MORE WHEAT NEEDED

New Zealand Journal of Agriculture, Volume 74, Issue 2, 15 February 1947, Page 113

MORE WHEAT NEEDED

By

G. k. McPherson,

Instructor in Agriculture,

Ashburton.

WHEAT must rank as one of New Zealand’s most important cropsif not the most important. From it bread, the principal staple food of the country, and other forms -.contain? ing wheaten flour are made.. The- poultry industry is also largely dependent on wheat, and . two byproducts of wheat, bran and pollard, are important stock foods. The history of wheat growing in New Zealand and the economic importance of the crop in the Dominion’s agriculture are discussed in this article; the place of wheat in the rotation, the growing and harvesting of the crop, the main varieties grown, and the fungous diseases and insect pests parasitical to wheat are also described*

yHE value of wheat was so obvious that it was naturally ■*- the . first crop to demand . the attention of early" settlers

in this country, and wherever it was possible to produce the crop it was grown. Under favourable soil and climatic conditions excellent yields were usually obtained, and with the demand for wheat from abroad the crop could be relied upon to.provide steady returns.,. ." .- ...

. The advent of refrigeration in the late' ’eighties, however, gave a tremendous impetus to - pastoral farming. ' The higher-rainfall areas were gradually grassed, down in permanent pastures, and with dairying and fat lamb production proving successful, wheat growing gradually became concentrated in drier areas where it was found advisable to plough and'regrass periodically. Wheat growing thus became restricted mainly to Canterbury and North Otago, where there was an annual rainfall of 25 to 35in. and large expanses of flat country suited to cultivation.

Today the system of farming operating throughout these areas consists largely of the blending of fat lamb

production and the growing of wheat. Other crops such as barley, oats, and peas are produced, but wheat is the main crop grown on many farms; in fact it is an essential crop in, the farm economy on many arable ’ • -

The relationship between wheat production and the total population of the Dominion is interesting. In 1880 there were 685 acres of wheat grown for every hundred head of population; in 1900 there were 26 acres of wheat for every hundred people, and in 1940 the figure was still further reduced to 15.4 acres of wheat for every 100 head of population. It has been estimated that the average annual consumption of wheat in New Zealand is 4.6 bushels per head of population. On present yields, therefore, one acre of wheat provides sufficient flour for about seven persons; based on a population of one and three-quarter million people, approximately 250,000 acres of wheat are therefore necessary to provide sufficient flour for civilian requirements . 1 . .. . . _jijf.-j._- • i ~

alone; additional acreage would ot course be necessary to provide wheat for the poultry industry, for resowing, and other purposes. . Before the war New Zealand required for all purposes about 9,500,000 bushels of wheat a year. The requirement increased during the war to about 13,000,000 bushels, the use of which was distributed somewhat as follows: — Bushels. Flour .. •. 8,000,006 Feed, poultry 4,000,000 Seed, resowing .. .. .. 500,000 Miscellaneous .. ... 200,000 Total '.. 12,700,000 About a quarter of a million acres has been sown to wheat annually in New Zealand in recent years. Table I below shows acreages and yields over the four seasons 1940-41 to 1943-44. In the yield of wheat per acre New Zealand is one of the leading countries in the world. For the period 1926 to 1936 Canada averaged 14.6 bushels per acre and Australia 11.5 bushels per acre. Over the same

period the area sown to wheat in these two countries annually averaged 25.5 million acres in Canada and 12.75 million acres in Australia. The suggestion frequently made that wheat yields in New Zealand are on the decline is not substantiated by 'Table 11, which gives acreages and yields of wheat in 10-yearly periods since 1890.

TABLE II: TEN-YEARLY ACREAGES AND YIELDS SINCE 1890 Period. Average yield Average annual per acre. acreage. 1890-1900 . 24.4 S '- 296,000 1900-1910 31.4 224,000 1910-1920 .. 28.0 229,000 1920-1930 .. 31.5 231,000 1930-1940 .. 31.1 244,000 1940-1944 .. 33.2 255,000

The excellent wheat yields obtained before and during the earlier part of this century no doubt entailed exploitation of the natural fertility of the soil, but yields have been maintained in more recent years, possibly because of the gradual replacement of horses by tractors, the more widespread use of fertilisers, and the growing of varieties more suited to the soil and climate. Canterbury provides the major portion of the Dominion’s wheat; it is also grown in Southland, Otago, Marlborough, and, to a small extent, Nelson, while the North Island contributes a small proportion. In the 1943-44 season. wheat areas of the Dominion were distributed as follows:

The low wheat acreages for the North Island and for Southland illustrate very well that where it is possible to produce and maintain highlyproductive permanent pastures wheat is not a popular crop. Even in Canterbury there is a tendency for the wheat area ■to decline in some localities where liming, topdressing, and the use of improved pasture and clover strains has resulted in a more permanent type of pasture. Varieties The wheat varieties Cross 7 and Solid Straw Tuscan have been sown on about 80 per cent, of New Zealand’s total acreage in wheat in recent years. Other varieties of less importance are Fife Tuscan, Hunters, Dreadnought, Jumbuck, Marquis, and

Tainui. Table 111 below shows the trend of the sowings of the main varieties grown in the Dominion during the past six seasons. The figures show that Cross 7 and Fife Tuscan are gradually replacing Solid Straw Tuscan and, to ' a less extent, Hunters, Jumbuck, and Marquis. The area in Dreadnought shows very little variation over the six seasons. The varieties listed can be classified into three groups: — (a) Solid Straw Tuscan, Fife Tuscan, and Cross 7. These are good-yield-ing wheats on the average . wheat land and their popularity is further enhanced because all of them are very suitable varieties for direct heading. (b) Hunters and Dreadnought. Both these varieties are now confined mainly to isolated pockets of fertile soil in areas not usually subject to very strong winds. Neither variety is suitable for direct heading, and they are therefore grown only in preference to Cross 7 or Tuscan in

those areas where the extra return obtained will more than compensate for the difference between the cost of harvesting by direct heading and the cost of stook threshing or picking up from the windrow. Both varieties are regarded as autumn wheats. (c) Jumbuck and Marquis. Although they can be sown in the autumn, both varieties are recognised as spring wheats. Usually they are reserved for sowing in late spring, when it is considered too late for sowing Cross 7 or Tuscan. Neither variety is suitable for direct heading. Main Varieties' Characteristics Solid Straw Tuscan.-— Usually referred to only as Tuscan. Less than 10 years ago it was the most popular

wheat grown, about 70 per cent, of the wheat area of the Dominion being sown in this variety. Today Solid Straw Tuscan occupies less . than 20 per cent, of the total area grown, and a still further decline in acreage of this variety seems likely in the future. Solid Straw Tuscan owes its popularity to the fact that it yields well on most soil types and is extremely resistant to shaking in strong winds. On the medium and lighter class of wheat land Solid Straw Tuscan has proved an exceptionally good wheat, but on heavy land it has a marked tendency to produce too much straw, and as the straw is inclined to be weak, crops frequently lodge so badly as to make harvesting difficult. This is its main defect. Tuscan is an autumn wheat, but it can be sown in the spring. Provided it does not lodge, it is a good wheat for direct heading.

Cross — This wheat was produced in New Zealand by crossing Solid Straw Tuscan with a Canadian variety known as White Fife. The berry, like that of Tuscan, is held very tightly in the chaff, and the wheat is therefore ideal for harvesting by direct heading. It matures 10 days to a fortnight earlier than Solid Straw Tuscan, which is important in some localities. The straw is shorter and stronger than that of Solid Straw Tuscan, which is an advantage on heavy land where Tuscan is liable to lodge badly. Some indication of the popularity of Cross 7 can be gauged from the fact that although it was not grown commercially in New Zealand until' 1935, in 1943 it occupied about 60 per cent, of the total wheat area of the Dominion. Cross 7 is more susceptible to loose smut than Solid Straw Tuscan. It is a good winter or spring wheat.

Fife Tuscan. Another New Zealandbred wheat, closely related to Cross 7, its parents being Solid Straw Tuscan and White Fife. In general appearance it resembles Solid Straw Tuscan. In length and strength of straw it is midway between Cross 7 and Solid Straw Tuscan. It yields slightly better than Solid Straw Tuscan, and experience suggests that it is less subject, to straw break. It is a suitable wheat for direct heading, and is recommended for areas where Solid Straw Tuscan is sown nowadays. First distributed for sowing in 1940, Fife Tuscan in four seasons became the third’ most popular wheat in the Dominion, occupying in the 1943-44 season 7.3 per cent, of the total area sown. It is a good winter or spring wheat and matures about a week later than Solid Straw Tuscan.

Hunters. -one time Hunters was a popular wheat, but with the introduction of the header harvester about 12 or 15 years ago the variety de-

clined rapidly in popularity. In the 1943-44 season Hunters occupied less than 5 per cent, of the total wheat area of the Dominion. On suitable country Hunters is an extremely heavy yielder, and although it -has a hollow straw, it stands up fairly well on heavy land. Unfortunately, as the berry is held loosely in the chaff, there is too much risk in leaving crops to the stage when they can be direct headed. Hunters is usually cut with the binder and threshed from the stook. Sowings of Hunters nowadays are confined mainly to areas of heavy, rich ground where invariably the yields are good. Hunters probably produces the best quality straw for feeding stock, and farmers occasionally grow this variety for a stock of good-quality straw. Because of its creeping habit of growth in the early stages Hunters takes a long time to mature and is best sown in late April or May. So far as is known it is not subject to loose smut. •

