The below snippet is taken from the book "Florida's best fruiting Plants" by Charles R. Boning. This is a good read for any one looking to grow fruiting trees in florida. it talks about selecting, planting, cultivating and fertilizing. This book also talks about different pests that attack fruiting plants and trees and how can one handle them.
PLATING A TREE
Planting a fruit tree is a simple endeavor. It requires nothing more than digging a hole, placing the root mass within the hole, and filling any voids. Nevertheless, many trees fail to proper because gardeners violate one or more of the four guidelines set forth below.
PLANT HIGH Perhaps the most common mistake made by beginning gardeners is to plant the tree too deep. Burying the root crown will weaken a tree over time. Trees should generally be planted with the crown of the root system raised 2 or 3 inches above the soil surface. It is far better to place the tree in a hole that is too shallow than in a hole that is to deep. Most trees settle slightly within a year after they are planted. By planting high, the gardener can ensure proper drainage, stimulate development, and prevent disease.
AVOID SOIL ADDITIVES Florida’s soil is mediocre to poor. As a result, many gardeners go to extensive lengths to prepare and enrich the planting hole. They dig a hole twice as wide and half again as deep as the root system of the plant. After planting, they fill the hole with an organic mix, usually some combination of topsoil, manure, peat, and compost. These preparations are unnecessary and are often harmful. The enriched planting hole discourages roots from extending out into the existing soil, limiting growth and making the tree prone to uprooting in high winds. Manure and other additives can burn tender new roots. In addition, buried organic matter can hold excessive moisture, causing fungal infections and other problems. With few exceptions, the best practice is to the tree directly in the soil that is present at the planting site.
DELAY FERTILIZATION In an attempt to stimulate new growth, some gardeners fertilize a new tree immediately after it is planted. This practice is usually harmful. A tree needs time to adjust to new surroundings. Tender feeder roots should be given a chance to develop and extend into nearby soil. To avoid sending the tree into shock, it is best to delay fertilization for about two months after planting. At that point, a light application of slow-release fertilizer may be administered. Some exceptions to this rule exist. For example, the mango seems to benefit from a light fertilization at planting. But, in most cases, immediate fertilization has a detrimental effect on plant development.
WATER REGULARLY Although established trees can endure some drought, regular irrigation is critical for the first four to six months after a tree is planted. A newly planted tree should receive a deep watering twice a week. Root-bound specimens should be watered three times a week for two months, and should be watered twice a week thereafter until they are well established. While the construction of a water-holding basin around a tree may be helpful, it is unnecessary where a thick bed of water-holding mulch is present.
Some fruit trees live long productive lives without human intervention. However, as a rule, those that receive proper care tend to be more productive than those that are neglected. The discussion that follows touches on basic cultivation techniques.
IRRIGATION Most fruit trees require irrigation, particularly during fruit set and periods of low precipitation. Plants constantly lose water through evaporation. At the same time, they require water to transport nutrients and distribute sugars. If deprived of sufficient water, one of the first functions that a tree will forgo is fruit production. By the time visual symptoms of stress appear-such as wilting or leaf drop- it is likely that serious damage has occurred. The goal is to apply the correct amount of water to supply the needs of the tree.
The average fruit tree benefits from a deep weekly or hi-weekly watering. However, requirements vary with the species, the age of the plant, drainage characteristics of the soil, the season and the amount of rainfall. The frequency of irrigation should decrease as the tree matures. Irrigation may be unnecessary during the rainy season. During early winter, when growth slows or stops, irrigation can be reduced or discontinued. However, from late February through April-a period marked by dry conditions in peninsular Florida-many species put out new flushes of growth, flower, and set fruit. Irrigation is critical to ensure that these functions take place without interruption.
Watering with a garden hose is an efficient form of irrigation small lots with young tress. However, as trees mature, they require greater quantities of water spread over a larger area. A minor task can thus evolve into a several-hour or daylong chore. The use or sprinklers can reduce the burden. A simple plastic donut with holes punched at different angles does a remarkably effective job of providing water to the root zone of a single tree. Soaker hoses work well for hedges or planting rows, but tend to deteriorate over time.
Drip irrigation systems supply frequent applications of water at a low flow rate and at low pressure. Such systems are very efficient. However, because they only supply water to a small area, they tend to concentrate root development in areas immediately beneath the supply points. Under-canopy micro sprinklers are slightly less efficient. However, they can be adjusted to cover a broader area. With both systems, the emailers have a tendency to clog. Overhead sprinklers are inefficient. Significant quantities of water are lost to evaporation and run off. Energy use is also high, however when cold weather threatens, overhead sprinklers can dramatically raise the temperature in the garden.
