The Home Orchard in Spring

New Zealand Journal of Agriculture, Volume 95, Issue 2, 15 August 1957, Page 111

The Home Orchard in Spring

SPRING activities in the home orchard are discussed in this article by S. P. Money, Instructor in Horticulture, Department of Agriculture, Wellington. They include routine spraying, application of fertilisers, cultivation, and descriptions of some of the insect pests which may be troublesome during the year.

SPRAYING THE spraying programme in the home orchard must be carefully carried out if crops are to be well protected. Efficient spraying equipment capable of applying the material to all parts of the tree is needed, and the sprays must be applied at the right time. Equipment which is satisfactory for young or small trees may be quite unsuitable for large bearing trees. Diseases and pests in home orchards are often worse at the tops of trees, nearly always because of inadequate spray equipment. The extra cost of satisfactory equipment for bearing trees is soon recovered from the harvesting of crops of good fruit which would be badly damaged or lost if not sprayed properly. Most full-sized trees require at least a gallon of spray material for efficient protection. When there are more than seven or eight mature trees, especially if they include some of the more vigorous stone fruit varieties, it is well worth while to invest in a

knapsack sprayer, which of course can be used for the spraying of. other crops. For large home orchards the purchase of one of the many small powered units now available should be considered. The first sprays in spring should be applied at the earliest noticeable bud movement, which is shown by loosening of the bud scales and swelling of . the buds. New tissue is exposed from beneath the scales and it is here that the leaf curl fungus of peaches and nectarines gains entry unless checked by a bordeaux spray cover. From this time on regular spray applications are essential to give continued complete cover to provide protection . against various diseases and pests. Care in the mixing of sprays is important. Serious damage can occur when the spray is too strong or whensprays are mixed indiscriminately. When proprietary brands of spray materials are used the manufacturers’ directions printed on the labels should be followed carefully. Valuable pieces of equipment are a measuring glass

and. small scales, which eliminate guesswork. Protection of Bees The movement of bees in the orchard at blossom time is essential for the setting of a crop. There are many natural factors which may interfere with this, such as prolonged cold, wet weather or strong winds over the blossoming period. Lack of bees may account for an absence of crop, especially when the failure is confined to one type of fruit which normally sets fruit satisfactorily and has blossoms at a different time from the rest of the orchard. In the home orchard, where usually there is a variety of trees blossoming at different periods, there is a tendency to apply the petal-fall sprays at one time for convenience. Apart from the sprays being applied at the wrong time on some trees, the greatest danger lies in poisoning bees. Applying insecticides to trees in full or part flower not only causes deaths among bees visiting the flowers, but among those in the hives to which infected material is carried. Many bees are killed in this way each year, and it is in the home orchardist’s own interest to take particular care not to endanger insects which are so useful to him.

Insect Pests It is important to inspect trees and berry canes periodically to check for insect pests. More than a casual glance is needed, and it will add interest, to the job if the home orchardist owns a small hand lens. This can be obtained for a few shillings and is invaluable for detecting early outbreaks of red spider or the eggs of other insects. The following descriptions of the main insect pests should help home orchardists to identify the various pests and thus to apply the effective sprays. Codling Moth The codling moth, a chewing insect, is the most troublesome with which home orchardists have to contend. This

insect is most familiar as a white, grub-like caterpillar which bores holes in apples and pears and is thus found there when the fruit is picked.

The adult moth is seldom noticed unless traps are set for it. It is an inconspicuous, light brown insect about Jin. long which flies at night. It lays its eggs on the leaves, twigs, and fruit of apples and pears, and the resulting caterpillars eat their way into the fruits to devour the seeds. Woolly Aphid The woolly aphid is a sucking insect found on apples and pears. This aphid is similar to other aphids except that it can secrete a white waxy covering, from which it derives its name. When large numbers of woolly aphids are present the. trees have patches on them which look like cottonwool. Severe infestations of these insects can destroy many buds on new growth and thus directly reduce future crops. The woolly aphid has a natural enemy, a tiny wasp which lays its eggs in the body of the aphid. The growing larva lives in the aphid, which it eventually kills. Aphids which have been parasitised in such a way can be easily seen as black bodies among a group of live aphids. A closer inspection with a magnifying glass will show a hole in each of these bodies from which the young adult wasp has . emerged. Red Spider. The red spider is a tiny, inconspicuous insect found on most tree fruit

varieties, raspberries, and black currants. An infestation if unchecked can cause a severe set-back to trees or canes. In winter and early spring the egg masses of this insect can be seen on the twigs and bark as a red, dust-like covering and are most evident in the shelter provided by wrinkles, cracks, and leaf scars.

