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Integrated Crop Management Schedule
for the Production of Christmas Trees
CLARK A. GRANGER, Ph.D
GENEVA DUNCAN-FROST, M.F.
Licensed Professional Foresters
- Circular 11 - Revised 11/99
MAINE DEPARTMENT OF AGRICULTURE, CONSERVATION
AND FORESTRY
Maine Forest Service
Division of Forest Health and Monitoring
50 Hospital Street, Augusta, ME
Augusta, Maine 04330-0168
Tel. (207) 287-2431
Integrated Crop Management Schedule for Christmas Tree Production*
| Week 1 | Week 2 | Week 3 | Weeks 4-5 | |
| April | Douglas Fir -
Check for symptoms of Rhabdocline or Swiss needlecasts.
Rogue severely infected trees from plantations before May
1.
Balsam Fir - Check for symptoms of Lirula and Isthmiella needle casts; rogue infected trees from plantations before June 1. |
Scotch Pine - Prune pine-pine rust galls from lightly infected trees; rogue heavily infected trees from plantations before May 1. | Scotch Pine -
Check for presence of Cyclaneusma
needle cast. Apply first
spray of chlorothalonil if warranted.
White & Scotch Pine; Norway & Blue Spruce - Check for presence of white pine weevil adults or previous year damage. Spray with Lindane or Dimilin if either is present and damage levels are unacceptable. |
All species -
Assess potential for weed competition. Apply
preemergence herbicides such as simazine if
warranted. Begin planting when frost is out and
ground will support planting activity. Plant as
soon as possible after trees are lifted at nursery. Don't interplant. Old problems may infest
new plants.
Balsam Fir - If balsam shootboring sawfly is a significant perennial problem, apply Lorsban 4E or Diazinon AG500 3 times at 5 day intervals beginning 2 weeks prior to bud break. Blue Spruce & Douglas Fir - Do not plant these species close to each other. |
| May | Blue Spruce &
Douglas Fir - Check for presence of Cooley
spruce gall adelgid. If
damage is unacceptable, spray with diazinon, carbaryl or
chlorpyrifos.
Norway Spruce - Check for presence of eastern spruce gall adelgid galls. If damage is unacceptable, spray with diazinon, carbaryl or chlorpyrifos. White Pine - Check for presence of currants and gooseberries (Ribes) within 900 feet of pine trees. Destroy any Ribes found. Prune infected branches from trees. |
All species -
Check for porcupine damage to Christmas trees.
Porcupines may be visible now in larger trees surrounding
production areas and may be easily dispatched with an
appropriate firearm.
Balsam Fir - Check for presence of balsam twig aphid nymphs. Spray with diazinon or Lorsban when 25% of buds show green beneath or through bud scales. Check for presence of yellow witches' brooms. Prune brooms from trees, taking care to make pruning cuts below galls at the bases of brooms. |
All species except
Scotch pine - Apply fertilizer as prescribed by soil
or tissue analysis.
Douglas Fir - Check for symptoms of Rhabdocline or Swiss needlecasts. Begin sprays of chlorothalonil if disease is present. Scotch Pine - Apply second spray for Cyclaneusma needlecast (chlorothalonil) and first spray for pine-pine gall rust (mancozeb) if galls are present and producing spores. |
All species -
Begin a program of regular plantation mowings to allow
sunlight to lower branches, shorten infection periods,
expose rodents, and control alternate host plants.
Balsam Fir - Check to see if birds are breaking tender new shoots by alighting on them. If damage is serious, construct artificial perches which extend about 4 feet above surrounding Christmas trees. Balsam & Fraser Fir - Check for presence of spruce spider mites in areas damaged last year. If necessary, spray with Kelthane or Savey. Rotate miticides to manage resistance. |
| June | Balsam Fir - Check
needles for presence of balsam gall
midge. Spray with
diazinon or Lorsban if galls are abundant.
Scotch Pine - Apply second spray for pine-pine gall rust. Balsam & Fraser Fir - Remove female cones (if any) from tops of balsam and Fraser fir trees. |
Blue, White &
Norway Spruce - Monitor for presence of yellowheaded
spruce sawfly. If
numerous, spray with carbaryl.
Douglas Fir - Apply second spray for Rhabdocline or Swiss needlecasts. Scotch Pine - Apply final spray for Cyclaneusma needlecast. |
Scotch Pine -
Apply final spray for pine-pine gall
rust.
Balsam & Fraser Fir - Monitor for presence of spruce spider mites. If abundant, or if damage is apparent, spray with Kelthane or Lorsban now, and again in 10-14 days. |
Blue Spruce -
Check for presence of Cooley
adelgid galls on new
shoots. Remove and destroy any galls found by July
15.