DRAINAGE Excessive water can be just as harmful as insufficient water. Over-frequent irrigation can encourage development of a shallow root system. A shallow root system can ruin a lawn and may cause the tree to topple in high winds. Few fruit trees will tolerate “wet feet” or saturated soil. Serious problems arise in low areas subject to periodic docking. Where drainage is inadequate trees can be planted atop mounds or in mounded rows. Unless the trees are elevated sufficiently, the roots will eventually grow down into wet soil and be visited by root rot and other problems, In areas prone to flooding and in areas with a high water table, the only alternative to mounding is to plant species that will withstand occasional flooding, such as the guava, jaboticaba, may haw, Ogeechee lime, pawpaw, and pond apple.
FERTILIZATION Most fruit trees will grow faster and produce greater quantities of fruit if they are fertilized on a regular basis. Slow-release granular fertilizers are ideal for most purposes, they provide even coverage and supply nutrients to the roots over a lengthy period. Fertilizer spikes provide uneven results because nutrients do not leach nut horizontally. Nearby plant roots can be burned while distant roots receive no benefit. Inexpensive, soluble fertilizers wash quickly through the soil. They provide no long-term advantage and can damage sensitive plants.
Fertilized should be evenly distributed beneath the canopy and should cover an area extending past the drip line. Most trees benefit from three or four applications annually, Applications in late February, April, June and September will ensure maximum growth. Many growers discontinue fertilization from September through February so as not to stimulate tender new growth during cold weather. Many gardeners presume that the best time to apply fertilizer is immediately before it rains, they are incorrect. A heavy rain can wash away nutrients and deposit them below the root zone. The best time to apply fertilizer is immediately after a heavy rain. As newly fallen rainwater filters down through the soil, it pulls nutrients into the root zone through capillary action.
Besides hydrogen carbon, and oxygen, which are present in the environment, plants require 13 minerals, Nitrogen (N), phosphorus (P), and potassium (K) are the primary macronutrients and the main ingredients in must fertilizers. Nitrogen is essential for vegetative growth and photosynthesis. It helps produce the rich color of healthy foliage. Nitrogen deficiency causes a general yellowing of leaves symptoms appear first in older leaves. Phosphorus promote flowering and roots growth. It is also essential to photosynthesis. Plants suffering from phosphorus deficiency are often stunted. Although the foliage may remain green, leaves tend to be small, older leaves are shed prematurely, and scorching may occur on lead tips and margins. Potassium assets the plant in building protein and is important to fruit production, symptoms of potassium deficiency appear as a pale mottling or as a browning or curling of leaf margins, Calcium, (Ca), magnesium (mg) and Sulphur (s) are also classified macronutrients but are usually plants in sufficient quantity to support growth micronutrients essential for plant growth include boron copper, iron, chlorine, manganese, polybdenum, and zinc.
While requirements vary among species, must fruit trees will achieve optimal growth it they recent regular application of a quality palm fertilizer such as a 10-3-10 formula with micronutrients. A balanced 10-10-10 formula may be applied in mature trees during period of flowering and fruit development. A high analysis, six-month, time-release fertilizer will serve to accelerate the growth of young species.
WEED SUPPRESSION. A weed is any plant that grows in a location where it is not wanted. Grass become weed when they encroach on areas beneath the canopy of a fruit tree. They retard the trees growth by competing for nutrients & moisture. Most gardeners use a combination of mulch & herbicides to suppress weeds around the base of a tree. Herbicides are chemical compounds that interfere with plant growth or metabolism. The herbicide Clyphosate is widely used in commercial & residential applications. It is highly effective, has relatively low toxicity and is not absorbed by the bark or roots of established trees.
Several precautionary notes are in order. When applying herbicides, the gardener must not allow the spray to touch the leaves of the tree. One moment of inattention can result in disaster. The task should never be performed under breezy conditions. Weed and feed lawn fertilizers should not be used in the vicinity of fruit trees. Some contain powerful herbicides that leach into the soil and that are taken up by roots that extend under grassy areas. These toxins can weaken or kill the tree over time. Finally weed whackers should never be used around the base of fruit trees. They destroy bark and can girdle and kill the tree.
