Thursday, 22 October 2009
Cacao (Chocolate) Tree 1928
From The Tropical Crops by Otis Warren Barrett, B.Sc. 1928
CHAPTER V CACAO
CACAO is in a class by itself as it is both a beverage and food crop. Coffee should be in the same category, but is not. Tea is virtually and financially twice as important as cacao, but in commerce and industry the reverse is true. Coffee is between three and four times heavier in trade and six or eight times more valuable.
Coffee costs by the pound, production-center price, about twice as much as cacao, and tea between two and three times as much, depending on where the value is calculated. Yet this cheaper commodity has not only about the same stimulating power as these two other beverages but in addition is a very nutritious food. The industrial world is fortunate in obtaining cacao so cheaply. Were it not for the disconcerting but comprehensible fact that in a single African colony native growers are today producing over half of the world's crop at about half the production cost a pound in other countries, the buyers would be paying not around ten cents (on an average) but probably over twenty cents a pound for the raw bean.
Cacao is one of the most interesting strictly tropical export crops. If its "butter," or fat, were a little more readily digestible, it would excel, perhaps, both coffee and tea. Chemists are obviating this negative feature by taking out the heavy fat and substituting one or more lighter ones—just as the factory manager covers up the bitter taste with sugar.
Three or four species of Theobroma produce Cacao seeds; the sixteen or eighteen others are not used. All are tropical American in origin. Authorities differ as to whether they are all cultigens.
The family Sterculiaces has about 750 species; it is related to the Tea Family.
About 98 per cent of the crop is produced by T. Cacao. T. pentagona is cultivated in Nicaragua and adjoining republics. T. speciosa and T. angustifolia are unimportant. Of T. Cacao there are some twelve or fifteen distinct types, distinguishable largely by their fruits. These may be yellow or reddish, long or roundish, small or large, bottle-necked, ridged, smooth, and the seeds also differ in color and flavor.
Cacao is an ordinary-appearing tree, 15 to 25 feet high, with thin, fairly large leaves. The striking peculiarity is its habit of producing the very small pinkish flowers and fruits in clusters, on "buttons" on the trunk and larger branches; in fact, the fruits are so closely attached to these buttons that their removal without injury to the bark requires trained pickers. The beautiful pods, as the fruits are called, ripen at all seasons, though there is usually one large harvest and several minor pickings in the year. Inside the thick granular-woody shell there is a scanty white pulp, sweet and well flavored and cool tasting, and large irregular-shaped flattened seeds, twenty to forty or more, somewhat like large plump lima beans, of a beautiful lilac-purple shade inside, sometimes pink.
Cacao probably occurs in the wild state in the jungles of northern South America; at least very close relatives of it have been discovered there. Centuries before Colon (Columbus) came over searching for pepper and cinnamon at fifty dollars a pound, this denizen of the coastal rain forests had traveled perhaps from the Orinoco around up to the "Tierra Caliente" of eastern Mexico. The seeds dried and roasted and steeped, with or without other substances, like the seeds of the Ceiba tree, were consumed as a food-drink by the upper classes. Small bags of the seeds were used as money. Without milk and sugar, bitter and gritty, the Emperor Montezuma quaffed fifty mugfuls a day and gave 2,000 more to his household because, besides the nutritious fat, starch, and proteids, they got a 2 per cent caffein stimulus out of the theobromine. Most coffee has only about half as much of the similar alkaloid, caffein.
The Aztecs, who were unquestionably the first to use cacao largely, named it "cacaoquahuitl." The Spaniards, having little respect in those days for aboriginal words, dropped the latter half. The British later transposed the letters.
Chocolate, the preparation of the ground seeds, was called by the Aztecs "chocolatl." The Spaniards were in that case content with substituting an "e" for the final "1"; and the English lexicographers divided it into three syllables and set the accent back on the first. The British grower insists on calling his cacao orchard a "cocoa walk." But correctly speaking cocoa is the flour left after taking most of the fat out of the ground seed, or chocolate.
The Spanish for coconut is "coco"; hence to avoid confusion in trade parlance, the Trinidad merchant sells "cokernuts" and cacao and buys Venezuelan cocos, and also local cocoas.
ECONOMIC STATUS OP CACAO
Few realize that cacao has recently been climbing to a very prominent place in the world's commerce. It is nearly half as large as coffee, over 500,000 tons. Since the perilous slump in price of the raw bean on account of the vast output of very cheap-grown stuff in the Gold Coast, the confectioners have profited: cynically speaking, 10-cent chocolate plus 5-cent sugar equals 80-cent candy.
