Learn about how to control pests of fruits using spray schedules!
General Formulas Used in Summer Fruit Spray Schedules:
i. Lead arsenate – 2 ¾ tbsp.
Wettable sulfur (mfr.’s directions) – usually 3 tbsp.
Nicotine sulfate –1 ½ tsp.
Hydrated lime – 1 tbsp.
Sticker-spreader, mfr. s directions
Water – 1 gal.
or
ii. Derris, cube root, or timbo powder (containing 4 or 5% rotenone) – 4 tbsp.
Wettable sulfur (mfr. s directions) – usually 3 tbsp. or Fermate – 2 tbsp.
Sticker-spreader, mfr.’s directions
Water – 1 gal.
iii. Dusts containing the ingredients in either of the above formulas may be purchased and substituted for sprays if dusting is preferred.
It is important that all powders are first made into a thin paste with a little water before adding to the main solution.
The second formula contains no ingredients poisonous to men or animals, and therefore can be used on ripening fruit. Restrictions, however, prevent its use on tree fruits at this time.
Spray Schedule for Apples:
1. Dormant Spray:
Applied before the buds begin to open in the spring.
Elgetol – 1 tbsp.
Water – 1 gal.
This dosage is sufficient to kill the tiny, shiny black eggs of the rosy, green, and grain aphids found on twigs around buds or in rough areas of the bark.
This spray may be applied safely at the above dosage up to the time the leaves of the blossom buds show ¼ inch of green color (green-tip stage) to control newly hatched aphids.
If the oyster shell scale is also a problem, an extra tablespoonful of Elgetol should be used. Seven and one-half tablespoonfuls of a miscible oil should be added if the tiny red eggs of the European red mite are also abundant on the undersides of the twigs and branches. This spray will also control the San Jose and the scurfy scale.
Any dead leaves under the trees should be wetted liberally, as Elgetol also destroys the apple-scab spore-producing centers in these dead leaves, which makes apple-scab control easier later on.
2. Delayed Dormant Spray:
Applied when the leaves of the blossom buds are out from ¼ to ½ inch.
Either formula 1 or 2.
Nicotine sulfate may be left out of the formula if the dormant spray was applied; otherwise it is of major importance for aphid control at this time.
This spray controls newly hatched tent caterpillars, other chewing pests, and prevents early apple-scab infection.
3. Preblossom Sprays:
Applied any time between the appearance of the flower-bud cluster and the opening of the blossoms.
Either formula 1 without nicotine or 2.
This spray is timed primarily for apple-scab and rust prevention on foliage. If much rainy weather occurs at this time, two applications should be made during this period.
4. Calyx or Petal Fall Spray:
Applied when the last of the petals are falling.
Either formula 1 or 2.
This spray is timed to prevent apple-scab and plum- curculio injury, and is of special importance in controlling codling-moth larvae which a few weeks later enter the blossom end of the fruit and are killed by the lead arsenate retained within the closed calyx. Nicotine sulfate is necessary when aphids were not controlled, when the small red nymphs of the apple red bug are present on new growth, and when the apple sawfly caused damage. So far the apple sawfly is limited to Long Island and vicinity. Green-fruit-worm injury may also be prevented with this spray.
5. Curculio Spray:
Applied about ten days after the calyx spray.
Either formula 1 without nicotine or 2.
This spray is timed primarily for the plum curculio, which at this time begins to make characteristic egg-laying scars in the young fruit. Green-fruit-worm and apple-sawfly injury begin to show up if not properly controlled by sprays. Apple scab and the apple rust also begin to appear on the foliage at this time if not controlled previously with the wettable sulfur or fermate. Nicotine sulfate may be left out if apple sawfly is not a pest.
6. Codling-Moth Cover Spray:
Applied about the middle of June.
Either formula 1 without nicotine or 2.
This spray is timed to help control codling-moth larvae and apple scab. If neither one is a problem nor the weather is dry, this spray may be omitted.
7. First Apple-Maggot Spray:
Applied when the apple maggot flies first appear, about July 1.
Either formula 1 without nicotine or 2.
