The Orchard and Vineyard

New Zealand Journal of Agriculture, Volume 59, Issue 6, 15 December 1939, Page 521

The Orchard and Vineyard

Contributed .by • the Horticulture Division

Orchard Notes l 1 ' < ■ • ( Harvesting the Fruit Crop

DURING the coming month fruit harvesting will occupy the attention of many orchardists . who produce stone fruit and early varieties of apples and pears, and time will be required ini preparing <;• for harvesting the main crop of pip fruits. Although < this important work must receive attention, a continuation of spraying, particularly for the control of insect pest's, is very important, as January may be regarded as a critical month, and nothing should be left ,to chance through pressure of work in other directions; otherwise severe losses in the main crop may occur. Hot, dry days; and especially warm nights,- favour codlin-moth activity, and much infection could occur if a satisfactory coverage is not ‘ maintained. Pests and Diseases Spraying of apples and pears" should follow along the lines indicated in previous notes. The general recommendation is for the continued use of a fungicide, preferably lime-sulphur plus colloidal-sulphur, but to reduce the strength of lime-sulphur as the season progresses. The maximum strength for the remainder of the season should be 1-200, with - colloidal-sulphur.;2lb. to 100 gallons. Trees showing any signs of a weakening < in foliage or a suspicion of spray injury are better sprayed with colloidal-sulphur as the only, fungicide, leaving; out lime-sul-phur ' altogether. . Arsenate of lead must added to all general spray applications, using not less than 1 Jib. to 'TOO gallons. Hydrated lime should be added to the

arsenate of lead before combining it with the sulphur spray. The quantity of hydrated lime used should be 21b to every pound of arsenate. In more humid districts, and where bitter rot (.Glomerella') occurs, ,it may become necessary (and is advisable) to replace sulphur sprays with' a weak Bordeaux mixture, strength lj-3-50. No danger of russetting from the use of Bordeaux can accrue if used at ,the strength recommended at this time - of the year. Timing the Spraying It is. necessary to anticipate possible picking dates for apples and pears, and thus to time the last spray application of arsenate of lead on any particular variety to avoid having an excessive spray deposit on the fruit when harvested. Especially is this necessary on early and mid-season varieties, as in some districts. it is necessary to , continue spraying right into the harvesting season to secure control of codlinmoth. 1 In most cases, spraying of late varieties ceases some time before the time for harvesting, and little trouble occurs. As already indicated, January may be regarded as a month for greater insect activity. In addition to increased danger of codlin-moth infection, trees may suffer from foliage pests, including red mite and apple leaf-hopper, and their activity , may extend up to the end of March. The most effective summer control for . red mite is to spray .with summeroil at 1 per cent, dilution. Summer-oil used at that strength ■' will destroy not only adult mite, but' also summer eggs'

Success depends on thoroughness in application, however, and any failure to secure control from spraying is an indication of incomplete coverage due to either carelessness in. applying or inadequate appliances. Examine the Foliage • Frequent : examinations of . foliage are necessary to guard against red mite becoming ' so well established ;as to cause material damage, before control measures . are . applied. Once bronzing of foliage through red mite injury occurs, the pest has perhaps passed its peak on the particular - trees affected and is rapidly on the wane, but the damage done is irreparable for that season, and the crop is seriously reduced in size and appearance. Apple leaf-hopper is another insect pest which causes .serious • damage to foliage, and fruit at times, and growers may be caught unawares unless on the alert. The control is to apply nicotine sulphate 1-800 before the insects become . winged. Once the insects are on the wing, control by spraying is not practicable. 1 Apart from , the weakening effect from foliage injury: caused by apple leaf-hopper, much of the fruit is so seriously marked that it is quite unsaleable without cleansing;. 1 ’: Cultivation and Cover Crops. , Light cultivation should continue at’ least until the end of January, when the final cultivation should provide a good seed bed for a cover crop. Blue lupin is the most favoured crop for enriching land deficient in humus, but it

must be'sown in January to make sufficient- growth by early winter. At the time of sowing, an application of Iscwt. of superphosphate is advised to assist the lupin crop. Thinning the Fruit s Although the maximum benefit from fruit-thinning may be secured by doing. this work z earlier, any < available time will be profitably employed in further thinning. ' By this time there should be sufficient indication as to whether the thinning has been adequate for the particular crop and. the seasonal conditions. In any case, it is an advantage to go over the trees a second time to remove fruit obviously undersized, diseased, or badly russetted,. which may increase the proportion of lower . grades or rejects if left. It is far better to avoid handling 'these 7 in the packing shed during the rush of a fruit harvesting season. . ..' With a possibly much-reduced fruit exportand markets in the Dominion likely 'to be more than adequately suppliedit is desirable that small and low-grade fruit should be reduced in quantity as far as possible. Small sizes, particularly, are in little demand locally, a fact which points to the ■necessity for extra thinning to secure larger fruit on the average and the elimination of small sizes. Thinning carried out on a normal crop . does not

