WORK FOR THE COMING MONTH.

New Zealand Journal of Agriculture, Volume XXII, Issue 1, 20 January 1921, Page 52

WORK FOR THE COMING MONTH.

THE ORCHARD.

THE FIRE-BLIGHT CAMPAIGN.

The fire-blight menace continues to be the most disturbing factor in fruitgrowing circles. Not only does this apply to the Auckland District, where the disease actually exists, but owing to its destructive nature and the probability of its sooner or later spreading farther afield growers of other districts are considerably, alarmed. In the meantime the Auckland District growers have formed a strong Fire-blight Committee, and are generally adopting energetic measures with a view to coping with the trouble as effectively as possible.

The Department has still a strong staff of permanent and temporary officers in the field locating and cutting out infection wherever found. Owners of affected hawthorn hedges are under notice to eradicate the disease from such hedges before 31st March next. The preliminary step advised is to reduce all such hedges to a height of not more than 5 ft. Subsequently, if necessary, advice will be given as to the best means of dealing with affected parts still remaining. .

Owing to the period between this and the end of March being recognized as a specially busy season for farmers, the shortage of labour is a factor which is fully recognized in connection with the cutting of hedges on the lines suggested. In view of this and the fact that the danger of further spread is limited until next spring, an extension of time will be granted in all genuine cases on application to the local Orchard Instructor, provided the applicant gives a definite undertaking to carry out the work and to destroy all primings before the expiry of the extended period. The reason why the present date (31st March) is retained in preference to a general extension to June or July is owing to the impossibility of the limited number of Inspectors being able to adequately attend to the large area infected if the whole of the work is thrown on to the latter end of the safety period. This can be risked only in the event of the intention of the farmer being known, and the most satisfactory way of learning this is by the farmer lodging an application for extension, which will be granted provided he gives the undertaking previously referred to.

Judging from articles appearing in the Press there are a few fruitgrowers who are sceptical relative to the whole matter of fire-blight and the control measures. Theories put forward are various, but the trouble is mainly attributed to cold winds, weakness of the tree, lack of proper plant-food, &c. Statements have been made to the effect that a similar disease affected our orchards in different periods in the past and was only temporary in its effects, disappearing as quickly as it came, &c. These opinions would no doubt be very consoling if there were any hope of their being correct, but unfortunately there are none, consequently their expression is calculated to do a considerable amount of harm in connection with the fight which is being waged and which must be continued against this disease. There may have been infections in the past resembling fireblightin fact, there are still some—but despite this it is quite safe to say that the present fire-blight disease has never previously existed in New Zealand.

Although the disease is new to this country, through the medium of American literature on the subject, combined with over twelve months’ practical local experience, its peculiarities have become well known to the officers of the Horticulture Division. There are, however, people who still appear to be in doubt as to whether fire-blight will actually kill trees or not. On this point there need be no doubt. Fire-blight will kill trees, and has already done so in New Zealand. Some trees are, of course, more resistant than others, but the hardiest of them are at least liable to be rendered more or less valueless from a fruit-producing point of view through blossom-infection, which is practically sure to take place any time the disease is allowed to be carried over from one season to the other in

their vicinity. The matters of weakness, strength, and cultural methods generally apparently play no part in the case. In America as well as New, Zealand strong trees and weak trees alike, under practically every known condition, are equally readily affected.

It is not suggested that these and similar channels of investigation should be ignored, despite the non-success attending similar efforts elsewhere, but possibly a considerable amount of time would be required for their operation. If one’s house were on fire it would be folly to stop to consider the installation of a highpressure water-service if other means of fire-fighting were available. In a manner of speaking our New Zealand orchards are on fire, a portion has already been destroyed, and if we wish to prevent a general conflagration we must energetically adopt the only known means of prevention available. The only effective means to hand for the control of fire-blight—which is the form of “ fire ” referred is to cut out and destroy all infected parts, and to do this'cutting-out so effectually as . to prevent the disease being carried over to the following season either on fruit-trees or any other plant. Anything short of this will mean that fire-blight will be always with us.

A. Campbell,

Assistant Director of the Horticulture Division.

AUCKLAND.