Norway Spruce - Check for presence of eastern spruce gall adelgid. Remove and destroy any galls found by July 30. White & Scotch Pine - Begin shearing when needles have attained 2/3 of previous year length. Complete by July 4. |
| July | Douglas Fir - Apply final spray for Rhabdocline or Swiss needlecasts. | White Pine, Norway
& Blue Spruce - Check leaders for wilting due to white pine
weevil. If found, prune
back to healthy tissue and destroy all portions removed.
Balsam Fir, Norway & Blue Spruce - Commence shearing. Complete by Sept. 1. Shear during dry weather where possible. |
Balsam & Fraser
Fir - Scout Christmas tree production areas and
headlands within 50 feet for sensitive ferns or fireweed, the alternate hosts of serious needlecast
diseases. Eradicate ferns or fireweed using
mechanical methods or herbicides such as glyphosate.
Scotch Pine - Check for Lophodermium needle cast damage on last year's needles. If present, apply first spray of chlorothalonil or mancozeb. |
Balsam & Fraser
Fir - Monitor for presence of spruce spider
mites. If abundant, or if
damage is apparent, spray with Kelthane or Lorsban now,
and again in 10-14 days.
Fraser Fir - Commence shearing. Complete by Sept. 1. |
| August | All species - Scout plantations for resistant weeds. If found, employ alternative herbicides next season to manage resistance. | Balsam & Fraser Fir - Monitor for presence of spruce spider mites. If abundant, or if damage is apparent, spray with Kelthane or Lorsban now, and again in 10-14 days. | Scotch Pine - Apply second spray for Lophodermium needle cast. | All species -
Assess competition by perennial weeds. Apply
glyphosate or other appropriate contact herbicides if
warranted.
Balsam & Fraser Fir - Monitor for presence of spruce spider mites. If abundant, or if damage is apparent, spray with Kelthane or Lorsban now, and again in 10-14 days. |
| September | Balsam & Fraser Fir - Check for presence of female cone buds. Flag for sale any trees with excessive numbers of cone buds. | Scotch Pine - Apply final spray for Lophodermium needle cast. | All species - Take soil and foliage samples for analysis by the University of Maine (Maine Soil Testing Service, 5772 Deering Hall, University of Maine, Orono 04469). | |
| November | All species - Check for porcupine feeding. Set traps at den entrances if necessary. | Begin tree harvest. Earlier harvest may affect tree keepability. Store baled trees standing vertically on damp ground out of sun and wind. | All species - Check for porcupine feeding. Set traps at den entrances if necessary. |
*Occurrence or development of some pests may be delayed by up to several weeks in far northern and east coastal areas of Maine. Where pesticide trade names are used, no discrimination is intended and no endorsement is implied.
Please note: Not all sites are suitable for Christmas tree production. Avoid culture on sites with poor water or air drainage (frost pockets), heavy or wet soils, excessively drained soils, soils with high pH (over 6.5), and soils shallow to ledge.
HOW TO RECOGNIZE THE INSECTS, DISEASES AND OTHER PROBLEMS LISTED IN THIS CALENDAR
Balsam Gall Midge - In early June, look for small green swellings on needles, often about 1/3 the distance from the needle base to the needle tip. In midsummer galls (swellings) turn yellow and by harvest time galled needles shed, leaving bare spots on twigs. In late May, on warm evenings, look for tiny, orange, mosquito-like insects on or around fir tips.
Return to: April May June July August September November Top
Balsam Shootboring Sawfly - On warm, sunny days in late April, look for black, winged adults about the size of large black flies or small ants. In late May, look for short, wilting shoots each containing a single, grub-like larva.
Return to: April May June July August September November Top
Balsam Twig Aphid - In early May, look for milky green aphid nymphs on the undersides of previous year needles in the lower crowns of Christmas trees. Aphids are approximately as long as the widths of needles and are somewhat difficult to see, so look closely. In early June look for sticky, curled and twisted needles on new shoots.
Return to: April May June July August September November Top
Cooley Spruce Gall Adelgid - On blue spruce in early May, look for white waxy wool-like substance on twigs near terminal buds. Also look for old galls. On Douglas fir in early May, look for white woolly substance on the undersides of fir needles. In June look for elongate green to pale purple galls on blue spruce. In July and August these galls turn brown and open to release aphids. In September look for tiny, black eggs on the undersides of Douglas fir needles.
Return to: April May June July August September November Top
Currants and Gooseberries (Ribes) - These plants serve as alternate hosts for the white pine blister rust fungus. In late April and early May, look for the developing green foliage of these plants. They leaf out before almost anything else and are therefore easy to locate at that time. All Ribes have leaves that are borne alternately on the stem, all have 5 petaled flowers, and none have stipules (leaf-like structures at the base of leaf stalks).