If 3 pounds of 10-cent cacao are put through the mill, resulting in 2 pounds of cocoa powder worth, say 15 or 20 cents, and 1 pound of cocoa butter (the yellowish at first, then white, fragrant rich vegetable tallow taken out of the hot ground semi-solid paste) worth, say 25 cents, there will be a gross profit of 35 per cent to 50 per cent for the factory.
The United States now imports about 425,000,000 pounds of cacao, or between three-sevenths and a half of the total production. The consumption in the confectionery trade is enormous and is increasing. All grades are used, but about 35 per cent comes from British West Africa, which produces about 225,000 tons, nearly half of the world's supply.
Brazil is producing heavily the past few years (since 1922) and has held rank as the second cacao country since the Great War. Ecuador is in danger of losing her place, in fact Nigeria is surpassing her already, and no one knows what Lagos will do later. Colombia and Venezuela could easily double their output. Trinidad and Sao Thome, old rivals, keep an even status, 18,000 to 30,000 tons. Costa Rica, Santo Domingo, and Nicaragua should expand, for they have ideal cacao climate and soil.
Cacao, as a food-drink, is not sufficiently appreciated. It is much more stimulating than coffee, ounce for ounce, and a good rich food; the butter is indigestible if taken in large amounts. Plenty of vanilla and cinnamon is needed to spice up cocoa and chocolate as a beverage; the semi-solid preparation is made from the powder—not too poor in oil—boiled thoroughly in as small a quantity of water as possible, then a little cream, spice, and plenty of sugar.
CULTIVATION OF CACAO
Cacao likes heat and humidity better perhaps than any other crop; i.e., it is a typical megatherm. Droughts it cannot well endure, nor elevations above 2,500 feet. It revels in red clay, probably because it holds moisture so well; but if this clay cracks under the strain of a long dry spell with no (almost indispensable) blanket of leaves, the roots suffer severely. Rich deep loamy alluvium along river banks is best, provided the valley is not exposed too much to the wind; or up along winding streams back into the hills if the slopes are not too rocky.
Forking is a common practice in most tropical American cacao orchards. The old method was very destructive to the roots, though it did, of course, aerate the heavy soils. In Trinidad in 1907 a laborer was ordered to fetch a spade and demonstrate to the writer the then current style of forking: he came with the spade, but said he could not proceed till he had a cutlass to chop the roots. Consequently, the writer devised the vertical forking method: a short-handled fork with strong straight prongs is thrust (by hand and foot) vertically into the earth, not too close to the trunk base; the handle is then moved backward and forward till the tines are loosened in the soil, then taken out. These tine holes let the air down 6 or 8 inches beneath the surface, no roots are broken—no "chopping" is necessary —and these enlarged tine holes fill gradually with fine surface silt and humus particles, held right where the feeding roots can utilize them. Twenty to forty vertical thrusts in the root radius of a medium-sized tree allow the roots to get their due supply of air, even in heavy clay soils.
Deep drains are necessary wherever the least trace of stagnant water might be suspected.
Cacao is a noble crop and will not endure the slights and lack of attention so commonly shown coffee and coconuts. In Trinidad the old creole planters have a wise adage, to wit: "Old Mis' Cocoa, she likes 'e soun' o' de human voice"; and, true enough, within ear-shot of the hut the trees bear twice as much as those receiving less attention.
Seed should be taken, of course, from the best parent trees, those which always carry a good number of pods, and which produce good plump beans of the correct color and flavor. This is not so easy as it sounds, but cacao planters are ahead of coffee growers in starting their seed selection right.
Seeds may be planted "at stake" or in beds in a regular nursery or in bamboo pots or palm-leaf baskets. Under favorable conditions, i.e., where there is shade and plenty of rain, two or three seeds may be planted in the hill, the most vigorous one to be left in situ in due course. In starting a new grove, however, where the young seedling has to meet sun, wind, and weeds, perhaps, there is better chance of success if it goes out into the open-space dangers well prepared to win out. In the writer's experience the bamboo-joint, one seed to the pot, is the best method; germination is better, and the seedlings can be kept in the pots till they show six or eight leaves, but by that time the tap-root is creeping out of the hole in the septum at the bottom of the joint. When taken to the hole, which should have been dug deep and wide and nearly filled with surface soil, weeks before the transplanting, the pot is thrust down into the loose soil, then with a hatchet or short machete one side is split off carefully and lifted out, earth is pressed up against the exposed soil cylinder still intact in the remaining half of the pot which is then left, erect and solid-set. The holes may be 10 x 10 feet on slopes but in rich soil 12 x 12 or 12 x 15 feet is better. This means 300 down to 240 to the acre.