Dreadnought. Dreadnought falls into somewhat the same category as Hunters. The straw is hollow and strong, but the grain at maturity is readily shaken out by strong winds, and is not usually left for direct heading. It is customary to windrow the crop and pick it up with a header harvester or thresh it from the stock, The grain of Dreadnought is relatively large. Compared with Hunters, Dreadnought has . less flag, and is

therefore superior as a cover crop for grass. The growing of Dreadnought is mainly confined to special areas of extremely good soil where it yields very well. Mainly sown in the autumn, Dreadnought is now regarded as quite a good milling wheat. Jumbuck. Some years ago Jumbuck was g rown fairly extensively in the North Island, but in recent years the variety has declined in popularity, j um buck has two bad features: the sraw is weak and the grain is held loosely n the chaff. Many crops are therefore inclined to lodge badly, and n s no f a wheat which can be left f Or direct heading unless grown in sheltered localities. Although it can b e sown j n the autumn, most of the Jumbuck grown nowadays is usually spring sown. Marquis. Like Jumbuck, Marquis is a w heat which has declined in popularity in recent years. In the . 1943-44 season it occupied 0.2 per cent, of the total Dominion acreage. The straw is inclined to be weak, and it is not a

variety which can be recommended for direct heading. The grain is small and a mottled red and yellow. Marquis is sown principally as a spring wheat. Very good results have been recorded in baking tests with flour from Marquis wheat. Tainui.— is an imported wheat with, a Tuscan-like habit of growth. The straw, however, is weaker than that of Tuscan, but it resists wind well. Tainui is an early-maturing

wheat and is used mainly for spring sowing, particularly in some of the wheat-growing areas of the North Island.

Place in Rotation The place occupied by wheat in a rotation depends very largely on the quality of the land, the climate, and the type of farming practised. Even under similar conditions of soil and climate, however, the position that wheat occupies in a crop rotation varies considerably. As most farmers endeavour to sow their wheat when the land is in the best possible heart, wheat is very frequently sown after grass, after peas, or after fed-off crops such as blue lupins or rape. On marginal land wheat generally follows grass or a lupin crop, provided the land is clean and the farmer considers the soil is sufficiently strong to produce a good crop. Wheat may follow wheat, but usually only in very strong country, and where the initial crop follows a period in which the land carried a good sole of grass. Under such circumstances the first crop may grow rank and develop a tremendous bulk of straw, and, should this happen, the second crop will frequently outyield the first. Experience suggests, however, that where wheat follows wheat the second crop is more susceptible to both take all and eye spot. It is recognised that the growing of too much wheat tends not only to deplete soil fertility, but also to impair the physical condition of the soil. It is usually difficult to work and difficult to establish and maintain a good sole of grass or clovers on land heavily cropped with wheat. Most farmers, therefore, adopt a rotation wide

enough to avoid damage to the soil either chemically or physic-

Porker and Baconer Competitions

In view of the all-round success of the Tomoana porker and baconer competitions during the past 6 years, the sponsors have decided to run similar competitions in July this year for both porkers and baconers. These will be held at Hastings, Patea, and Westfield, and £lOOO in prize money will be offered.

There will be £lOO in prizes for porkers and baconers in each district pig council area, making a total of £7OO for the North Island. A grand championship will be decided at Westfield for both porkers and baconers, with prize money of £135. Special prizes amounting to £165 will be offered to members of Young Farmers’ Clubs entering the competitions throughout the North Island.

ally. A routine largely practised throughout wheat-growing areas is: On heavy land a crop of wheat every four or five years; on medium land every five to seven years, and on marginal land every eight to ten years.

Preparation of the Land

Wheat is produced under such a wide variety of soils and climates that no hard-and-fast rules can be laid down for methods of cultivation, which must vary from district to district and often a great deal from paddock to paddock . on individual farms. It is probably true, however, that in nine years out of ten no crop responds better than wheat to early and efficient cultivation.

It must be remembered, however, that the production of wheat is only one section of a farmer’s activity, and that all his other, farming operations are interlocked with or related to it. Any factor which influences one section of his work may indirectly affect all his other activities. It very frequently happens, therefore, that the methods the farmer intended to adopt in the matter of cultivation for wheat and the methods he was eventually compelled to adopt may be, and frequently are, totally different. The type of soil, weather conditions, the presence or absence of twitches of various kinds, the prevalence and size of stones, the power available, and the success or otherwise of other farm crops are some of the factors which frequently dictate to the farmer the type of cultivation he must pursue.