In spring the tiny spider mites hatch out and move about the tree in search of food. These are sap-sucking insects and during the dry summer they cause the foliage to lose colour. In the early stages the foliage looks unthrifty, but when infestation is severe the leaves take on a bronze appearance. Leaf-roller Caterpillar The leaf-roller caterpillar is a chewing insect which has the habit of providing protection by either bending a leaf over itself and sealing this down with threads or sealing two leaves

together. This type of protection makes it essential to spray thoroughly. As the leaf-roller caterpillar is not controlled by DDT, spray programmes should be modified to include arsenate of lead where this pest is a problem. Apple Leaf Hopper The apple leaf hopper is usually seen only when disturbed and then it may be noticed as a very small white, insect flying about in the shade of the tree. In the home orchard it is not as serious as in commercial orchards. It is a sucking insect and the damage it causes can be seen as a fine mottle of the leaves. The effect of this insect, like that of the red spider, is more noticeable in dry weather. MANURING Lime Lime affects the soil both physically and chemically. It is not a fertiliser in the sense of blood and bone, but it supplies calcium, one of the essential elements for plant growth. At the same time lime has the effect of reducing soil acidity, though too much lime can bring the soil to a neutral or even alkaline condition, which can be detrimental to plant growth. Types of Lime Three types of lime are used in the home orchard, burnt lime (calcium oxide), hydrated lime (calcium hydroxide) , and agricultural or garden lime or ground limestone (calcium carbonate) . The equivalent rates of application of these various types of lime are: 11b. of burnt lime = IJlb. of hydrated lime or 21b. of agricultural lime. Burnt lime is not very useful to the home orchardist, as it is caustic and could damage plants, besides being difficult to store. Hydrated lime, used for bordeaux spray mixture, can be used quite safely for liming in the orchard. It should be stored in a dry place, either in a strong paper bag or in a' tin with a tightly fitting lid. Ground limestone (agricultural or garden lime) is the most commonly used and cheapest form of lime for garden application. Almost all lime now sold is of good quality, but as the size of the particles can vary considerably and fineness is important, it is wise to inspect lime before it is purchased to make sure it is finely ground. The quality of lime is not related to its colour. Application of Lime Lime should not be applied haphazardly. A common mistake by the layman is to guess the application rate. This can be harmful, especially where only light dressings of lime are needed. It is wise to measure the area where

lime is to be applied (stepping will do) and then to weigh out the amount of lime at the rate decided on. If there is a very large area, it should be divided into workable portions and the amounts of lime for the various sections applied in turn so that over-all application is even. On most soils which are of average acidity 3oz. to 4oz. of agricultural lime per square yard is sufficient. Where the soil is very acid more may be needed, but when this is necessary it would be well to find out from local Department of Agriculture officers the normal lime application for the district. The acidity of soils is measured on a scale called the pH scale, which ranges from pH 0 to pH 14; pH 7 is neutral, acidity increases toward pH 0, and alkalinity increases toward pH 14. The best range for most plant growth is pH 5.6 to pH 6.5, a slightly acid condition. A rough guide can be obtained by using indicator strips. These are small booklets of coloured paper which change colour according to the degree of acidity. These booklets should be available through seedsmen.

Fertilisers The main aim of fertilisers is to give the plants sufficient nitrogen, phosphorus, and potassium for healthy growth. A brief explanation of the functions of these elements and examples of the most common fertilisers used in the home orchard follows. Nitrogen Nitrogen is responsible for stem and leaf growth. Too much nitrogenous manure will promote excessive growth at the expense of flowers and fruit. Some examples of the nitrogenous manures are:— Dried blood (12 per cent, nitrogen). Blood and bone (about 7 per cent, nitrogen, 11 per cent, phosphorus). The nitrogen in this fertiliser becomes available more slowly than that in dried blood. Meat meal and bone (less than 6 per cent, nitrogen, about 11 per cent, phosphorus). Sulphate of ammonia (20 per cent, nitrogen). A very soluble, quickacting form of nitrogen, but excessive use of it tends to acidify the soil. Nitrate of soda (15 per cent, nitrogen). This is similar to sulphate

