THE TOMATO.

New Zealand Journal of Agriculture, Volume VI, Issue 3, 15 March 1913, Page 283

THE TOMATO.

CULTIVATION AND DISEASE-CONTROL EXPERIMENTS.

T. W. Kirk,

F.L.S.

The outbreak of disease amongst tomatoes in the Christchurch district had become so serious and had caused such heavy monetary losses that growers were almost in despair. They therefore appealed to the Department for assistance. The Government arranged to conduct cooperative experiments in two glasshouses in the district in order, to ascertain, the various causes of the outbreak, but the owners of the houses asked for such high terms that the Department could not accept them. The Canterbury Fruitgrowers’ Association then very kindly agreed to co-operate-and endeavour to secure houses on more favourable conditions. This they did, with the result that a house was obtained at Redcliffs from Mr. Maffey, and one at Spreydon from Mr. Odering.

It was felt that some of the growers were proceeding upon wrong lines, inasmuch as they set out their plants in very heavily manured soil, and kept up .what was regarded as an excessive degree of humidity in the houses. These condition's were specially encouraging to fungus disease. It was therefore decided to take Mr. Maffey’s house and treat it as a whole on lines approved by the officers of this Department, whilst Mr. Odering’s should be divided into a number of plots and a series of experiments be conducted therein. ■

The conditions under which the houses were taken were as follows : The grower to place his house at the disposal of the Department for experimental purposes, he undertaking to perform the work required by the Department in conducting the experiments. The Government to pay for the plants and fertilizers, soil-fumigants, &c., and for the use of the house. In each case the owner to have the crop.

. The following instructions in regard to the treatment of the two houses above referred to were given to Mr. Reid,- Orchard Instructor, the local officer in charge of the experiments '

Please arrange to have both houses sprayed as soon as possible with a 2|-per-cent. solution of formalin for disinfection purposes. As arranged with you verbally, Mr. Maffey’s house will receive what we consider to be the best possible treatment in manuring, spraying, watering, cultivation, &c. Mr. Odering’s house will be used for experiments, for which purpose it will be necessary to subdivide into eight plots : Plot 1 to be treated with Apterite according to the directions on the package 2to be treated with Vaporite according to directions on

package ; 3 to be treated as soon as possible with 2 oz. of kainit per square yard—this fertilizer to be lightly worked into the soil; 4to be treated as soon as possible with 2 oz. of sulphate of iron per square yard, to be lightly worked into the soil; sto be treated as soon as possible with 1 oz. of kainit and 1 oz. of sulphate or iron per square yard, to be lightly worked into the soil; 6, a good dressing of stable manure, such as Christchurch growers are in the habit of using ; 7, a light dressing of stable manure ; 8, 1 oz. of superphosphate and f oz. of bonedust per square yard. 6 and 7 will be applied when the plants are commencing to fruit. 8 will be divided into three, and applied, at intervals of a fortnight, the first application to be made when the plants are commencing to fruit. This quantity will not be considered as arbitrary, but subject to increase if the plants show later that one or two more dressings will be beneficial. Mr. Maffey’s house will receive similar treatment to this plot. Spraying for the control of fungus diseases will commence as soon as the plants are well established after transplanting. This will apply to all plants in both houses.. Thermometers (self-registering maximum and minimum), hydrometers, and diaries for recording results shown by these instruments will be forwarded to you at an early date. m ~T „ T. W. Kirk, Director of Orchards, &c. The experimental work in Mr. Odering’s house is not yet completed, but it is anticipated that the report will be available for the next issue of the Journal. Another series of experiments is being undertaken in the Hutt Valley, for the benefit of the tomato-growers in the Wellington District, arrangements having been made between the Department and the Hutt Tomato-growers’ Association. A glasshouse has been secured belonging to Mr. Hobbs, on the main Hutt Road, and arrangements have been made for a piece of land at Mr. Brassell’s, so that both indoor and outdoor experiments may be conducted. Both properties are being worked in co-operation with the owners, and the testing will' be carried out throughout the varying seasons of the twelve months. The following is Mr. Reid’s report on Mr. Mafiey’s house Mr. E. A. REID’S REPORT. The dimensions of Mr. Maffey’s house'are 38 ft. by 17 ft. It has glass sides and ends, and floor of concrete. This floor was laid by Mr. Malley, sen.., mainly for control of eelworm. Operations were commenced on the 31st July. The house was disinfected with a solution of 2|-per-cent. formalin. A warm day was chosen, and the whole of the interior was thoroughly drenched, . the solution being applied with a spray-pump. The house was then closed until the following day.