reduce the . bulk of fruit fit for market, but brings about more uniformity in size, with an increase in the average size of the remaining fruits. Handling the Crop \ Fruit harvested during the coming month will be mainly stone fruit, although a fair quantity of Gravensteins and other early apple and pear varieties will appear on the markets. 7 Very great care is required in handling stone fruit’ to avoid wastage. Maturity for picking should be regulated according to the;distance the fruit is intended to travel. Fruit for near markets may, approach a tree-ripened stage of maturity, and if special packages, either trays or crates, are used, the fruit may even travel some distance. For long distances, and unless there is rapid delivery to the markets, peaches should be picked while still firm. ■ 1 Care should always be taken in avoiding any contact between sound fruit and fruit affected with brown rot. Special tins which may be sterilised should be used for picking if any rot is present, and no diseased fruit should be handled when picking sound fruit. " . • ~ Particular attention should be given to maturity for picking apples. Fruit for, immediate sale on the local market should /be allowed .to reach a

greater degree of maturity than fruit intended for cool storage or for export. Under the abnormal conditions prevailing, the bulk of the apple crop could with advantage, be left to. gain rather more maturity than is usual when picking largely for export consignment. Packing Shed Hygiene , Packing shed hygiene and care in handling, are important factors in minimising subsequent storage rots in fruit'. Reject fruit should not be allowed to remain in or about the packing shed to rot, but should be ■ removed and destroyed or fed to pigs. Grading machines accumulate, dirt very - quickly under . certain conditions, and require cleaning at frequent intervals to avoid marking of fruit, which is very detrimental to appearance, keeping quality, and market value. > With the possibility of much greater quantities of fruit having to be held for later jnarkets - without extra cool storage facilities 1 being available, growers 1 should make ; some provision for orchard storage in sheltered and cool positions under shelter belts or in plantations, but avoiding positions exposed to. prevailing winds, which may cause excessive wilt in fruit. Fruit will develop less wilt if. storage cases are paper-lined. ■ —N. J. Adamson, District Supervisor, Nelson.

Citrus Notes .. .. \ ; Value of Orchard Records Book

WHEN these notes appear the , 1939 citrus production year will ‘be closing, and it may be appropriate to suggest that as from January 1, 1940, citrus i growers producing lemons, oranges, and New Zealand grapefruit endeavour to begin regular diaries in which is set down a daily summary of the day’s activities, matters of particular interest observed' in the orchard,' out-of-pocket expenses connected with the orchard, and questions for, the Orchard Instructor at his next visit. Need for Records ' Some 7 growers may consider that it is neither feasible nor necessary to attempt any such summary, but recent

efforts to obtain costs of lemon production clearly demonstrate the necessity for such ' records to be kept. If growers with bearing groves of : more ' than 200 citrus trees kept such records, they would be invaluable whenever any survey required is to be undertaken. - Records of this kind would also tend to summarise results achieved or possible from any block of citrus trees. ' Every orchard has its trees of infior strain, some of which bear coarse ■ O r ill-shaped fruits, some which have , . , never, borne- a reasonable crop per tree, and others which have succumbed to borer, bark blotch, or collar , rot., These trees should be noted in 'an orchard records book, together with the

efforts being made towards improvement. Only by such means will the grower be in a position to decide which trees require to be eradicated, drastically pruned, treated for disease, or ■ budded over to a better strain. . ' ■ ■ Efforts are 'being, made to improve the existing varieties of citrus in New Zealand,' and each grower ■'can assist by marking ' those trees in the grove which are outstanding in both quality, and quantity of the fruit borne. This is most necessary ’for the lemon, New Zealand grapefruit, z and sweet orange. “Off Type” Trees Now is the time to bud over or topwork, a few “off type”, trees. The process of .budding is better demonstrated

than described, and the co-operation of the local - Orchard Instructor - is available for this purpose. Few citrus growers have begun reworking trees, but it is undoubtedly necessary when the. percentage of inferior type , fruits grown is noted. ! Treat each tree in the orchard as an individual; and record its shortcomings and l endeavour to rectify them.. The keeping qualities of lemons are often closely related to field practices, but these are exceedingly difficult to

check unless the grower endeavours to retain an accurate record of his field practices. This record is also of great value in efforts towards disease eradication and control. Note the date when the ■' disease was seen, the special symptoms, and the methods employed for its control. ” All such records noted are of value to the Instructor and to the research worker in their efforts towards disease control and the particular difficulties encountered from season to season. . - ,