Shade is nearly always necessary. Cacao is by nature a jungle denizen and dislikes wind; in fact, strong winds at the time the flushes of tender new leaves occur at the tips of the branches may whip them to pieces in a few hours. Too much shade, however, conduces to fungous attacks of all kinds and thus to low yield. Several species of Erythrina, called Dadaps in the Orient and Bocares in the American tropics, are the favorite shade-producers. They have one exasperating fault: whenever their shade is most needed, during a long drought, they always shed every leaf, letting the sun down to the ground, cracking open the red clay and torturing the cacao roots.
To make the trunk branch out at the height of 3 feet, three or four main branches preferred, a little cautious pruning may be necessary the second year after transplanting (or planting at stake). Thereafter pruning is a fine art in the cacao grove. Not only must the tree be kept balanced and open but the two sorts of vertical sprouts must be removed promptly, twice or thrice a year gone over by an expert with experience, a very sharp knife, saw, and paint-pot. One of these suckers has plenty of leaves and may be left to form a new trunk if the old one develops canker; the other water-sprout will shoot up 4 to 5 feet in a few months, with hardly any leaves, and will distract the tree's attention from fruit production unless promptly removed. The proper removal of cacao side-shoots is a very difficult pruning operation. They should be taken off carefully, close up to the parent trunk, without injuring the bark, and with the application of some thick bland paint or wound wax to promote quick healing-over of the scar.
HARVESTING CACAO PODS (PLATE IV)
The fourth or fifth year there should be a number of fruits. If any set the third year they should be removed to avoid lowering the young tree's vigor. From the fourth to the fortieth year the tree should bear two crops, one long and heavy and one a few months afterward more irregular and uncertain. A fruit cushion, or button, may produce four or even six pods almost simultaneously, so that their bases, crowded together on their one-inch peduncles, become squeezed out of shape. Cacao, when free from fungous pests, is almost too prolific.
Since by the tenth year some of the pods may be borne too high for the pickers to reach with the cutlass or shorter knife, there is on most estates a pole-picker—a triangular blade mounted on a handle 6 to 9 feet long. Some of these blades have on one side a down-curving prong with cutting edge, so that a downward pull will sever a pod on the upper side of a high cushion. Most pods are removed by upward jabs of the pole-knife, and probably one-third of these jabs cut into the bark of the cushion or wood near thereto. Knives nearly always carry germs of the black-pod rot (Phytophthora jaberi), and therefore every cut is an inoculation. A tarred rag, wrapped around the base of the blade, touched to the bark wound would prevent most of the trouble.
The pods drop to the ground. Unless weeds are unusually bad, the gatherers never miss a pod, red or yellow. To save bending over, a favorite trick of the gatherer is to thrust the point of the cutlass into the pod, then with a quick swing and recoil the pod is hurled 10 or 15 yards away to a pile which is later broken in situ, perhaps, or packed down by burro or mule (purposely bred very small to pass under the branches easily) to a general breaking ground.
Cacao picking is interesting work, requiring much more intelligence than coffee picking. The cacao pod shows certain indications of its maturity to those who know, but these signs can hardly be put into words and even the most intelligent experienced pickers cut many a pod that lacks a week or two of being fully ripe. Five to fifteen pods a tree at a picking is probably a fair average. Many fine old trees, 8 to 12 inches in diameter and 15 to 25 feet high, give less, while a vigorous young tree may yield twenty-five to seventy-five beautiful purple and orange fruits at one cut. About twenty pods are required to make a pound of dry seeds. From 300 to 500 pounds to the acre is the outturn: the average probably runs around 425 pounds.
The breaking is always an interesting task. Usually heaps of a few thousand pods, here and there near paths, are made in the shade. Two sharp short blows of the machete or heavy knife by an expert, three or four by the regular peon, breaks the semi-woody shell around its equator, disclosing the white pink-streaked mass of pulp and seeds, which is tossed in a pile for the women strippers. A good breaker will handle 500 or so pods an hour; but only a specially trained wrist can hold out all day without cutting either fingers or seeds. Stripping the seeds from the placental strings running lengthwise of the seed-pulp cylinder looks simple, but is a difficult operation. The seeds in their delicious but scanty ice-cream-like pulp are shoveled into sacks, pannier baskets, or head baskets, and sent down to the fermenting boxes. The empty half-shells are left to rot usually right where they were broken. In a year the crumbled black mass may be flung about under the near-by trees to help out the blanket. A liberal dusting of lime over the heap, occasionally, hastens decay and lessens the number of mosquito larvae in the up-turned shell halves.