On the 10th August the house was resoiled to a depth of 5 in. to 6 in., fresh turf soil being carted in from one of Mr. Mafiey’s allotments ; this soil was of a loose sandy nature, and, having a good turf, would be well supplied with humus at a time when plants required it for assimilation. The plants were .raised from selected seed by

Mr. Mafiey. Seed was sown on the 12th June, and on the Bth July the plants were pricked out into boxes, ample room being allowed the plants for robust development, short-jointed sturdy plants being the aim. The soil, both for seed and pricking out, was sterilized by heating to 210°. It was noticeable that by using . the sterilized soil .the plants were slow in getting a start, but later on made up for the delay by rapidity of growth and sturdiness, while sterilization prevented any possibility of eelworm infection. . .

. On the 9th September the plants were, set out in the house at a distance of 2 ft. between the rows and 1 ft. between the plants. The plants “ came away ” in good style, and :on the 19th September the first spraying of Bordeaux mixture ” was given, at a strength of 3 lb. of sulphate of copper, 5 lb. of lime, and 50 gal. of water. On the 27th September the plants were tied and trained, as recommended by Mr. S. F. Anderson (see Department’s Journal, No. 2 of Volume iii).

A second spraying was given with Bordeaux mixture on the 2nd October, and on the Bth the —which up to this time had received absolutely no manure — given a dressing of superphosphate and bonedust, at the rate of 1 oz,. of superphosphate’ and f oz. of bones per square yard. This was lightly raked in. On the 22nd October a third spraying was given with Bordeaux, and a fourth on the 9th November, the fifth and final spraying being given on the 25th of the same month. On the 18th November a second dressing of superphosphate and bones was given, at the same rate as the former dressing. As the plants were growing strongly this was deemed sufficient, and no further manure of any description was given.

The fruit colouring at this time, 9th December, sulphur was used and tested for control of “ spot ” (Cladosporium fulvum), and later on, 20th December, the plants were again sulphured. Experiments then ceased as far as spraying and sulphuring were concerned.

Concrete Floor. The use of a concrete floor for control of eelworm, (Heterod&ra radicicold) is to .my mind excellent. Up to the present time .we have no remedy within reasonable cost that will combat or check eelworm ravages [experiments with soil-fumigants, &c., are being conducted in Mr. Odering’s house, and a full report will no doubt appear later], and until such time as a reliable remedy is forthcoming a concrete floor and changing the soil every season is the only reliable safeguard against eelworm infection, and this is borne out by the number of practical commercial growers who have already adopted this remedy. Care must also be taken that nothing but sterilized soil, or soil absolutely free from eelworm infection, is used in rearing the plants.'

Plant-propagation.