HOME ORCHARD . . . of ammonia except that it does not acidify the soil. Phosphorus Phosphorus (phosphate) stimulates root development and generally helps to stabilise plant growth. Some examples of phosphatic manures are: — Superphosphate (20 per cent, phosphorus) Basic slag (16 to 22 per cent, phosphorus). The phosphate becomes available very slowly. Basic slag has various amounts of minor elements which are of value to plant growth. Bonedust (25 per cent, phosphorus, 3 per cent, nitrogen). . This manure is slow acting and used largely for bulb growing in the flower garden. In the home orchard it can quite well be replaced by superphosphate. Potassium Potassium (potash) is an important fertiliser for hardening vegetative growth, thus effectively balancing the effect of nitrogen. It is important also

in helping to colour fruit. On some soils potash can be “fixed” very easily, so that even after potash has been applied excessive growth or - lack of colour may be still apparent. On such soils additional side dressings of potash should be applied. The main sources of potassium are: — Sulphate of potash (48 per cent, potassium oxide) Muriate of potash (50 per cent, to 60 per cent, potassium oxide). These two fertilisers are both highly soluble forms of potash, but there can be a tendency for muriate of potash to burn plants with which it comes directly in contact, particularly if the foliage is wet. Wood ash (1 to 10 per cent, potassium oxide). The amount of potash available depends on the type of wood which has been burnt, but in any case wood ash, though not useful enough to replace the potassic fertilisers mentioned, is always worth putting on the garden in the small quantities usually available from garden incinerators. Application of Manure With continuous cropping adequate fertiliser applications are essential, but

the quantities and types of fertilisers used must differ according to the natural fertility of various soils. The following mixtures may be used, as a guide for a balanced fertiliser: — For Apples, Pears, Apricots, and Plums Parts by weight Blood and bone .. .. 2 Superphosphate .. .. 2 Sulphate of ammonia .. 1 Sulphate or muriate of potash .. .. 1 For Peaches and Sub-tropical Fruits Parts by weight Blood and bone . . . . 1J Superphosphate .. . . 1J Sulphate or muriate of potash . . . . .. 1 For Citrus Parts by weight Sulphate of ammonia .. 2 Blood and bone ... .. 2 Superphosphate .. ... 3 Sulphate or muriate of potash .. .. .. 1 For trees from 3 years to 5 years old 21b. per tree is sufficient on most soils, but this could be increased by Jib. to fib. per year until the tree is 10 years old. The rate reached by the time the tree is 10 years old should be the annual dressing thereafter. Trees and berry canes which are losing vigour should receive increased amounts of nitrogenous fertiliser, and potash may be reduced or eliminated for a year or two. On the other hand for trees that are too vigorous and not fruiting satisfactorily nitrogen should not be applied and potash applications should be increased. Fertilisers should be applied at least 3 weeks before bud movement is expected. The common fault of applying the fertiliser too close to the tree should be avoided. The main feeding area of trees and bushes is just short of and just beyond the ends of the branches. The fertiliser should be placed in a circular band Ift. from the butts of small trees and shrubs and up to 3ft. from the butts of large trees to just beyond the spread of the branches. SPRING CULTIVATION Where the orchard is not in lawn and has been deeply cultivated during winter, light cultivation round the trees should begin as soon as the weather is favourable. After wet weather this type of cultivation is most helpful in reducing excess water. Continued cultivation from this stage is essential if weed growth is to be kept under control, and in turn this will help to conserve moisture as the weather becomes drier. Disease control, too, is assisted by cultivation, because it eliminates some of the plants that harbour pests and diseases.