Fire-blight : Since writing the orchard notes for last month an unlooked-for development has taken place in regard to this dread disease. Further infection has taken place in the inner suburban area of Auckland, and in the outer suburbs on the western side, reaching in this direction as far as the very borders of large commercial areas. From the time the infection took place early last season at Te Papapa the Department has adopted a vigorous policy of inspection and destruction of infected trees where necessary, with a view to limiting the infection to a definite area. This work is now being helped on by the . honorary inspectors working under the Auckland Provincial Central Fire-blight Committee in conjunction with the Department in the commercial areas. However, the domestic orchardist and the general public may greatly assist by immediately reporting to the Orchard Instructor for their district any suspicious symptoms which may appear in their orchards from time to time. In view of the fact that hawthorn is a means of carrying over the disease from one season to another, all persons residing in the commercial fruitgrowing areas are asked to cut out their hawthorn wherever possible, in order to increase the possibility of successfully dealing with' the disease in those areas. There is no other known method of successfully dealing with this disease than cutting out infected parts, and destroying the same by burning. General operations : The most important routine operations for the month are cultivation and spraying. Citrus-growers who have so far been unable to get bordeaux on to their lemons at the falling of the blossom-petals from the main spring-crop flowering should lose no time in applying this at 4-4-40 strength, and in cases where verrucosis or grey scab is bad this spray should be repeated after about four weeks have elapsed. , Spraying summary : Peach, nectarine and plumcommercial lime-sulphur 1-125, or self-boiled lime-sulphur 8-8-50, when the fruit begins to ripen, and further as circumstances demand. Pear, apple, and quincecommercial limesulphur 33 0 test, 1-100, in conjunction with arsenate of lead, paste i|lb. or powder j lb. to 50 gallons, every twenty-one days. To this may be added, if necessary, Blackleaf 40 at the rate of 1-800 for control of woolly aphis. Lemon and orange —bordeaux, 4-4-40, when petals have fallen from the main-crop blossoms (if not already applied). The commercial lime-sulphur application should be continued on pip-fruits wherever black-spot is showing. In cases where black aphis of the peach is giving trouble McDougall’s Insecticide, 1-50, should be used. A second application may also be necessary to effectually control this insect —J. W. Collard, Orchard Instructor, Auckland.

HAWKE’S BAY.

A number of the various varieties will mature for picking in the immediate future, and care should be taken in the selection of fruits to pick. Immature fruits shrink badly soon after removal from the trees, while fruits allowed to remain on the tree to attain the maximum development and colour have a very short marketing-period, becoming overripe rapidly. . Experiments have indicated that the best results can be obtained by picking only fruits which have a distinct

change of ground colour towards light yellow. This will necessitate going over the trees several times at intervals, but the uniformity of fruit marketed will well repay the extra care. Once fruit is picked it should be shaded from the direct sunlight as soon as possible, and stored or marketed without delay. Little can be added to the spraying operations recommended last month, except to stress the necessity of keeping all pip-fruit covered with arsenate of lead, to meet the attack of the brood of codlin-moth which can be expected at this season of the year. W. H. Rice, Orchard Instructor, Hastings.

NELSON.

With the month of February the apple harvest commences in earnest. Growers should therefore complete arrangements without delay and see that necessary supplies of packing-materials are on hand. Important modifications have been made in the export regulations regarding size and colour; these must be studied and the pickers instructed accordingly. Great economies can be made if the picking-teams are right. Teach them what to pick. Picking for export is by no means an easy job. While apples that are too small and immature must be left on the tree, all mature apples of sufficient colour must be gathered ; any that are overlooked now and gathered later give no end of trouble if included in the pack. Apples below C grade should be placed in separate boxes by the pickers or placed in a heap at the butt of the tree ; this precaution will save double handling later. As far as possible gather the fruit when it is cool, and place it in the shade. Among the necessary improvements in- the export pack are two very important ones. First, the box into which the goods are finally placed must be carefully examined before packing ; a lot of fruit is lost for lack of this precaution. See that the box is strongly and well made. Put aside a doubtful box without hesitation. The second point is the matter of stencilling. Have you the right quantity of paint on your brush ? Is that stencil straight and in the right place ? . Not only must stencils look well, but they must be very clear, and always in the same place. Nearly every time that fruit is handled those marks have to be read. Bad marking is not encouraging to a buyer.: Towards the end of the month autumn rains can be expected to commence, and spraying precautions must be renewed. Further application of lime-sulphur and arsenate of lead will be required. Orchard cultivation generally should now cease. Where necessary a covercrop can be sown now. The present time is more especially suitable for sowing lupins or peas. • —W. C. Hyde, Orchard Instructor, Nelson.

