|Carrot (Daucus carota L. var. sativus Hoff.)
French: Carotte; Spanish: Zanahoria; Italian: Carota; German: Möhre
|Under Temperate Conditions
Biennial, cropped as annual. Harvested part: root.
Growth cycle for root production 100-180 days depending on cultivar.
Plant density: about 100/m2 (for half-long cultivars). Yields 25-50 t/ha (half-long cultivars). Requires light or well-textured soils, rich in decomposed organic matter; does not tolerate acid, alkaline or saline soils. Adapts well to climatic conditions.
In kg for crop yielding 30 t/ha : N = 90-120, P2O5 = 30-45, K2O = 150-300.
Adequate rate of fertilizer use in normal soils is estimated to be 120 kg N, 100 kg P2O5, 200-250 kg K2O per ha. It is recommended that one-quarter of the total N should be applied at sowing and the remainder in two topdressings. P2O5 and K2O should be incorporated in the soil before sowing. Direct use of organic manures should be avoided.
N deficiency impairs root colour by diminishing carotene synthesis. Excessive N may not only delay root growth and reduce keeping quality but may also increase the nitrate content, an important factor in roots to be processed for use in babyfoods. Excessive K can reduce uptake of Mg. Chloride salts should be avoided because excessive Cl reduces carotene content.
Boron is an important nutrient; foliar spray application is beneficial where calcareous soils contain <1 ppm B and where there is less than 18 ppm B in the leaves.
Under Tropical/Subtropical Conditions
Carrot (Daucus carota L.)
Directly seeded. Harvested four months after sowing. Plant density: 435 600 plants/ha. Preferably grown in loose, deep, well-drained soil. The crop is adapted to highland conditions in the tropics. Target marketable yields in intensive commercial production = 25 - 37 t/ha.
Plant analysis data
Apply well decomposed organic matter to prevent forked root development. Excessive N may also be partly responsible for splitting or forked roots; heavy N treatments also promote foliage growth at the expense of root growth. Fertilizer should be applied at least 7 days before sowing, as the crop is susceptible to salt injury. Carrots respond well to B and to lime and Mg applications, as well as to N, P and K . N and K are applied before root enlargement, about 30 days after germination.
Present fertilizer practices
On light sandy soils in semi-arid conditions apply 20t/ha of organic manure, 60 kg/ha N, 60 kg/ha P2O5 and 120 kg/ha K2O. All organic manure and P2O5 and 20 % of N and K2O broadcast before planting; 40 % of N and K2O sidedressed 30 and 60 days after planting.
Brazil (Minas Gerais)
General recommendations are, firstly, 40 kg/ha N, 320 kg/ha P2O5 and 240 kg/ha K2O incorporated in the soil at planting and, secondly, 80 kg/ha N and 40 kg/ha K2O broadcasted in 2 applications 15 and 30 days after planting.
Philippines (Los Banos)
A broadcast application of 500 - 600 kg/ha of a 10-25-25 mixture is recommended, or in K deficient soils 1 000 - 1 200 kg/ha 5-10-16 .
BIENZ, D.R.: Carrot splitting and second growth in Central Washington as influenced by spacing, time of sidedressing and other cultural practices. Proc. Amer. Soc. Hort. Sci. 86, 406-410 (1965)