Vegetable Growing for HOME and MARKET GARDENERS

New Zealand Journal of Agriculture, Volume 101, Issue 3, 15 September 1960, Page 257

Vegetable Growing for HOME and MARKET GARDENERS

By the Horticulture Division

Potatoes

POTATOES are a most important food crop in New Zealand and are grown by farmers engaged in general agriculture and by markel gardeners and almost all home gardeners. They have no decided flavour, but there are extremely strong preferences among consumers based on cooking quality, size, colour, and shape, and home gardeners' selections are often mainly guided by personal preference.

THE selection and introduction of new varieties have made possible a choice of potatoes suitable' for producing profitable crops on a very wide range of soil types, many of which would have proved unsuitable for potato growing in the past. Main crop potatoes are grown commercially in most areas of New Zealand, but over 75 per cent of the main crop comes from the South Island. Early crops are produced in the warmer frost-free districts. Selection of Varieties Early selection of varieties to be grown is desirable and an order should be placed with a seedsman in sufficient time for the varieties to be obtained. It is a mistake to leave ordering of seed tubers until late in the season and thus because of poor supply be forced to substitute a less desirable variety. Where home gradeners and commercial growers are in doubt as to choice of varieties for their district they may consult the nearest office of the Department of Agriculture. Department of Agriculture Bulletin No. 277, “Crop Production”, price 25., has a

comprehensive section dealing with all aspects of potato growing. The following descriptions of some of the best known early, main crop, and late varieties are intended as a reference for the home gardener who may wish to try new varieties. Aucklander Short Top (sometimes referred to as Sutton’s Supreme) is suitable for growing on the medium to light soils in both the North and South Islands. It can be grown as an early potato, but has a thin skin and must be handled carefully. Under reasonable conditions it produces a good proportion of table potatoes. This variety is popular in windy districts because its habit of growth is lower than that of many other varieties and thus it is less readily buffeted about. Aucklander Tall Top is similar to Aucklander Short Top, but it matures three or four weeks later. The main advantage with this potato is that it produces heavier crops than Aucklander Short Top on lighter land. On soils of average or heavy texture the tubers tend to be coarse and misshapen.

Arran Chief: This popular variety has been grown in New Zealand for many years. It does well on medium to heavy land which is well drained. It produces a heavy yield of well shaped tubers which handle and store well. Arran Banner: Medium to light soils suit Arran Banner best; on these it produces heavy crops of good quality tubers. The variety is relatively early and has become increasingly popular because tubers cook well even when immature. When grown on heavy land it produces large, rough tubers which frequently develop hollow heart. Arran Banner is grown widely on the lighter soils of both Islands. Chippewa: This early main crop potato has a wide soil range and grows well in both Islands. Though it has a low growing habit, it has a foliage which is easily damaged by wind and does best in sheltered localities. Tubers are white, smooth, round, and of good quality. Chippewa is subject to blight. Red Dakota is the only popular coloured variety grown in New Zealand. It does best on a sharp silt loam and is commercially popular in North and Mid Canterbury. It is popular with home gardeners in all parts of both Islands and good crops are obtained on various home garden soils, but on very heavy soils, misshapen tubers are often produced. Tubers have a good texture when cooked and tend to be favoured rather for baking than for boiling. Very deep eyes tend to make these tubers more wasteful than smoother varieties for culinary purposes. Many home gardeners consider this disadvantage is offset by the excellent keeping qualities of Dakota.

