Selection of Site for Growing Raspberries

New Zealand Journal of Agriculture, Volume 73, Issue 5, 15 November 1946, Page 427

Selection of Site for Growing Raspberries

PRESENT production of raspberries in New Zealand is lower than for a number of years because of a steady decline in both acreage and average yield of plantations during the past decade. Considerable interest is now being shown in the industry by prospective growers, and this article by J. P. Hudson, of the Horticulture Division, offers guidance to those who are thinking of planting raspberries. Other aspects will be considered in future issues of the “Journal.”

A number of'' factors have contributed to the falling-off in both area and yields of commercial raspberryplantations during the’ past few years. A similar, serious decline has occurred in Great Britain and Canada (though not, apparently, in Tasmania), and a year or two ago it was even feared that - the raspberry would go out of z commercial production altogether in England. - Overseas the greatest single reason for the decline has been disease, and ; especially a complex of virus , diseases, the widespread attacks of which robbed the canes of vigour and fruiting capacity. .This problem has been attacked . with promising ' results ’by energetic teams of research workers, '■ and there is now a good prospect of more satisfactory raspberry crops being grown in Britain. Reasons for Decline ! In New Zealand several factors have contributed to the decrease in acreage and yield.- Of these the following are important:—.' . . 1. The increasing difficulty of finding suitable casual, labour for harvesting the crop. This will probably always be one of the raspberry grower’s main worries, and is one for which a prospective - grower should have in mind a clear solution ■ before planting is begun. 2. The poor prices returned for raspberries during. the 1920’s and early 1930’s when many stocks deteriorated. y " 3. The incidence of diseases and pests. It seems clear that if a grower > starts with healthy, vigorous planting stock,, he 'can now confidently expect to be able to control the common diseases and pests by . proper management. The production of, healthy.. planting stock is a different . problem, which will be dealt with in a subsequent article. ’; '' ' 1 ’ V ' ' ' • '■ I- ?. - 4. The, planting .of .' raspberries on unsuitable sites where - economic production' is too' ". dependent on favourable weather. '

Choice of Soil and Site. Like most crop plants,, the iasj» berry has a marked preference for certain types of soil, site, and ; situation. Any attempt to grow the crop under unsuitable conditions is bound to reduce the grower’s chance of financial success. Two fundamental facts , should always be borne in mind: 1. Where the raspberry grows wild, in many parts of Europe and Western Asia, it flourishes in cool, moist climates (for . exaifiple Scotland), and the cultivated varieties inherit this preference; and 2. the • fibrous feeding roots of the raspberry may extend many . feet.' around the - plant, but are nearly all within the top few inches of the soil. The raspberry will also, however, send roots deep into a welldrained soil, and so obtain a constant moisture supply in summer V when the surface ' soil may start to dry out. ' „ ' In a deep, ■ well-drained" soil. the raspberry produces far deeper roots than most- growers, imagine, as the accompanying- photographs clearly show? Even in such soils there are still many ’ fibrous . feeding roots near the surface which serve to collect moisture and plant foods- from - the fertile top soil. * In addition, however, each crown sends a root system j deep down into the sub-soil.' In a well-drained soil, thoroughly wetted by an adequate winter rainfall, these deep ; roots can draw on the tremendous' reserve of moisture available .in • the lower layers. In considering an area for raspberry' growing, careful thought should be given to .. its suitability from . each • of the points of view, of soil,' drainage, rainfall and water supply, frosts, and wind. , ‘ ■ Character. of Soil „ • The ideal soil is a deep, medium loam, .grading gradually, without any hard layer, into a free-draining subsoil. In districts subject to summer drought a . heavier soil is to be preferred, as

it holds moisture better in a-dry spell. Light or sandy soils can be used for raspberry growing, but only if heavy applications of humus are made to hold moisture or. if artificial irrigation is . available to . prevent the soil from drying out in periods of drought. Heavy clay soils, on the other hand, are difficult to maintain in suitable physical condition without deep cultivation, which would injure the fibrous root system of raspberries; ' Moreover, the'root system is apt to be sparse in clay soils, resulting in weakly canes.

Soil Drainage The area must be well drained and never subject to flooding or to even temporary waterlogging after wet weather. If the. water table rises all roots submerged for more than a few hours will subsequently die. Canes may reroot, but the loss of roots will not only, affect the crop borne by existing canes but will also reduce the strength of the canes which will grow and bear the following crop.

Very many .failures of raspberry plantations, can be traced either to flooding of the area or to temporary waterlogging during abnormally wet weather. ■ The . greatest care should be taken to avoid planting, raspberries where such conditions may. occur. Local tradition and hearsay may give some indication as to whether a;particular paddock is, , ever flooded, but expert opinion should be sought about the drainage character of the soil. The water table may not reach the surface in a wet spell, and its rise may thus not have been noticed by former occupants of the land. But water-

logging leaves indelible traces in the soil which can, be : recognised by an expert, who will examine the soil to a depth of at least 2ft. 6in. either by digging or with a soil auger. Orangecoloured mottling and the presence of small dark-chocolate or purple lumps in the subsoil are among the indications that the drainage is impeded.

Though waterlogging of the soil is so detrimental to the growth of raspberries, it may be possible to remedy this fault in an otherwise suitable area by a careful system of permanent drains; but these must be laid correctly and maintained efficiently. It is, of course, far easier to drain an area before planting the raspberries than after'they have been established. If a; drainage scheme is contemplated, expert. advice should again be taken to ' make sure ■ that the scheme'; is practicable and will achieve the/required results. The whole ' success of the venture may well depend on the efficiency of the drains.

