Introduction
Cauliflower (Brassica oleracea var. botrytis) is the most popular vegetable among cole crops. It has a small, thick stem, bearing a whorl of leaves and a branched tap root system. The main growing point develops into a short shoot system whose apices make up the convex surface of the curd so the curd is a prefloral fleshy apical meristem. The edible part, i.e. curd color is generally white and may be enclosed by inner leaves before its exposure. Curd color varies with the variety and environment. It may be white or cream-white. This is a leading cole vegetable because of its delicious taste, flavor, and nutrition. The curd contains an appreciable amount of vitamin B, vitamin C, folate, calcium, and protein. The curd is also a rich source of glucosinolates, which have anticarcinogenic properties. It is generally used as a cooked vegetable either singly or mixed with other vegetable pickles. Frozen cauliflowers are also available in the market.
India is the second-largest producer of cauliflower in the world, after China. During 2012-2013, India produced 78.87 lakh tonnes of cauliflower from 4.02 lakh hectares. The average productivity in India is about 19.6 metric tonnes/ha. West Bengal is the leading state both for area and production followed by Bihar and Madhya Pradesh. Odisha, Gujarat, Haryana, Asom, Uttar Pradesh, and Maharashtra are the other major cauliflower-growing states. With the development of new varieties, it is now being grown in non-traditional areas of Andhra Pradesh, Tamil Nadu, and Kerala also.
Table of Content (toc)
Climate and soil
Cauliflower is a thermo-sensitive crop. Temperature affects the vegetative, cursing, and reproductive phases of cauliflower. It can grow at an average temperature of 5-8°C to 25-28°C. During vegetative growth, some varieties may withstand temperatures as low as -10°C and as high as 40°C for a few days. The optimum temperature for the growth of young plants is around 23°C and 17-20°C in later stages. In temperate regions, the growth of young seedlings may cease when the temperature is slightly above 0°C, while early varieties in plains and other tropical regions can grow well up to 35°C. The new genotypes in this group are capable of forming curds at around an average temperature of 30°C. Different varieties require specific temperatures for curd development. If the temperature is high, the crop continues to grow vegetatively, and if lower, it only forms small curds (buttons). For desirable curd development, plants must pass the juvenile phase and may attain certain optimum growth. This period varies from variety to variety and group to group. Higher or lower temperatures for a particular variety or large fluctuation in temperature at the time of curd development may cause some disorders.
Cauliflower can grow on sandy loam to clayey loam soils, which are well-drained and rich in nutrients. Fairly deep loam soils are ideal for growing cauliflower. The soil must be rich in organic matter. Soils with poor drainage should be avoided, especially for raising early and rainy season crops. The optimum soil pH for good growth is 5.5-6.5.
Varieties
There are 2 separate groups of cauliflower-tropical and snowball. The tropical group has a large number of varieties adapted to widely varying temperature conditions in different areas. On the basis of the curd maturity and temperature requirement for curd initiation and development, cauliflower can be divided into 4 maturity groups. Of these, 3 groups are typical Indian cauliflowers, while the fourth is Snowball type. Seeds of Indian cauliflower can be produced in plains of northern India, but Snowball types set seed only in the hilly areas, mid-hills above 1,000 m AMSL elevation.
Important varieties/hybrids of each group along with their pedigree breeding method, chief characters, and their sources are given below.
September-October maturity (Early 20-27°C)
Pusa Meghna (IARI, New Delhi) – Recurrent Selection
Extra early maturity, semi spreading type, light green, glabrous, smooth, non-blistered leaves, curd weight 350-400 g, average yield 12.5 tonnes/ha.
Pusa Kartik Sankar (F1) (IARI, New Delhi) –
Early maturity, curd compact, retentive white, medium size, weighing about 475 g, average yield 14.5-16 tonnes/ha, resistant to downy mildew.
