THE TOMATO.

New Zealand Journal of Agriculture, Volume VI, Issue 5, 15 May 1913, Page 491

THE TOMATO.

CULTIVATION AND DISEASE - CONTROL EXPERIMENTS.

In the March Journal an ’ account was given of experimental work undertaken in Christchurch in connection with cultural methods and disease-control work in tomato-houses. The experiments at Mr. Odering’s house have now been completed. Following is Mr. E. A. Reid’s report :

Mr. Odering’s tomato-house, referred to in my report published in the March issue of the Journal, has dimensions of 88 ft. by 28 ft., .inside measurement. The walls are built of brick to a height of 3 ft. ; a ventilator 4 ft. square is situated at each end of the house. The top ventilators are about 7 ft. long by 2 ft. in width, five being situated on the west and six on the east sides of the house. Bottom ventilators, 4 ft. by 1 ft., are built into the brick walls at intervals of 4 ft.

The entrance-door is in the centre of the east side. For experimental purposes the house was divided' into eight plots, four being on each side of a path 3 ft. wide, running the full length of the house. From the path a 3 ft. pathway to the entrance-door was also reserved. This gave sections 1,4, 5,6, 7, and 8 275 square feet, and sections 2 and 3 about 256 square feet. The following ground-plan will convey an idea as to situation, &c., of the various plots.

East side.

The Experiments.

The experiments were for the control of eelworm and fungus diseases. Tests regarding humidity and fertilization, and tests with . selected plants for resistance to disease, were also carried out. Tomatoes had been grown in the house, in the same soil, for four seasons, and the soil was badly infested with eelworm,, as a glance at photograph No. 9 will show.

Operations.

Operations were commenced on the 29th July, 1912. Section No. 1 was treated with 56 lb. of apterite. Section No. 2 was treated with 46 lb. of vaporite. These soil-fumigants were lightly dug in. Section No. 3 received a dressing of 2 oz. of kainit per square yard ; section No. 4 received a dressing of 2 or. of sulph. of iron per square yard ; section No. 5 received a dressing of 1 oz. of kainit and 1 oz. sulph. of iron per square yard. All these dressings were lightly worked into the soil. Sections 6,7, and 8 received no treatment, being reserved for a test of

selected plants, and simply dug over. On the 2nd September, 1912, the house was disinfected with 21, -per

cent, solution of formalin, applied as described in the experiments carried out in Mr. Maffey’s house (see Journal of Agriculture, Ist March, 1913.)

• Sections 1 and 2 were planted on. the 9th September, 1912, there being a distance of 2| ft. between the rows and 1 ft. between the plants. On the 16th September, 1912, sections 3 and 4 were planted, and on the 23rd September, 1912, sections 5,6, 7, and 8. The plants for sections 7 and 8 were raised by Mr. Maffey from the same seed as Mr. Odering’s plants. All plants were propagated and grown in sterilized soil, and, with the exception of section 6, all the plants were sturdy and well grown. The plants in section 6 were of the ordinary type, but were weaker in. constitution than the plants in. other sections.

On the 10th October the plants had hardened sufficiently for the first spraying with the Bordeaux mixture, which was applied at a strength of 3 lb. sulph. copper, 5 lb. lime, to 50 gallons of . water.

On the 15th October, 1912, all sections-received a dressing of 1 oz. superphosphate and | oz. bonedust per square yard. This was lightly raked into the soil.

On the 31st October, 1912, the plants were sprayed with Bordeaux of the same strength as formerly.

. On the 18th November, 1912, all sections were again dressed with fertilizers, in the same proportions, as the former application, and lightly raked in.

On the 28th November, 1912, the plants were sprayed with Bordeaux, and on the 24th December, 1912, the plants on the east side were sprayed with the ammoniacal carbonate-of-copper solution. The plants

on the latter side of the house were then reserved for testing this solution, while the Bordeaux mixture was continued on the west side. The plants on the west side received in all nine sprayings of Bordeaux mixture at intervals of about fourteen days ; while the east side received three sprayings of Bordeaux previous to the 24th December, 1912, and six sprayings with the carbonate of copper, also at intervals of about fourteen days. No other manures or sprays were used throughout the experiments until the 21st February, 1913, when the plants on the east side were dressed with superphosphates, at. the rate of 2 oz. per square yard. ,

Plants.