CANTERBURY.

Spraying : The notes which appeared in the November Journal still hold good for both pip and stone fruits. At this period lime-sulphur may be applied at the strength of iin 120 on apples and pears. The second period of mothinfection may be expected about the third week of this month. Reworking trees : The latter part of this month and February is a good time to bud to better varieties all poor and worthless kinds. Be sure the buds to be used are taken from trees known to produce a high-quality fruit. Insert the bud on the outer or underneath side of the limbs. Besides the bark lifting more easily, a better-shaped tree will be obtained than if the buds are inserted on the inside.

Summer thinning : Wherever trees are found to have too much growth throughout the centre, superfluous growths only may be cut to within six or seven buds from the base from which they spring. The leaders should not be touched. Heavy branches should not be cut at this time. Thinning should not be commenced until after the terminal buds have set. This will open up the centre of the tree and admit sunlight, which aids the development and ripening of wood and fruit-spurs. Cover-crops : Growers intending to grow a crop between the trees for greenmanuring purposes should order their seed so that it will be on hand when required. Cultivation : The land should be given a thorough cultivation, so as to break any crust which may have formed and to check the growth of the weeds. Handhoeing should be done around the trees, so as to loosen the soil missed by the cultivator.

Marketing fruit: Care should be exercised that fruits are not allowed to become too ripe before being picked. The time to pick is one of the most

important problems in the successful marketing of fruit. With stone-fruits the degree of ripeness depends upon the distance from the markets. They should arrive on the market sufficiently firm to permit the retail fruiterer to hold them in good condition for from two to three days. Early apples are ready when they have attained full colour, and the fruit-stalk will readily part from the spur when the fruit is bent upwards with a slightly twisting motion. Early pears should be picked as soon as they have reached full size and before they begin to colour, and then the -stalk readily parts from the spur. Both early apples and pears should be placed on the market without delay. . Fruit for identification : From time to time specimens of fruit are submitted for naming without any description of the habit or growth of the trees, or any particulars whatever. It is advisable that the specimens should be accompanied by a description of the tree ; when the fruit ripens ; the name, if any, which it is locally known by, and any other information which would be of assistance. At least three specimens (typical), with stems attached, should be' sent. —W. K. Dallas, Orchard Instructor, Christchurch.

OTAGO.

The reported prevalence of green aphis throughout Otago was not exaggerated. This disease has caused considerable damage to peach crops, especially early varieties, hundreds of trees being defoliated and defruited by its attacks. When trees become infested the first precaution must be to remove the tips of the shoots where infection is bad, and destroy by fire immediately, otherwise the insects will crawl back up the trees. Spray at once with Blackleaf 40 at 1-800, with 4 lb. of soap dissolved in each 100 gallons of spray-mixture. Watch the effect, and repeat the spraying if necessary. Growers will be very busy marketing the stone-fruit crop at this time, but attention must be given to the necessary spraying to ensure this year’s crop, and prepare for next year’s also. Pests and diseases, such as woolly aphis and mildew, must be dealt with now, as next season’s crops are dependent on the preservation of buds and laterals. Do not trust to luck ; take practical measures by removing infected twigs and burning them. Spray well with Blackleaf 40 at 1-800 for woolly aphis. Use lime-sulphur at 1-120 for mildew if the weather is cool, but I strongly advise atomic sulphur at 8-10 lb. to 100 gallons of water : under the present warm droughty conditions. Black-spot is in evidence ; it is not serious at present, but growers are reminded that further infection is likely. If wet weather should set in careful watch should be kept, and lime-sulphur at 1-120 applied if the disease shows signs of further development. Spray again with arsenate of lead for codlinmoth, and also for cherry and pear slug if necessary. Budding of fruit-trees can now be attended to where a change of variety is desired. Where grafting has been done during the dormant season the ties will need cutting. At the same time the new growths should be protected by tying, to prevent their being wrenched off by the wind.

—J. H. Thorp,

, Orchard Instructor, Dunedin.