CACAO FERMENTATION AND PREPARATION
When the seeds arrive at the "sweating room," the process is no longer agricultural but chemical. Much training and clear judgment is required in cacao fermentation. Much has been written regarding the proper temperature, size of bin or box, manner of mixing, duration, exposure to the air, but as no two batches are alike, no rules can be laid down. The smell of the almost hot (100° to 125° F.) pulp, the way the vinegary claret-like liquor flows out at the bottom of the (cubic yard more or less) box, the color of the seed-coats, the texture of the slippery beans, have to be learned very slowly.
After two or three, possibly four days, when the seeds have been mixed several times to mingle the cooler beans near the outside of the box with those getting too hot near the center, the batch, weighing a quarter of a ton, is taken to the drying trays or perhaps to the perforated floor of a dry-house, or possibly, if the weather is wet and the estate well outfitted, to a dehydrator.
Sometimes the seeds are washed when leaving the sweating house. If so, they present a cleaner appearance, but most growers believe that washed beans are weaker. In some estates in Venezuela the seeds are fermented in pits in the ground. Yeast germs, bacteria, and enzymes find the fermenting boxes a veritable paradise. The lees liquor is run off into a seep-tank or into a near-by stream. It might be utilized as a weak vinegar if filtered and clarified. The tight seed-coat of the cacao bean is not so easily handled as the loose parchment endocarp of the coffee drupelet. Moreover, the cacao seed is four to six times heavier than the coffee. If the weather happens to be cloudy, no amount of raking over, turning, stirring, on the huge trays can prevent molds from attacking the sticky surfaces of the seeds, and unless some form of artificial heat is available the batch may sour. However, if dried too fast at first the thin brownish-yellow or reddish hull may crack open exposing the purplish seed itself, which would certainly affect the price if not the flavor. A hundredweight of fresh beans gives about 47 pounds in the bag; 100 pounds of fresh pods turns out only 25 pounds of dry seed.
After some days of anxious attention, however, the beans begin to give the faint susurrant or murmuring sound which delights the tray gang. Every night and during every shower the big trays must be rolled in under a shed or a roof must be rolled over them; even dew would spoil them. In some countries the beans are "danced" when nearly dry. They are made up into a flat-topped heap, a foot deep by 6 feet in diameter, sprinkled with powdered fine red clay and then with a little water, trodden by four or five barefooted laborers, walking around and around on the heap, while two or three shovelers at the rim keep the pile from getting too shallow. After ten minutes or so every bean in the heap is glazed with a thin film of clay which protects the seed from molds between tray and chocolate factory. There is much variation in the thickness of this hull: a thin membrane over the Ceylon and Java seeds, and a tough coat on the tropical American.
Cacao goes into larger sacks than coffee, for no apparent reason: 200 pounds vs. 125 to 150. Unlike coffee it does not carry very well over long routes and great care must be exercised to avoid danger of mustiness or even dampness in the warehouses. During the World War many thousands of tons accumulated in the Accrá warehouses (Gold Coast), overflowed, grew stale and finally a vast quantity of this third-class stuff was offered gratis, it is said, to any and all ship's captains who needed ballast on the home run; and scarcely a pound was wasted after all, they say.
Arrived finally at the factory, the beans are carefully tested, no two lots being just the same, and a blend formula worked out: so many Accrá sacks for bulk, so many Arribas from Ecuador and perhaps a little high-class Granada, which ought to make a very fair grade liquor for the candy manufacturer. Liquor, of course, is the solid ground bean, usually run, while warm and therefore semi-solid, into cakes about 15 x 25 x 2½ inches.
After a slight roast, in order to toast the skin up brittle and to bring out the delightful aroma, not nearly so strong a bake as is given to coffee, the beans are de-hulled in one machine and sent on to the nibber which breaks them into coarse and fine pieces and removes the "chit," or embryo. These nibs, or broken seeds, may be winnowed and screened out into several grades. Then the different sorts, from several countries probably, are mixed and conveyed on belts or from spouts to the hoppers of the grinders. It is a strange sight to see the warm dry rattling nibs go into the open mouth in the center of the top stone, and run out a creamy paste at the outer rim.