Do Not Over-cultivate ..While endeavouring to conserve moisture at this season of the year, do not over-cultivate. Humus or organic matter is generally deficient in citrus orchards, and , excessive cultivation during the hot summer months often nullifies efforts towards the building up. of the organic matter during the winter months, either by weeds, cover crop, or by green manuring. —A. M. W. Greig, Citriculturist, . ' Auckland.

Viticulture ' , ; ' , Pasteurised Unfermented Grape Juice

FOR home use. in pasteurising unfermented grape juice, an open boiler for heating the must and scalding both the bottles and corks, and an ordinary jelly filter, may be made to serve the purpose. After the grapes have been stemmed and crushed, the juice is extracted by pressing them in a clean sugar bag or cheese cloth and running the liquid into a vessel, where it is allowed to deposit some of its solid matter. This vessel should be placed for a few hours in as cool a place as possible to avoid fermentation and to allow the bulk of the solid matter to separate from the liquid. - . . ; ’ From this settling vessel the partlyclarified must is poured into an open copper, heated up to 180 deg. ■ to 185 deg. F. and kept at that heat for half an hour. A , steam-jacketed boiler is the best for this purpose, but 'an ordinary boiler will answer the purpose if the liquid is frequently stirred to prevent burning. All scum arising should be skimmed off, and at the end of half an hour the juice run into a fresh settling receptacle properly sterilised. A small barrel which has been steamed' or washed out with boiling water and closed with a bung which, has been sterilised by dipping it for a few minutes in, boiling water will do for this purpose, or a demijohn similarly treated will answer the purpose for smaller quantities. . > > The high temperature in the boiler will coagulate the albumen and other

flocculent matters, and, for that purpose, the temperature should never exceed 190 deg. F., at which some of the albumen will redissolve; nor should it be less than 175 deg. F., or it will not coagulate. A thermometer should be used, but if such is not available the juice should be heated till it steams, but it must .not-boil, as boiling spoils the flavour. ) ' - T In the barrel, much of the albuminoid and. viscous matters in the must, which will have been coagulated during the first heating process, are deposited. It will take about 24 hours to clear. This renders the operation much easier. After this, the must may be filtered through a conical flannel bag or any suitable filter and run into sterilised bottles, which are then securely corked with well sterilised corks, leaving a space of from 2 to 2J inches between the . liquid and the cork. (The corking is sometimes done after the final heating and while the bottles are still hot, when the bottles can be filled up to the cork). x These bottles are placed on a thin board (if the fire is direct) in the copper,, and the temperature gradually brought up to 175 deg. F., at which temperature they are maintained for half an hour .and then cooled to prevent the' unfavourable x effect of . the continued heat on the 'colour and flavour. A thermometer placed in one of the bottles or in a bottle of 1 water indicates the exact'degree of heat. It, is essential, in order to sterilise the must, that the above temperature be

reached but not exceeded, as a higherdegree of heat at the final heating would coagulate a fresh lot of albuminoid matters, which would cause their precipitation and make the liquid turbid. ' , Champagne or other strong bottles should be used for the second sterilisation, and the corks tied with strong string to prevent their being blown out. When this is done the contents will keep indefinitely unless mould penetrates the corks. ■ This may. be prevented by dipping the necks of the bottles into a 2 per cent, solution of sulphate of copper (3 to 4 ozs. of bluestone in 1 gallon of water) and then laying the ■ bottles on their side for some days, after which, if they are noticed to be leaking, they should be. placed on one side for immediate use and the remainder 'dipped at the neck in bottling wax. Care should be 'taken in melting the wax to keep it stirred to prevent it burning and assuming a gritty appearance. ' • \. Grape juice 'thus, -bottled may be kept sound for years. It will' greatly , improve by keeping for a few months before it is used. . ' ' ■ . 1 .| i - / ■ - - . - ■■ ■ .; To obtain a coloured juice from black 'grapes, heat the crushed berries, and juice to 160 deg. F., or steaming point, and hold it there for a few minutes; then press out juice as . soon as it can be handled and proceed as above. . ' Other fruit juices can. be treated in the same manner. —J. C. WOODFIN, Vine and Wine Instructor, Te Kawhata.