Following grass it is the usual practice to skim plough and summer fallow for wheat. After a paddock has been down in grass three or four years or more there is generally a tendency for some of the various kinds of twitches to appear in the sward in varying amounts. Summer fallowing affords an opportunity of cleaning the land of twitch not only for wheat but also for any subsequent crops. Cross skimming may even be adopted if twitch is fairly prevalent.

Instead of skimming, the ground may be surface worked with cultivators and harrows before deep ploughing. 'Beside serving as a means of cleaning the land, summer fallowing of the ground with intermittent cultivation gives the turf plenty of opportunity to decay, and when the land is eventually deep ploughed an excellent tilth usually results. Where the presence of stones makes skimming difficult it is usual, provided twitch . is absent, to sow the wheat in one furrow.

Wheat is usually harvested during late January and February. Where

wheat follows wheat, therefore, there is usually insufficient time to rot the stubble, and it is customary to burn the stubble and deep plough only. Similarly, after peas, rape, or flax, provided the land is clean, it is not usual to do any preliminary surface cultivation before deep ploughing.

The kind of implements used in the preparation of land for wheat varies according to soil. conditions, climate, and the individual ideas of the farmer. Many soils throughout Canterbury contain stones, and here the cultivator and hustler are largely used. In other wheat-growing districts disc harrows frequently replace the cultivator. Whatever the method of cultivation adopted, the final aim, for autumn-sown wheat particularly, should be to have a good depth of cultivation with a fine soil underneath and the surface moderately rough or cloddy. If the surface is left too fine, winter rains are liable to cake the ground, and the wheat may then develop an unthrifty appearance in the spring.

Time of Sowing

Wheat is either autumn or spring sown, although such references to the recognised times of sowing do not comply strictly with the generallyaccepted limits of these seasons. Wheat sown during April, May, or June is usually referred to as autumn wheat and that sown during August and September .as spring wheat.

When seasonal conditions permit farmers try to sow the bulk of their wheat in May and June, as experience over a great many years has shown that wheat sown during these two months will in most cases and in most districts outyield wheat sown at any other period. Wheat sown in May and June does not usually make much growth during the winter, but it gradually develops a good rooting system so that with warmer conditions in the spring tillering is promoted and growth is inclined to shoot fairly rapidly. Moreover, should a dry spell occur in the later stages of growth, the extensive rooting system developed throughout the long growing period enables the wheat to withstand it much better than springsown wheat.

When wheat is sown in the spring success is largely dependent on an adequate rainfall during the critical months of November and December. For this reason spring sowing of wheat is usually resorted to only when autumn sowings have been made impossible by weather conditions or some other factor. Wheat has

PREPARATION OF SEED-BED AND SOWING OF WHEAT

—Deep ploughing for wheat in the Methven district. Wheat drilled without subsequent harrowing. The back coulters have completely obliterated the marks of the front coulters. Below Skim ploughing grassland for wheat.

generally to be spring sown after turnips and after potatoes, unless these are dug early. Spring sowing of wheat is confined mostly to areas of good land, and districts with a relatively high rainfall offer the best promise of success. The lighter plains land of Canterbury, where 20 to 30 bushels an acre is an average yield, is not suited to spring sowings of wheat.

Seeding for Wheat

The type of soil, the time of sowing, and the quality of the grain are the three principal factors which influence the seeding rate per acre. On the medium and good wheat land of Canterbury the seeding rate for autumn wheat usually varies between 1J bushels and 2 bushels per acre, the heavier seeding being used mainly nearer the hills, where there is a higher rainfall. On the lighter and drier soils a seeding rate between 1| and 1-i bushels per acre is common. As wheat sown in the spring has not the opportunity to tiller to the same extent as’autumn-sown wheat, heavier sowings are the rule with spring wheat, 2 bushels to 2J bushels per acre usually being sown.

The quality of the grain also affects the seeding rate per acre. ■ Seed wheat which has been slightly sprouted or which contains chipped or broken grain needs to be sown at a heavier rate than well-developed wheat which has been machine dressed. The Department of Agriculture instituted a scheme some years ago for the certification of all the more important varieties of wheat grown in New Zealand. This . enables growers to obtain lines for sowing which are relatively free from diseases and foreign varieties.

Manuring of Wheat

During the past 20 years a large number of wheat-manuring experiments has been conducted by the Department of Agriculture in the main wheat-growing areas of the Dominion, but more particularly in Canterbury. The results of these comprehensive trials may be summarised as follows:

(a) An application of lewt. of superphosphate increased the average yield by 4.1 bushels per acre.

(b) An application of lcwt. of serpentine superphosphate gave a result equivalent to lcwt. of superphosphate.

(c) Other forms of phosphate such as ephos, Nauru, and basic superphosphate gave a result inferior to either superphosphate or serpentine superphosphate.