This spray is timed to kill the adult flies before they begin egg-laying. It also helps control codling-moth larvae and Japanese beetles. If no flies can be seen on the foliage and fruit at this time, and the other pests including scab, are not a problem, the spray may be omitted.
8. Second Apple-Maggot Spray:
Applied after most of the flies are out (about the middle of July).
Either formula 1 without nicotine or 2.
This application is timed to control the later-emerging apple-maggot flies and will also help prevent damage from codling-moth larvae and Japanese beetles. This spray may also be omitted if these pests and scab are not problems.
Diagnosing Injuries on Mature Apples:
From the number of mature apples received each fall for diagnosis of their troubles, it appears that many gardeners only discover the defects at picking time. The correct diagnosis of the cause of the defects at this time will help in anticipating and controlling them.
The rosy apple aphid produces dwarfed, misshapen apples, sometimes referred to as nubbins.
The apple rust produces raised, bright orange-colored spots near the blossom end of the fruit; and the quince rust makes small, sunken, dark-green spots with dead tissue underneath. Both these diseases spend part of their life cycle on red cedars—the apple rust as brown golf-ball-like growths on the twigs; the quince rust in cankered areas on the limbs and the trunk. Red cedars in the neighborhood of apple trees should be removed or kept free of rust infections.
The plum curculio causes russet, half-moon-shaped scars, which sometimes distort the growth of the apple.
The apple red bug produces deep or shallow dimples in the fruit, often accompanied by much russeting.
The codling moth produces a hole in the fruit with brown fress sometimes protruding from it. This injury should not be confused with that of the apple sawfly, which occurs only on small, partly grown apples.
The apple maggot causes the apple to be slightly dimpled and furrowed, with a tiny, dark, discolored area in each dimple, indicating where the egg was deposited under the skin. The fruit, when cut open, shows numerous small winding tunnels in which tiny white maggots may sometimes be found.
Apple scab produces grayish-black roughened or cracked areas on the fruit, and in severe cases misshapen apples.
Boron deficiency in apples at harvest time causes more or less misshapen apples, which, when cut open, show brown, irregular, corky areas in the flesh. There is heavy dropping of the affected fruit shortly before harvest, as they tend to riapen about a week ahead of normal fruits. This deficiency may be overcome by applying, in the early spring, 3/4 ounce of borax for every inch in diameter of the tree trunk in a wide ring under the tips of the branches of affected trees. Applications should be repeated every three years.
Sooty blotch and fly speck are two different diseases that show up on fruit in the late summer. The first disease produces sooty black blotches on the skin of the apple; the second disease produces black shiny dots like those made by flies. The fungicides in the summer sprays usually keep these diseases in check.
Spray Schedule for Pears:
i. Dormant Spray:
Applied early in the spring before the buds open up.
Elgetol – 2 tbsp.
or
Miscible oil – 7 ½ tbsp.
Water – 1 gal.
This spray is very important for the control of pear psylla, the most serious pest of pears. It should be applied when the tiny flies are on the twigs and before they begin laying their tiny yellow eggs on the spurs. The first few warm days in the early spring will bring out the flies in great numbers. All parts of the trees, including the trunks, should be thoroughly sprayed.
ii. Preblossom Spray:
Applied when the flower buds begin to separate in the cluster.
Either formula 1 or 2 as used for apples.
This spray controls the mosquito like pear midge, which produces partly grown pears full of maggots, and pear scab. If neither pest has been a problem, this spray may be omitted.
iii. Petal-Fall Spray:
Applied when the last of the petals are falling.
Either formula 1 without nicotine or 2.
The spray is effective in the control of the codling moth, green fruit worms, and pear scab.
iv. Curculio Spray:
Applied shortly before the middle of June.
Either formula 1 without nicotine or 2.
This spray is necessary only if the quince curculio is present and damaging pears by its feeding and egg laying. “Wormy” pears in the early fall are caused by this insect.
Spray Schedules for Sweet Cherry, Sour Cherry, and Plum:
i. Dormant Spray:
Applied before the buds swell in the early spring.
Elgetol – 1 tbsp.
Water – 1 gal.