Cool Storage Notes Overhaul of Refrigerating Plant

FRUIT cool storage chambers wilJ now be empty, and few : refrigating plants, if any, will be operated until the new season’s crop is ready for storage. Therefore, an opportunity presents itself to have a thorough' inspection made of all the working parts of the plant in order that'repairs and renewals ; may be '/ effected, and all of the, equipment of the store put into good running condition 1 before/ the plant is again required for storage. The parts of the ammonia compressor which require inspection are the main bearings, especially if these have given any trouble during the past season’s run. The suction and delivery valves of the compressor also should be removed for inspection, as cracked or broken plates will need to be replaced, . or pitting of the valve or seating may require , attention. Worn spindles of stop and expansion valves require renewing, and the seating of faulty valves will also need attention. ■ ■ ;/■ ■: . \ , Thorough Overhaul The owner of a private cool store would be well advised to have a ■ thorough overhaul of the electrical and refrigeration plant, including the condenser pump, carried out by . his ■ refrigerating engineer during ■ the time the plant is not required. When an. ammonia compressor is not to be operated for some time it is always advisable to close the’ suction and delivery stop valves 1 of 1 the compressor and make sure that the compressor, gland is perfectly tight. All stop and expansion valve glands should also be inspected, and the gland nuts tightened with a ' spanner. Flanges, also, should be tightened, as these precautions will' avoid the leakage of ammonia. ' ' , '' ' . ’ > '' , ' - ..•• , Much of the . work of scraping the cooling coils may be carried out by the- hands employed on the orchard. These pipes should be thoroughly cleaned of all old paint. and rust, and then painted with an anti-corrosive paint, such as aluminium paint. Drip trays': and , drainage pipes should be cleaned and painted. 1 \ All ammonia piping on the expansion side of the compressor which is outside of the cool chambers should be covered with insulation. Condenser coils also will require • to be

scraped clean of all old paint and rust and repainted. ■ '■*'* ' '■.'J/ 1 ' V»-. ! Cool Chamber Doors Cool chamber doors are constantly in use during the year, and their padding 1 often requires ’ attention. . They should be removed' from .the hinges for examination and the . padding repaired if this is found to be necessary, as a cool chamber door with faulty padding is a potent source of leakage and loss of efficiency. At the close ; of the season’s run all waste fruit should be removed from the cool chambers and packing shed, and the floors swept clean and the chambers thoroughly disinfected. To fumigate a cool storage chamber a sulphur and formalin candle is recommended. The door of the chamber should be kept ,tightly closed for 48 hours after lighting the candle.

Cost of Holding Fruit The total costs'* of holding fruit in any particular store are made up .' of a number of fixed and variable charges, the more important of which are as follows: 1. Capital charges on building and plant. 2. Depreciation. . ' 3. ■ Labour and supervision. ' 4. Fuel or . electricity: 5. Oil, ammonia, calcium chloride, other stores, and repairs. 6. Insurance and rates. The whole of ■ these, together with miscellaneous and incidental costs', must be spread over the total number of cases of fruit handled, and it follows

therefore that as a proportion of . the charges are fixed, the resultant cost of refrigeration per case is more a function of the degree of utilisation of the plant than it is of any other single factor. Not only is the utilisation of the available, space an important factor, but the size of the store and of the plant, the relation of one to the other, and the thermal efficiency must be. taken into., account when dealing with costs of fruit cool storage space. When estimating these costs, each item of cost should be examined and considered in the light of its relative importance and its bearing on all the inter-related factors that make for efficient and economical storage. Refrigeration Requirements Refrigeration consists in the removal of heat. In a fruit ’ store this process presents problems of biological engineering much more complex than is generally recognised by the fruitgrower. ' The . total heat-removal requirements of a case of fruit over a season are very much in excess of the refrigeration effect necessary to chill the warm fruit down to. say, 35 degrees Fahrenheit. The ammonia system is called upon to remove heat arising from many different sources, which may be classified as follows: (a) The sensible heat of the chambers. ' ' ‘ 1 ' ■ (b) The,: heat leakage through the walls. - . " i (c) The sensible heat above, say, 35 degrees Fahrenheit of the warm fruit and cases. (d) The heat, of respiration of the fruit. • (e) The heat generated by lighting.. (f) The body heat of workers in the chambers.. - I .<

