RYE-GRASS STRAIN INVESTIGATION.

DATA FROM TRIALS AT THE PLANT RESEARCH STATION.

E. Bruce Levy,

Agrostologist, and Wm. Davies*, Plant Geneticist, Plant

Research Station, Palmerston North.

In this Journal for July, 1929, it was pointed out by the writers that marked variation existed in commercial lines of perennial rye-grass. In the account of the early trials the fact of the annual Italian ryegrass element in the lines of different origin was clearly set out, and some idea was given that marked differences existed in the behaviour of the perennial rye-grasses of various origin, apart altogether from the Italian rye-grass present in the line (Table .1, page 4,- July, 1929). The present article deals in greater detail with the trials , conducted. at the Plant Research Station, Palmerston North, and aims to set out the technique employed and the results gleaned to date.

In our preliminary report we stated that Hawke’s Bay and Poverty Bay rye-grass as commercially handled in New Zealand was as a type quite different and apparently quite superior to rye-grass harvested in other parts of the Dominion. While the tabulated results as set out here are based largely on data secured from one- and two-year-old plots, yet much confirmatory field evidence has been secured from areas sown by the Fields Division extending over a considerable period. Further than this, circumstantial evidence of farmers who have used Hawke’s Bay rye-grass for many years and evidence collected by the writers on the Hawke’s Bay and Poverty Bay flats would lead us to the definite conclusion that, provided the conditions are good enough to. grow rye-grass, the Hawke’s Bay strain will maintain itself as a dominant in the sward for any number of years. So marked, in fact, is the superiority of this strain over other strains that the Department of Agriculture this season initiated an extensive scheme of rye-grass seed certification, which really represents the first practical step towards a righting of the rye-grass strain position in New Zealand. J

Details of Trials and Technique employed.

The trials include (i) broadcast plots, (2) turfs or seed of rye-grass from various habitats planted or sown in rows, and (3) single spaced plants.

(l) BROADCAST PLOTS.

Where sufficient seed is available broadcast seedings are made, and the standard, plot adopted is acre in area, the measurement being 30 links by 6f. links. • The amount of seed sown is 40 lb. , per acre. These plots are sown in duplicate, and are subdivided transversely into three parts to allow a triple system of utilization to be carried out. One part is mown consistently once every week with a lawn-mower ; the second part is mown with a motor hay-mower when the grass is in the 6 in. to 8 in. “ cattle stage;/ and the third portion is similarly cut at the hay stage when the grass is in flower. No reseeding is permitted to take place. The plots are uniformly manured with superphosphate and sulphate of ammonia, and a -high standard of soilfertility is maintained throughout the period of the trials.

Detailed observations have been made from time to time on the behaviour of each line under this triple system of utilization, and a system of relative marking by eye estimation is employed. A scale of marking, 0-10, has been adopted in respect of differences between plot and plot. Establishment, relative growth, persistency, recovery after cutting, type as shown by morphological and colour differences, swarding characteristics, and disease resistance or susceptibility are measured in this way. Eye estimations in regard to persistency and swarding characteristics under weekly cutting are wherever possible supported by accurate statistical analyses of the sward in situ, using the pointquadrat method.

No stock-grazing has been done on the trial plots under consideration, but the same lines or representatives of the same types have been sown out in the field on all'the leading soil-types in New'Zealand, and the behaviour of each line or type in the field is closely correlated with that in the mown series at the Plant Research Station. All told, 3,590 plots of rye-grass, representing some 300 different lines, have been sown out and are under grazing trial in the field. These field trials are yielding important data which it is hoped will form the subject of a subsequent paper by the writers.

In the trials at Palmerston North no effort has been made to secure cut weights of herbage produced by each line or type. We are of the opinion, so far as species and strain trials are concerned, that mere weights as such, without further and complete botanical analyses, are not worth while. The need for botanical analyses of cut herbage, <if weights are used as a measure of increase or decrease, can be readily seen from a glance at Table 7. The enormous increase in white clover would largely counteract loss of rye-grass as far as the weight measure was concerned, and this could be shown only by dissecting out and separately weighing the components of the cut herbage of each plot, or by some comparable system of accurate estimation of the botanical content of that herbage. From our experiences with a limited working staff it is more practicable in preliminary trials where wide differences occur to concentrate on the testing out of a large number of lines; and

to analyse these by eye estimation carried out at regular intervals, supported by accurate notes taken in the field, together with sward analyses in situ of representatives of the major types that assert themselves.

Up to date between 1,700 and 1,800 lines of perennial rye-grass seed have been received at the Plant Research Station for testing in the ground trials, and of these some 1,500 lines have been sown in broadcast plots in duplicate and subjected to the aforementioned triplemowing scheme under constant observation and note-taking.