Doon Early is a first early variety which grows well on a wide range of soils. It cannot be recommended for use commercially, but it has proved excellent for home gardens. Doon Early produces a smooth tuber of superior quality and matures rather earlier than Epicure, but the yield is a little lower. It is susceptible to late blight. Certified seed is not available for Doon Early. Dunbar Standard is now becoming more widely known. It is very late and very tall. It produces heavy crops on a wide variety of soils in both Islands. Tubers are large, round, white, of very good quality, and store well. Epicure is a popular home garden early variety. It produces good crops in medium to light soils, where under favourable conditions it will mature in 10 weeks. Tubers are round, rather deep in the eye, and develop a pinkish tinge in the skin after being dug. Ham Hardy and Glen Ham produce excellent heavy crops of oval, whiteskinned tubers on a wide range of soils. Ham Hardy is earlier than Glen Ham, a main crop variety. Ham Hardy produces fuller, rounder tubers than does Glen Ilam, but of the same texture. Inverness Favourite prefers a heavy but well drained soil to produce good crops. On light soils crops have a high percentage of small tubers. The tubers are round to oval and smooth skinned. Inverness Favourite is a main crop variety. Iron Duke: The round tubers of Iron Duke make it an attractive potato for preparation. It is a heavy cropper which does well on heavy soils, provided they are well drained. A few commercial crops are grown, mainly in North Canterbury and parts of the Wellington Province, but it is grown more widely in home gardens. Iron Duke has reasonably good resistance to late blight, but is subject to the viruses mosaic and leaf roll and deteriorates very rapidly when infected with the latter. Jersey Bennes is an early variety which yields well, but best in a cool climate and sheltered situation. It is more popular in the southern part of the South Island than it is further north. It grows in a wide variety of soils. It is subject to late blight. Katahdin has similar growth characteristics to Chippewa. Both are early main crop potatoes and have tubers of similar size and colour. Both are susceptible to blight. King Edward: This early main crop variety is a very popular potato in Otago and Southland. It prefers a cool climate without prolonged dry periods and tends to grow best in heavy to medium silt loams. The tubers are smooth skinned, oval, particoloured (white splashed with pink), and have shallow eyes. The variety is subject to late blight.

Northern Star: The tubers of this variety are round and smooth with pink eyes. It is a late main crop variety suitable for heavy land. On anything lighter than heavy silts a large number of small tubers are produced. Northern Star is often found growing as a rogue in white-skinned varieties. It has lost popularity and is now seldom grown. Sebago: A main to late variety of good quality that has shown consistently high yields during trials, Sebago

is becoming very popular among both home and commercial gardeners. It tolerates a wide range of soils and climate. The tuber is oval, white, with shallow eyes, and of excellent quality for cooking. It has shown a tendency to succumb to infection with the fungous disease Corticium, indicated by gaps in the rows where tubers have failed to grow. Up-to-date: This old main crop variety produces tubers of good shape and quality which will grow in a wide range of soils and climatic conditions, but it is not now widely grown because of its susceptibility to late blight and virus diseases. However, home gardeners still growing this variety are enthusiastic about it. Certified seed is no longer available for Up-to-date.

Popular Varieties The following varieties are popular with home garden and commercial growers. Varieties with the heaviest yield are not always the most popular, because of market preference and sometimes because a variety is not well known or is liable to damage and does not keep well. Some potatoes are used in different districts both as an early and late variety. Early Mid season Late AUCKLAND Home Garden Cliffs Kidney Arran Banner Arran Chief Epicure Aucklander Sebago Short Top Commercial Aucklander Arran Banner Short Top Ham Hardy Aucklander Sebago Short Top Arran Chief Epicure WELLINGTON Home Garden Epicure Inverness Sebago Favourite Katahdin Aucklander Iron Duke Short Top Ham Hardy Glen Ham Inverness Chippewa Chippewa Favourite Arran Banner Katahdin Glen Ham Dakota Dakota Commercial Epicure Aucklander Sebago Short Top Inverness Arran Banner Glen Ham Favourite Iron Duke Glen . Ham Ham Hardy Iron Duke Dakota CHRISTCHURCH Home Garden Epicure Dakota Sebago Arran Banner Aucklander Arran Chief Short Top Chippewa Glen Ham Dakota Katahdin Sebago King Edward Glen Ham Ham Hardy Ham Hardy Commercial Epicure Ham Hardy Sebago Arran Banner Dakota Ham Hardy Aucklander Dakota Short Top Glen Ham Glen Ham Sebago DUNEDIN Home Garden Jersey Bennes King Edward Sebago Red King Arran Chief Edward Arran Banner Inverness Arran Chief Favourite Inverness Favourite Katahdin Chippewa Commercial Jersey Bennes King Edward Arran Chief Red King Inverness Edward Favourite Chippewa Sebago Ham Hardy The varieties Chippewa and Katahdin are very similar and the stocks in New Zealand cannot be differentiated.