(d) Increasing the superphosphate application from lewt. to 2cwt. per acre resulted in an average yield

increase of only 0.2 bushels per

acre. The larger application cannot, therefore, be recommended.

(e) The use of potash in association with superphosphate did not prove profitable.

(f) The use of carbonate of lime with superphosphate gave indifferent results, and the use of the mixture could not be generally recommended.

(g) The use of a nitrogenous manure, such as sulphate of ammonia, could not be generally recommended, although an application of lewt. per acre in the spring may be profitable with crops having a yellow and unthrifty appearance and showing general symptoms of nitrogen starvation.

The manuring of wheat in New Zealand today is based very largely on the results of the trials mentioned. Most farmers drill lcwt. of superphosphate or lcwt. of serpentine superphosphate per acre down the coulters when sowing their crops. An increase of 4 bushels per acre as a result of using either of these phosphatic fertilisers would not only be profitable to the farmer, but, based on an average sowing of 250,000 acres, it would also represent an increase in the Dominion’s total of about 1,000,000 bushels annually.

After Cultivation

The treatment the wheat crop receives after drilling is influenced largely by the variety sown, the soil type, and the kind of weather experienced during the winter. In a normal season the majority of farmers would harrow their crops once with tine harrows—usually in Septemberand then follow immediately with the Cambridge roller. The object of the harrowing is to break any surface crust which may have formed as a result of winter rains. The rolling breaks any clods still remaining, packs the fine soil around the young wheat plants, and provides a smoother surface for harvesting operations, particularly on stony ground.

, During a mild winter with very little . rain the soil may remain open and friable, and harrowing would then be necessary only to kill weeds. With a very wet winter, however, the reverse is often the case, especially on a clayey soil. The soil may pack down very hard and become so consolidated that it is extremely difficult to provide a surface tilth. In some cases crops may be harrowed two or three times, or the grain drill with the coulters down may be used in an endeavour to provide a surface tilth.

It is a common practice in Canterbury to sow down to grass in a wheat crop. The grass and clover mixture is either drilled or. broadcast in the spring either before harrowing and rolling or between harrowing and rolling.

Grazing of Wheat

Farmers sometimes graze their wheat in the spring because of a shortage of sheep feed, but wheat is generallygrazed with sheep only in certain districts and then only in seasons when there appears a danger of the wheat growing very rank and eventually lodging. Lodging makes harvesting operations more difficult; wheat which grows rank is also prone to develop mildew, and badly-mildewed wheat usually means a poor-quality grain. The greatly increased sowings in recent years of the short-strawed Cross 7 variety no doubt explain why there has been a considerable reduction in the acreage of longer-strawed. wheat it has been necessary to graze because of rank growth. Grazing is probably practised most frequently in areas of very good land of the sandy loam type. On the heavier clay type of soil grazing is less frequent, as the trampling of the sheep tends to encourage cracking of the ground should a dry spell occur.

The use of a large mob of sheep to obtain rapid and even grazing is recognised as the best method of grazing wheat. - Probably more farmers would graze wheat if they had large enough flocks to graze it off quickly and evenly.

Fungous Diseases Bunt, Ball Smut, or Stinking Smut.— This disease develops into balls of smut in place of the grain. These balls do not break up unless crushed or broken during threshing. The disease produces a distinctive fishy smell which can be readily detected in a sample of grain, as compared with loose smut, which cannot be detected by smell.

Contamination of the grain is usually made during threshing, when the spores of the broken smut balls stick to the healthy seed, usually in the crack of the grain or in the hairy end of it. Since the spores of ball smut are carried on the surface of the grain, this disease can be controlled by pickling or dusting of the grain.

The old wet pickles using bluestone or formalin were efficient methods of controlling the disease, but they had the disadvantage that the germination of the seed was very often adversely affected. The wet method has now been replaced by dry dusting of wheat, using mainly mercuric dusts. The obvious advantages of dry dusting over the wet pickles are. that it is easier to apply, dry dusted seed is more convenient to drill, and the dusting of the seed can be done at any time between harvest and sowing. Mercuric dusts are used at the rate of 2oz. per bushel. Nowadays most of the stationary and portable seed-dressing plants are fitted with dusting machines which perform the dressing and dusting of the grain in one operation. Some farmers dust their own seed. For this purpose a 40-gallon oil drum operated on a somewhat similar principle to a concrete mixer is generally used.

Loose Another fungus disease of wheat, loose smut may be seen in crops after the head has emerged from the shot blade. The smut develops in place of the grain, forming a black powdery mass (the spores of the smut) which is blown away by the wind. In a ripe wheat crop heads affected with loose smut can be found well below the level of the filled heads.

