ASPARAGUS.

Auckland Star, Volume LXVI, Issue 70, 23 March 1935, Page 6 (Supplement)

ASPARAGUS.

EXPERIMENTS IN GROWING. The Minister of Agriculture, in a [Bulletin on asparagus growing, says:— 3otanically, asparagus is a member of ithe family liliaceae, and is related to Ttlie lilies. It is a native of the North Temperate zone of the old world, and ■was introduced to America by the early settlers. The asparagus maritinms, "which grows wild in sandy places on Tthe Mediterranean coast, resembles most ■closely in appearance the cultivated •form which, however, has hitherto been called asparagus officinalis var. altilis. In England the distinct variety known as asparagus officinalis var. prostatus, grows wild on the south-western -and western coasts and also on those of YVexford and Waterford in Ireland. The plant is perennial, forming a matted rootstock or "crown." The rootstock consists of creeping underground stems or rhizomes from which roots arise, new ones being produced each year. A large proportion of the roots are thick and fleshy, and in these food is stored; others are more fibrous and absorb "water and other substances from the soil. The fleshy roots may spread for a distance of 10ft to 12ft outwards and Sft downwards, which is a. point worthy of consideration when cultivating the plantation. Stems up to sft high are sent up annually. The asparagus of commerce is the young buds and stems when they have developed to a height of 12in to ISin. The buds are rounded ■or pointed in shape, and covered with overlapping scales that vary in colour from the pale green to deep violet with Teddish green and purplish green predominating. The colour, however, is no guide to the variety, for buds of all colours may be found in a single bed of any variety. On the stems are fine, needle-like growths, which are actually modified branches and not true leaves. The actual leaves are little scales. The flowers which are less well-known to the casual observer than are the red terries that result from them, are quite small and arise in groups of two or three at the junctions,of the branches. They vary considerably in size and colour; some are very small and , coloured pale green, others are nearly Ain long, reddish green or yellowish in colour. The very young "flowers contain the rudiments of both stamens and pistil, tut as the flowers grow one or other • of these fails to develop fully, so that some flowers produce pollen only; these are "male." Others have a stigma and eventually form berries; these are "female." In the male flower there is a number of long stamens producing the yellow pollen, and an undeveloped pistil can be seen; in the female flower there is a seed-box and a definite stigma; at the base there are undeveloped Btamens. Occasionally both the stamens and the pistil develop, and when this occurs , the flowers are hermaphrodite, that is, they produce pollen and also form berries. As a rule, however, the plants are dioecious, that is, each, plant produces either all male or all female flowers. Associated with either sex, certain other characters may be detected; the male plants show a greater vigour and yield a larger number of buds that develop early; the female plant yield fewer but slightly larger buds later in the season. This fact has suggested to growers the possibility of establishing beds containing male plants only, for, besides securing a larger yield a male bed does not become overcrowded by the springing up of a large number of seedlings, which always arise in beds of plants of both sexes. Experiments have been carried out in Germany, U.S.A., and England with the following results :-rThe system recommended is to transplant one-year-old crowns, not into their old quarters, but into a new bed, when their sex is revealed in the second year. "When planted, four inches apart in rows twelve inches apart, the plants are not ■weakened as would occur if they were left for two j'ears in their seed bed. Considerable attention has been paid to this problem in the United States, , Specially in California, where asparagus plants flower at one year old, so that transplanting into a second bed is uii- - necessary. The experiments show that the yield of buds from male plants exceeds that from female plants by 35-50 per cent. This difference in yield was especially marked in the early part of the season, when G54.41b were gathered from the male plants, and 385.51b from an equal number of female plants, showing that the male plants are more precocious than the female. American workers seem to be confident that this separation of the male plants will prove entirely practicable for commercial growers in their country. To test the possibility of establishing beds consisting entirely of male plants, an experiment is being carried out by the Royal Horticultural Society at Wisley, where, incidentally, asparagus grows exceedingly well on the light Bagshot sands. The variety chosen was Conover's Colossal, and the plants were obtained by sowing in drills two inches apart and transplanting at two-three years old. Ultimately the crowns were set on the flat, two feet apart, in several beds each containing approximately 50 plants. An endeavour was made to have plants of one sex only in each bed. The results, howevpr, whilst in each bed a particular sex predominates the plants are nevertheless mixed and some seem to send up both mulo and female shoots. An examination of the flowers in these beds in 1032 showed that while the majority were of one sex only, some were hermaphrodite, that is besides producing pollen they were also capable of setting seed. It is therefore apparent that rogning must continue for several years after tiie crowns are set out in order to secure beds occupied entirely by one sex. A marketable crop was obtained between April 18 and Juiie 3, 1933. and from a series of 10 beds thc / total number of saleable stems was 5330. Of course 3238 stems were obtained from the male beds, and 2092 from the female, and moreover in every comparable pair of beds throughout the experiment the male beds produced a significant preponderance of stems, compared with the female beds. A similar experiment was started at the Worcestershire County Council demonstration plot at Perdiswell in 1930. The crowns were transplanted at two years old, since the sex could only be determined in the second summer after sowing.

Transplantation- iliil not appear to be at all detrimental to the crowns, but care had to he taken that frowns from a. single seed, and not "double crowns" •were planted. The first cutting: was ■j;naAe> in. 1933, when a very marked dif-

ference between the yields from the male and female beds was recorded. During the first period of the cutting season (April 20-May 22), the weight of the crop from the male plants was 100 per cent greater than that from the female plants,, while during the second period the crop was 75 per cent greater. Taking the season as a whole, the yield from the male plants was nearly 90 per cent greater than that from the female. The average weight of the female buds was slightly greater than that of the male buds; 120 female buds weighed ;">lb 9oz, and a similar number of male buds 51b Ooz.

The female flowers', .'are pollinated by bees and, when fertilised, give rise to berries, which are conspicuous features on the plants in autumn. The berries are round, the size of a large pea, and in March they become bright scarlet. Within the berries are three to six black, angular seeds, which can be extracted by macerating the berries in water.