TOBACCO RESEARCH

Nelson Evening Mail, Volume LXXIII, 12 June 1939, Page 4

TOBACCO RESEARCH

ADVISORY COMMITTEE’S ANNUAL REPORT ESTABLISHMENT OF UMUKURI STATION VALUABLE ACTIVITIES IN FIRST YEAR’S WORK The first annual report of the Tobacco Research Advisory Committee indicates that very valuable work has been carried out in the short time that the Umukuri Research Station has been in operation. In addition to the establishment of the station, many experiments were commenced and eleven acres of tobacco grown. Seed-bed experiments have already produced interesting results in connection with mosaic infection of the plants. The report was as follows:

Advisory Committee: Sir Theodore Rigg (chairman >. Dr. E. Marsden. Mr J. A. Campbell. Mr W. K. Dallas. Mr L. J. Schmitt, Mr H. L. Wise. Mr I. Hamilton, Mr C. C. Nash. Mr J. F. Balck, Mr B. T. Rowling, Mr F. A. Hamilton: research officer and secretary, Mr J. M. Allan.

During the year the Research Committee attained its objective of establishing a Tobacco Research Station in the Motueka-Riwaka district. An area

of approximately 18 acres of land situated at Umukuri was secured on longterm lease, with the option of purchase at the end of five years. The soil is of a type very suitable for tobacco culture, and is representative of considerable areas of tobacco land in the district. iThe property is centrally situated and excellent facilities for irrigation are provided by the Brooklyn creek which runs through the property. Possession was obtained on the Ist of May. and the

work of establishing the station commenced immediately. Later two acres oi the area were purchased from the lessor as a site for the buildings.

In January, 1938. Mr G. L. Copp, formerly of the Cawthron Institute, was appointed assistant to the Tobacco Research Officer, and in August Mr R. C. Mickell was appointed to the position }f farm foreman.

Three meetings of the Research Committee were held during the year. Every effort was made to secure the functioning of the Research Station during the 1938-39 season and to inaugurate the full research programme. Working expenses were provided for

Vom the annual grant from the Tobacco 3oard, calculated at id per pound on he previous season’s tobacco crop, and in equivalent grant from the Govern-

ment. As no provision had been made or capital expenditure the committee approached the Government through he Department of Scientific and Industrial Research, and in September a jrant of £2250 was made available for aui'ldings and equipment. Sufficient working equipment was obtained during the year to enable the *esearch programme to be put into effect. A two-roomed whare was built

o provide temporary accommodation "or the Research Officer. The erection if three flue-curing kilns and the bulkng and grading sheds was commenced n December. 1938. and was completed v the middle of February. 1939. Three

automatic stokers were very kindly ti pplied on loan by Messrs Vale and Company. Heating and Combustion Engineers. Christchurch, for use with the

kiln. A further contract for buildings was put in hand in March. 1939. the buildings to be completed in May. These buildings comprise a glasshouse, -'umping plant, garage, toolshed and minor buildings.

The first field day was held at the Research Station in January, and was well attended by about 150 tobaccogrowers and other interested persons.

During the year, the committee suffered a severe loss in the death of Mr J. A. Campbell. Director of Horticulture. Mr Campbell was an original member of the Tobacco Research Committee and rendered invaluable assistance in the inception of the Tobacco Research organisation.

The Research Committee approved a very extensive programme of research to be shared between the Research Station and the Cawthron Institute according to facilities available. The work of the Research Station was confined l'oi the present to field experiments, and that of the Cawthron Institute covered a soil survey of the tobacco soils of the Motueka-Riwaka district and chemical and mycological investigations. TOBACCO RESEARCH STATION The research programme commenced in August with an extensive series of seed-bed experiments. The experiments included varying fertiliser treatments, the inclusion of trace elements in the fertiliser formula, the use of different seed-bed covering materials, and different. methods of raising the seedlings. The field programme was an extensive one, and in all eleven acres were placed under experiments, with the experiments arranged on uniform soil types on the property with the aid of the detailed soil map, made by the Cavrthron Institute. The experiments are as follow: 1. Rate of Fertiliser Application: Standard fertiliser was applied on two soil types at rates equivalent to 000, 360. 1.000 and 2.0001 b. 3—B—6 mixture.