Affected heads are bare, with no grain or chaff, and of a dark colour. Some of the spores that are blown away land on healthy developing grain, germinate, and ' enter the grain, to stay there until that grain is in turn sown. There is no reliable treatment that can be carried out on the farm to control loose smut. The disease may be controlled by immersion of the grain in hot water, but the difficulty of the hot water treatment is that the difference between the temperature required to kill the smut and the temperature that will kill the wheat germ is small, and great care is required, while treating the wheat to ensure the killing of the smut without killing the germ. Fanners should endeavour to buy seed from a cro P hot water-treated see , or from a crop that is known , nearly free, from loose smut. The use of Government Certified seed will ensure that the resultant crop is practically free from loose smut. Some varieties such as Hunters appear to be immune from loose smut, while Tuscan and Fife Tuscan are not very susceptible to it; Cross 7, on the other hand, appears to be rather susceptible. , ... m.- . „„ Take All. This can be a very se; ou disease of wheat, althoug t appears to be affected by seasonal c nd ions, some years there may be very little while in other years patches of it will show up fairly extensively. Take all is a fungoid disease which attacks plants at and below ground level, and the presence of the fungus causes a blackening of the base of the stems. The disease has a tendency to occur in crops in more or less circular patches. Near the centre of affected

areas the plants may die before the ears, appear. Even if flowering does take place, however, affected heads will contain no grain or only partiallydeveloped grain. The disease is also reported as occurring in barley and barley grass, and it may occur in other S r^sses - . Once the disease appears in a crop nothing can be done to control it. The infection can apparently survive in the ground for some years. Control measures can be best applied by not sowing a second wheat crop for, say, Ave years m a field that has been affected with take all. When sowing wheat after grass, a rape crop, or at least a good fallow before sowing, assists in eliminating take all infection which may have been carried over on Grain from a diseased crop should not be use d for seed. Burning of diseased straw will also assist in. con- , n - „ disease trolling the disease. Mildew.— This disease appears as a whitish mould on the leaves of affected plants. Usually the mould appears on the upper, surface of the leaf, but if the attack is a severe one, it may extend to the lower side and also to the sheaths and stems. Mildew is most prevalent in rank crops, and particularly in damp and muggy seasons. Thick seedlings are recognised as a predisposing cause of mildew. In some ocalities w heat is grazed in the spring to reduce the leafage -d render the crops less susceptible to later attack crops less susceptible to later attack b y mildew. Rust. There are two kinds of rust found in wheat — rust and stem rust. Leaf rust occurs in most crops in varying degrees every year, but the total damage it causes would be very difficult to assess. In New Zealand it

7 ' • . '* A ! r ' ' 1 illlJillßßlOilliißirf Above—Direct heading a • heavy crop of wheat in | '//the Wakanui district. . Left Crop of Hunters wheat in stock. ' ' Threshing a crop of wheat with an auto beader.

is not considered of any great economic importance.

In most seasons if stem rust occurs at all, it is present only to a slight extent in the wheat crop. Occasionally, however, severe infection may occur in individual crops, usually crops which are very late sown in a season with damp, muggy weather just before harvesting.

There is no method so far known of treating either the seed or the crop to control rust. Control would appear to be along the lines of breeding rustresistant strains.

Root Rot. This is caused by Fusarium, a weak parasitic soil fungus which may attack and kill wheat plants from the seedling stage to the flowering stage. The fungus attacks the rooting system of the plant and the basal portion of the stem. If plants are attacked in the early stages of growth, the disease is known as “seedling blight.” Severely-affected plants wilt and die, but only very occasionally is the damage sufficient to necessitate the crop being ploughed up. If the disease causes only a check in growth, the plants may assume a stunted yellow appearance in the spring a condition known as “spring yellows.” Infection at or near flowering time produces a bleached and sterile head commonly referred to as “white heads.”

There are no known methods of control of the disease. Stimulation of the growth by efficient cultivation, good drainage where necessary, and not drilling too deeply offer the best means of prevention.

Eye — This disease is caused by a fungus which attacks the lower portion of the stem of the wheat . plant, producing brown areas which are frequently elliptic, giving rise to the name eye spot. The effect of the fungus is to weaken the straw, so that should a high wind occur near flowering time, a badly-affected crop may collapse. A partially-affected crop presents a

tangled appearance, lodged straws being mixed with upright ones. In addition, when the straws become lodged the flow of sap to the head of the plant is partly arrested, with the result that the grain may be somewhat pinched.

Eye spot was first recorded in New Zealand in the 1942-43 season, when a disastrous outbreak occurred in the Taieri district of Otago. It has also been recorded as occurring in other districts in New Zealand, but only to a minor extent.

The mode of transmission of eye spot has not been completely determined. Initial infection of an area may take place through the seed, or it may be introduced to an area with infected straw or by harvesting machinery. There is' a suggestion that the fungus builds up on an area. A field showing slight infection one year may show severe infection the following year if the paddock is again sown •in wheat.