Pusa Kellkl (IARI, New Delhi)
Early maturity, the optimum temperature range for curd initiation and development 22-27*C. curd compact, retentive white, curd weight 500-600 g, average yield 18 tonnes/ha, suitable for early sowing during the first week of June under north Indian plains maturing during the second fortnight of October.
Pusa Ashwini (IARI, New Delhi)
Early maturity, curd initiation, and development take place at a temperature range of 22- 27C. Suitable for transplanting during July and reaches marketable maturity during the first fortnight of October; compact with retentive white color. The average curd weight is 500 – 600 g with a yield potential of 16-18 tonnes/ha.
Pusa Deepali (IARI, New Delhi)
Plants erect, leaves waxy green ith rounded tips, compact curds, self blanching habit, curd weight 350-400 g; average yield 15 tonnes/ ha.
Kashi Kunwari (IVR, Varanasi)
Curds semi-dome type, white, compact, curd weight is 350-400g and average yield is 30-35 tonnes/ha.
Early Kunwari (PAU, Ludhiana)
Curds yellowish, very early maturity, leaves bluish-green, wavy with a waxy bloom, the average yield is 8 tonnes/ha.
November maturity ( Mid-early 16-20°C)
Pusa Hybrid 2 (F1) (IARI, New Delhi) – CC-32 x 18-19
Plants medium size, semi-erect, curds white, creamy-w) – CC-32 x 18-19hite, highly compact with average curd weight of 907 g, average yield 25-27 tonnes/ha, and field resistance to downy mildew.
Pusa Sharad (IARI, New Delhi)
Leaves bluish-green with long petiole, curds semi-dome shaped, retentive white, very compact, curd weight is 900 g, average yield 24 tonnes/ha.
Pant Gobhi 4 (GBPUAT, Pantnagar)
Medium plant size, semi-erect leaves, curd compact, creamy white, the average yield is 17-18 tonnes/ha.
Punjab Giant 35 (PAU, Ludhiana)
Curd cream color, compact, average yield 17 tonnes/ha.
December maturity (Mid-late 12-16°C)
Pusa Paushja (IARI, New Delhi)
Leaves, bluish-green, narrow with conical leaf top, curds retentive, white color, very compact, curd weight 900g, the average yield is 40 tonnes/ha.
Pusa Shukti (IARI, New Delhi)
Green leaves with broad round leaf top. Curd is white, curd weight 9o0 g. average yield is 44 tonnes/ha. Tolerant to downy mildew and black rot.
Pusa Shubhra (IARI, New Delhi)
Plants erect, bluish-green leaves, curds compact, white curds compact, weight 700-800 g average yield 25-30 tonnes/ha, resistant to black rot.
Pusa Himiyoti (IARI, New Delhi)
Plants erect, bluish-green leaves, curds retentive white, curd weight 500-600 g, average yield 25-30 tonnes/ha. Can be grown both in hills (April-July sowing) and north Indian plains.
Palam Uphar (CSK HPKV, Palampur)
Curd compact, creamish-white, average yield 25 tonnes/ha.
Kashi Agahani (IVR, Varanasi)
Curd compact, creamish-white, average yield is 25 tonnes/ha.
Pant Shubhra (G8PUAT, Pantnagar)
Curd compact, slightly conical, creamish-white, the average yield is 25 tonnes/ha.
Snowbell group (Late 10-16°C )
Pusa Snowball1 (IARI, New Delhi)
Straight leaves, self-blanching habit, curds compact, medium, and snow-white in color, crud weight 500-600 g. average yield 25-30 tonnes/ha.
Pusa Snowball K1 (IARI, New Delhi)
Leaves puckered, serrated and light green in color, curd, snow-white color, high-quality curd weighs 500-600 g, average yield 30 tonnes/ha, tolerant to black rot.
Pusa Snowball KT-25 (IARI, New Delhi)
Leaves light green, curd white, and compact, self-blanching, curd weight 500-600 g, average yield 17.5-30 tonnes/ha. Late maturity, can be grown both in hills and north Indian plains (October-November sowing), resistant to black rot.