-(2) TURFS OR SEED FROM VARIOUS HABITATS PLANTED OR SOWN IN ROWS. Where turfs are collected in the field or where insufficient seed is available to sow the standard broadcast plot the row system of testing is adopted. The rows are either 15 links or 30 links long and are 2 ft. apart. When the seed is well up or the transplanted tillers well established the bed to half its width is sown broadcast with a more or less lawn-seed mixture not containing any seed of the species under trial in the rows, and this half portion is treated as a broadcast plot and cut weekly with a lawn-mower. Thus half the row is tested as under, broadcast conditions and the other half is kept intercultivated. It is our opinion that the intercultivated-row system alone is not an adequate test for pasture plants, particularly those that definitely have their crown above ground. Rye - grass, cocksfoot, red clover, and timothy come within this category. Some 250 lines of rye-grass have been planted or sown, in the above trials.

(3) SINGLE SPACED PLANTS.

In the broadcast plots eye differences as to type manifested themselves after some eight weeks from sowing. In order to study the individual plants that in the aggregate gave rise to that eye difference single plants were taken at random, 100 from each broadcast plot. These were put out 2 ft. apart each way and studied as single plants from the point of view of growth-form, recovery after cutting, persistency, colourvariation, disease resistance or susceptibility, &c. This single-plant trial is yielding also a certain proportion of promising types, which are now being used as a basis for selection and for the working up ultimately of elite strains. The single-plant study is also showing up to a marked degree the entire lack of uniformity of type even in what we consider the best of the Hawke’s Bay lines, indicating that enormous possibilities for improvement await the skilled hand of the plantbreeder and strain-ecologist.

In regard to the general procedure in the economic breeding of pasture plants and in the building-up of improved strains from selected material, and having due regard to the fact that these studies are merely in their infancy, we hold the view that the first step is to test out large numbers of types drawn from every corner of the globe, both as broadcast plots and as single spaced plants that are in all cases submitted to a number of contrasting schemes of management ; to study growth-form in relation to yielding-power and persistency ; to study type, tillering-capacity, seasonal growth, disease-resistance, and the like, both of the aggregate strain and of the dissimilar individuals that

make up that aggregate. Following on this preliminary survey, the more likely growth-forms can by mere selection and culling be grouped together to produce improved aggregate types that are likely to be vastly superior to the existing commercial types. Concurrently with this analysis and selection should go the genetical analysis of the several more likely growth-forms with a view to producing economically superior and more useful lines that are, within reason at any rate, genetically pure and are likely to remain so indefinitely under a carefully controlled' scheme of seed-production. During August, 1929, some 5,500 single plants of rye-grass, representing fifty-three distinct lines of seed, were planted as spaced plants, and a special report on the behaviour of these will be made at a later date. x .

Progress Results of Broadcast Plots

After two years’ concentrated work at the Plant Research Station, and as a result of several years’ widely distributed trials and observations throughout the country, there is in the minds of the writers no shadow of doubt that the Hawke’s Bay rye-grass as a type is superior, for New Zealand conditions at least, to any other commercial strain from any other source. Prior to this work species, or mixtures of these, were accepted in New Zealand as the only thing one had to consider in the laying-down of pastures. This work .emphasizes that strain counts more than species, and that source of origin is a factor to be reckoned with in the buying of grass and clover seeds. The Department is fully alive to the situation created by this work, and in order to give 'some means of guarantee as to type and district of origin it inaugurated and carried out, under the direction of Mr. J. W. Hadfield, Agronomist, the scheme of rye-grass seed certification already referred to. We recognize in this scheme the germ of an organization that may surpass in economic importance the stud-book of the stock-breeder and the' milk test for the dairy cow. The support that seed-merchants and farmers are giving to this movement must ultimately be reflected in pedigree-seed production not only for New Zealand’s own requirement, but substantially the basis of a large seed-export trade.

Classification of Commercial Rye-grass according to Type

In our trials we have been able to recognize six types within the commercial rye-grass of New Zealand, and as this classification is referred to throughout the present article descriptive notes of each type are given hereunder. Type. 1. — Hawke’s Bay, Poverty Bay, and a few of the best Sandon lines have in general been placed in this group. Characteristically deep green in colour, making dense leafy growth at all seasons, and showing rapid recovery after cutting. Type 2. — The bulk of Sandon rye-grass has gone into this group. Rather lighter in colour than Type I,' especially marked in the. early growth stages; and this colour difference has later proved to be directly associated with a relative lessened persistency. , ■

Type 3. This group comprises the best of the South Island lines, which, while showing a fairly good colour, were as a whole more greyishgreen in the early growth-periods, of divaricating habit in the broadcast plots, and having the individual plants open at the crown with more or less prostrate shoots. This type - has persisted as well as Type 2 up to date, but not nearly so well as the best “ true perennial lines of Type 1. ■ ■ - ' •

' Type 4. The light-greyish-green colour, divaricating habit, and loose open crown associated with “ false perennial " is typical of this group, which includes most of the Southland, Otago, and Canterbury fines, and - may be regarded as the average “ false perennial ”■ coming from South Island districts. There is a very decided falling-off in persistency as compared with Type 3.