2. Variation in the Percentage Nitrogen and Potash in the Fertiliser: Nitrogen and potash was varied from half to double, both singly and in combination in the standard fertiliser. <3—B—6). 3. The addition of Lime. Magnesia and Boron to the Fertiliser: Lime was applied at the rate of one half, one, and two tons per acre: magnesia as magnesium carbonate lOOlbs per acre; and boron as hydrated borax 201bs per acre. 4. The use of Fish Meal as a source or Organic Nitrogen: Fish meal was used as an alternative to dried blood as & source of organic nitrogen in the fer5. Chlorine and Sulphur Content of the Fertiliser: As the inclusion of a percentage of chlorine in the fertiliser is beneficial to the quality of tobacco, varying percentages of chlorine were added to the standard formula. High sulphur content of the fertiliser adversely affects the quality of tobacco. In this experiment ingredients of low sulphate content were used. 6. Variety Trials: Seed from 107 different varieties and strains were used. Comparisons were also made w'ith seed of the same strains grown overseas and in New Zealand. 7. Topping and Lateralling Trials: The effect of variations in both time and method of topping and lateralling were investigated. 8. Comparison of Glasshouse-raised

and Bed-raised Seedlings: Seedlings grown in the glasshouse until about cne inch high and then pricked-out into the sede-bed until sufficiently large to transplant into the field were compared with seedlings grown from seed in the seed-bed without pricking-out. 9. Mosaic Investigations: Observations on the Mosaic disease were made over all the experiments.

The Research Officer has been fully occupied with the activities at the Tobacco Research Station, leaving no time for work among the growers. The year has proved a difficult one, both on account of the adverse climatic conditions and the fact that during the first year of work many obstacles had to be overcome and much temporary and makeshift equipment utilised.

The year may best be regarded as a preliminary to the actual work of the Research Station, which has been most useful in training the staff to deal with research work and to smooth out the details of the long-range programme so that, after trial, it can be set out to give the best results. By next season the Research Station should be well equipped in every way to deal with the full programme. SEED-BED EXPERIMENTS The work of the Research Station commenced with building seed-beds and preparing them for subsequent sowing and pricking-out. The beds were ready in August. Eight seed-beds were sown between the 11th and 14th of August, and two others on the 21st and 28th of the month. Germination commenced 12 days after sowing, and a good strike was obtained x in all beds. Insect damagp was practically non-ex-istent. The early growth of the seedlings was slow, but in the later stages soon caught up to and exceeded that of the pricked-out seedlings. Even those beds that were sown a week and a fortnight later, respectively, were ready for transplanting at the same time as the earlier sown beds.

Of the seedlings raised under glass approximately one half were grown in a commercial glasshouse at Nelson, and the rest at the Cawthron Institute. Those grown in the commercial glasshouse were sown a few days earlier than those in the seed-beds, while those at the Cawthron Institute were sown about the same time and later as the seed came to hand.

Pricking-out commenced at the end of September, and continued as the seedlings were ready. All precautions v ere taken to prevent the transference of mosaic during this operation. The results obtained from the seedbed experiments were not very marked, except where no fertiliser, a half application and a full application, were compared. Those seedlings receiving no fertiliser had hardly made any growth at all at transplanting time, and remained yellow and stunted: those receiving a half dressing had made almost the same growth as those with the full application, hut when almost ready for transplanting began to yellow and show starvation symptoms, which became more apparent as time went on. whereas the latter remained green and contmutd to grow rapidly.

In the experiment where seed was sown in the glasshouse in an endeavour to produce 500. 1000. 1500 and 2000 seedlings per box <l6.iin x Ilin), the actual numbers obtained were approximately 600. 1200 . 2000 and 2700. Of these th ; 1200 lot boxes were the most satisfactory. They gave the best percentage strike on pricking-out. and made more rapid growth. The 600 lot were equally good, but the number per box was not an economic proposition. Fair results were obtained with the 2000 lot, but many of the weaker seedlings did not survive transplanting and with the 2700 lot a considerable percentage died.

FIELD EXPERIMENTS Transplanting commenced under favourable conditions on the 4th November, and was completed on the 16th. The strike was good but soon after the planting was completed a period of strong winds set in. and was responsible for the destruction of about an acre of plants on the light sandy area along the Brooklyn Valley road. This area was replanted along with the misses throughout the crop early in December. Mosaic made its appearance in the beds containing pricked-out seedlings just before transplanting, and by the time the replanting was finished a large number of affected plants had been found. In thoise beds in which the plants had been raised from seed without nricking-out, only four affected seedlings were seen. At replanting time in the field. 11 per cent, of mosaic was found in the latter plants. These were pulled and replanted. In the pricked-out plants practically 90 per cent, were found to be affected. As it was not possible to replant all, only the most severely affected were pulled and replanted.