Seed True potato seed is borne in small berries developed from potato flowers, but tubers are used for planting because vegetative reproduction is the easiest method of ensuring that a variety remains true. Both home gardeners and commercial growers should use certified seed whenever it is available. These seed tubers are produced under the certification scheme, under which crops are inspected during the growing season by Department of Agriculture officers. Only tubers free from visible symptoms of virus disease are certified. Tubers used for seed vary in size, usually from 1 to 4 oz. The quantity needed per acre is approximately 7 cwt for 1 oz tubers, 14 cwt for 2 oz tubers, and so on. Planting Tubers should be planted in soil which has been thoroughly and deeply cultivated. Rows should be 28 to 30 in. apart. Tubers are planted 3 to 6 in. deep, depending on size of seed; 2 to 4 oz seed for instance should be planted 4 to 5 in. deep. The distance between the tubers in the rows varies with size and variety from 12 to 18 in., but an average for most varieties with 2 to 4 oz seed is 15 in. Commercial crops are usually ridged at planting. This permits shallower planting with better drainage.

Care of the Growing Crop . . The soil should be kept lightly cultivated between rows to keep down weed growth and the spaces between the plants hand hoed. For weed control in commercial crops tine harrowing is begun 10 to 14 days a ter planting. For both commercial and home garden crops fairly frequent but shallow cultivation in dry weather will help to conserve moisture.

Parts by Fertiliser Weight Application Medium to light soils Sulphate of ammonia .. 1 4 cwt per acre Superphosphate .... 3 or 1 i to 2 02; per sq. yd. Rich silty loams . . Sulphate of ammonia .. 1 6 cwt per acre Superphosphate .... 5 or 2 to 2J oz per sq. yd.

Home gardeners tend to mou d up the rows as soon as plants are about 6 in. high. This is important for early crops where there is a danger of frost, as it gives protection until frost risk as passed. In commercial growing moulding is done in stages but must be com P leted before growth of plants P recludes further use of implements. After rain is the best time to mould if Possible, as the soil is then in the best condition and moisture is retained, The purpose of moulding is to protect tubers against late blight and attacks by the potato moth on exposed tubers, which may also be greened if left uncovered. Where late blight is a problem the moulding should be steep and pointed to allow maximum run-off of rain so

that there is less chance of late blight spores washing down to the tubers. Manure Rnt|i h ffardpnpr? and rornmorcial growers can get deta iled advice on manur j n g f ro m local officers of the n pn a r f m pnt of Aprimiltiire Tn General manuring S can be considered for two classes o f soils; medium to light sods and r j cb iify’i oams °

In some areas it may be desirable to apply sulphate or muriate of potash. One part by weight can be added to either of the above mixtures. Diseases Virus virus infection of potato crops can be costly, as no control is possible once the plant is infected. Virus diseases of potatoes appear in many forms, some of the symptoms of infection being as follows: Leaf roll causes stunting of the plant and severe inward rolling of the lower leaves, giving a spoon-shaped effect. Rolling of the upper leaves sometimes occurs because of root injury or dry conditions. The yield of severely affected plants is poor.

Mosaic causes dwarfing of the plant and mottling of the leaves, the plant becomes open, and in severe cases the foliage becomes pale with wrinkled leaves reduced in size. Yield is greatly reduced. Crinkle causes severe dwarfing, and leaves are crinkled, mottled, and curled downward. Loss of the bottom leaves is often accompanied by early maturity and a very low yield. Masked viruses: Quite often virus diseases are masked, that is, their symptoms are not seen in the plant growth, though they reduce yields. Virus diseases make saving of reliable seed difficult for home gardeners and commercial growers in many areas. Control: (1) Use certified seed. (2) Rogue from a crop from which it is intended to save seed any plants which show peculiar growth symptoms. Late Blight The late blight organism is widespread in New Zealand and during prolonged warm, humid periods the blight rapidly damages or destroys large areas. Late blight appears first as blackened patches on leaves, which become limp. The disease extends to the whole plant, with the stems blackening and collapsing. As the spores of the fungus are motile (swimming type), they can, if washed down on to the soil, infect the tubers. Good moulding gives some protection against spread of infection to the tubers. Control: Late blight can be prevented by spraying regularly with bordeaux mixture or proprietary preparations containing copper oxychloride. The latter may not be quite as effective as bordeaux, but are much easier to prepare and are therefore favoured by home gardeners. Some people prefer dusting to spraying. In districts where late blight commonly occurs it is wise to spray at 14- to 21-day intervals, depending on the weather, from an early stage of growth. If there is continued high humidity or prolonged showery weather, it may be necessary to spray more frequently; at intervals of 10 days or even seven days in extreme circumstances. When a crop has become infected with late blight before it has been sprayed and has been considerably damaged it may be best to cut the tops off and remove them from the area. Of course this will reduce yield, but it can prevent damage to or even complete loss of tubers. Blighted tops must be removed from the area immediately or little will be accomplished. Ordinary and Powdery Scab Ordinary scab is generally found on potatoes grown in ground very rich in humus and where liming has been heavy, whereas powdery scab occurs