Type 5- This - type'shows characteristic colour-differences very soon after . soil establishment. Germination is as rapid as in Italian ryegrass, but. looked on as a plot it typically assumes a steely grey-green colour’ quite distinct from the yellow green ,of Italian rye-grass or of the deeper green of true perennial rye-grass. The plants are spreading in habit of growth, and while making rapid seedling growth are unable to recover after being cut back. In many respects this, type shows close, affinities with Italian , rye-grass, and in some ways is suggestive of a derivative of crossing between the normal ," false perennial ” of Type 4 and ordinary Italian. Single-plant studies have emphasized the approach to Italian rye-grass characteristics. in this, form, but it is important to note that in no case has the type shown the vigour associated : with Italian rye-grass' in the first year.

. Type 6. — Normal Italian .rye-grass sold as "perennial” or merely as rye-grass.'' Single-plant studies have shown that there was a trace of perennial rye-grass in some of the lines placed in this group. The plots were all rapid in growth from seed,, typically erect, and light yellowish - green in colour. Recovering well from the earlier cuts, Italian, rye-grass failed to last the season, going out first and most completely on the weekly-mown section.. . . ,

Distribution of the Types in New Zealand.

In Table i is set out the distribution in New Zealand . of the commercial .perennial rye-grass types according to source of -origin as supplied with the seed. The figures indicate that most of the samples definitely stated to be of Hawke's Bay and Poverty Bay origin approach the “ true perennial ” type, whereas lines from' Southland and Canterbury, including South Canterbury, are 'definitely of the " false perennial” type. Sandon rye-grass on the whole inclines towards the “ true perennial " fact, a few of the best Sandon linesunder , test were indistinguishable from the average Hawke's Bay lines. Sandon rye-grass, however, taken as a whole, . contains an excessive proportion of Italian rye-grass, some of the lines being dominant Italian with very little perennial. South Canterbury . rye-grass. is perhaps more 1 predominantly Italian rye-grass than that from other sources of origin in New-Zealand.’ Occasional samples were received, however, from Southland, Canterbury, 1 Otago,' Marlborough, ' and theWairarapa, which proved to be-dominant Italian/ ... . e.- ;

Rye-grass Types handled at Main Distributing Centres

In Table 2 is set out the position as regards the type of rye-grass handled at the main distributing centres in New Zealand. Auckland handles rye-grass from all over New Zealand, but draws a not inconsiderable proportion from the Hawke’s Bay and Gisborne districts. . It would appear as if rather less than half the Auckland supplies' are of the “ true perennial ” type, i . . '. The East Coast towns, Hastings, Napier, and Gisborne, deal in the main with locally-grown seed, as shown by the preponderance of the “ true perennial ” types that are handled. A small proportion of seed from the South Island, however, is brought in by these towns, especially in years when the local harvest is below normal. The inadvisability of this procedure is self-evident, and is emphasized by the poor results that have been obtained from sowings of Southern

seed made from , time to time in the East Coast districts. Palmerston North and Feilding draw a good deal of their supplies from the adjacent Sandon district, a small proportion is bought in Hawke’s Bay, and a good deal from the South Island. The number of samples under test from Wellington was small, and the figures for this centre therefore had little significance. It is apparent, however, from our tests that Wellington deals in large part with rye-grass seed from the South Island.

Christchurch and Ashburton draw their supplies of rye-grass seed from the surrounding districts. The towns of South Canterbury — Timaru, Geraldine, and Waimate —are also supplied by local growers. Dunedin, Gore, and Invercargill appear to deal wholly with Otago and Southland rye-grass. The whole supply of the South Island towns being drawn from local sources is preponderantly of the “ false perennial ” type; the data emphasize really that these towns are export centres sending considerable quantities of their rye-grass to the North Island and overseas. This export means failure of the rye-grass in any permanent pastures sown down in the North Island, and militates against New Zealand gaining pride of place in the seed trade overseas.

The only consolation —if that it —we have in the meantime is that no overseas country is producing a true perennial rye-grass type suitable for pasture purposes. The imported lines we have had under test are, as a whole, no better than the false perennial from the South Island.

Imported and New Zealand Types compared. All the English, Irish, and Scottish lines have failed badly during the second year of trial; pedigree lines of leading Scotch firms, special indigenous perennial lines, Pacey’s Evergreen, &c., as sold by leading English firms, have likewise gone out. Lines from Germany, Sweden, and Poland range from bad to good false perennial ■ type, while an American line sold under the name of “ Oregon awned perennial rye-grass ” proved to be nothing more than ordinary Italian.

