In the Orchard and Vineyard

New Zealand Journal of Agriculture, Volume 63, Issue 5, 15 November 1941, Page 433

In the Orchard and Vineyard

Orchard Notes

Spraying for the Control of Diseases

OPERATIONS in the orchard during this and the following months will be directed mainly to the production of a good crop. Spraying for the control of disease, cultivation of the soil, and thinning of the. crop must be given full attention, for it is upon these operations that the health and vigour of the trees depend, and with- . out which best quality fruit cannot be produced. From this period onwards fruit trees will be in heavy foliage and it will be more difficult to effect a complete spray coverage, but every part of the tree must be completely wetted if maximum results are to be obtained. This can be accomplished only by attention to pressure, spray nozzles, discs, and thorough application of the spray. Sufficient pressure to ensure good penetration to all parts of the tree should be the aim of every fruitgrower. Codling Moth Codling moth will become more active as the warmer weather approaches, and unless the spraying is thorough, complete control cannot be expected. Spraying at regular intervals should be carried out as the season advances so that the growing fruit will always be well covered. Slight modifications to the spray programme recommended in . previous notes may be necessary mainly because of weather conditions and prevalence of disease. To guard against foliage injury, lime sulphur should be reduced in strength to 1:180 with the addition of colloidal sulphur at strength 2:100. In many cases it may be preferable to delete the lime sulphur from now on, using only colloidal sulphur, especially on such varieties of apples as Cox Orange Pippin, Dunns Favourite, and other varieties 1 known to .be susceptible to spray injury. Should wet weather intervene soon after spraying operations, it is advisable to apply an extra spray rather than risk the disease spreading throughout the orchard. This is the season when the apple leaf hopper usually becomes • active. Although the hopper may not be noticed, the mottling of the foliage caused by these insects in the nymph stage will indicate its presence, and steps

should be taken for its control. Impairment of the foliage is likely to cause considerable dropping of fruit at a later stage. The addition of nicotine sulphate to the ordinary spray programme at strength 1:800 is effective for the control of apple leaf hopper. Red Mite Red mite not destroyed by sprays applied during the dormant period will become active during this month, especially if warm weather is experienced. The injury caused to the foliage by this pest is reflected in the quality of the fruit produced, both size and colour being affected. Its first appearance may be noticed by the bronzing of the foliage, impairing it to such an extent that functioning powers are greatly diminished. No effort should be spared to rid fruit trees from the ravages of red mite. The only spray recommended up to this stage of growth is summer oil at strength 1:100. One spray will suffice if it is applied thoroughly and the mite has not gained too strong a hold, otherwise a further application at the same strength

will be necessary. Care must be taken not to apply an oil spray within from ten to twelve days after a sulphur spray has been applied; otherwise considerable damage to both fruit and foliage will be : done. Much damage is caused by leaf-roller caterpillar, more especially towards the end of the season, and it is advisable to -keep a close watch for this pest. It may be necessary to apply an extra lead arsenate spray or lessen the intervals between sprays should leafroller. become troublesome. Reports indicate that where lead , arsenate at strength 11 lb.:100 has been applied earlier in the season than is the case with many growers, leaf-roller caterpillar has been kept to a minimum. Spraying Pear Trees . Spraying as previously recommended should be continued during the month and , future months for the control of pests and diseases of pear trees. Where Bordeaux mixture is used on some of the hardier varieties and those more susceptible to black-spot in preference to lime. sulphur, the strength

recommended is 11:3:50. If used stronger, roughening and ru'sseting of the skin may result. Here, again, thoroughness of application is the key-note to success. Pay attention to the lead arsenate spray for the control of codling moth, especially with the earlier varieties. Stone Fruit Spraying. Applications of sulphur sprays for the prevention of brown-rot will : be necessary on peaches, nectarines, and plums from now on to the end of the season. Humid conditions, favourable for the 1 production of brown-rot, are •liable at this time. Consequently, lime sulphur at strength 1:180 to 1:200 plus colloidal sulphur at 2:100 ’ should be applied at intervals of from two to three weeks. Any fruits seen on the trees . affected with brown-rot should be destroyed to stop the spread of infection, . and in no case should clean fruit be handled at the same time as diseased fruit. It will be necessary to apply.■ nicotine sulphate at strength l:8Q0 for the control of black and green aphis, while leaf-roller caterpillar can be controlled by ; an application of lead arsenate ,li:100 plus hydrated lime 3:100. ■ ■ ; - Thinning of Fruit The judicious thinning of fruit is not carried out as much as it should be. Good quality fruit is always in demand, : and ■ any ■ money spent in this