MULCH Organic Mulch serves at least six important purposes. First it conserves soil moisture by limiting evaporation and runoff. Second, it adds organic matter and nutrients to the soil. Third, it draws earth worms in to the root zone and encourages the development of beneficial microbes. Fourth, it reduces the population of nematodes microscopic worms that can harm the roots of the plant. Sixth, it suppresses weed growth.
Fruit trees surrounded by a thick layer of mulch tend to be far more vigorous than those growing from a patch of bare earth. Mulch should be distributed in a ring beginning 6 inches away from the trunk and ending just beyond the drip line formed by the canopy. Mulch that accumulates around the trunk can lead to the transfer of fungal rot and disease. The mulch bed should be maintained at a thickness of 6-8 inches.
Some gardeners place a layer of weed block fabric beneath the mulch. This step is unnecessary. The material tends to deteriorate over time and is unsightly when exposed. It may also slow the migration of soil-based organisms into the mulch and may inhibit the dispersal of organic matter into the soil. Grass clippings should not be used as mulch. They break down rapidly and may harbor numerous weed seeds.
PRUNING Some fruit trees require pruning to develop proper shape, to remove crossing or damaged limbs and to control size. The overall objective is to develop a strong framework of limbs that will support a heavy fruit crop. Pruning cuts are of two types. A heading cut removes shoot terminals or branch tips. It encourages the growth of buds beneath the cut, leading to thicker, bushier growth. A thinning cut remove an entire shoot back to a main branch or side shoot. It is used to open up trees and promote light penetration.
Tropical and Subtropical species are usually pruned after harvest in the late summer or early fall. Deciduous species are usually pruned during period of dormancy.
SUN AND SHADE All fruiting plants require light to conduct photosynthesis. Most prosper in full sun. As a general rule, the greater the exposure to sunlight, the greater the production of fruit. However, young plants of certain species, air layers, and newly grafted plants cannot cope with intense sunlight. They must be exposed in small increments. The use of shade cloth over the planting site aids in this endeavor. It can be gradually stripped away to allow the plants to adjust to the outdoor environment. Shade cloth also limits evaporation, moderates heat, and offer some wind protection.
STAKING AND TRELLISING Young trees and trees with poorly developed root systems may benefit from staking. The need is most acute in open areas prone to windy condition and in loose, sandy soil where roots are unable to obtain a solid purchase. The material used to fasten the tree to the stake must not constrict the trunk. If guy wires are used, a tube or rubber hose should be used to prevent chafing. Once a tree is established – usually after the passage of a single growing session- the stake should be removed so that it does not interfere with normal development.
Four of the five vining plant profiled within this book – muscadine grape, kiwifruit, passionfruit, and pitaya–require a trellis or some other support system. Blackberries and other brambles may benefit from a single-wire trellis. A trellis maximizes the plants expose to sunlight keep fruit away from the ground, protects against attack by ground-dwelling pests, and makes the fruits easy to harvest. Although a chain link fence can serve as a temporary “trellis,” such an arrangement may fail over the long term. Vines soon become intertwined with links. The result is often a cascade of tangled foliage and a ruined fence.
FRUIT TREE PESTS
Many creatures that inhabit the garden are not pests. Lady beetles, assassin bugs, face wings, Ichneumonid wasps, and praying mantises all play an important role in keeping other insect populations under control. Honeybees and various flies and beetles assist in pollinations. When pesticides are applied needlessly or carelessly, they can wipe out these helpful insects. Pesticides should not be thought of as a “preventive measure”. They should be applied only when insect begin in overrun a tree, when their presence can no longer ignored.
With that said, Florida is home to an extraordinary number of pests native and imported. Many are difficult or impossible in control. Every gardener can expect to lose fruit to one or more of the flowing animals.
CARIBBEAN FRUIT FLY The Carli bean fruit fly, Anastrophe Suspensa, is an extremely destructive pests of many types of fruit crops. It is most prevalent in south Florida, but has been detected throughout the peninsula. It is abundant from march through September. The fly measures about a third of an inch in length. Its wings are marked with irregular dark brown bands. The abdomen terminals in a spike like ovipositor. White maggots hatch about two days after the female fly deposits its eggs under the skin of the fruit. They tunnel through the pulp and render the fruit unfit for human consumption. The list of species attacked by the Caribbean fruit fly is extensive. Chemical pesticides are ineffective. Several types of traps have been tested with mixed results. The only sure way to prevent infestation is to bag individual fruit.