This spray helps control brown rot and destroys the eggs of the black cherry aphid on sweet cherries. This application may also help control black knot—black knotty growths on branches and twigs caused by a fungus.
ii. Petal-Fall Spray:
Applied when the last of the petals have fallen.
Either formula 1 or 2 as for apples.
This spray is effective in destroying plum curculios and preventing cherry leaf spot and brown rot. On English Morellos, lead arsenate should be reduced to 1 tablespoonful to prevent arsenical injury to twigs.
iii. Shuck Spray:
Applied when most of the shucks (dried blossom remains) have fallen from the small fruits.
Either formula 1 without nicotine or 2.
This spray controls the same pests as the previous spray. This spray should be repeated in two weeks if plum curculios are numerous.
iv. Summer Spray:
Applied when the fruit first begins to show color.
Either formula 1 without lead arsenate and nicotine or 2.
A sulfur dust may be substituted for the spray. This spray is very important for the control of brown rot, which usually attacks ripening fruit most severely.
Formula 2 will help control the cherry fruit fly, which causes “wormy” cherries, when the weather is damp more than one application may be necessary for disease control.
v. After-Harvest Spray:
Applied on sour cherries only after the fruit is picked.
A low-soluble copper spray, mfr.’s directions
Hydrated lime – 6 tbsp.
A good sticker, mfr.’s directions
Water – 1 gal.
Complete defoliation from cherry leaf spot may occur in rainy years unless this spray is applied. The lime will help repel Japanese beetles.
Spray Schedules for Peach:
1. Dormant Spray:
Applied before the buds begin to swell in the spring. May also be applied in the late fall.
Elgetol – 1 tbsp.
Water – 1 gal.
This spray is essential to the control of peach leaf curl, which produces a thickening, curling and reddening or yellowing of the leaves, with their subsequent dropping off. This spray may also help control brown rot by destroying the spore centers.
2. Petal-Fall Spray:
Applied when the last of the petals have fallen.
Either formula 1 without nicotine or 2.
The lead arsenate should be reduced to 2 tablespoonfuls, as the peach is very susceptible to arsenical injury. This spray is important for the control of the plum curculio.
3. Shuck Spray:
Applied when most of the shucks (dried blossom remains) have fallen from the small fruits.
Wettable sulfur (mfr.’s directions) – usually 3 tbsp.
Cryolite – 2 ¼ tbsp.
Sticker-spreader, mfr.’s directions
Water – 1 gal.
This application helps control brown rot; peach scab, which produces small olive spots on the fruit and brow spots on the leaves; and the plum curculio. More than one arsenical spray should be avoided on peaches, as defoliation, shaggy bark and gum-exuding dead, cracked areas (cankers) on the branches may result,
4. First Summer Spray:
Applied two or three weeks after the shuck spray.
Either formula 1 without lead arsenate and nicotine or 2 as used on apples.
This application helps control brown rot and scab.
5. Second Summer Spray:
Applied two to four weeks before the fruit ripens.
Either formula 1 without lead arsenate and nicotine or 2 as used on apples.
This spray helps prevent brown rot on the ripening fruit. To prevent Japanese-beetle injury, the hydrated lime should be increased to 6 tablespoonfuls in formula 1. Several of the above sprays may be necessary to keep the beetles from the ripening fruit.
Spray Schedules for Quince:
i. Petal-Fall Spray:
Applied when the last of the petals are falling.
Either formula 1 or 2 as for apples.
This spray helps control leaf diseases, codling moth, and Oriental fruit moth. When applied twice more at two-week intervals, it will help control tie quince curculio.
ii. Summer Sprays:
Applied at ten-day intervals throughout the summer, beginning two weeks after the last curculio spray and ending about three weeks before harvest.
Summer oil emulsion – 4 tsp.
Nicotine sulfate – 1 ½ tsp.
Water – 1 gal.
These applications are necessary to avoid a complete loss of the quince fruit from the attacks of the several broods of the larvae of the Oriental fruit moth.
Spray Schedules for Grapes:
Bordeaux mixture:
Copper sulfate (monohydrated) – 2 ½ tbsp.
Hydrated lime – 3 ½ tbsp.