If the ordinary liquor, which is well ground and finished, is taken to the conching cylinder and submitted to several hours furious beating by the relentless piston, back and forth rapidly, the result is a smooth mellow cream of distinct flavor and of higher price.
The bean is marketed as cocoa powder and cocoa-butter or as some form of bitter or sweet chocolate. The shells or hulls, however, are used for stock feed. The amount of clay adherent to the hulls is seldom or never sufficient to damage their value as a cattle-feed ingredient. Cocoa shells may still be obtained, cleaned, in packages for human consumption; formerly they came in sacks, cheap and popular. The shells or seed-hulls contain about 11 per cent fat, while the "dust" (embryo chits and particles of the seed) may have around 28.5 per cent, too rich for stock feed.
VARIETIES OF CACAO
Probably 98 per cent of world's cacao is produced by the fifteen or twenty varieties of Theobroma Cacao. In Central America, especially in Nicaragua, and to a very slight extent on some estates elsewhere, there is cultivated a weakish but rather high-quality species, T. pentagona. This is sometimes mentioned as the "Alligator" cacao, a name which should be dropped, since it leads to confusion with the patashte (Theobroma or Tribroma bicolor).
The varieties of the common species may be grouped under three types, the Forasteros, the Criollos, and the Calabacillos. Of these the Forasteros turn out at least ninety pounds in every quintal marketed, while the Criollos are probably a little ahead of the "poor little squashes", to translate Calabacillos literally.
Of the variations of color of pod, color of seed, shape and size of pod, there is almost no end. According to some cacao specialists, the pinching-in of the basal portion of the fruit indicates that the type is not pure.
The commonest form of the Forastero type is a purple-red fruit with only slight ridges, the tip moderately rounded, and the base with not more than a suspicion of a bottleneck. The seed should be slightly angled, plump, and of a pale purple or lilac shade inside. Yellows, in most tropical American plantations, are not common. They seem less resistant to disease, but there is a feeling that their beans have a better flavor, though no expert could pick out with certainty these beans from a basket of stripped seeds at the breaking heap. Some forms of Forastero pods are covered with a network of deep longitudinal corrugations and shallow crosswise warty wrinkles. Rarely the entire surface is smooth even at the base. Quite often considerable yellow color shows in the depressions between the red ridges, but practically never is a pod really two-colored.
The famous old Criollo type is much commoner in Venezuela than elsewhere. "Criollo" means native-born, and "Forastero" is the Spanish adaptation of the Portuguese word forasteiro, meaning foreigner. The Criollo pod is much more slender and more ridgy than the Forastero and is usually yellowish. The base of the pod is more or less prolonged into a bottle-neck and the tip is rather acute, never rounded. The seed is flatter, longer, and light-colored. The flavor of the well-fermented seed is unquestionably better in some hardly explainable way, and is less bitter, but it may lack body, as the coffee blenders say. The Criollos usually are shy bearers and weak growers.
The Calabacillo has a pod about one-half the size of the Forastero, very short, with a small sharpish tip and practically no ridges at all. The color is almost always dark purplish-red. The bean is small and very bitter. The reason for planting this inferior variety here and there throughout the plantation is because the pickers can always obtain a few pods, whether rainy or dry season, pod-rots and canker or no, from these vigorous but smaller-growing trees.
The Nicaraguan T. pentagona is undeniably a high-grade cacao but there are cases in which canker has wiped out whole plantations. The pod is hardly medium-sized, mostly yellow, strongly five-ridged.
The patashte (T. bicolor) does not resemble the true cacao at all. It makes a tree 30 to 50 feet high, straight and slender. The leaves are large and rounder. The fruit is a striking object: oval or oblong, twice the weight of a Forastero, covered with a dark olive skin, with sharp-edged ridges, the larger running lengthwise. The shell is woody or almost like pottery. The seeds are large, flattened and rounded in a scanty pulp. The natives of Central America employ these seeds in making "dulces" but they are never used like true cacao.
PESTS AND DISEASES OF CACAO
There are six fungous diseases which seriously affect the price of chocolate, besides about twenty species which in certain places may sometimes attack root, stem, leaf, or fruit. Of insect enemies cacao has perhaps fewer than any of the other major crops of the tropics.
Deer, squirrels, and monkeys spoil a few ripe pods now and then. In Trinidad and northern South America the agouti (a brown-meated rodent the size of a rabbit) and the closely related paca (the meat of which resembles chicken breast) are blamed for the loss of a small percentage of the fruits borne low on the trunk.