The plants for sections 1 to 6 were propagated by Mr. Odering from. seed supplied by Mr. Maffey, while from the same lot of seed Mr. Maffey raised the plants for sections 7 and 8. The propagating-soil was sterilized by heating to 210 deg. At the time of setting out, the plants in sections 1,2, 7, and 8 were sturdy, and rather stronger than those in sections 3,4, and 5, while the plants in section 6 were the weakest, being slightly drawn up, and not so well hardened off as the plants in other sections. Owing to the soil in this house being rather damp and cold, the plants were late in being set out in the permanent rows, and it was not until the 23rd September, 1912, that this work was completed. Many of the plants in section 6 “ damped off,” and were replaced by other plants, and, later on, some plants received a severe check by eelworm, • and were again replaced. When the plants had grown sufficiently for training, pegs were driven in •at the end of each row, and a light' wire was fastened from this peg to the wall, about 3 in. or 4 in. above the surface of the soil, the twine for training each plant being fastened to this wire close to the base of the stem. This gives the plants more stability, and when spraying - or working amongst them saves them from being knocked about. I certainly think this method an improvement on the system of fastening the twine to the plant. Of course it involves more work, but the necessary free movement when working' amongst plants .is made easier if the plants are securely tied. Many growers, I understand, adopted this method some time ago. With this exception the plants were pruned and trained as recommended by Mr. S. F. Anderson in the Journal of Agriculture, page 118, August, 1911. .

Spraying

It will be noticed that Bordeaux mixture, strength 3 lb. of sulph. of copper, 5 lb. of roche lime, and 50 gallons water, which was used no' less than nine times, again proved successful in controlling fungoid diseases, including “ spot ” (Cladosporium fulvum). I may state that this solution was always tested with blue litmus paper before applying,,

and on one occasion no less than 8 lb. of lime, instead of the, usual quantityviz., 5 lb. —was used before the Bordeaux solution stood the test, the lime proving of inferior quality. This shows it is always advisable to test this mixture before applying, or the results might be disastrous through no apparent cause. Litmus paper can be procured from any chemist. A packet costs 4d., and contains twenty papers, so the test is very inexpensive. I omitted to mention that in Mr. Maffey’s experiments a solution of ferro-cyanide was used. It is a more delicate test. than the litmus paper, but, being a deadly poison, it would be dangerous to have on hand unless carefully guarded, especially where children are concerned, so I prefer to recommend the litmus paper.

After the application of the Bordeaux mixture no injurious effects to foliage or fertilization were noticed. The objection to the Bordeaux is the amount of sediment left on the fruit after spraying, necessitating washing or wiping before sale. This entails much extra work. To obviate this, if possible, the plants on the east side of the house received only three sprayings with Bordeaux. The ammoniacal carbonate of copper was then used. This solution can 'be purchased ready prepared at 12s. 6d. per gallon jar. The proportions recommended by the Department for this experiment are 1 pint of the solution to 15 of water. This solution was successful in controlling fungoid diseases especially “ spot ” (Cladosporium fulvum). It leaves no sediment on foliage or fruit. It is evident, however, that further tests will have to be carried out, as towards the end of the season the repeated sprayings every fourteen days seemed to cause the leaves to turn a yellow colour, although the , injury did not affect the crop, as all trusses of fruit had well set before the injury became noticeable. A comparison between the yield of crop on the east and west sides, and also a glance at the photographs, will show the condition of plants, ' and bear out the above statement. Specimens of affected plants were forwarded to the Government Biologist, Mr. Cockayne, for examination. He reports as follows : “ The yellow colouring of the leaves of the tomatoes submitted, under cover of your memorandum of the 26th ultimo, is not due to any specific organism, but is apparently entirely caused through spray injury. The conditions under which carbonate of copper is injurious are not properly known.” This being the case, it would not be advisable to recommend this spray until further experiments and tests have been carried out. I understand this work will be continued by the Department at the Hutt. The results of the experiments will, I am sure, be awaited with interest.