In this connection the following analysis of data comparing New Zealand and overseas types is illuminating :

From these figures it will be seen that the average imported commercial type falls, as it were, in performance and behaviour between

Types 3 and 4. Persistency trials after eighteen months (see Table 6) would indicate that it was nearer Type 4 than Type 3. The high susceptibility of the imported lines .to rust-attack emphasizes also the poor-growth and strain characteristic of these lines. Certainly, then, it would appear that New Zealand has nothing to gain by importing rye-grass for the purpose of improving the . position as it exists to-day. Undoubtedly, the problem .that lies ahead of us is to .make the best possible use of the available true perennial type we have in the Hawke’s Bay and Poverty Bay districts ; to sink any parochial differences we may feel, and to set to work in real earnest to propagate and improve this strain, not . only for the country’s own requirement but also to make fame for New Zealand rye-grass overseas, even as the Dominion is now famed for its butter, cheese, lamb, and apples, remembering also the value of another string to our bow in times of trade depression. The Department of Agriculture • will be behind any such effort with the certification scheme now in operation. .

Need for Certification Scheme in New Zealand.

The need for a proper scheme of certification is emphasized by the following statement, which is based on our trials in respect of lines stated to be of Hawke’s Bay, Poverty Bay, and Sandon origin respectively.

In the present certification scheme only those lines in column 1 would pass field inspection for mother seed. Those in column 2 would pass as fit for permanent pasture seed, while those in columns 3 and 4 would be rejected.

The point we wish to make here, however, is that none of our trials of rye-grass of guaranteed origin from Hawke’s Bay and Poverty Bay have - shown . 100 per cent, false-perennial characters, and it would appear as though some 5 per cent, of the lines sold as Hawke’s Bay are of South Island origin and some 17 per cent, of the Sandon lines are definitely South Island type. This also does not take into consideration the possibility of adulteration of Hawke’s Bay, Poverty Bay, or Sandon with seed of Southern origin ; and, while we do not wish to stress this point, many of the lines reputed to be of the former origin under strict, weekly mowings have not stood this severe test as well as one would have liked. Price quotations, also, from overseas, particularly from Australia, would indicate that much false perennial of South Island origin was -being sold in that country under, the ' popular name ; of Poverty Bay rye-grass.” : ■'

An article by Professor R. G. Stapledon, of the Welsh Plant Breeding Station, Aberystwyth “Herbage Seed Production in New Zealand: IV. Perennial Rye-grass and Dogstail,” published in the Journal of the Ministry of Agriculture (London) for September, 1927—is of interest in this connection. A summary is given of experience with New Zealand rye-grass at Aberystwyth. The comparative behaviour of authentic lines of Hawke’s Bay rye-grass now being tested at that station will be of the utmost importance to seed growers and merchants in New Zealand.

True Perennial and False (or Pseudo) Perennial compared

The difference between the true perennial rye-grass and the false perennial becomes apparent very soon after soil establishment. The true perennial (Hawke’s Bay and Poverty Bay type) is rather less rapid in seedling growth, and after about eight to ten weeks takes on a distinct deep-green colour, the individual plants tending to be upright and the numerous tillers closely packed. Normally false perennials (Southland and Canterbury strains) establish more rapidly, and soon take on a yellowish and then a greyish-green colour. The crown is fewer-tillered and open, the whole plant being divaricating rather than erect, and the tillers loosely packed at the crown.

The false perennials and the true perennials made approximately equal growth during the first winter following autumn sowing ; both were outyielded as winter producers by Italian rye-grass. When the system of differential cutting was initiated in the early spring, however, the false perennials did not show the ability to recover from frequent •cutting, whereas the true perennials consistently showed rapid recovery even under the most severe weekly clipping treatment. Italian ryegrass recovered well from the earlier spring cuttings, but failed to persist .after mid-season. The false-perennial types, therefore, while having none of the advantages of rapid winter and early spring production ■characteristic of Italian rye-grass, have also none of the persistency attributes of true perennial rye-grass.

i The colour differences noted in the broadcast plots of Hawke’s Bay as compared with South Island seed have definitely proved on the past year’s experience to be associated with differences in persistency, seasonal production, and time of flowering. The deep-green, erect-leaved, tufted, and multitillered Hawke’s Bay type has maintained itself even under frequent cutting, while the lighter greyish-green' colour and divaricating habit of the Southern rye-grasses has been associated with lack of tillering and the inability to persist either in the hay section, under infrequent cutting in the “ cattle ” section, or under the system of weekly cuts. At all seasons during the past year the trial grounds presented a checkerboard appearance, where the more persistent actively-growing true perennials were alternated with the non-persistent almost truly annual rye-grass of the South Island.

This is quite apart from a consideration of the Italian rye-grass •element, which is all too often found as an admixture in our commercial perennial rye-grass. Many lines from Hawke’s Bay and Poverty Bay contain a small proportion of straight-out Italian rye-grass usually derived from maiden seed paddocks, but from a purely practical standpoint the small amount of Italian in the sample is of little consequence

for permanent pasture sowing so long as the sample is predominantly of the proper pasture type. In illustration of this principle we may mention one line of Hawke's Bay rye-grass under test which proved to be more than half Italian, but the remainder of the sample was true Hawke's Bay type. That plot now at eighteen months old is far and away better than adjacent plots sown with false perennial rye-grass which originally contained no trace of Italian. For pasture purposes, therefore, it is better to sow a good perennial rye-grass type even if the sample is found to contain a trace of Italian, than to sow the false-perennial annual forms no part of which will last into the second year of grazing.