important operation will be more than recovered when grading and packing. Not only will size , be increased by proper thinning, but uniformity of size will be achieved, •. another important factor when considering ■ handling costs. All diseased and malformed fruits should be eliminated at thinning time, leaving only those which will be of marketable value. While there is no hard and fast rule regarding thinning, as much depends on the size of the crop and the capabilities of the tree to carry the crop, generally speaking, it is advisable to reduce the crop of apples to, at most, two or three fruits in a bunch of five and often to a single fruit, especially with short-stemmed varieties, to prevent them from being pushed off the spur as the fruit grows, and also to prevent damage to fruit by rubbing against each other. . Fruits which are allowed to remain in close contact with one another make spraying more difficult, and also create a good' harbour for codling moth and leaf-roller caterpillar. As the centre fruit in a cluster of apples is usually short stemmed, this is the first to be eliminated, the others being reduced as necessary to produce good, average-sized fruits. Care should be taken not to damage the fruit spurs when thinning. If thinning shears are not available the work can be done quite easily without' damage to fruit or spurs by the pressure of: the thumb and forefinger, severing

the stalk at the base of the apples. In fact, many growers prefer this method because of the damage which sometimes occurs in the piercing of the remaining fruits by pruning shears, especially when in the hands of an inexperienced thinner. With peaches, apricots and nectarines, the best time to begin thinning is soon after the stoning period. If left later, much value will be lost in the size and quality. These fruits should be reduced to singles, and if the crop is very heavy with close fruit spurs, it is often advisable to denude some spurs entirely. Attention to Grafts Fruit trees grafted during the sealson will require some attention during November. Scions will be starting to grow, and it will be necessary' to release any ties to prevent injury to and possible death of the scion by strangulation. This release can be done very simply by drawing the sharp edge of the knife through the tying material. < Should the newly-grafted trees be in an exposed position, protection from wind damage can be obtained by tying the new shoots to stakes until they have grown sufficiently strong to withstand any,chance of breakage. . - 1 ' —G. STRATFORD, District Supervisor, Dunedin.

Citrus Notes

Recognition of Mandarins

CONTINUING with the recognition of the varieties of citrus fruits most commonly, grown in New Zealand, we have now to consider the mandarins. . ■; The mandarin species is characterised by small foliage; the rind of the fruit is easily separated from the pulp and the sections of the pulp from each other. As a general rule, the smoother the rind, the more juicy the fruit. As a class,' mandarins dry . out more quickly than sweet oranges. It is not possible

to subdivide the mandarin; varieties according to growth, habit, as the habit is inclined to. vary according to soil conditions. Satsuma or Oonshiu This was formerly' the standard Japanese variety. It is thornless and a pendulous dwarf grower, and is the most frost-resistant of all mandarins. The fruit is at its best just as it reaches maturity. If pulled, the rind is readily broken, and part remains attached to

the pedicel or fruit stalk. The fruit is flat in shape, bright orange colour, rind rough, loose, and easily separated from the pulp. There is almost no core, but a.small cavity of 3-Bin. ; is present; there are few seeds, the flesh is' orange colour, darker than* the rind, and not very juicy. , 1 • ’ Three Satsuma sports —Wase, Owari, and Silverhillhave arisen, and two of these are being distributed in New Zealand. ' ’ ' •