Importance of Rainfall Other things being equal, the weight of a raspberry crop varies in proportion to the soil moisture, ■ and the crop can be grown' most 'economically where the soil moisture supply can be maintained most easily and cheaply.

Ideally, there should be an adequate annual rainfall, sufficiently well , distributed throughout the.year to ensure that, the' soil immediately below the surface never dries out. It is an advantage, however, if the latter half of the summer, when picking is in progress, tends to be dry. In areas' with an insufficient annual rainfall, but • where conditions are otherwise suitable, artificial irrigation would be worth considering as a means /of - making. raspberry growing

possible. The added expense of irrigation might be . balanced by the regular and ; increased crops produced, as a result of being able to give the canes water as and when they need'it’ It is essential to prevent the feeding roots near the surface from drying out, as their death affects both the present and. the following year’s ' crops. This is especially important in soils where the raspberry. does not produce deep roots.

Raspberries with the deep type of root system will not be nearly so dependent on a regular summer rainfall (or irrigation) as those whose roots all lie near the surface, but such deep root systems can be produced only in soil which never becomes waterlogged at the lower levels even in prolonged wet weather.

When a prospective grower is considering an area he should make care-, ful inquiries about.'the climate of the district, . and ■. especially about the amount and monthly ' distribution of rainfall recorded over - a long period. Hearsay; evidence. will not be as satisfactory, as the official records, which should be available at the local library in the ‘ annual . “Meteorological Observations” published by the Department of Scientific and - Industrial Research up to and including 1938. Total rainfall for the year is recorded in . the New Zealand Year Book, but this, figure, is much less important than the distribution of the rainfall during the year. Further detailed information about a particular area can be supplied by the Meteorological Office, P.O. Box 722, Wellington, or by the local representative of the Department of Agriculture.

Frosts Reduce Crops

The site should not suffer from late spring frosts, which may considerably reduce the crop. “Frost pockets” should be avoided; generally ■ sites elevated above the valley bottom, and with a definite slope to encourage cold air to drain 'away, will be least liable to frosts.

. -flowering varieties of ’ raspberries are less damaged by frost than early-flowering types. Even when a proportion of blossoms is lost by frost, damaged canes usually produce some fruit from secondary growths, but this crop is later and not as heavy as the normal one.

IDEAL deep soil

Labour Saver for Orchardists

NAIL STRIPPER A labour-saving device for orchardists, ■ known for many ' years but still absent - from many case-mak-ing benches, is the nail stripper. This lines up a number of nails, heads all , the one way, so that the case-maker can quickly., seize a few ' between . finger and thumb instead of having to dip into a . tray and arrange the nails the right way by. hand. Neat, well-made ■ nail Strippers may be bought, from orchard supply organisations, -but the illustration 'may be a sufficient guide to the orchardist should he desire to construct one himself. A handful of nails is placed in the feed hopper and, assisted by the vibration of hammering during Case-making, they slide down into the lower shelf, which is fitted with a number of slots which allow the body of the nail to drop through but hold the head up. The nails are then in the right position to be taken by the case-maker. A small proportion of the nails drops through to the lower tray, but these can be returned to the hopper. A. R. GRAINGER, Orchard Instructor, Christchurch. DOMINION'S. SHEEP FLOCKS THE annual “Return , of\ Sheepowners,” containing the number of sheep and lambs 'in each county, the names of owners' of flocks on April 30, 1945, and . comparative, figures for 1944, has '.' just been published and copies are available from the Publisher Department of Agriculture, Box 3004 Wellington, at £5 ss. each.

. .... . : —: ■ BUDDING OF FRUIT TREES

Budding is universally adopted as the best and most economical. method of raising young trees. The operation of budding is fully described 'in Bulletin No. 81, “The Budding ■ of Pip and Stone Fruit Trees.” This bulletin is available free from your nearest office of the Department of Agriculture.

The district meteorological' records should also be consulted about frost, but this information is of less value than the rainfall records, as'frost is a more localised phenomenon than' rain, and is . markedly affected by detailed topography. Some idea of the severity of , frosts can often be obtained from a'study of the types of plants which . thrive in neighbouring gardens.' ' Freedom from High Winds " Especially during the ’ summer months when ; picking is •. in ' progress, freedom from ; high < winds is ■ very

desirable, "as is absence of 'salt winds, which cause severe damage to. the foliage. Adequate shelter will -be especially needed in districts subject to ' hot, drying winds in spring and summer, as these seriously debilitate raspberry canes. ' Security of tenure is, of course, necessary, as raspberry plantations should have a life of at least 7 to 10 years, and much longer if site, soil, and other factors suit the . v crop. ■■ f Photographs by Photo News, Ltd.

Orchardists* Labour Saver — 1 Case-lining Bench

' Illustrated above ,is a type of bench in use by a Horotane grower for holding case-lining paper -and fitting it into the cases, which is done before the case’ goes to the packer. An operator can work at each end of the stand. . f,.-. - •This stand carries little weight, when in use and is therefore lightly constructed. The , sketch- gives sufficient detail for requirements of timber to . be assessed. The four slots inside the walls'of the paper rack are for use with .light pegs which work freely and hold the paper at the sides sufficiently to keep it'from being blown about: - A. R. GRAINGER, ' ' ' Orchard Instructor, Christchurch.'