In the leaf-shoots, seed-heads, and general seed crop the types of rye-grass show some characteristic differences. In the seedling stagesthe true perennial is invariably folded in the leaf-bud and the tiller is flat-stemmed. At a similar growth-stage the false perennial usually tends to roll or at least to be less perfectly folded in the bud, and the tiller just below junction of blade and sheath is more or less circular in cross-section. In the period just prior to panicle-production both the true and the false perennial incline towards a rolling of the leaf in the advanced tillers. The true-perennial seed-stalk stands stiffly erect with but slight tendency to droop in the seed-head itself. The false-perennial seed-stalk is not so erect, but divergent, with a decided droop or arch of the seed-head. This characteristic is perhaps not. so marked in heavy seed-crops, but is extremely marked in crops which have been grazed until fairly late in the season- is, in the lighter' seed-crops where the heads are not drawn up but are permitted to assume their natural divergent and drooping habit. The true Italian rye-grass is always rolled in the leaf-bud, and the tiller stem is alwayscircular in cross-section. The seed stem is erect and taller than those' of the foregoing perennial types, and the admixture of the latter in either is readily discernible by this tallness, together with a marked drooping of the head and well-marked awn of the seed..

The true perennial is never awned ; the false perennials are never strongly awned, but in a percentage of cases short awns or awnpoints appear, especially near the apex of the panicle and in the apical and subapical florets of some of the lower spikelets. Many lines of false perennial show scarcely any awn, but the seed itself is usually bigger than the true perennial and the individual spikelets of the seed-head are broader and not so compact. There is no doubt in our minds that the absence of awn on these false perennials has been largely responsible for acceptance of this type by seed-buyers, who relied in the past so implicitly on the belief that unless a line was awned it must necessarily be perennial rye-grass. In our field inspection work during the past year in connection with rye-grass certification we definitely rejected any paddock that contained even a trace of heads carrying these short awns. The general divergent nature of the seed-stems and arched droop of the head in every case confirmed the short-awn diagnostic feature and identified the line as a false perennial rye-grass. We should like, however, to record our firm belief —even against knowledge in specific instances of hard dressing to remove awns —that most seed-merchants have bought and

sold these awnless false-perennial lines in • the best of faith and belief that they were handling and offering true. perennial rye-grass seed. The general behaviour, growth-form;, and structure of the false perennial would indicate intercrossing of perennial and Italian rye-grass, and from our general experiences we are of the opinion that the shortlived, rye-grass, characteristic of Southern seed has been derived firstly by unconscious selection of short-lived strains of perennial rye-grass ■consequent upon seed-production . for long-continued periods under arable and short lea conditions, and. secondly by the admixture in seedlings of this -lived perennial rye-grass with Italian, with resultant intercrossing.* It seems, therefore, that the false perennials are derivatives first by strain selection towards short-lived perennials, followed by an intercrossing of this type ■ with Italian rye-grass. ■ ■

Data in Relation to Recovery after cutting.

- The ability, to recover after cutting is an important feature of a good strain of rye-grass. It is essential for pasture-production that a strain should show the ability to make year in and year' out an .abundance of new leafy growth immediately after grazing or mowing. In this respect the true perennial alone fulfils • the requirement. During the first nine months of the trials, Italian rye-grass beat the true perennial in recovery, but after the second hay-cut recovery of the true perennial was twice as rapid and complete compared with the Italian. At the peak of the Italian rye-grass growth this type produced in thirty-five days after the first cut as hay, 150 points, with Type 1 = 100; and at five days after the second hay-cut produced only 51 points, with Type 1 = 100. The false perennials, particularly those of Types 4 and 5, failed badly to recover after each cut, and what recovery was made after the hay-cut was definitely of a stalky nature rather than leaf. The following observations made eleven months from sowing down and seven days after the second hay-cut on 17th February, 1930, give the relative recovery figure of the various types exclusive of Italian rye-grass (Type 6) that was contained as an admixture in certain of those lines. Type 1 gave best recovery = 100.

‘ ■ Type 1. Types,. Type Type 4. Type 5. . 100 . 87 .70 ■ 34 15 / At no time during the year did the false perennials approach the true perennial in recovery, and this trait, taken in consideration with the low persistency of these types, marks the false . perennial as the least desirable of all rye-grass types to grow. It . scarcely outlives the Italian in persistency ; it fails badly to recover after cutting, and its total yield is far below either that •of the true perennial or the Italian, f

The high recovery figure for Italian rye-grass emphasizes the value of this species above all others for temporary-pasture work, but we would here stress the advisability of buying strongly - awned lines of seed, for it would seem that much of Type 5 finds its way on to the market .as Italian rye-grass, and this type cannot be compared with Italian in production and ability to recover after grazing of cutting. Swarding Characteristics of the Six Main Types.'