Return to: April May June July August September November Top
Cyclaneusma Needlecast (also called Naemacyclus needlecast) - In April, look for yellow two and three year old needles with dark brown bands shedding from trees. In May look for off-white, waxy fruiting bodies of the causal fungus on brown needles. Return to: April May June July August September November Top
Eastern Spruce Gall Adelgid - In spring, look for brown galls at the base of previous years host growth. In June look for green galls at the base of present years host growth. By late August, green galls will have opened to release adelgids and turned brown in color. Return to: April May June July August September November Top
Female Cones - Conifers produce both male and female cones. Male cones produce pollen in May then fall from trees and are of little significance. Female cones are produced as trees begin growth in May, develop to 2-4 inches in length by July, then disintegrate to leave only cone "spikes" in September. Female cones are undesirable because they are formed at the expense of green shoot growth, causing gaps in trees, and because their remnants are unsightly.
Return to: April May June July August September November Top
Female Cone Buds - Cones develop from cone buds produced the previous year. By learning to identify female cone buds, growers can harvest trees before female cones have a chance to develop and lower tree quality. Look for slightly larger than normal, barrel-shaped buds on present year foliage near the tops of trees in September, and flag for sale any trees containing large numbers of cone buds during the upcoming harvest season.
Return to: April May June July August September November Top
Fireweed - This attractive plant serves as the alternate host of fir-fireweed rust. Growing one to six feet tall with long, narrow leaves, it begins producing racemes of showy magenta-pink flowers in late June and early July.
Return to: April May June July August September November Top
Lirula and Isthmiella Needle Casts - During the summer, look for brown second and third year needles, especially on lower branches. Brown needles often exhibit a dark or black central line. Current year foliage is still green.
Return to: April May June July August September November Top
Lophodermium Needlecast - In spring, look for yellowing then browning of previous year needles. In the summer dead needles drop, leaving only tufts of new green growth on branch tips. In the fall, look for tiny, black, football-shaped fruiting bodies on dead needles.
Return to: April May June July August September November Top
Pine-Pine Gall Rust - Look for globe-shaped swellings on stems or branches at any time of year. In mid-May through mid-June, look for sporulation by the causal fungus (yellow-orange spores) on the surface of galls.
Return to: April May June July August September November Top
Rhabdocline Needle Cast - In early April, look for yellowish brown to purplish brown needles. Heavily infected trees will shed previous year needles by early summer, leaving only present year foliage. By late fall yellow spots may be visible on current season foliage. Return to: April May June July August September November Top
Sensitive Fern - This is probably the most important alternate host plant for fir-fern rust. It is named sensitive fern because of its sensitivity to late spring and early fall frosts. Fronds are stiffly erect, originate from a creeping rhizome, and are not finely cut or lacey. Sensitive fern often grows in open, moist areas.
Return to: April May June July August September November Top
Spruce Spider Mite - Look for yellowish to rusty brown mottled needles. Mottling is apt to be more severe at needle bases. Needles heavily damaged from mite feeding may eventually turn brown and fall from trees. Mottling tends to persist on needles damaged in previous years so is conspicuous year-round. New foliage may become mottled by July. Mite populations may be assessed by holding a sheet of white paper beneath a branch, then tapping the branch vigorously. Mites will drop to the paper where they may be easily seen and their numbers assessed. If only an occasional mite is found, there is little need for concern. But if mites are abundant, controls should be applied quickly.
Return to: April May June July August September November Top
Swiss Needlecast - In April, look for yellow needles and thin foliage on affected trees. The undersides of infected green and yellow needles may contain rows of tiny, fuzzy black fruiting bodies. In July and August two and three year old needles may fall from trees, especially from lower branches.
Return to: April May June July August September November Top
White Pine Weevil - In late April, on warm days, look for small mottled brown weevils (snout beetles) about 1/4 inch long feeding and laying eggs just below bud clusters on leaders of white pine. Look also for pitch flow associated with this activity. In July, look for wilting in new terminal growth on trees due to larval feeding activity. The larvae responsible are white, slightly curved, up to 1/4 inch long and present under the bark. Portions of trees with larvae present should be destroyed.
Return to: April May June July August September November Top
Yellowheaded Spruce Sawfly - In June, examine new growth for small larvae with reddish-yellow heads and yellowish-green bodies. When fully grown in early July, larvae are about 3/4" long. Sawflies often feed gregariously.
Return to: April May June July August September November Top
Yellow Witches' Broom - In winter and early spring, look for brushy growths (brooms) devoid of foliage within crowns of balsam fir Christmas trees. In mid-May, new growth from broomed tissue is lighter green than surrounding foliage and this makes it easier to locate and remove brooms than at other times of the year. Look for swollen areas on branches where broom tissue originates.
Return to: April May June July August September November Top