. J, (g) The heat of air exchange caused by opening of doors. t . (h) The latent heat of . moisture condensation on the coils or in the battery. (i) The frictional'heat of the . brine or air circulation, systems. Relative Demand ! The accompanying sketch shows in graphic form the relative magnitude of the various components of the season’s refrigerating demand on a fruit cool store in Victoria (Australia) with 29,000 case capacity and handling a total of 48,000 cases in the period from January 26 to December 1, totalling 309 days, during which the refrigeration plant ran for 2319 hours. The construction of the building was timber, with lOin of wood shavings for insulation, which was double-boarded on both sides, and building paper was placed between the double boarding. The refrigeration tonnage of the ami monia compressor ..was 16 tons, and the system of cooling was brine circulation with air delivered over false ceilings. The area of the outside walls was 25,376 square feet. Importance of Insulation This stresses the importance of insulation in. relation to running costs.. Not only is the . thickness ’ of the insulation important, but the actual material is also important. The conditions for the maintenance of quality ( in cool stored fruit are temperature, humidity,, and ventilation. . Temperatures must be maintained in each chamber according to the tolerance of the variety being dealt with. For apple storage in New Zealand temperatures range from 32 degrees to ; 37 degrees ' Fahrenheit. Steady, unvarying control of temperature conditions, throughout the storage period is of major importance. ’ The control, of . humidity in storage chambers is of /great importance. Shrivel and wilt in fruit are ■ simply, the result of J the evaporation of moisture from the fruit. If the fruit is maintained 'in a saturated atmosphere no evaporation can occur. Chamber. humidities of 85 per cent, to 90 per cent, are easily attainable in direct expansion systems,’ and a welldesigned system fitted near to the ceiling of the cool chamber will give superior results for fruit cool 1 storage. Advantages of Direct Expansion System The following are the advantages of the direct expansion system where

ceiling coils and drip trays are installed: — ' , (a) Facilitates temperature control in space, and, where > automatic control, is installed, in time also. ' ' ' (b) Provides conditions favourable to the maintenance of correct relative humidity. ? ■

• (c) Enables chambers to be held at different temperatures . for different 'varieties.. ■ (d) Enables the plant to run at higher thermal efficiency because of the higher suction temperatures.' ■ i (e) Eliminates the complication of auxiliaries. ■ • ■ ■ . . I . . (f) • Saves, power required, by auxiliaries. ’ (g) Avoids the introduction of frictional heat by ( auxiliaries. ' ' ,' ' (h) Reduces the depreciation on plant occasioned by brine corrosion. (i) Saves cost of calcium chloride. (j) Saves cost, of brine concentration. , (k) Saves cost of battery room, ducts, and false ceilings. (1) Lends itself to automatic, and semi-automatic control, and enables the plant to; take advantage of low off peak energy rates. 1 .

Dimensions 1 The following , are suitable inside dimensions of cool storage chambers for cooling with overhead direct ' expansion coils. Space has been allowed for vertical :, air movement among the fruit cases:—

In Nos. 1 and 2no passage'is allowed for; in No. 3 a 2ft passage is allowed for; and in Nos. 4,5, and 6 a 3ft passage. Dunnage among the fruit cases is not necessary " when space is provided , for vertical : air movement. ■Should (the process of gas storage be further developed commercially, there should be little difficulty in adapting this direct expansion system to that method. ' ■ i ' . ' . The physiological aspects of the be-, haviour of different varieties of apples in cool storage, the effect* of soils, seasons,. pruning, manuring, etc., are allimportant ’in the holding ■ of fruit in cool storage, and require to be studied closely by the owner' of the fruit, as the temperature tolerance of certain varieties of apples, such as Jonathan and Sturmer, vary- as the quality of the fruit, as well as its length of cool storage life, is affected by these factors.

—A. POWELL, Cool

Storage Officer.

Length. Width. Height. 1. .. . . . . 14' . x 8' . x 10' 6" . 2. ■:. . . . . 21' x 10' x 10' 6" Ml 3. < . . . .. 21' x 12' x 10' 6" - 4. . . . . . . 30' x 21'-' x. 10' 6" 5. . . . ... 42' x 21' x 10' 6" 6. . . . . . . 50' x 28' x 10' 6"

Method, of Stacking. Capacity Length. Width.'. Height. (c/s.) i 8' x X 8' i‘ J 8' X X ' 8' = 8' = ' 512 512 .12' x X 10' 10' X X 8' = 8' = 960 960 ■ 12' x X 12' 12' X X 8' = 8' = 960 960 17' [x X 18'■ 18' X X .8' \ = 8' = 2,4482,448 24' x X 18' 18' X X 8'. = 8' = ' 2,680 2,680 28' . x X 25' 25' X X 8' = 8' = 5,600 5,600