The ability of a rye-grass to persist and sward out and completely cover the ground is one of the most important attributes of any type. A weak rye-grass that tillers but little, or one that relies on persistency by reseeding, . will never make a good permanent sward, and certainly will, never keep weeds out of a pasture. White clover, particularly under phosphatic manuring, often becomes much too dominant in a pasture, and this is certainly the case where a weak hon-tillering, poorswarding type of rye-grass is used. .

The point - quadrat analyses in Table .6 show in average figures according to source of origin the state of.the pasture sward within the same plots nine months and eighteen months , respectively after the plots were laid down. In Table y are given .- similar results of some representative lines from different sources of origin sown in a further series of plots in the autumn of 1929. These analyses are arranged according to type, and both sets of analyses were made on the “ weekly mown ” portion of the plots.

One line only of Type 2.

Viewing the above persistency figures some consideration should be shown in regard to the severity of the trial to which these turfs have been subjected. Weekly mowing with a lawn-mower is a severe test, not only from the point of view of clipping back the rye-grass but also from the strong competition that arises by the incoming and spread of volunteer white clover and weeds. As a matter of general interest the white clover figures have been included in Table 7, and it is interesting to note that the plots in which the weaker types .of rye-grass were sown have on the whole run dominantly to white clover. No white clover was sown in laying down these plots. This state of affairs has without doubt been the experience of many farmers sowing down ordinary commercial rye-grass, and particularly under systematic topdressing with phosphate.

Even among the genuine Hawke’s Bay rye-grass there are lowpersistency lines, but in no case have we met with extremes as shown in groups 4,5, and 6. A few lines show very high persistency considering the treatment, and we have already initiated work at the Plant Research Station to reproduce as rapidly as possible a supply of seed (Line Ba. 12) for further experimental work, which we hope may ultimately form the nucleus of an elite persistent strain well above the standard of the present Hawke’s Bay average lines.

In addition to the point-quadrat analyses presented in Table 7, eye determinations were made of the same plots at twelve months. The following figures are of interest as correlating the two methods (of analysis :

Whatever the method of analysis it will be fairly obvious that the true-perennial rye-grass types are from two to five times as persistent as the Italian and false-perennial types ; and the elimination of these latter from the seed trade and substitution by the former types ■ must very rapidly'lead to a marked improvement in the rye-grass position in New Zealand. True perennial rye-grass is so fundamental to economic grass-production -that every step towards an improvement of existing strains must reflect itself in increased national wealth. The false perennials have no place whatever in the economy of New Zealand grasslands ; they have none of the advantages of a good Italian ryegrass on the one hand or of true perennial rye-grass on the other, while they have the disadvantages of both.

Resistance to Disease,

During the year the trials under study have shown that both broadcast plots and single plants belonging to the various types'of rye-grass show marked differences in degree of resistance to rusts which attack both leafage and flowering-stem. From the pasture standpoint leaf-rust

(Puccinia coronata) is by far the most devastating in its effect. Stalkrust (P. gfaminis) attacks the plant very, late in "the season, and may not be an important economic factor even in seed-production. Without exception during the season under review Type i —true perennial ryegrass — well as typical Italian rye-grass, was relatively highly resistant to rust-attack, whereas the false perennials were badly attacked by leaf-rust during the summer. The effect was general, both in the Plant Research Station area tests and in the field experiments, and was most noticeable in spring-sown plots. Table 9 is self-explanatory, and is based on spring-sown broadcast plots at the Plant Research Station on which accurate rust data were obtained.

. It will be noted that imported lines of rye-grass were rather more susceptible to disease-attack than even the false perennials, and this was pretty generally the case throughout the experiments. Even the one or two apparently quite good perennial lines from British seed firms rusted badly under our local conditions. Rust-attack generally appeared early in December and was most severe during January and February. It would appear that rust-attack is closely associated with strain in rye-grass and is relative to the vigour of the type concerned. Just so soon as a type fails to maintain high vigour and stops growing as summer approaches it immediately becomes susceptible to rust. The more vigorous Hawke’s Bay strain resists the attack until late in the season, whereas the weaker-constitutioned false-perennial types cease growth , early in the season and immediately fall a prey to rust-attack. The production of young leaf well into the summer and as early in the autumn as possible, both by better utilization and stimulation by nitrogenous manuring, seems to be the keynote of success in reducing rust-attack on rye-grass. To accomplish this the use of the more vigorous true-perennial types is the major factor.

Palatability of respective Types.

A criticism of the Hawke’s Bay rye-grass strain from the point of view of palatability is strong in the minds of many farmers in the South Island. There is no doubt that the rye-grass types vary in palatability in the early stages of growth, and this is well demonstrated by the results of grazing trials with eighty-five lines at Marton Experimental Area as recorded in Table 10.