GRAY SQUIRREL The eastern gray squirrel Sciurus carolinensis, will eat seeds and nuts; however, is favorite food is fruit. It will sometimes knock down scores of fruits take several bites out of each, and less the ruined fruit to spoil. The squirrel seems in target the largest, sweetest, most desirable fruit in the grove. It will repeatedly risk its life to return to the tree that is the source of such delicacies. These destructive tendencies make the squirrel a extremely unwelcome visitor to the home orchard. Most commercial repellents have little effect. Traps can reduce populations our will not eliminate the problems. A permit is required to relocate the gray squirrel.
NUMATODES Nemalodes are the most populous group of multi-called animals on earth. Tens of thousands of these microscopic worms can exist within a cubic foot of soil. Young plants are particularly susceptible in nematode damages since their roots are relegated in the upper level of soil where nematode populations are concentrated. Mulch can reduce the number of nematodes within the root zone.
BOAT TAILED GRACKEL The boat tailed grackle, Quiscalus major, is a common pest throughout much of Florida. This large bird is noisy and aggressive. Because of it black, indecent coloration, it is often mistaken for a crow. The boat tailed grackle consumes great quantities of lychee, longan, iccuat, and other small bodied fruit. Scare devices are somewhat effective, but will be ignored unless they are periodically moved or readjusted.
WEEVILS The disappears roots weevil, Diaprepes abbreviates, is serious pest of many fruit trees. It is about ½ inch in length, dark in color with bright orange stripes along its abdomens. The adult feeds on foliage cutting munded notches in leaf margins. The larva feasts on trees roots. An aggressive program may be required to control this pest. Oil sprays can reduce the deposit of eggs on foliage. Approved soil barrier pesticides may prevent the larva from penetrating the soil surface and damaging the roots.
SCALE INSECTS Scale insects feed on plant fluids. They attach themselves to the host plant, protected beneath thin shells that superficially resemble miniature fish scales. Bleary intention can reduce tree vigor or cause gradual decline. Scales can be controlled by sprays of oil and approved pesticides.
THRIPS, in particular the red banded thrip, selenothrips rubrocinclus, attack many fruit species in Florida. They are thin and their presence in difficult to detect. They pierce the surface of foliage and fruit, causing stippled lesions and leaf deformation. Severe infestation can cause defoliation. Approved pesticides are somewhat effective in controlling this pest.
MITES Mites are tiny insect that cause widespread damage to fruit crops in Florida. The rust mine feeds predominantly on fruit surface, causing bronze colored blemishes. The spider mite usually feeds or mature leave. Broad spectrum pesticides are often ineffective against mites and specially crafted miliciods may be needed to suppress populations.
WHITEFLIES The adult whitefly resembles a tiny white moth and measure less than 1/6 inch in length the larva feeds on plant juices. The whitefly accounts for significant agricultural losses. Infestation cause tree to lose vigor. In addition, this insect is responsible for transmitting several plant viruses. This pest is difficult to control with broad-spectrum pesticides. Insecticidal oils or soaps provide some relief. Multiple applications may be necessary.
EASTERN COTTOTAIL REBBIT The eastern cottontail rabbit, Sylvilagus floridanus, is found throughout Florida. While it will eat fruit that dangles within its reach, it poses a far more serious threat. The rabbit is capable of girdling a fruit tree by gnawing at the bark. It is especially attracted to members of the Rosaceae family, such as the apple. The best way to prevent rabbit damage is to erect a fence or to wrap the lower trunk with protective material.
ROOF RAT The roof rat, Rattus Rattus, attacks banana, citrus, lychee, papaya, pineapple, and other fruit crops, often by hollowing out the fruit interior. The roof rat can be killed with a trigger trap. However, such traps should only be set during the nighttime to avoid injury to birds and other species. Several poison baits are also approved for combating this pest.
APHID The aphid is an extremely common pest of many fruit trees and ornamentals. This pear-shaped insect is tiny, measuring less than 1/8 inch in length. It congregates on the underside of developing leaves. It can from dense colonies, sapping the energy of the plant and causing the distortion of new growth. Populations tends to peak in the spring. The aphid is relatively easy to control. Insecticidal oils and soaps are effective and usually have relatively low toxicity.
FRUIT TREE DISEASES
Plant diseases manifest themselves through many symptoms, including leaf blight, soot blight, panicle blight, rots, cankers, leaf spots, wilts, limbs dieback, and general dieback. They are often difficult to diagnose and can easily be confused with nutritional deficiencies or pest-related damage. The discussion that follows is limited to a few common diseases with well-recognized symptoms.