The success of tomato.-culture depends to a very great 'extent on the care in selection of a good type of plant and fruit for seed purposes. Many growers simply select a fair type of fruit and pay no attention whatever to the parent plant, nor do they give any thought to the plants in the vicinity, consequently the number of plants with one truss of fruit and no leader is becoming noticeable. The cause of this peculiarity in some measure may be due to relying solely on selection of best type of fruit, and a plant having only one fruit-truss will naturally possess some good specimens, and a grower not having taken into consideration the constitution and environment will no doubt select these for seed purposes. I am inclined to think that this indiscriminate selection by growers of their own seed, season after season, is causing a deterioration in the constitution and vitality of the plants, thereby making them more susceptible to disease and less resistant to sudden climatic changes. I would suggest paying more attention to the selection of both fruit and plants for seed purposes, and occasionally introducing fresh stock, in order to preserve sound vitality, and also give plenty of room to young plants when “ pricking out ”_-say, boxes of dimensions 12 ft. by 18 ft. Allow six rows and four plants to a row in the box. This will provide ample room for strong development; and aim at getting sturdy short-j ointed plants, these being better able to resist disease owing to their strong constitution. The Department has a good illustration of this in Mr. Odering’s house. This subject will be again dealt with in the report on experiments in this house.

Ventilation.

No side or bottom ventilators were used at any time during the experiments, top ventilators being relied upon, and occasionally, during a very warm day, the end doors were used. The use of side ventilation by an inexperienced grower is apt to cause trouble, and the idea of this experiment was to simplify matters and demonstrate that the risk of disaster by indifferent use of side ventilators could be avoided. Many instances have come, under my notice where growers, when the house has become too warm, have at once opened the side ventilators, thereby creating a cold draught on the plants in the vicinity. Should any of these plants have been weak in constitution they have at once collapsed, the trouble being in many cases put down as “sleeping disease —quite ah erroneous impression. This experiment proved that this risk of collapse can be obviated by a judicious use of the top ventilators with the assistance of an occasional use of the end doors during the very warm days. Moreover, it is unnecessary to undertake the extra work of manipulating two sets of ventilators when one set

answers the purpose. At least it does so in this district, although conditions may be different in the North Island and necessitate the use of side ventilators. Many of the commercial growers in Christchurch have no side or bottom ventilators in their tomato-houses, but rely solely on top ventilation, occasionally making use of the end doors in very warm weather. This fact speaks for itself, and' bears out the above contention that side ventilators, unless used very carefully, are better left alone, and that it is better to rely solely on the method adopted in the above experiment.

“ Sleeping disease ” as known in this district is not the true “ sleeping disease,” which is due to the attack of a soil fungus known as Fusarium lycopersici.

Temperature.

The average maximum temperature, taken daily at 1.30 p.m., from the Bth October, 1912, to the Ist January, 1913, ranged from 61° to 104°, .the average daily maximum for this period taken daily being 81-s°. The average minimum temperature for same period ranged from 40° to 61°, the average minimum taken daily being 50°.

It was suggested that a maximum working-temperature of, say, 75° to 90° was desirable, but with a variable season and severe changes in temperature almost constant attention to ventilation was required to keep the atmosphere anywhere near this range.- . However, the average maximum temperature of 81-5° proved a very fair working-temperature for tomato-houses.

Watering.

To test. for humidity of the atmosphere in the house a Lloyd’s hygrodeik was used. This instrument, having a carefully graduated chart, makes the matter of ascertaining the degree of moisture per cubic foot in the atmosphere a simple one, and particular attention was given to ascertaining the most favourable degree of humidity for fertilization. It was noticeable that when the humidity was over 70° the pollen was inclined to become pasty, whereas under this reading it was freer, and the lower the humidity the more easily the pollen moved, thus becoming more useful for fertilization purposes.

Mulching.

To test the question as to whether plants succeed without a mulching of stable manure, no manure or mulching of any description was used. A light raking of the surface soil answered the purpose. The use of stable manures as mulching . can easily be abused, resulting in many cases to injury to the plants by too much forcing, and also creating a condition favourable to -development of fungoid diseases. For these