With regard to the percentage of mosaic occurring in both seed-bed and field, it must be borne in mind that a heavily infected crop was grown on the entire arer. the previous season. The old stalks were supposed to have been

completely removed in the following June, but when working the land prior to planting, much old tobacco refuse was turned up. Therefore much visible infective material was present in the soil. The amount of mosaic in the |. ricked-out seedlings in the beds indicated that considerable infection must have occurred from such tobacco refuse during pricking-out. The absence of mosaic in the plants raised directly Lorn seed without pricking-out indicated that where there were no injured tissues and no handling, infection did not occur. The subsequent infection found in the plants in the field might 1

well be traceable to the infective ma terial present there.

The season was a very unfavourable one for tobacco, being too cold in the early part of the season, and the crop was severely by wind, and during the latter part of the season it was too dry, and much of the leaf when harvested was badly wilted, which was not conducive to good results in curing. During the early part of the season growth was poor, and what growth was made took place when the crop had already started to mature. Differences v/ere not apparent in the field in the majority of the experiments, even when ; there was considerable difference in fertiliser or other treatment.

As the three flue-curing kilns and the grading and bulking shed were not completed until the middle of February much of the tobacco leaf was too mature before the kilns were ready for use. Owing to over-maturity the best results were not obtained in curing, as i* was too late in the season before all Ibe more mature leaf could be harvested, and attention turned to leaf at the correct stage of maturity. Harvesting operations commenced on 11th February, and were completed on 20th April. Grading the leaf is yet to be done, and differences may become apparent in the experiments when the plot yields and quality indices are available when the grading is completed.

The only experiment in which obvious results were apparent was that in which plants grown directly from seed in the seed-bed were compared with plants raised by the usual method in the glasshouse. Not only did the former make considerably better growth but showed less than 10 per cent, mosaic infection as compared with over 90 per cent, infected in the latter. Growers have shown very keen interest in this experiment. and many intend growing some seedlings for themselves next season. The results of this experiment should prove to be of considerable practicable importance in the control of mosaic.

DISTRICT EXPERIMENTS The only actual plot experiment outside the Research Station during the past season was one on the property of Mr J. T. Heath, Pokororo, to determine the effect of lime and magnesia on the tobacco crop grown on land believed to be deficient in these plant foods. Acute deficiency symptoms had been shown by the crop in the previous season on this area. Lime was found to have little or no effect on the appearance of symptoms, but magnesia supplied as lOOlbs of magnesium carbonate per acre completely prevented the trouble. It was found impossible in the first season to undertake more outside plot experiments owing to the work of establishing the Research Station, and getting the full programme initiated there. Also a number of difficulties have yet to be surmounted before yield and fertiliser experiments can be undertaken in co-operation with farmers. Co-operative experiments were entered into with the two main manufacturing companies. Messrs W. D. and H. O. Wills (New Zealand), Ltd., and the National Tobacco Company, Ltd., and their growers to try out the use of New Zealand seed selected by the Tobacco Research Officer during the previous season, and for growers to try for themselves the method of raising their own Seedlings that proved so successful at the Research Station.

general Considerable work was put into getting the Research Station in order, including the destruction of weeds (docks, yarrow, sorrel and couch, cleaning up the stream banks, levelling the site for the buildings, and when possible proceeding with the erection of fences. The Research Officer represented the Department on a Government Committee formed to formulate a plan for the tobacco industry. CAWTHRON INSTITUTE REPORT The Institute has been responsible for several important aspects of the tobacco investigations. These include a soil survey of tobacco lands, chemical in- \ estigations relating to soil properties and quality of tobacco leaf, mycological studies relating to the incidence of mosaic and seed-borne diseases, and entomological studies relating to insect pests of tobacco. SOIL SURVEY OF TOBACCO LANDS With a view to the extension of the tobacco industry on the most suitable soils of the Nelson district, the Tobacco Control Board recommended that a detailed survey of tobacco lands be undertaken. This recommendation was approved by the Research Committee and wofk was commenced by the Institute in the Motueka-Riwaka district in June. 1938.