Pusa Snowball cauliflower Hybrid 1 (F1) (IARI, New Delhi) –
CMS-based hybrid, curds attractive snow-white color, self blanching habit, curd weighs 500-600 g, the average yield is 25-30 tonnes/ha, partial resistance to black rot.
Cultivation
Nursery raising
Cauliflower is propagated through seed. A healthy nursery is very important to raise a good crop. The time of sowing depends upon the cultivar and temperature requirement for curd formation. The nursery of the group I needs special care because the temperature is not very congenial at that time. The width of beds of this group should not be more than 60 cm, so that water can easily percolate up to the middle portion from the broader channel, made in between beds. The nursery should be covered with sirkis to protect young seedlings from dry and hot winds. The channels may be filled with water every evening. The nursery of October and November maturity groups need protection from the heavy downpours. Therefore, seedlings should be raised in rain shelters. The nursery for December and Snowball groups is comparatively easy to raise because of favorable climate conditions during the period. Raised nursery beds (15 cm high) should be prepared to facilitate proper drainage.
Nursery beds should be thoroughly prepared by adding well-rotted farmyard manure or compost @ 10 kg/m². Treating nursery beds with formalin may be avoided due to its adverse effect on the seedlings in the initial stage. Before sowing, seeds should be treated to get rid of fungal diseases. However, to control seed-borne diseases hot-water treatment at 50°C for 30 minutes is the only remedy. About 600-700 g seeds for early types and 300-400 g for mid and late types are sufficient to raise crops for a hectare area. The seeds are sown in furrows 7-8 cm apart. After sowing, cover the seed with a mixture of fine soil and sieved farmyard manure, and cover the beds with dry grass before watering. The grass cover shall be removed when seedlings start emerging.
Transplanting
The seedlings are ready 3-6 weeks after sowing. In early maturity, 5-6 weeks old and in mid-season and late types 3-4 week old seedlings should be transplanted. The seedlings for September and October maturity are transplanted in mid-July and August, respectively. The mid-season varieties are transplanted in September-October, while late Snowball types, during the second fortnight of October in north Indian plains. Transplanting distance varies according to variety and time of planting. Transplanting of September maturity is recommended on raised beds at a spacing of 45 cm x30 cm. For mid-season and snowball varieties, a planting distance of 45 cm x 45 cm and 60 cm 45 cm is ideal.
Cauliflower requires 120 kg N, 100 kg P, 60 kg K for proper growth and optimum production. Half of N and whole of P and K should be applied as basal dose and the rest of N in 2-3 split doses, on split 30 days after transplanting.
Starter solutions are a mixture of soluble fertilizers and water used for the quick establishment of seedlings and checking transplantation shock. The fertilizers dissolve easily in water and the nutrients are readily available for young seedlings. Dipping of cauliflower seedling roots at transplanting in IBA (1mg/liter) + starter solution of ammonium sulphate and superphosphate (1:2) and 2% Captaf solution induces earliness, increasing curd yield and protects plants from damping off. Combined foliar spraying of GA, (100 mg/liters), NAA (120 mg/liter), and Mo (2 g/litre) enhanced the total yield. A similar increase in yield may be obtained by the spraying of GA, (50 mg/liter) and urea (1 g/litre).
Aftercare
Cauliflower is a very sensitive crop and any check-in of its growth at any stage results in buttoning. Crust formation after first irrigation is more common in heavy soils, hindering water and air penetration to roots affecting growth adversely. During the rainy season, when the crop is raised on the ridges, adequate earthing-up is more useful. Hoeing and weeding operations should not be deep to avoid injury to the shallow root system. The weed problem is very serious in this crop because of wider spacing, frequent irrigation, and high fertility. Pre planting application of stomp (Pendimethalin) or Basalin @2.0-3.0 liter/ ha helps control weeds. Application of weedicides supplemented with 1-2 hand-weedings is enough to keep the crop weed-free.