Owari is a thornless tree of spreading dwarf habit. The fruit is large, up to 3in. in diameter, flat, and carries a high colour; there are about nin,e segments, and the pith is open and generally seedless. Wase is similar to Owari, but the tree is more frost-resistant and fruit ripens earlier. ' Thomy, also known as China or wil-low-leaved, is generally renowned for the flavour of its fruit. It is claimed to be the best flavoured of all mandarin varieties. The tree is very slender in growth and almost thornless; the leaves are small, narrow, and deep green, and the fruit is usually borne singly at the tips of the slender branches. The tree is a prolific mid-season variety. The. fruit is an average size, paler in colour than many, and the rind is smooth and loosely attached. There are 10 to 13 sections, irregular in size but well defined, . and the flesh is coarse-grained. There are generally between 15 to 25 seeds present, which is a major disadvantage of the variety. Navel Mandarin •This is possibly a sport from Thorny. It differs from Thorny in being larger, having a thinner rind, and also having / a distinct navel. The flavour is good, . but generally not up to the standard of Thorny. Canton, has pointed leaves similar to Thorny, and the wood is free from ■ thorns. The rind, however, has not the same pleasant aromatic perfume, but. is deeply coloured and thin. This variety is hardy and prolific, the flavour of the fruit being fairly good. There is a wide group of mandarin hybrids, but _ only a_few- can- be - mentioned. These are King, Clementine, Temple, and Ellendale Beauty. King.— This variety appears to be a mandarin-sour, orange hybrid, as the ,shape of fruit, rough rind, and susceptibility to verrucosis are sour orange characteristics. The tree is : upright in growth, generally thorny, and foliage < is a dark green, resembling sweet orange foliage. The fruit is large, with rough rind separating easily from the flesh. There are 13 regular sections, which are easily separated from each other, and about 20 seeds. This is a late variety, which is generally prolific and palatable. ■ Clementine is another sour orange mandarin hybrid. It is very hardy, matures early, and has a delicate, spicy flavour entirely different from any other citrus fruit. The rind is round, pebbled, and with a groove at the apex. The rind fits tightly to the segments, but it can be peeled like a mandarin. There are nine segments and about five seeds. ’ Temple . is a sweet orange-mandarin hybrid, characterised by the size and colour of the fruit, which is larger than

any of the mandarins. The fruit is a deep orange red colour, and the rind is , smooth and leathery but thin, and separates easily from the pulp. There are 10 to 12 sections with very thin partitions, the flesh being free from

rag and very juicy. The flavour is characteristic, and there are about 20 seeds. f Ellendale Beauty is another sweet orange-mandarin hybrid. The tree has a very compact growth. The fruit is not as large nor of as deep a colour as Temple, but is flatter and a brighter red; otherwise it is very large, smooth, and has a thin rind. It is orangeshaped and has a pithy core. In next month’s notes reference will be made to the remaining miscellaneous citrus varieties and their recognition. —A. M. W. GREIG, Citriculturist, Auckland.

Cool Storage Notes

Re-packing Fruit for Marketing

r | 'HE season is now well advanced, 1 and the cool storage stocks of fruit will be considerably reduced. All lines of fruit still held to supply market requirements during the remainder of the season will need .to be opened up for examination. Very few lines will be suitable for marketing without re-packing in order to remove fruits which have deteriorated during storage „ ... . ... Granny Smith apples which were placed m storage at the correct stage of maturity wrapped in oil wraps and held at a flesh temperature of 32deg. to 33deg. F. should still be in sound condition. The larger sizes should be . carefully examined and placed on the market first . to avoid undue deterioration. They may be tested for the development of discoloration by removing samples of the fruits into ordinary atmospheric temperatures and keeping them under observation for several days. The Delicious variety should not be held

for a further period unless they are * n a cr^s P rm condition. ** would be beneficial if fruit reQuired for re-packing is removed from f storage chambers in small quantitles and immediately returned to the P o °l chamber when re-packing has been carried out. If not marketed withm seven to 10 days it should be reexamined and any faulty fruits removed before despatch to the market. This precaution will assist in maintaining the fruit in good condition unti i it is required for marketing, .. TTTI ~ „ ~ , . „ Whe £ the f™!? h ? s bee ? removed fr °™ c ° ol chambers at the; close of the fruit season the chambers should be thoroughly 1 cleared of refuse and waste fruit; this also , applies to the packing shed. Rejected fruit should , ot be left in cases, and all waste fruit should be immediately removed from the vicinity of the packing shed and COOl store -

A. A. POWELL,

~ Cool Storage

Officer, Wellington.

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