most frequently under cool, damp conditions. These diseases detract from the appearance of potatoes for marketing, but tubers that are severely affected with scab are usually of excellent quality when peeled and cooked. Pests Potato Tuber Moth The potato tuber moth may attack the growing crop or lay its eggs on exposed tubers. The grubs hatching from the eggs burrow into the tubers and, apart from this immediate damage, further generations of grubs in stored potatoes can cause a line to be severely damaged. Thorough moulding of the crop is important in preventing tuber moth damage. In districts where tuber moth damage occurs regularly crops can be sprayed with lindane. The first application should be made before the moth appears. Applications should be repeated as required. Looper Caterpillar Looper caterpillar is sometimes troublesome on the tops of potatoes and can be controlled by DDT sprays.

Wireworm Wireworm, the larva of the click beetle, is sometimes troublesome in home garden crops. The grub, which has an elongated yellow or brown body with a hard black head, burrows into the tubers. Ground recently broken in from grass is often infested, but cultivation of the soil tends to reduce the wireworm population. Eelworm Eelworm damage somewhat resembles that caused by scab, but can be distinguished by a large number of small eruptions which when cut are inclined to be watery. Crop rotation reduces the rate of infection. Digging Early potatoes are dug. before they are mature and the skins firm. Because of this most early potatoes are liable to be damaged unless carefully handled at all stages. This does not affect the home gardener, who usually digs a few plants at a time, but is important to the commercial grower. Early potatoes should not be dug too soon after rain, because if large amounts of soil sticking to potatoes go

into the bags, the prices paid for a line at the markets will be affected. The main crop is usually dug from the end of March onward. The crop should be fully mature before digging, as any tendency toward immaturity causes losses in storage. It is usual to delay digging until soil conditions become cooler or even light frosts occur, so that the crop will be dug in the best condition for storage.

Tubers may be left on the ground for an hour or two after digging to harden before bagging and storage. However, this practice may also expose the crop to potato moth infestation and sun scald. Storage Potatoes must be stored under good conditions if losses are to be kept to

a minimum. Commercial growers are tending to store in bulk in sheds with a high stud for good ventilation. There is room here for grading and bagging as required. Any stored potatoes must be adequately protected from frost. Potatoes store best at about 50 degrees F and can tolerate a humidity range under storage conditions of between 70 and 90 per cent.

Controlling Springtails on Crops

SPRINGTAILS are minute (up to the size of a pinhead), soft bodied, wingless springing insects which eat the seed leaves and growing points of plants before and just as the true leaves begin to appear. They vary from yellow to dark blue, and their colour and smallness make them hard to see on cultivated ground, where they may be causing serious damage though they are unseen. They live mainly on decaying vegetation and can be found on pastures, where they normally do very little damage. On spring-sown crops of turnips or chou moellier hordes of springtails often attack the germinating plants and decapitate them before they break through the surface. The odd plants that do manage to survive to the first two-leaf stage have pieces chewed out of their leaves rather like the earmarks of sheep. Springtail infestations are best identified by placing a piece of white notepaper on the ground and then gently brushing a hand toward the paper. If the infestation is serious, numerous springtails will be observed landing on the paper and control of them will be imperative if the succeeding crop is to survive. The crop should be sown and then the ground sprayed with a suitable insecticide within two days of sowing. If spraying is left any longer, the springtails may eat the germinating shoots even before they are through. Fifty per cent malathion at l-J pints per acre gives effective control, as does i lb per acre of lindane. One spraying with any of these materials controls springtails for two to three weeks by which time the crop has reached the four- to six-leaf stage and is usually strong enough to repel any further attacks. —D. L. JANETT, Farm Advisory Officer, Department of Agriculture, Pukekohe

jri L n n.JxlXn -l.rx i Book Reviews H . I nr 1111 ii - iLijrirL>

“Principles for British Agricultural Policy”

THIS book has been a long time in the making. It was sponsored by the Nuffield Foundation in 1945, but for various reasons publication has been delayed until this year. The book is the work of a committee, though careful editing gives a continuity of style and presentation. Apparently the various sections were prepared by experts in the particular fields and then discussed by the committee. The foreword emphasises that the aim has been to establish principle’s on which long-term policy might be basednot policy itself, which is the responsibility of Government. To this end there are sections covering, the history of British agriculture, technical aspects, strategic considerations, and finally the economic aspect.