ANTHRACNOSE Anthracnose is an important fungal disease of mango, avocado, and other fruit crop. It often manifests itself as dark, spreading lesions on the skin of fruit. These lesions coalesce and eventually spread decay to the interior of the fruit. Spores may be transferred by rainwater dripping from dead wood or other infected parts of the plant. The disease is most prevalent during periods of warm, rainy weather. Anthracnose can be controlled through the use of fungicidal sprays.
PHYTOPHTHORA ROOT ROT Phytophthora root not is a common fungal disease of fruit trees in Florida and elsewhere. The fungus lies dormant in the soil until activated by wet weather. It then infects root tissue. If left untreated, root rot will generally kill the host plant. Symptoms include a reddish discoloration of the inner bark at the base of the trunk, along with widespread necrosis of the outer roots. The disease can be avoided by planting susceptible species in high, well-drained sites. If the disease is recognized at an early stage, approved fungicides, applied as a soil drench, may save the tree.
FIREBLIGHT Fire blight is a serious disease that affects members of the Rosaceae family. It is caused by the bacterial pathogen Erwinia amylovora. The disease is spread by insects and is triggered by persistent wet conditions. The classic symptom is that an entire limb will experience sudden dieback, giving the appearance of having been scorched by fire. In addition, oozing cankers form in the bark of infected trees.
Fire blight is difficult to control. Infected limbs should be severed well below any portion exhibiting signs of infection. Pruning shears or other tools must be disinfected after each cut. Severed branches should be burned or bagged and removed from the orchard.
CITRUS CANKER Citrus canker is a disease caused by the bacterial pathogen Xanthomonas axonopodis. Infection results in raised brown lesion on fruit, leave, and stems, followed by premature fruit drop and general decline. The disease is highly contagious and can spread by garden shears, landscape equipment, wind-driven rain, animals, and people. No treatment exists. The only known control is the destruction of an infected tree and other trees in the vicinity. Eradication efforts have been only marginally effective and have resulted in numerous quarantines and the removal of millions of trees.
CITRUS GREENING Citrus greening, caused by the bacteria Liberibacter asiaticus, is a new disease in Florida. It has caused extensive damage in other regions of the world. Insects transmit the disease from one plant to another. Symptoms include blotchy yellowing of leaves, lopsided fruit that drop prematurely before coloring, followed by gradual decline and the death of the tree. No effective controls exist. Citrus greening represents a very serious threat to commercial and dooryard citrus in Florida.
VERTICILLIUM WILT Verticillium wilt, a fungal disease, attacks a wide range of fruiting plants. Te fungus can lay dormant in the soil for decades. When conditions are right, it invades the roots of the plant and spreads upward, destroying the plant’s vascular tissue. Infection is hard to detect until substantial damage has occurred. The most recognized symptom is dieback along one side of a tree. Verticillium wilt is common on land formerly used for the production of vegetable. Where the disease is present, the grower should plant resistant species and should take extra care to ensure adequate drainage.
CERCOSPORA LEAF SPOT several fungi within the genus Cercospora inflict damage on the foliage of fruit trees. Spores from infected plants are dispersed by wind and rain. Warm, wet conditions accelerate the spread of the disease. Symptoms include circular spots with gray centers and dark brown to reddish-brown margins. Infected leaves turn bronze to light brown, then grayish. The disease first affects older leaves. Inner branches may be denuded, leaving only clusters of leaves near the branch tips. The disease can be controlled through the use of fungicide sprays.
POWDERY MILDEW Powdery mildew can be caused by several fungi and is prevalent on many crops. The disease manifests itself in the form of white lesions appearing on foliage, whitish-gray discoloration of twigs and emerging growth, aborted blossoms, and blemished fruit. It may lead to loss of tree vigor and reduction in yield. Several fungicides are effective at treating the disease.
ALGA SPOT Alga spot, sometimes referred to as red rust, is a relatively minor disease, caused by the algae Cephaleuros virecens. Symptoms appear as pale green circular spots on leaves, which eventually turn reddish-brown. Alga spot is most prevalent during periods of wet weather and may be transferred from one tree to another by wind-driven rain. The grower can prune out infected branches to prevent further spread.
SOOTY MOLD Sooty mold is not really a disease, as it does not directly attack plant tissue. However, its effects are similar. The fungi that cause the disorder are associated with the liquid exudates of various small insects, including aphids, mealybugs, scales, and whiteflies. Sooty mold shows up as a black, velvety coating on the surface of leaves. Once the underlying insect problem has been solved, it will dry up and flake off. Sooty mold is unsightly, but is rarely a serious threat to the health of the tree.