From these - figures it will be seen that the straight-out Italian rye-grass (Type 6) is most palatable, and that those of Types 4 and 5 —the definite false-perennial types, which presumably have some Italian in their make-upcome next in. the relative palatability scale, while the true perennials of Type 1 and the good types of false perennials of Types 2 and 3 fall off considerably in palatability. This was obvious in all the grazing trials undertaken in the field, particularly in the early stages of growth. The true perennials are firmer in the leaf, and apparently are not so palatable as the somewhat quickergrowing, laxer, and broader-leaved types. We concede this point to our critics, but we would like to point out that it is really not a question between the palatability of Hawke's Bay rye-grass and Canterbury or Southland rye-grass, but between one type of rye-grass and another. A true perennial rye-grass from Canterbury or Southland — and there are a few under trialis neglected by stock in the presence of false-perennial types equally with the Hawke’s Bay lines ; conversely a dominant Italian rye-grass from Hawke’s Bay is equally palatable to the Canterbury or Southland Italian, and much more palatable than the true-perennial types of those districts..

Again, in regard to types, palatability is relative according to the season of the year. Type 1, on recovery after cutting for silage or when the seed-heads are cleaned off during the summer period, throws definitely . a . greater proportion of leafage rather than stem, whereas the-false-perennial and Italian types tend to throw up a second crop of seed-stalks. At this stage the true perennials—' young leaf —are highly palatable, and the false perennials-throwing mainly stem—are less palatable. -

Selective grazing by stock, again, is relative, and we may get in the same paddock with the same rye-grass type relatively high-palata-bility patches and low-palatability patches due to stage of growth. If a portion of the paddock is ever so slightly the more palatable—be that due to strain, manuring, utilization, Ac. —those slightly, more palatable portions under selective (light) grazing will be eaten and the rest of the paddock neglected. If the paddock is now spelled for a few days and stock are returned to it later, the previously sweeter and more palatable portions have made sweet young growth, which is again readily eaten, while the neglected portions have become increasingly unpalatable. Thus utilization under selective grazing may exaggerate as the season advances a degree of palatability slight only at the commencement of grazing. It may be noted here that all the palatability trials have perforce been limited to pastures not older than two years. It is not possible .to compare the palatability of old pastures of true perennial rye-grass with those of false perennial, owing to the almost complete disappearance of the false perennial after about eighteen months.

The practical aspect of the palatability controversy that we would like to emphasize is this : so far as New Zealand commercial rye-grass is concerned, if a farmer sows two lines, A and B, in. the same paddock side by side, and if the A portion of the paddock is eaten more readily than the B portion, this .fact would plainly indicate that two types of rye-grass-had been '.sown; and that the A type is in all, probability a false-perennial or annually-inclined type, and that the B type, is, a true

perennial and the more persistent type. As Table io would indicate, high relative palatability in the initial stages of the pasture-growth points clearly to the wrong type of rye-grass so far as the making of permanent pasture is concerned. True perennial rye - grass is, after all, a highly palatable and nutritious feed, and one has only to visit the Hawke's Bay and Poverty Bay flats to realize what a boon it would be if those excellent, high-carrying, true-perennial rye-grass swards could be reproduced all over the better soils of New Zealand. . .

• Our thanks are due to Messrs. Madden, Gorman, and Saxby, Assistants in Agrostology, for point-quadrat analysis data and general assistance in regard to these trials. The field staff under Mr. J. W. Todd, Farm Overseer, Plant Research .Station, did faithful work in the care of .plots and in conducting the mowing ; trials.,..au

. * Member of Staff of Welsh Plant Breeding Station, Aberystwyth, seconded to Plant Research Station, Palmerston North. t See article, Certification, of Grass and Clover Seeds,” by J. W. Hadfield, in this Journal for November, 1929.

f But may contain a trace or some Italian rye-grass. t Many lines contain a fair percentage of Italian.

*ln his paper; The Artificial Hybridisation of Grasses,” Welsh Plant Breeding Station, Aberystwyth, Series H. No. 2, Mr. T. J. Jenkin, M.Sc., records 74-3 per cent.. success fin hand-crossing perennial and Italian rye-grass. These seeds germinated quite readily and produced vigorous plants. It had been further ascertained by Mr. Jenkin that the hybrid plants were equally self-fertile to average progeny plants of Italian or perennial crossed inter se.

f More detailed evidence on recovery of types will be given when dealing with single-plant studies in a subsequent issue of the Journal.

District of Origin. True Perennial, Types i and 2* — Number of Lines. Best Type of False Perennial, Type 3— Number of Lines. False Perennial, Types 4 and 5 — N umber of Lines, Dominant Italian, Type 6 — Number of Lines. Total Number of Lines under Trial. Percentage of True Perennial. Hawke’s Bay ... ■ 175 I 8 5 189 93 Poverty Bay . . 32. 2 I 35 92 Sandon • .; , 46 3 8 7 64 ' 72 Mid and North Canterbury 7 16 56 17 96 7 South Canterbury .... 3 9 38 34 84 4 Southland 3 27 269 ' 9 308. 1 Manio to to /. 2 a 16 2 24 8 Wairarapa . . . . 5 1 3 3 12 42 Marlborough . . . . 2 . ■ 7 1 I II 18 Imported . . 1 9 7 1 18 6

Table 1.- Strain Analysis of 841 Lines of Commercial “Perennial” Rye-grass of stated District of Origin.