Sprays for Control of Insect Pests and Diseases in the Home Orchard

APPLES AND PEARS Time of application Treatment Pest or disease Buds showing Bordeaux mixture (6oz. of Black spot green tips copper sulphate and soz. of hydrated lime to 4 gallons of water) or lime sulphur (1J pints to 4 gallons of water) ' Petal fall *Lime sulphur and DDT (J Black spot, powdery pint of lime sulphur plus mildew, codling Joz. of DDT 50 per cent. moth. bronze wettable powder to 4 beetle gallons of water) |3 weeks later JLime sulphur and DDT (J Black spot, powdery pint of lime sulphur plus mildew, codling loz. of DDT 50 per cent. moth, bronze wettable powder to 4 beetle, leech gallons of water)' ♦Bordeaux mixture 3 : 4 : 50 strength (4oz. of copper sulphate and soz. of fresh hydrated lime to 4 gallons of water) may be used on pear trees in place of lime sulphur sprays. t Repeat this spray at intervals of about 18 days until a month before the apples are ready to pick. ~ J If leaf-roller caterpillar is troublesome, use arsenate of lead (IJoz. plus 21oz. of hydrated lime to 4 gallons of water) instead of DDT. In late spring woolly aphids may become troublesome and sprays of lindane wettable powder or emulsion may be used. In January or February summer oil (J pint to 4 gallons of water) may have to be applied to control red mites. Two sprays 10 to 12 days apart are necessary. Oil sprays must not be applied sooner than 14 days before or after sulphur sprays. BERRY FRUITS (Except Strawberries) Time of application Treatment Pest or disease Bud movement Bordeaux mixture (6Joz. of Leaf spot, botrytis, copper sulphate and soz. leaf-roller caterof hydrated lime to 4 pillar gallons of water) plus loz. of arsenate of lead Fruit set Bordeaux mixture (sJoz. of Leaf spot, botrytis copper sulphate .and soz. of hydrated lime to 4 gallons of water) After harvest Bordeaux mixture (as above) Leaf spot STRAWBERRIES Time of application Treatment Pest or disease Pre-planting Bordeaux mixture. (3oz. of Leaf spot (foliage dip) copper sulphate and 3oz. of hydrated lime to 4 gallons of water) Mid-August ) Mid-September I Repeat above spray Leaf spot Mid-October J ■ After harvest Repeat above spray as re- Leaf spot quired at monthly intervals

STONEFRUITS* Time of application Treatment Pest or disease Bud movement Bordeaux mixture (6oz. of Leaf curl, shot hole, of leaf buds copper sulphate and soz. of bladder plum, hydrated lime to 4 gallons brown rot of water) Repeat the anove spray in 7 to 10 days at 4oz. : soz. : 4 gallons strength where leaf curl has been particularly severe in past seasons or when the weather is cold and wet after the first spray. tßefore blossoms Lime sulphur and colloidal Brown rot, shot are fully open sulphur (J pint of lime hole, leaf rust sulphur plus IJoz. of 40 per cent, or 2Joz. of 25 per cent, colloidal sulphur to 4 gallons of water) * Lime sulphur sprays should not be applied to apricots, as their foliage does not tolerate this spray. A 3:4 : 50 bordeaux spray (4oz. of copper sulphate and soz. of hydrated lime to 4 gallons of water) should be applied instead. t Repeat at intervals of 3 to 4 weeks until 3 weeks before picking. Where leech (pear or cherry slug) is troublesome apply DDT (50 per cent, wettable powder at Joz. to 4 gallons of water). If aphids are present, lindane emulsion (1 fl. oz. to 4 gallons of water) should be added. Brown Rot In home orchards where brown rot has been particularly troublesome use of one of the newer spray materials which have shown great promise under trial may be valuable. These sprays can be used with safety on apricots. A suitable spray programme is:— Time of application Treatment Remarks During flowering Dichlone (joz. to Joz. of Do not mix with season 50 per cent, material to summer or winter 4 gallons of water) oil Rest of the Captan (loz. to 2oz. of 50 Do not mix with season at 2- per cent, material to 4 summer or winter to 3-weekly gallons of water) . - ■ oil, borde a u x intervals mixture, or lime sulphur CITRUS TREES Time of application Treatment Pest or disease Petal fall of Bordeaux mixture (4oz. of Verrucosis and main blossom copper sulphate and soz. of other fungous hydrated lime to 4 gallons diseases of water) Spray in October, November, and December with the same mixture if verrucosis has been troublesome. Early February Summer oil (1 pint to 4 Scale insects, sooty gallons of water) mould Late May Bordeaux mixture (as for Brown rot, hard petal fall of main blossom) wax scale plus summer oil (as above)

Wood Shavings Prevent Cutting up in Farm Gateways

THE wear and muddy condition of farm gateways caused by stock continually passing through, especially in wet weather, can be avoided if a load of wood shavings is placed in the gateway, as in the accompanying photograph. These, can be obtained from mills or joinery works, often at no cost. They are clean and will not cling to the feet and legs of cows, which is . a great advantage in the milking shed. Another advantage is that they do no harm or damage to the feet of animals as often occurs when sharp stones become wedged between the claws of the hoof. This is one of .the causes of the disease foot abscess that is common in dairy cows. —B. L. GRINDELL, Livestock Instructor, Department of Agriculture, Wairoa