Re: Арека и Хамедорея / Хоби, Развлечения / Цветарство и градинарство

ARECA PALM
Chrysalidocarpus lutescens (Areca lutescens) is usually referred to as Areca palm, but has also been called yellow palm, butterfly palm, yellow butterfly palm, cane palm and golden feather palm. Stems are many clustered, slender, and sometimes branching. Areca palms may reach 30 feet tall. Leaves are ascending, curved at the apex with sheaths and petioles yellow or orange tinged. This palm originated in Madagascar and is widely grown outdoors in the tropics. In temperate zones they are popular as specimen plants for indoor use because they can tolerate relatively low light conditions.
Areca palm seedling plants are currently available as 2 1/4 to 3-inch liners established in small pots or cavity trays, or as 10 or 14-inch seedlings having bare roots or rooted in community trays. Seedlings should be transplanted at an early developmental stage (spike or 1st leaf stage). Finished plants can be obtained in a wide range of sizes growing in 6 to 52-inch size pots.

PRODUCTION
Arecas are propagated from seed with approximately 50 seeds to an ounce. Viable seeds, soaked for 10 minutes in a solution of hot sulfuric acid, can be expected to germinate in about 6 weeks. Fresh seed, yellow to ripe, should be planted with the top of the seed barely visible and germination temperature maintained between 80 and 85°F. Lower temperatures will increase germination time 100-200%. Seed storage at low humidity and low temperature is detrimental to germination. Cleaning seed is not essential if they are planted immediately. If seeds are to be stored, clean the yellow to fully ripened red seeds, air-dry them at 80-90%, treat with a seed protectant, and store at 75°F.
Best production light level for Areca palms is 5,000 to 6,000 foot-candles, or about 50% shade. Plants should receive a fertilization regime of 3.5 lb nitrogen per 1,000 ft2 a month from a 3-1- 2 ratio fertilizer. A level teaspoon of Osmocote 19-6-12 fertilizer (about 5 g) applied to a 6 inch pot every 3 months, or 200 ppm nitrogen from a 9-3-6 fertilizer applied weekly will supply the required fertilizer. Arecas respond equally well to liquid or slow release fertilizers when nitrogen levels are equivalent. Arecas need supplemental micronutrients to prevent chlorosis. Incorporating micronutrients (1.5 lb Micromax/yd3) to the soil is preferable to foliar sprays which can cause phytotoxicity. Phosphorus should be supplied only from fertilizers such as the 19-6-12 or 9-3-6 mentioned earlier.
Good quality Areca palms contain 1.5-2.5% dry weight of nitrogen, 0.1-0.3% phosphorus, 0.7-2.0% potassium, 1.0-1.5% calcium, 0.3-0.6% magnesium, 10-60 parts per million (ppm) copper, 50-300 ppm manganese and iron and 25-200 ppm zinc. Plants are tolerant of both atmospheric fluoride (F) and F in the medium if pH is maintained above 6.0. Tissue F levels of 16 ppm were found in leaves with no necrosis, while leaves with necrosis had only 21 ppm. Areca palms appear to be more tolerant to ethylene than most foliage plants.
The pH of the potting medium should be maintained near 6.0 with the addition of dolomite to keep fluoride unavailable to the plant. Mixes that have produced good quality palms include commercial mixes and peat:sand (3:1 by volume) and peat:pine bark:sand (6:3:1 by volume).
Areca palms can tolerate low soil moisture, but best growth is obtained if plants are not subjected to drought conditions. Arecas are hardier than most foliage plants and tolerate short durations of 32°F, but some necrosis might occur. Long durations of 32°F or lower will severely damage or kill the plants. For best growth, roots should be kept at 70-80°F with air temperatures up to 95°F. Plants can be shipped satisfactorily for 2 weeks at 55-65°F.
If spray or water residue causes the Areca to be unattractive, plant shines are a possible method of removal. Nine plant shines were used on Chamaedorea elegans with satisfactory results. Additionally, a 5% oxalic acid solution followed by rinsing cleansed Chamaedorea seifrizii of mineral salts.

PHYSIOLOGICAL PROBLEMS
1) Fluoride toxicity
Symptoms -
Foliar necrosis frequently starts as small spots, then progresses until entire leaflets are necrotic.
Control -
Maintain pH between 6.0 and 6.5 to keep fluoride unavailable. Avoid water, medium components and fertilizers (superphosphate) that contain fluoride.
2) Excess soluble salts
Symptoms -
Fronds are necrotic and have tip dieback and root systems have few active hair roots.
Control -
Arecas are more sensitive to excess soluble salts than most foliage plants. Fertilizer suggestions should be followed closely with soluble salts monitored regularly.
3) Leaf chlorosis
Symptoms -
New leaves are light yellow with either interveinal or overall chlorosis and may be small with necrotic tips. The probable cause is micronutrient deficiency due to iron, manganese or zinc. Iron deficiency causes interveinal to general chlorosis of newest leaves. An indistinct interveinal chlorosis of new foliage occurs when manganese is deficient. When zinc is lacking, new leaves are small with necrotic tips.
Control -
Iron, manganese and zinc chelate supplied at 400, 200 and 200 ppm of the element respectively, can cause foliar damage.
4) Chlorotic-necrotic spotting
Symptoms -
Fronds may have numerous necrotic spots along their entire length.
Control -
Spots sometimes are caused by foliar applications of micronutrients or copper- containing fungicides. Both copper chelate, 100 ppm copper, and cupric hydroxide fungicides result in phytotoxicity and should not be used on this small areca palms.
5) Poor or slow seed germination
Symptoms -
Seeds do not germinate properly.
Control -
Maintain proper soil moisture and temperature. Excess water will keep soil saturated and temperatures low and reduce or delay seed germination.