So far the soil survey has been confined to the alluvial flats and gentle slopes within the Motueka, Umukuri and Riwaka district. The major soil divisions based on the nature of the parent material, e.g., granite, limestone, and basic rocks, were* first drawn, and these main groups of soils were then separated into sub-types based on textural variations, e.g., sand, sandy loams, silt loams, etc. Consideration has been given, in delineating soil types, to the presence of underlying gravel, height of water-table, etc. So far. 3400 acres of land have been mapped and the boundaries of the various types delineated. The soil survey has already shown the presence of considerable areas, now in other annual crops or in pasture, which are suitable for tobacco. On the other hand, instances are not infrequent of land being used for tobacco where the nature of the soil renders the production of high quality leaf unlikely. With a view to the best utilisation of the land at the Research Station, a detailed soil map has been made for the guidance of the Tobacco Research Officer. CHEMICAL INVESTIGATIONS In connection with the soil survey of

tobacco lands, a considerable number of soil samples has been collected and examined in the chemical laboratory for texture and plant food constituents.

Special attention has been paid to the boron status of representative soils at the Tobacco Research Station, and a commencement has been made with chemical determinations on tobacco leaf.

The boron determination of soils at the Research Station show that the coarse sands are very low in this constituent, the figures being 0.03 p.p.m. boron for the coarse sands as against 0.075 p.p.m. and 0.06 p.p.m. boron for the fine and medium sands. These figures suggest that hydrated borox may prove beneficial, particularly on the coarse sands, in the manurial treatment of tobacco and other crops. Some 19 samples of tobacco leaf grown at the Institute and in the Riwaka district have been examined for lime, magnesia, iron, manganese, boron, nitrogen and phosphoric acid. The average figures for six samples of Riwaka leaf are as follows:

magnesia varied from 0.20 per cent, to 1.83 per cent, on the dry matter, suggesting that in certain cases magnesia is :n deficient supply. Manganese varied nitrogen varied from 1.54 per cent, to 2.77 per cent, and boron varied from 18 p.p.m. to 32 p.p.m. The amounts of lime and phosphoric acid showed relatively small variation. The work which has been done, although only of a preliminary nature, suggests the possibility of both magnesia and boron deficiency in certain samples and emphasises the desirability of securing standard data for high quality American and New Zealand leaf.

Arrangements have now been made for the collection of typical samples of Riwaka leaf for chemical examination in respect to quality of tobacco. SEED GERMINATION STUDIES Previous studies of the germination of tobrcco seed used for the commercial crop in the Nelson district have shown great variation in the percentage germination of different lines of seed. The data have suggested that period of storage and the presence of seed-borne diseases may influence greatly the number of vigorous seedlings obtained from different lines of seed. With a view to obtaining more information on these points, studies have been undertaken relating to (a) the effect of age on the germination of tobacso seed, and (b) the effect of disinfectants on seed germination.

(a) Effect of Age on Seed Germination: For the purpose of the investigation seed less than one year old, seed one year and two years old. seed eleven and fifteen years old were available. Using a standard procedlure in every germination test, the studies have shown that in the case of twenty sets of seed four months old at the commencement of the experiments, little difference in geimination was found during an ensuing period of four months. In eight sets the final germination rate was approximately the same at the initial rate: in ten sets the final germination rate was appreciably greater and in two sets the final germination rate was appreciably less.

In the case of eight varieties of tobacco seed imported fresh from U.S.A. ir 1937, germination tests a year later showed only minor differences in the germination rates for the two years. With one exception the germination percentage in the second year stood as high as 90 per cent. In the case of seed stored for eleven and fifteen years respectively marked reduction in the germination percentages was found. For nine varieties stored for a period of eleven years, the germination percentage varied from 33 to 88. with an average of 65 per cent. This percentage would be still further reduced if the germination figures at 14 days from sowing were taken. In the case of seed stored for 15 years the percentage germination was 5.5 per cent, at 14 days and 33 per cent, at 30 days from sowing.