Pilfering by the human biped, in groves near settlements, is quite serious in many countries.
The terrible black pod-rot, Phytophthora faberi, is the worst pest in all cacao groves. In fact it is debatable whether tropical planters have a worse fungous enemy, since this species not only destroys at least 15 per cent of the world's cacao crop, but has long been killing coconuts by the thousand in nearly all the grove regions in both hemispheres, and lately has begun to attack the soft-barked hevea, increasing the cost of automobile tires. It works in two guises: The most noticeable is the attack on the fruits, from one-half inch in length to full maturity; and canker of the bark. Opinions differ as to which form is the more important. A minute white spore sprouting on the surface of a pod—of any size at any season, or of any variety—finds a pore in the skin. The hyphae, or white thread-like roots, burrow rapidly into the cells and in two or three days (for a young fruit just starting) or a week or so the whole tissue of the shell is rotten, a brown spot at first, enlarging apace and finally turning black. The pulp and seeds are not attacked till after the shell has been destroyed. Mature fruits even badly affected may contain healthy seeds but they are consigned to the heap of rodent-gnawed pods and under-ripes, second-class product which may go in with a half-musty batch, 1 per cent of the total output, perhaps.
The small fruits, killed by this insidious pest, dry up, hang, black and hard for weeks perhaps, and drop off. Of course, the optimist may say that the tree could not carry all its set fruits through to maturity, hence the fungus might as well thin them down. It is a marvel that flowers can come out of any cushion which has had a pod killed on it. When the rot finishes the pod it creeps up the peduncle into the soft thick bark covering the button. In three days after a spore has entered, a cancerous area of brown decayed tissue—canker—is beginning to spread around the point of inoculation; and unless the tree is in good health a large area of bark may be killed, a branch or even the trunk may be girdled. Although in most groves, 70 per cent or more of the cushions have been invaded, one time or another, by their greedy enemy, a very large proportion of them block the spread of the hyphae in some manner. Sometimes the canker, starting probably from several jab wounds made by the picker's hook, spreads rapidly and once the sap supply is cut off by a ring of infection that part of the tree above or beyond it is gone.
The brown pod-rot, Diplodia cacaoicola, is serious, but is not to the same extent as Phytophthora. It also may cause the terrible canker areas on the stem and larger branches.
The comparatively new water-pod disease, Monilia sp., of Ecuador is rather serious. Once the fungus gains entrance into a fruit the seeds are doomed to destruction.
The witches'-broom, Marasmius perniciosus, of Surinam has for twenty-five years or more caused very serious losses. Similar fungi on tea and coffee cause a peculiar bundling of abnormal branches which, of course, bear no fruit.
Various fungi invade the root system. In rich soil one can almost always find long white threads of fungus hyphae running along the cacao roots as if looking for a chance to break in. Species of Fomes have learned how to get through the bark cuticle, and the finest trees will wilt and die as if struck by lightning.
Thread blights, Marasmius spp., are not important, except in a newly planted grove, with rotting stumps and plenty of rain. They kill a few leaves, and hold them suspended by the threads.
Lichens do no harm to the trunk, but like mosses and ferns are unsightly. Bromeliads, or "wild pines", and all epiphytic growths should be pushed off with a forked stick once or twice a year. In very wet situations it may be necessary to brush the trunks occasionally.
The papery cacao leaf is not easily invaded by fungi, but the bark and fruits are good hunting grounds for parasites.
Plant-lice, Aphis spp., and scales often infest the flowers, peduncles, and young fruits. Boring beetles sometimes attack the branches or small trunks.
The economic status of the various kinds of thrips remains uncertain; while some of them may aid in fertilizing the flowers, others probably are harmful.
- ► 2015 (35)
- ► 2014 (55)
- ► 2013 (41)
- ► 2012 (88)
- ► 2011 (104)
- ► 2010 (43)
- ▼ October (5)
- ► 2008 (48)
- As an armed forces brat, we lived in Rockcliff (Ottawa), Namao (Edmonton), Southport (Portage La Prairie), Manitoba, and Dad retired to St. Margaret's Bay, NS.
Working with the Federal Govenment for 25 years, Canadian Hydrographic Service, mostly. Now married to Gail Kelly, with two grown children, Luke and Denyse. Retired to my woodlot at Stillwater Lake, NS, on the rainy days I study the life and work of A. Hyatt Verrill 1871-1954.