Inevitably it has not been too easy to separate principles from policy and in view of the fact that the committee of six included the president, vicepresident, and general secretary of the National Farmers’ Union it is not perhaps surprising that at times the principles appear to have been influenced by policy!

The book is at its best in its history and description of British farming. The chapter on strategic considerations shows strongly the influence of the war and immediate post-war years and the last section covering future food requirements and possible increases in world food production, which one might have imagined would be of considerable importance in policy making, is compressed into a few pages. In the summing up the authors come to the conclusion that the principle of permanently maintaining British agriculture at a level higher than is economically justifiable rests largely on the strategic argument. This is now almost certainly outdated and there are, in fact, probably stronger grounds, even if controversial ones, on the economic and social sides in favour of something like present British agricultural policy.

The book is well written and very readable. A minor complaint is the inadequate indexing. There are numerous references to Australia and New Zealand, but neither country is considered worthy of a place in the index, being less fortunate in this respect than the U.S., the U.S.S.R., and ■Switzerland. Incidentally the members •of the committee should have been aware that New Zealand soils are not naturally particularly favourable to pasture production.

The composition of the committee and the conclusions reached suggest that at times “must have been some animated discussion and some difficulty in reaching an agreed draft. The moral for New Zealand is that the protection of U.K. agriculture will almost certainly continue. Thus this book besides being valuable for reference on technical matters is worthy of study by all serious students of agricultural economics not only in New Zealand but in other countries supplying agricultural products to the U.K. market. —J.V.W. Oxford University Press. 18s. net in U.K.

“Principles and Methods of Animal Breeding”: R. B. Kelley

TN recent years several revised editions of older books on animal breeding have appeared of which Dr Kelley’s is the latest. As in the two earlier editions it is aimed mainly at breeders of livestock, with students forming a second intended audience.

Dr Kelley is a man of much experience in the livestock world and his book bears ample testimony to this. His knowledge and obvious love of the history of animal breeding form a basis of several introductory chapters. Unfortunately, however, the subsequent chapters cannot be recommended. They do Dr Kelley little credit either as a geneticist or as an essayist.

From a genetic viewpoint the book is unsatisfactory. Many basic concepts in animal breeding are omitted; genetic correlations receive no mention; heritability estimates, their derivation, and meaning are barely discussed, and the subject of the nature and origin of variation is inadequately covered. In sentence structure and phrasing the text needs the attention of a competent editor; for instance, Dr Kelley describes proven sires as “proven-for-daughters-production pedigree bulls”. When such phrasing is confounded by obscure genetics the result is alarming. Thus on page 127 a paragraph reads, “When for a more complex genetic situation in a random breeding flock or herd the value 1-q is equal to that of q,

the number corresponding to the second power used for expansion of the binomial in the simple situation will then be large”. Unfortunately such examples as the two quoted are common and make reading a cumbersome exercise.

For the student the book is insufficient in its coverage of animal breeding and is far too imprecise in the discussion of basic genetics. For the breeder it is likely to prove difficult to read and to comprehend. Apart then from the interesting introductory chapters the book cannot be recommended. ' —C.P.McM. Angus and Robertson Ltd. 48s.

“Odhams Fruit Growers Encyclopaedia”: Edward Hyams

THIS book by a British fruitgrower is prepared in the form of an alphabetical encyclopaedia on all aspects of fruitgrowing. It is a comprehensive publication written for the grower in Britain and has some excellent photographs of a number of pests and diseases.

Much of the information, however, does not apply to New Zealand and is of little value to growers here. It may be of interest to the amateur horticulturist because of its general coverage and manner of presentation. —R.G.H. Odhams Press Ltd. 30s.

“Native and Adapted Cattle”: R. B. Kelley

THIS book will be read with absorb- -®~ ing interest by the keen cattleman, though its direct applications to cattle production in New Zealand are limited. Dr Kelley has spent a lifetime studying the cattle breeds of the world. Many of these are strange to New Zealanders, who have been associated with stock of British origin only. Yet far more of the world’s cattle have their ancestry in the East and in the hot and dry areas of the world than in the British islands. Dr Kelley is famous in his own country for the advocacy of cattle of Asiatic origin for the more difficult parts of Australia. This book should occupy a place on the shelf of every progressive cattle breeder. —C.P.McM. Angus and Robertson Ltd. 50s.