Mulching.

No stable manure or mulching of any description were used in the house. A light raking of the surface soil prevented caking. This house was mainly used for conducting experiments with remedies for

the control of eelworm. To enable these remedies to have an equal chance, all the sections received the same fertilizers and the same proportions per square yard. All sections were infested - with eelworm, and, in. spite of this pest being a continual drain on the flow of sap, the plants grew and bore fruit much better than was anticipated ; in fact, some of the visiting growers expressed surprise at the growth and fruitfulness of the plants, especially when so badly infected with eelworm. The photographs ■of the roots will give an idea of the degree of infection. Again, it must be remembered that this was the fourth crop of tomato grown in the same soil. Under these handicaps the dressing of fertilizers given proved ample, hence it is evident that the proportions per square yard of manures required for tomato-houses recommended by the Department are fairly correct. .

I omitted to mention that late in the season the east side received a dressing of 2 oz. of superphosphate per square yard. This was applied when the plants appeared to be of a sickly yellow colour, the idea being to try to stimulate them. The dressing was, however, of little consequence, as it was late in the season before the damage by car-bonate-of-copper spray became • noticeable, and the dressing had . but little effect.

Watering’ and Humidity.

A Lloyd’s hygrodeik was used to test the humidity, the reading being taken daily from the 28th November, 1912, to the 6th March, 1913. It ranged from 42-7 to 74-1, and averaged for the season 67-5, slightly lower than in Mr. Maffey’s house. Mr. Odering watered the plants in the evening, as a rule after 5 p.m., and. with few exceptions fertilization was never interfered with by too high a humidity. On these occasions Mr. Odering watered earlier in the day. This raised the humidity above 70 deg., and, as in Mr. • Mafley’s house, the pollen was useless for fertilization when the . humidity was above 70 deg., thus bearing out the contention that it is advisable to water during summer weather not earlier in the day than 3 p.m. There is no doubt but that the watering of house-grown tomato-plants early in the day, coupled with overmanuring, is to a very great extent accountable for the ■ fruit failing to set, and the poor crops which consequently result. I would suggest that growers should purchase a hygrodeik and test this question for themselves. - It is a matter of great importance. i

Temperature.

The maximum temperature,. taken daily at 1.30 p.m., from the 28th November, 1912, to the 6th March, 1913, ranged from 53 deg. to 90 deg., ’ averaging 74-1 deg. for the season. The minimum temperature for the same period ranged from 34 deg. to 55 deg., averaging 42-7 deg. for the season. The maximum temperature, 74-1 deg., is a safe one

for tomato-houses, but the minimum, 42-7 deg., is rather low. At times it was much too low, especially when the reading was 34 deg., but this occurred at the latter end of the season ; in fact, it was the reading for the last two weeks which lowered the minimum average. For the earlier part of the season the reading was never lower than 40 deg. The average minimum temperature of 50 deg. in Mr. Maffey’s house was more satisfactory, and was well above danger-point. It must, however, be remembered that Mr. Odering’s house, owing to its situation, is much colder than Mr. Maffey’s.

worm.

Eelworm (Reterodera radicicola) is necessarily a dreaded . enemy of tomato-growers. Many are the. questions, asked by growers of the Department as to some satisfactory means, of control. Soil-sterilizing has been tried by a few growers. Others apply a solution of carbolic acid, and “ rest ” the soil for a. season, in the interval growing cucumbers in troughs, the next season reverting to tomatoes. Some growers have laid down concrete floors, bring in fresh soil, and clear both plants and soil out at end of the season, again renewing the soil to a depth of 5 in. to 6 in. This latter method requires a reserve of fresh soil to draw upon, and also means extra labour, but it is satisfactory in controlling eelworm ; moreover, it pays the grower for his extra trouble. Many growers, however, have not the necessary reserve of soil for this treatment, and sterilizing soil with the appliances at present available is too costlytoo expensive in fact for tomato-culture when handling soil in large quantities. To sterilize small lots for propagatingboxes is simple enough, but to prepare several tons is a very different matter. With regard to dressing the soil with carbolic, and growing cucumbers in troughs, I should recommend growers to carefully . read Bulletin No. 20, on eelworms, by Messrs. T. W. Kirk, E.L.S., and A. H. Cockayne, Government Biologist, especially page ■4, paragraph relating to life-history, and also page 5. , ■ '