Lead arsenate – 2 ½ tbsp.
Sticker-spreader, mfr’s directions
Water – 1 gal.
Commercial Bordeaux powders or low-soluble coppers may be substituted for the home-made Bordeaux mixture in the formula.
Four applications are necessary in normal years to control black rot – (1) just before the blooms open; (2) just after bloom; (3) two weeks later; (4) as the berries begin to touch in the cluster.
These sprays will also help control rose chafers and powdery and downy mildew in wet summers. Lead arsenate may be left out of die last two sprays if Japanese beetles are not a problem.
Spray Schedules for Currants and Gooseberries:
1. Dormant Spray:
Applied before the buds begin to open in the early spring.
Elgetol – 1 tbsp.
Miscible oil – 7 ½ tbsp.
Water – 1 gal.
This application controls the San Jose scale and the eggs of the currant aphid, both important pests of currants but rarely of much importance on gooseberries. When there are no indications that the San Jose scale is present, the miscible oil may be left out of the formula, and application may be delayed until the buds begin showing green tips.
2. Unfolding-Leaf Spray:
Applied (only if dormant spray was not applied to control aphids) when first leaves are partly unfolded.
Nicotine sulfate – 1 ½ tsp.
Soap flakes – 3 tbsp.
Water – 1 gal.
The undersides of the leaves must be thoroughly coated to hit the aphids feeding there. When aphids are not controlled, the leaves become pocketed arid curled with red and yellow markings; many leaves may drop off; and the fruit will not ripen properly.
3. Currant-Worm and Gooseberry-Fruit-Worm Spray:
Applied when the young, green, black-spotted worms and the greenish fruit worms or their injuries are first observed (usually near the latter part of May).
1. Derris, timbo, or cube root powder, containing 4 to 5% rotenone – 3 tbsp.
Powdered skim milk or soybean flour – ½ tbsp.
Water – 1 gal.
or
2. A 0.5% rotenone dust
or
3. A pyrethrum spray or dust (for currant worms only)
The above sprays or dusts will also take care of the bright red or older orange-yellow, black-striped nymphs of the four-lined plant bug which sucks the juices from the young leaves of currants and gooseberries, leaving numerous small brown spots and stunting the growth of shoots.
This injury usually occurs during the month of June. The nicotine sulfate formula given in the unfolding-leaf spray may also be used for these pests.
4. Disease Spray:
Applied when the fruit is about half grown.
Formula same as for grapes without the lead arsenate.
This spray is necessary for leaf-spot diseases on both currants and gooseberries only if much wet, rainy weather occurred during the spring.
Spray Schedule for Raspberries:
1. Green-Tip Spray:
Applied when buds show about ¼ inch of green.
Elgetol – 2 tbsp.
Water – 1 gal.
This spray controls spur blight, or purple cane spot on red raspberries, which appears as dark blue or purplish spots on the canes around the buds during August. These spots become gray by the following spring. The buds are injured, and the fruiting laterals are sometimes killed where these spots occur. Older plantings are usually afflicted with this disease. Other cane-spot diseases may also be controlled by the use of the above formula.
2. Cluster-Bud Spray:
Applied just as the blossom bud clusters are forming (early May).
Either formula 1 or 2 without sulfur as for apples.
3. Preblossom Spray:
Applied just as the first blossoms begin to appear (about ten days after cluster-bud spray).
Either formula 1 or 2 without sulfur as for apples.
The formula used in these two sprays controls the raspberry fruit worm, which produces wormy berries, especially on early varieties of red raspberries. The spray is directed against the tiny, light-brown beetles which appear when the new foliage is unfolding and feed on blossom buds, leaves, and later the blossoms themselves, causing considerable damage to the yield, as well as wormy berries. These sprays or dusts also destroy the spiny, pale-green worms that feed on the undersides of the foliage and are the larvae of the raspberry sawfly.
Red spider may become a problem during hot, dry seasons and may be controlled.
Japanese beetles are also a major problem in heavily infested areas. Cheesecloth covers, or rotenone sprays or dusts are the only protection recommended until the berries are picked. Any of the sprays recommended for Japanese beetles may be used after picking is completed.