reasons artificial manures, applied as before mentioned, were solely relied upon, and . although the amounts at first sight appear to be small, yet a little calculation of same proportions per acre will convince one that the supply was sufficient, considering the soil in this house was well supplied with humus. The plants were sturdy, healthy, and fruitful, plainly, showing they had ample nourishment. I am inclined to think that watering after 8 a.m. during fine or warm weather may seriously affect satisfactory fertilization. I should prefer to water the plants after the heat' of the day —say, not earlier than 3 p.m. . Some growers think that this method is apt to cool the house too much at night, but . I do not think it makes any material difference. During warm summer weather I certainly prefer afternoon watering, as it cannot interfere with fertilization, while watering in. the morning on a warm day raises the humidity at once, and may, as mentioned above, interfere seriously with fertilization.. Again, when watering plants, water, do not sprinkle; on the other hand, do not soak. Water the soil so that the particles of soil will move freely asunder and will not stick together when handled. The humidity in Mr. Maffey’s house from the 6th November, 1912, to the Ist January, 1913, taken daily, ranged from 40° to 94°, averagingdaily for this period 68°. I hope to make further comment on this question when the experiments are completed at Mr. Odering’s house, as the Department also dispensed with mulching of any description in this house.

Spraying.

It will be noticed that Bordeaux mixturestrength 3-5-50 was used no less than five times, commencing as soon as the plants had hardened after transplanting, and at no time were . injurious effects noticeable. Knowing that there is a great difference of opinion among growers as to the Bordeaux solution being injurious, particular attention was given to this matter, and I am confident that spraying, carried out properly, in no way injures the fertilization and setting of fruit. Regarding' disease-control, right up to a fortnight after the last sprayingvery little “spot” (Cladosporium fulvum) was noticeable, and there was no sign whatever of other fungoid diseases. The fruit ripening rapidly, and to lessen, if possible, the work of wiping off the Bordeaux sediment, sulphur was blown on the plants with bellows. Later on the “ spot ” became noticeable, but even then not to any injurious extent. Taking into consideration that other houses on the same property and only a few yards distant from the experimental house • were severely attacked .by .“spot,” and. that Mr. Maffey had to move freely from house to house, the test was . severe, and in this experiment the

Bordeaux solution, 3-5-50, proved an excellent preventive. I do not consider that sulphur had any appreciable effect in controlling spot.” - . Growers complain about having to wash or wipe the fruit after using Bordeaux. These growers will be interested to know that the Department is experimenting with carbonate-of-copper solution in Mr. Odering’s house, and if this solution proves successful in controlling fungoid diseases the question of extra labour for wiping and cleaning the fruit will be solved, as the carbonate-of-copper mixture leaves no sediment or deposit.

Other Remedies.

For slugs. and woodlice, or “ slaters,” tobacco-dust and lime were used, the tobacco-dust especially being very effective. McDougall’s fumigators were used for control of green aphis, and proved excellent. The cost is reasonable, 12s. a dozen, one fumigator being sufficient for 1,000 cubic feet. The operation is simple.

The Crop.

Unfortunately, no record of crop and prices, &c., from this house was kept by ' Mr. Maffey last season, so I cannot make any definite comparison between the crop of that season and that of the present one. Mr. Malley. states that the present crop is the best harvested for some seasons. Altogether 622 lb. of tomatoes were marketed, at an average price of B|d. per pound, which is a fair record for a house of small size.

Conclusion.

In conclusion, there are several items in this report which I have not dealt with fully— humidity, fertilization, watering, and spraying —as we have similar experiments on hand in Mr. Odering’s house under slightly different conditions, and I wish to compare notes with these experiments before reporting on such important subjects. Thanks are due to Mr. Maffey for his hearty co-operation in carrying out the experiments, and also to Mr. J. Maffey, “ The Cutting,” Redcliffs, for his assistance.

In looking over young orchards in the Nelson District recently, a fact which struck me very much was the great superiority of “ rods ” or sticks (yearlings) over the pinched or “ headed ” trees. In some cases pinched yearlings are being sold as two-year-olds. On these trees the buds on the lateral growth are frequently semi-dormant, and do not come away well the first year. T. W. Kirk. ■ - ' ' .