Tuatara: Volume 2, Issue 1, March 1949
The Cawthron Institute owes its origin to the munificence of Thomas Cawthron, who left practically the whole of his fortune, valued at $250,000, for the establishment and conduct of a scientific institute and museum.
The original trustees, appointed under the will of Thomas Cawthron, decided, on the recommendation of a Scientific Advisory Committee, that the major activity of the Institute should be research in the interests of New Zealand agriculture with reference to problems of both farmers and orchardists. The proposals of the Trustees were approved by the Supreme Court and early in 1920 the nucleus staff under the Directorship of Professor (now Sir Thomas) Easterfield was appointed and work was commenced.
Three main departments of scientific research were established in 1920 and these were maintained with but little change until the close of 1941 when a Biochemical Department was formed to handle more effectively plant and animal nutritional problems. The principal work of the four scientific departments is connected with (a) soil and general agricultural problems; (b) plant chemistry and mineral deficiency problems of stock; (c) insect problems of farm, orchard, and timber, and the biological control of noxious weeds; (d) fungus disease problems of fruit, hops, tobacco, and market garden crops. A technical museum, having special reference to the primary industries of Nelson and the natural history section of museum work, forms an integral part of the Institute and provides suitable facilities for the presentation of the work of the research departments to the general public.
Since the inception of the Institute seven additional bequests of a total value of some $50,000 have been received. In addition, the work of the Institute has been assisted from time to time by grants from the Empire Marketing Board, local bodies, and the primary producers of New Zealand. In recent years the Minister of Scientific and Industrial Research has given increased financial assistance for soil, mineral deficiency, tobacco, fruit, and entomological investigations of the Institute.
In several branches of research work, the staff of the Cawthron Institute collaborate with officers of the Department of Scientific and Industrial research. Entomological, tobacco and hop research, at Nelson, are conducted on a co-operative basis, both Cawthron and Government officers sharing in the research programme.page 3
Work of the Institute.
The Nelson district in which the Cawthron Institute is located has a climate which favours horticulture, and it is in this branch of agriculture that very marked development has taken place in recent years. The whole of the tobacco and hop industries of New Zealand are located in the Nelson district. In addition, Nelson has a very important section of the apple industry together with considerable acreages of small fruits, tomates, and market garden crops.
Arable farming, dairying, and sheep farming are all represented in the agriculture of Nelson, and at different times problems connected with these branches of agriculture in addition to horticultural crops have been investigated by the Institute.
One of the interesting features of the Nelson district is its diverse geology. Ultra-basic rocks of serpentine, basic rocks of melaphyre, page 4 acidic granites, in addition to several well-defined sedimentary formations, outcrop in the district and exert a pronounced effect on the properties of the different soils. The study of the soils of the Nelson district and their uses for different crops has given information of great value not only to agriculture in the Nelson district, but to other areas in New Zealand where similar soils occur. Striking deficiencies of lime, phosphate, and potash have been found in several soils, while minor element deficiencies of cobalt, boron and magnesium have been identified on particular soils and studied intensively.
Although the work of the Cawthron Institute is not confined to the Nelson district, a great deal of its work is associated with the soils and special crops of Nelson. The work of the entomological department at the Cawthron Institute, however, has a more general application to agriculture outside the Nelson district in that the parasitic control of insect pests and the biological control of weeds, as a rule, apply in equal measure to agriculture throughout the whole of New Zealand.
In several aspects of both soil and insect research the Cawthron Institute has gained special distinction for the initiation and development of work of major importance to New Zealand agriculture. This is particularly true in connexion with the work carried out by the Institute in soil surveys, trace element deficiency, the parasitic control of insect pests, and the biological control of noxious weeds.
One of the important investigations commenced in the inaugural year of the Cawthron Institute was a reconnaissance soil survey of Waimea County, Nelson. This survey constituted the first systematic soil survey conducted in New Zealand which gave due recognition to the important part placed by both geological origin and texture in soil properties. Although modern methods of soil classification have necessarily entailed a revision of the soil groups identified in these early surveys, the units set out on the soil maps have required little alteration and have proved invaluable in the conduct of investigations relating to animal health, plant nutrition, and the manuring of crops.