What is required is a remedy by which old soil can be satisfactorily treated and freed from eelworm at little cost. A remedy of this description would revolutionize tomato-culture under glass. . Mr. Odering’s house was excellent for experimenting with remedies for control of eelworm. The house, as before stated, was divided into sections or plots. No. 1 was treated with 56 lb. apterite; No. 2 with 46 lb. vaporite; No. ' 3 with 2 oz. kainit per- square yard; No. 4 ' with 2 oz. sulph. of iron per square yard; No. 5 . with 1 oz. sulph. of iron and 2 oz. kainit per square yard. All dressings were lightly dug in. Nos. 6,7, and 8 were reserved for testing of plants, the'soil receiving no treatment.

The photographs of the roots of plants taken from each section will, I feel sure, illustrate the effect of the remedies, while a further com-

parison of the crops harvested from each section will enable readers to form their own conclusions without further comment on my part. The photographed roots are typical of the general condition of the plants throughout the sections in which they were grown.

Regarding plant-selection, a glance at the photographs showing a comparison between the plants usually raised commercially and the selected and carefully propagated plants will illustrate such a marked difference that I' feel sure growers will study this matter more comprehensively. A comparison of the yields from these sections is also worth noting. This will serve to further bear out the remarks made on plant-propagation in report on experiments in Mr. Maffey’s house.

Seed-selection.

I should like to add a few more remarks .to a paragraph under heading of “ Plant-propagating ” contained in my report on experiments in Mr.. Malley’s house. It will be noticed that in these experiments all plants for both houses were raised from the same lot of seed, the variety being Clarke’s Favourite. Now, I selected nearly thirty distinct types of fruit from the plants grown from this seed, thus plainly indicating that the type of Clarke’s Favourite in this strain of seed was faulty, and required more careful selection and building up. To carry this out brings us back to cross-fertilization. This is a subject requiring detailed description, and space will not permit of any further remarks in this paper. , Crop.

Thanks are due to Mr. Odering for his hearty co-operation and attention to instructions ; also to Mr.. W. W. Day for his assistance in carrying out the work connected with the experiments.

Conclusion.

. In conclusion, I should suggest that growers give—(1) More attention to seed-selection; (2) aim at propagating sturdy short-jointed plants; (3) be sparing with. manures ; (4) when watering, keep humidity as low as possible, in order to aid fertilization; (5) keep the. house clean and free from decaying rubbish; (6) when spraying, spray, and , spray thoroughly, especially the under-sides of the leaves, and always test the Bordeaux solution before applying.

< ■■ 88 ft.■■............. > A No. 5. No. 6. No. 7. No, 8. Sulph. of iron and Ordinary Selected Selected kainit. ■ plants. plants. plants. (P lants this side sp rayed with Bordea ux.) cc 3 ft. pathway. No. 4. No. 3. No. 2. No. 1. Sulph. of iron. Kainit. ■ . ■ 3 Vaporite. Apterite. (Plants this side sprayed with carbonate of copper.) V

No. 1 . No. 2 . No. 3 . No. 4 . .. 527 lb. . .. 345 „ . .. 268 „ . .• 277 „ . Apterite .. .. 1 Vaporite Kainit .. • .. j . Sulph. of iron .. .J 1 Sprayed with am- - moniacal carbonate of copper. 1;417 lb. • - ■- - No. 5 . .. 403 lb. . Snip of iron and kainit .. ’ No. 6 . .. . 298 „ . No treatment, ordinary plants I Sprayed with BorNo. 7 . .. 367 „ . ,, selected plants | deaux mixture. No. 8 . .. 445 „ . * • 5 5 ’ / 1,5131b. * ?5 /

The following is a statement of the yield of tomatoes from the different sections :-