SUB-CLOVER TYPES

Manawatu Standard, Volume LVII, Issue 160, 8 June 1937, Page 5

SUB-CLOVER TYPES

EXPERIMENTS’ RESULTS. PLANT ELSE ARCH ACTIVITIES. “Now that subterranean clover is becoming more widely used’ in New Zealand there is a great deal of attention being focussed on a study of this very useful pasture species,” said Mr L. W. Gorman, assistant agrostologist at the Plant Research Bureau, Palmerston North, in a recent lecture to sheep farmers at Massey College. About 100 different samples of seed had been grown at the station, being obtained from Australian research stations. After making- general observations for a period of three years a more intensive study had been commenced and that had been in progress for over two years. Seed from each sample had been sown in boxes in February, 1935, and the resulting seedlings planted out in May to be allowed to grow and join up to form the equivalent of a broadcast plot. Completed records over a period of a year formed the basis of the conclusions arrived at.

“A previous single-plant trial demonstrated that subterranean clover was an annual species which set seed by complete self-fertilisation and each different sample grown was practically 100 per cent, uniform to the one plant type,” continued Mr Gorman, “lint although there was very little variation within the one sample there were extensive differences between different samples being grown under similar conditions. MAIN CHARACTERISTICS. “It was found that all samples could he classified as belonging to one or other of four groups. The general characteristics of these groups arc as follow: — ' “Group 1. —Each strain included in this group had small dark green-col-oured, indistinctly marked leaves. The plants were stemmy and prostrate in habit. Jn the year of planting thy) time of commencing growth was delayed till the beginning of August, and even then the growth consisted of only a few short trailing steins bearing a number of florets, but very few leaves. Flowering commenced very early (the first week in August). Subsequent growth was limited in amount and these plants were the first to die olf in the summer (last' week in December). The total production for tins growing season was extremely low. As the result of heavy summer rains ro-cstablishment from shed seed was very early (third week in January). For the next three months growth was rapid and production good. After cutting (early in May) these strains, together with all others, remained dormant till mid-July. Leaf growth then commenced and production has been quite good, but early maturity is indicated by the fact that flowering has been general during the last week in July of this year. “Group 2.—The strains of this group arc leafy and have a leaf size greater than those of Group 1. In the year of planting growth was early and good right from the beginning of August till the cud of December. The total yield of green herbage was very high. The commencement of flowering varied between September 13 and October 18. Good seed setting followed, lie-establishment of seedling plants commenced before the end of January and rapid growth follow’ed. This group gave the highest production for the autumn period and lias been able to make a moderate amount of growth in mid-winter.

“Group 3.—-This group closely resembles Group 2 in that habit of growth, time of flowering, and seasons of production are as already given. The essential differences which define this group are:—(l) Growth is very limited till after the beginning of September (one mouth later than that for Group 2), and (2) total production is of good average only,' being at all times considerably below that of Group 2. Autumn establishment and growth was good, but from the beginning of May till the end of July this group has been completely dormant. “Group 4.—When in full growth these strains are large-leaved, but throughout the early part of the spring they appear as small leafy rosettes and productive growth does not start till as late as the last week in September. From that time onward growth is very rapid, and within the following eight weeks there is a greater yield of green material than is made by strains of any other group, even when these others commence growth eight to ten weeks earlier. Flowering did not occur till after the middle of October and these late strains continued to make good growth till the end of December, and actual death did not occur till mid-January (two weeks later than for other groups). This late dying-off was followed by delayed germination and re-establishment was six weeks later than for Groups .1 to 3. Fairly good autumn growth followed till the beginning of May after which growth remained dormant for a period of two months. .Towards the cncl of July the plants of these strains appeared as small leafy rosettes giving good ground cover, hut not making any productive growth.

STRAINS CLASSIFIED. “For the purpose or identification a number of ‘strain’ names have been used ill Australia, and samples sent to us have been referred to as being under one or other of 25 different names. The names of the strains which come within each of the groups are as follow:—Group 1 (early flowering .and low production) : Dwalganup, Daiiak, Spf'inghurst, Muhvala. Group 2 (midseason flowering, early growth, very good production) : Burnerang, Myall, Nangcela, Bacchus Marsh. Group 3 (mid-season flowering, good average production) : Mt. Barker (commercial), Mt. Barker (selected), Western Australia, Kybybolite, Goroke, Wangaratta, Orford, Orford selection, Hill’s Small seeded, White seeded. Group 4 (late season flowering, late growing, but heavy production in the late spring) : Tallarook, Romsev, Bona, Kvneton, Macarthur, Wcnigup, Bass.” After dealing with comparisons of strains, Mr Gorman added: “Practically all of the subterranean clover seed sold commercially in New Zealand in past years has been of the Mt. Barker type. This strain, together with the others of similar type but dilfercntly named can he relied upon to give reasonably good results, and until superior strains are available commercially the sowing of the Mt. Barker type is quite worth while. . . In conclusion, I might say that from a study of existing strain differences a classification of strains into well-defined groups has proved possible .and, from further discussion on the merits and demerits, of individual strains, Burnerang, Nangcela, Myall, Bacchus Marsh, Mt. Barker and Tallarook appear to he strains well worthy of extended experiment and field trial. Unfortunately, seed supplies-of Burnerang, Nangcela, Myall, or Bacchus Marsh are not available in commercial quantities, but _ atthe present time while we are studying these strains we are also growing seed increase blocks of the most promising strains. When seed stocks are available it will be essential to have the growing, harvesting, and distributing of these strains protected by a system of seed certification.”