Among the soils of the Waimea County which have proved of special interest to Nelson, and indeed to the whole of New Zealand, may be mentioned Moutere loams and Kaiteriteri loams. The Moutere soils have furnished spectacular deficiencies of lime, phosphate, nitrogen, potash, boron, and magnesium, several of which have seriously limited both yield and quality of crops—particularly of apples grown on these soils.
The Kaiteriteri group, derived from granite, has proved of no less interest in view of its association with marked deficiencies of cobalt, boron, and magnesium. In no part of New Zealand are the characteris- page 5 tic properties of the soils so divergent and the value of soil surveys in the development of agriculture so clearly apparent.
The success achieved by the Institute in soil survey work in Nelson led to the establishment of a Soil Survey Division by the Department of Scientific and Industrial Research and the initiation of a reconnaissance survey of the volcanic ash soils of the central North Island territory of New Zealand. The Cawthron Institute was intimately associated with this and other surveys which were carried out in Taranaki, the Waikato, North Auckland, Hawke's Bay, and other parts of New Zealand. The reconnaissance survey of the volcanic ash soils proved of very great value as some of the soils were associated with stock ailment. When, as a result of other investigations, the cause of “bushsickness” was identified as cobalt deficiency, the survey of the volcanic ash soils made possible the immediate application of this discovery to practically the whole of the affected country in the North Island.
In more recent years soil survey work at the Institute has been concentrated on the detailed mapping of the alluvial soils of Nelson for the expansion of the tobacco industry. The results of the survey show that the Waimea County has some 10,000 acres of soil texturally suitable for the culture of flue-zured tobacco. Tobacco soil maps prepared from the soil examinations are proving of great value in the sound expansion of the tobacco industry.
Trace Element Investigations.
The Cawthron Institute has played an important part in the identification of trace element deficiency affecting both animals and plants in different parts of New Zealand. The investigations of the Institute have comprised studies of cobalt deficiency on the granite soils of Nelson Province and on the loess soils of Southland; boron deficiency on two soil types in the Nelson district and on several soils in Central Otago, and magnesium deficiency of apples and tobacco on the granite and Moutere Hills soils of Nelson.
In regard to cobalt deficiency, studies of “bush-sickness” in sheep on the granite soils of Glenhope were commenced in 1928, and of lamb ailment in Southland in 1934. Evidence was slowly accumulated which ruled out a theory of iron deficiency as the cause of these stock ailments and suggested another element which was contained in certain iron ores and soil “licks” which had proved beneficial in the treatment of stock ailment.
Aided by the announcement from Australia that cobalt was an element of nutritional importance to stock, chemists at the Institute quickly showed that cobalt overcame stock ailments at Glenhope and Southland, and that there was an actual deficiency of cobalt in the soils, pastures, and organs of affected animals. The work carried out page 6 by the Cawthron Institute on cobalt “licks” and the use of cobaltized fertilizers has had a wide application not only in New Zealand but in other countries where cobalt deficiency has been identified.
As a result of the investigations carried out by the Department of Agriculture in the North Island and by the Cawthron Institute in the South Island, it can be said that cobalt deficiency on New Zealand has been overcome; the production of fat lambs and successful dairying has become possible over hundreds of thousands of acres which were formerly seriously affected by stock ailment or under suspicion.
Similar work has been carried out by the Institute in regard to the incidence of boron deficiency in apples, apricots, plums, and grapes on certain fruit soils in Nelson and Central Otago. Surveys of the boron content of soils and fruit have been carried out in all fruitgrowing districts of New Zealand and methods for overcoming boron deficiency have been studied. The investigations have shown that boron deficiency in fruit trees can be controlled by the use of half a pound of borax per tree or by the use of borax sprays at 0.1 per cent. strength. One of the interesting features of the experiments on apples was the adverse effect on keeping quality when borax was used in excessive amount.