There is no evidence to support the view that any one variety of wheat is

more susceptible to eye spot than another.

Refraining from using seed from an infected crop, burning of stubble of infected crops, practising a wide wheat rotation, and avoiding the distribution of infected straw are precautionary measures which are recommended in areas subject to eye spot.

Insect and Other Pests

Hessian Fly. This insect, which attacks barley as well as wheat, was introduced into New Zealand about 1870. It is present in varying amounts in most wheat crops every year. In some wheat-growing areas it is the cause of considerable loss annually, while in other areas the damage it causes is not considered great.

A detailed study of the life cycle of the hessian fly has not yet been carried- out under New Zealand conditions In the spring the adult fly lays eggs on the leaves of the wheat plant. The maggot which hatches out crawls down between the stem and the leaf sheath', feeding as it goes, and usually comes to rest about the second node from the ground, but in some cases- actually below ground level. At the node- where i-t- - comes •to rest it completes its- feeding,- and- then - turns to a pupa. - Because--of the col dur and shape, the pupal stage of the insect is often referred to as the “flax seed” stage. The insect winters in the stubble in the pupal form, and emerges as the adult fly in the spring to attack the new crop.

Plants attacked early by hessian fly may produce a poorly-developed ear. At the point where the pupa rests the stem is nearly always indented and weakened, and hessian fly infestation may lead to much straw break during high j; winds. Affected crops are re-

duced in yield and harvesting may be made more difficult. Of the more common varieties of wheat grown, Tuscan appears the least susceptible to attack by hessian fly; Hunters, Dreadnought, and Cross 7 seem to suffer most. In Tuscan it is unusual to find more than one “flax seed” on each stem, but the “flax seeds” frequently occur in twos and threes on Hunters, Dreadnought, and Cross 7. As the hessian fly overwinters in the “flax seed” stage in wheat straw and wheat stubble, destruction of the straw by burning seems the best means of control. Deep ploughing of wheat stubble would also reduce the number of pupae which may develop into the mature insect in the spring. The general practice throughout Canterbury of sowing down to grass in the wheat crop undoubtedly assists in perpetuating this menace. Wheat Bug. ln certain localities in New Zealand the developing wheat grain is sometimes attacked by bugs which suck the sap from the grain and at the same time inject into the grain something which apparently causes the gluten to change so that satisfactory bread cannot be made. The condition is known as “sticky dough” or “slimy gluten.” In New Zealand there are three species of insects which attack the wheat grain and produce this “slimy gluten” condition. However, the fact that two of the insects are natives to be found in most pastures and that the damage annually is considered of minor importance suggests that it is only under exceptional circumstances that the bugs attack wheat. There is no known means of control. Stem Weevil. lntroduced from the Argentine, stem weevil was first recorded as being present in New Zealand in 1927, but it was not until about 1933 that it was associated with damage to wheat. During the winter the insect remains in the soil in the adult stage. In October it lays its eggs on the wheat plant and the small white grubs which develop begin to bore into the stem of the plant. If the plants attacked are very young—this applies particularly to spring-sown wheat the grub usually bores down the centre of the succulent stem and the destruction of plants or tillers it causes in this way may be sufficient to result in a thin crop. - When the wheat is attacked at a later stage of growth the grubs usually concentrate on one of the lower nodes of the stem and create a weakness in the straw at this point. Toward harvest the weakened straw

readily succumbs to high winds. A great deal of straw break in crops in midsummer which is regarded as wind damage is primarily due to earlier infestation of the crop by this weevil. The weevil also attacks barley and ryegrass. There are no methods of control of this insect. Grass-grub.— The grass-grub, which is a native of New Zealand, is responsible for damage to wheat crops every year, and sometimes the damage has been sufficient to necessitate resowing. Usually, however, it is confined to patches in crops or it may cause 'some thinning out of the whole crop. Evidence of grub attack is first noticed about May, and ‘damage may continue until early in October. Crops which show grub damage are usually rolled to pack the soil around the roots of the wheat and encourage the development of new roots. Slugs. Occasionally wheat crops are attacked by slugs, usually where the wheat follows a pea crop. The slugs feed on the leaves, usually when the wheat is 3 or 4in. high. If the attack is ’ a severe one and the leaves are badly damaged, it may be advisable to plough up the crop. Harvesting Perhaps no phase of wheat production in New Zealand has undergone such a revolutionary change as the methods of harvesting. Before 1930 all the wheat grown was cut with the binder and stocked. It was then either threshed from the stock, or, if a mill was not available, it was stacked and later threshed from the stack. In 1930 two header harvesters were tried out on wheat. Eight seasons later the number had increased to 300, and these threshed about 35 per cent, of the total wheat grown. Today probably 90 per cent, of wheat grown in Canterbury is threshed with header harvesters either by direct heading or by the windrow method. Varieties such as Tuscan, Fife Tuscan, and Cross 7 are generally direct headed, while varieties which tend to shake readily, such as Jumbuck, Dreadnought, and Marquis, may be windrowed and threshed from the windrow, or they may be stock threshed. Because of its valuable straw, Hunters is usually cut with the binder and threshed from the stook. In some wheat-growing areas where the climate seems unsuitable for header harvesters to operate satisfactorily it is still a common practice to thresh from the stack. When crops are threshed with header harvesters the sacks of wheat are usually left in the paddock until they are collected by motor lorry and