Distributing Centre. True Perennial, Types I and 2 —- Number of Lines. Best Type of False Perennial, Type 3— Number of Lines. False Perennial, Types 4 and 5— Number of Lines-. Dominant Italian, Type 6— Number of . Lines. Total Number of Lines under Trial. Percentage of True ’ Perennial. Auckland 25 ■ ' 3 23 3 54 46 Hawke’s Bay and Poverty 120 I ' 4 125 96 Bay Palmerston North and 89 14 25 9 137 65 Feilding Christchurch and Ash7 18 48 14 87 8 ■ burton Timaru and South Canter3 8 37 34 82 4 bury Dunedin . ; .. 2 ■ . j. 42 ’ ' 2' 47 4 Gore and Invercargill . . . 2 . -29 - 259 .. 8 298 , 1 .

Table 2.- Strain Analysis of 830 Lines of New Zealand Commercial “Perennial” Rye-grass as sold in the several Main Distributing Centres of the Dominion.

Origin. Relative ■ Recovery after CuttingPlots Eleven Months old. Relative Excellence of Turf produced after Twelve Months. Relative, Persistency at Twelve Months as shown by Point Analysis Relative Degree of Rustresistance. New Zealand Type i IOO IOO IOO IOO New Zealand Type 2 87 . 91 86'1 New Zealand Type 3 70 80 . 88 [ 36 New Zealand Type 4 34 55 ' 40 r SO New Zealand Type 5 .. ... 15 25 32 J New Zealand Type 6 22 18 IOO Imported 49 42 55 ■ 35

Table 3.-Comparison of the Six New Zealand Rye-grass Types with imported “Commercial Perennial.”

' District of Origin. True Perennial free of Italian■ Number of Lines. True Perennial containing a Trace or 'some Italian— Number of ■< Lines. * False PerennialNumber of Lines. Dominant Italian—■ Number of Lines. ; 7 (I) . (2). ' ' ■ (3) ■ ■ (4) Hawke’s Bay . , . . - . . 135 40 . . 9 ■. 5 Poverty Bay . . / . . 25 7 . .2 . . 1 Sandon . . ... 17 "29. 11 7

Table 4. -Strain Analysis of Rye-grass Lines reputed to be of a certain District of Origin.

■ - Origin. - Average Hits per 100 Points examined. Relative Persistency Figure with Average Hawke’s Bay Seed = 100. ■. After Nine Months. After Eighteen Months. Hawke’s Bay . . . . 41-6 25-6 ; IOO i Sandon , ' . . .. 31'3 19'6 L 77 Wairarapa 31-2 10-4 : 41 Marlborough . . , . . ' . . 29-0 7-0 ■ 27 Mid-Canterbury .. .. 28-2 7 -o 27 Southland . . . . ■ 29'7 7-2-28 Imported “ Commercial ”, 3°-6 4-6 18 South Canterbury .. 29-0 3’0 12

Table 6.-Point-quadrat Analyses of Representatives of 104 Rye-grass Lines sown November, 1928.

Type. First Analysis made at Six .. Months —’Hits per loo Points. Second Analysis made at Twelve Months— per 100 Points. Percentage of Persistency of Rye-grass, 6-12 Months Total Rye-grass. White Clover. Total Rye-grass. White Clover. i and 2* 7 2 2 34 . ■ 40 47 3 •• 75 2 26 ■ 36 . 35 4 • • 78 I 17 57 22 5 • • 83 . I .12 ' 55 .1.4 6 .. 71 I 6 ' 57 ' 8

Table 7.— Point-quadrat Analyses showing Average ding-capacity and Persistency of the Representative Rye-grass Types under Weekly Mowing Trials (195 Lines sown March, 1929; 57 Lines critically examined).

Method. Type i. Type 2. Type 3. Type 4. Type 5. Type 6 Eye estimation .. IOO 91 80 55 25 22 Point-quadrat IOO 86 88 40 . 32 18

Table 8.— Showing relative Persistence and Excellence of Turf produced after Twelve Months’ Weekly Mowing (Type 1 placed at 100).

Type. Most resistant at ioo. True perennials . . IOO False perennials 36 Imported seed . . . . 35

Table 9. —Relative Rust-resistance of the Major Types.

Type i. Type 2. Type 3. Type 4. Type 5. Type 6 51 ■ 54 54 79 95 IOO

Table 10.—Relative Palatability of Rye-grass Types at Eight Months after Sowing. (Most Palatable Type at 100.)