More recently, studies of fruit trees in the Nelson district have shown the presence of magnesium deficiency on the Moutere Hills type of soil. Premature defoliation of trees had been noticed in certain apple manurial experiments of the Institute. Injection of different elements into the limbs of affected trees showed that magnesium salts were highly beneficial in controlling defoliation. Analyses of the leaves of affected trees showed a high deficiency of magnesium. The identification of magnesium deficiency in apples under commercial conditions of culture was of considerable interest. The Nelson work paralleled similar investigations carried out by Long Ashton workers and suggested the possibility of a fairly common occurrence of magnesium deficiency in horticultural crops on soils naturally low in bases, particularly where excessive amounts of potassic manures have been used. An interesting feature of the Nelson experiments on the control of magnesium deficiency in apples trees has been the success achieved with ground dolomite in restoring affected trees. This magnesium compound used at the rate of twelve pounds per tree has given more permanent benefit than the use of the corresponding quantity of magnesium sulphate.
Parasitic Control of Insect Pests.
Orchardists in New Zealand will always remember the spectacular success achieved by the Cawthron Institute through the introduction of Aphelinus mali parasite for the control of woolly aphis which, for page 7 many years prior to the introducation of the parasite, had been one of the serious pests of New Zealand apple orchards.
The parasite, obtained through Dr. Howard, United States of America, established freely in New Zealand and very quickly brought about a great reduction in woolly aphis, thereby saving many thousands of pounds in the cost of oil sprays.
Similar work has been carried out by the Institute in the introduction of the parasite, Habrclepis dalmani, for the control of Golden Oak Scale. Liberations of the parasite were made at Nelson, Christchurch, and New Plymouth. In every case the parasite was an outstanding success and gave an effective control of Golden Oak Scale.
A more recent introduction by the entomologists at the Institute has been that of Rhyssa persuasoria, for the control of the horntail borer which attacks pine plantations. The parasite has been liberated at several centres in the South Island of New Zealand and has multiplied rapidly. There is every indication that the parasite will prove valuable in the control of the horntail borer.
Biological Control of Noxious Weeds.
Although several insects have been introduced with a view to the control of noxious weeds in New Zealand, success has been somewhat limited. The Cinnabar moth and the ragwort seed fly were both introduced for the control of ragwort but so far have not been successful under field conditions in the control of this weed.
The Chilean saw-fly was likewise introduced in an attempt to control piri-piri, but although quite effective under laboratory conditions, this insect, so far, has not been successful under field conditions.
The gorse seed weevil, Apion ulicis, however, has established freely at all points where liberations have been made. Examinations of gorse pods show that the weevil is exerting a marked effect on gorse seed production and should eventually be an important factor in controlling the spread of the plant.
The recent introduction of the European beetle, Chrysolina hypersizi, for the control of St. John's Wort appears to be an outstanding success and is proving very effective in the control of this noxious weed in the Awatere Valley, Marlborough.
The establishment of the Entomology Division of the Department of Scientific and Industrial Research at the Cawthron Institute under the direction of Dr. D. Miller, Chief Entomologist to the Institute, has greatly strengthened entomological research at the Institute. The work carried out by the Government entomologists on the parasitic control of the White Butterfly and the Diamond-back Moth has been very successful and has resul ed in immense savings to farmers throughout New Zealand.
Fungus Disease Investigations.
The horticultural crops of Nelson provide great scope for Cawthron mycologists. Their services have been in constant demand by orchardists, tobacco growers, and market gardeners, for the identification of diseases and for advice concerning their control.
Outstanding work has been done by the mycologists in the study of “Black-spot” of apples, “Brown-rot” of stone fruit, diseases of small fruits and tomatoes. In recent years very detailed studies have been made of tobacco mosaic and the factors which operate in its dissemination in the tobacco gardens. The importance of the seedling bed stage in mosaic transmission has been established and the necessity for the greatest care in handling plants to avoid infection has been stressed. Several tobacco diseases, new to the Nelson district, have been identified by the mycologists. Among these may be mentioned “Angular leaf spot,” “Verticillium Wilt” and “Black Root-rot.” The early identification of diseases and the application of suitable control measures have been of great importance in the successful development of horticulture in the Nelson district.
In this brief review of the work of the Institute it has been possible to describe only the more important activities of the Intitute. During the twenty-nine years of work at Nelson a great variety of work has been successfully handled and no less than 470 scientific papers have been published by members of the staff.
The success of the Institute has not depended solely on the results achieved by research. Of almost equal importance has been the great influence exerted by the Institute on farmers and citizens throughout New Zealand, in creating an appreciation of the value of scientific research.