transported either to flour mills or grain stores. Should rain intervene before the wheat is collected, it may be necessary to turn the sacks at intervals to prevent undue sprouting. Conclusion In many of the larger wheat-pro-ducing countries of the world, such as Canada, India, and Australia, the wheat crop is grown on the poorer and drier soil types and yields generally vary between 10 and 20 bushels per acre. In New Zealand it is the heavier, more fertile soils in the wheatgrowing areas which are looked upon as ideal for wheat, although a proportion of the wheat crop is also grown on the poorer soil types or on what is commonly referred to as marginal wheat land. On the good wheat land yields of 60 bushels per acre are not uncommon, and few farmers would sow wheat on land where the yield would be likely to fall below 20 bushels per acre.

Preparations for Wintering Stock At this time of the year the aim should be to reduce the stock on the farm to the number which can be wintered in reasonable condition. An attempt should bb made to finish off stock which are culled from the breeding flock or herd before winter begins, and sufficient selected breeding stock should be kept to maintain or if possible increase production next season. Dairy herd. — By now milk production will be declining and dairy cows for culling should be dried off and disposed of. Calves should continue to graze around the farm ahead of the milking cows. , Pigs.— An attempt should be made to finish off all pigs, except breeding stock and those which it is estimated can be wintered reasonably well, by feeding such crops as green maize, carrots, and marrows to supplement dwindling supplies of separated milk. Sheep flock.— Cull ewes should be finally disposed of, as well as all cull lambs and other dry stock which cannot be wintered. Replacements of breeding ewes should be made. On most, farms the aim will be to enter the winter with breeding stock only. Ewes should be finished two weeks before tupping, using any secondgrowth rape, greenfeed, or young growth of grain for the purpose. Dipping should take place at least two weeks before tupping and both ewes and rams should be dagged before the rams go out. During tupping “box” the breeding flock frequently.

WHEAT VARIETIES

. ■ < , ' . : . ■ ■ • 1; HOLDFAST ' . Kf- 2. MARQUIS ■ . < ' . 3. CROSS 7 , ' , 4. JUMBUCK •5. HUNTERS ' 6. SOLID STRAW TUSCAN I 7. DREADNOUGHT '■ 8. FIFE TUSCAN ■

* First season this variety was grown commercially.

Wellington 6,308 2,7 ' Hawke’s Bay .. 0.8 ' 3.6% North Hawke’s Bay .. 2,033 2,033 0.8 ! 3.6% North Balance North [ Island Island 221 0.1 > 1 Canterbury 181,538 77.6 x Otago .. Marlborough .. . 28,228 7,921 12.2 1 3.4 1 96.4% South Island Southland .. 6,970 2.9 Nelson .. 567 0.3 1

Province Acreage! Percentage of grown total area

Harvest of Acres Bushels per acre. Total production bushels. 1940-41 .. .. .. .. 243,197 34.1 8,305,845 1941-42 .. .. . . .. 258,002 33.6 8,671,244 1942-43 .. .. .. .. 286,998 34.2 9,819,342 1943-44 .. . . . .. 233,786 30.8 7,208,485 Average .. .. 255,495 33.2 8,501,229

TABLE I: ACREAGES AND YIELDS OF WHEAT 1940-41 TO 1943-44

Variety 1938-39 1939-40 1940-41 1941-42 1942-43 1943-44 S.S. Tuscan .. 45.9 29.91 38.44 33.45 23.94 19.82 Cross 7 .. 33.14 38.94 41.63 48.74 59.35 59.48 Fife Tuscan • — • ■ — *0.10 0.92 3.29 7.32 Hunters .. 9.3 9.6 8.39 7.00 4.79 4.76 Dreadnought 4.4 5.26 6.59 6.25 4.52 5.8 Jumbuck .. 3.1 . 2.27 2.12 1.20 • 1.12 0.8 Marquis .. 1.9 ' 1.85 1.01 0.44 0.37 0.2 Other varieties .. 2.26 2.27 1.72 2.0 2.62 1.82

TABLE III: PERCENTAGES OF TOTAL AREA SOWN TO VARIETIES IN 1938-39 TO 1943-44