(b) Effect of Disinfectants on Seed /

Germination: Alcohol, silver nitrate and uspulun have been compared in relation to the effect they exert on the germination of. tobacco seed after treatment with these chemicals. Six varieties of tobacco seed of high germinating power were used for the experiments. The results of tests made on treated and untreated tobacco seed showed that none of the chemicals exerted an appreciably adverse effect on the germination of the seed. On the contrary, alcohol gave an increase in germination rate in the case of four out of six varieties: silver nitrate gave an increase in one out of six varieties, and uspulun gav? an increase in one out of six varieties. In no instance was the reduction after treatment with chemicals greater than 3.5 per cent. One important aspect of the studies has been the effect of storage after treatment with disinfectants, on the germination of tobacco seed. Two lines of tobacco seed were used in this experiment. and germination tests were carried out at weekly intervals during a period of 12 weeks following disinfection of the seed. Storage of the seed prior to the germination tests under these conditions made relatively little difference to percentage germination of the seed. In five cases out of six, the final figures showed as light increase in percentage germination over the initial figures.

MOSAIC INVESTIGATIONS (a) Factors Affecting Mosaic Dissemination: In co-operation with the Tobacco Research Officer, the results of last season’s work relating to the incidence of mosaic disease were prepared for publication. The data pointed clearly to the tobacco seedling bed as the most important factor in the spread of mosaic. (b) Effect of manurial treatment on susceptibility of tobacco plants to Mosaic disease: It is well-known that under certain conditions excessive use of nitrogenous manures increases susceptibility of plants to fungus attack wh’le the liberal use of potash reduces the severity of certain diseases. It was considered possible that mosaic disease mighl show similar reaction to variations in the manurial programme. A series of pots in the glasshouse and of field plots on adjoining land were arranged to give information on this point.

The manurial treatments included in the tests were (1) complete fertiliser (N +P+ KL (2) complete fertiliser plus tiace elements, (3) complete fertiliser pius one additional dose of nitrogen, (4) complete fertiliser plus one additional dose of potash, (5) complete fertiliser with only one half dose of nitrogen. (6) complete fertiliser minus potash.

Tobacco plants of the Harrison Spec ial variety were used throughout th tests. Inncculation with mosaic viru was carried out when the plants wer 12 inches high. In the glasshouse al pots inoculated, irrespective of treat ment, developed typical mosaic symp toms. In the field out of 260 plant which were inoculated under differen treatments all but one develops mosaic. The experiments have showri fairly conclusively that variations it the manurial programme as outline< above do not inhibit the incidence o mosaic in tobacco plants. An interesting feature of the expcri ment, however, was the growth and ap pearance of the mosaic plants under th different manurial treatments. In everj I case mosaic retarded the developmen of the plants, but this was more notice able with some treatments than wit! others. Mosaic plants were character ised by paucity of loaf development oi the stem and of sucker development ii the leaf axis. At maturity, mosaic plant were considerably shorter and mort spindly in appearance than the correaponding controls. Dwarfing and sparse ness of leaf were especially noticeabli in plants receiving an extra dose o potash. On the other hand, plants receivini rn extra dose of nitrogen did not ex liibit such marked stunting and redllC : tion of leaf area. Mottling of the leave was clearly evident in most mosaii ! plants under the high nitrogen treat i inent. but the failure in chlorophyll de velopment did not appear to be so com : plete as in the case of mosaic plant I under other manurial treatments. Th< j behaviour of plants treated with com plete fertiliser less potash tended to b< similar to plants receiving additions! ! nitrogen, suggesting that within limit* I (certain ratio of N/K rather than nitro I ;.en alone operates in overcoming tht ; dwarfing tendency produced by th< virus. I INSECT INVESTIGATIONS I Examination of tobacco leaf held if | store bv one of the manufacturing com jpanies revealed the presence of two coai mololitan pests of stored tobacco. Tht I insects were the tobacco moth EphestU ! eleutella and the cigarette beetle Lasio- ! derma serricerne. Larvae of Ephestifl ' remained in the larval stage over win* | ter. and commenced to pupate about tht end of September. The moths emerged a‘ the beginning of November. Suggestions w’ere made for the treat* ing of infested leaf and the cleaning uji of all sheds ired for the storage of tobacco. Woods’ Great Peppermint C ure For Bronchial Coughs, Colds, influenza

I.inn? (CaO) 4.86 per cent. Magnesia (MgO) 0.81 per cent. Iron (Fe) 0.014 per cent. Manganese (Mn) 0.0048 Nitrogen (N) Phosphoric acid 2.05 per cent (P205) 0.49 per cent. Boron (B) 24 p.p.m. In these six samples of tobacco leaf.