Irrigation
First irrigation is given just after transplanting the seedlings. The number and frequency of irrigations depend upon weather, soil type, and variety. However, optimum water supply is a must, both during growth and curd formation stages. For early and mid-season groups, irrigation depends upon the intensity of the monsoon. As raised bed planting is recommended in both groups, irrigation is given in furrows. However, 5-8 irrigations are generally required for cauliflower crops but heavy irrigation should be avoided. Drip irrigation is preferred in cauliflower fields.
Blanching in Cauliflower
Blanching is a method to protect the curds from attaining yellow color after their direct exposure to the sun. This is quite common in early-mid season varieties spreading and open plant types. The blanching may be done by placing the leaf on the curd or tying the top leaves immediately after the curd exposure. Most of the late types commonly known as the snowball type have self-blanching habits.
Physiological disorders
Cauliflower suffers from several physiological disorders, which manifest in different types of disease syndrome. Some may be genetically controlled, whereas others may be due to environmental, organic, and inorganic nutritional imbalance. Important among these are described here.
Riceyness in Cauliflower
There is the sporadic lengthening of peduncle of prefloral buds giving ricey appearance on curd surface. The main causative factor is temperature fluctuation higher or lower than the optimum required for a particular cultivar and genetic susceptibility i.e. hereditary factors. Heavy application of N and high humidity may also cause riceyness. Selection of proper varieties for a particular time of cultivation, optimum application of nitrogenous fertilizers, and planting of resistant and tolerant varieties minimize this condition. Fuzziness: In fuzziness; lengthening of all pedicels of prefloral buds takes place leading to a velvety appearance of curd. Sowing at a normal time minimizes fuzziness. Delayed planting may lead to fuzziness as curd maturity starts early.
Bracting in Cauliflower
It is the emergence of small green leaf tips (bracts) from in between segments or prefloral buds of curds. Prevalence of high temperature especially after curd initiation or fluctuation in temperature at curding stage increases this disorder besides genetic susceptibility. The selection of proper varieties may reduce it.
Blindness in Cauliflower
It results in no curd formation. Plants grow without terminal bud and fail to form any curd. Causes include pre-and/or post-transplanting factors damage to the terminal growing point due to low temperature, cutworm damage, or rough handling of transplants. Hereditary factors also play role in this.
Buttoning in Cauliflower
It is the development of small curds in young plants. Causes of this disorder are-a limited nitrogen supply, transplanting of old seedlings, water stagnation in the field, planting early maturity varieties late in the season. This disorder can be reduced by a supply of adequate N and timely field transplanting.
Pinking in Cauliflower
The appearance of pink color on the surface of the curd is known as pinking. Varieties differ in their sensitivity to pinking. Insensitive varieties (Snowball types), pinking may aggravate due to exposure to low temperature, but more due to genetic susceptibility.
Browning (Brown-rot or red-rot) in Cauliflower
This is caused by boron deficiency; more common in calcareous soils having pH above 7.5; resulting in the appearance of water-soaked areas in the curd center and in the advanced stage pink or rusty brown area appears on the curd surface. The affected curd exposed to sunlight during the development causes browning of curds and hollow cavities in the stem. It can be controlled by soil application of borax 20 kg/ha or Solubor 10 kg/ha. Foliar application of Borax 0.1 or 0.2% before the curd formation stage can also be effective.
Mineral deficiency
Diseases caused by mineral deficiency are described below.
Whiptail of Cauliflower
The deficiency of molybdenum especially in acidic soils causes a whiptail in cauliflower. Normal leaf blade development fails, and the only strap-like savoyed leaves are formed. In extreme cases, only mid- rib develops, hence the name whiptail is given to this disorder. This condition is associated with acidic soils, hence soil pH should be maintained at 6.5-7.5 by application of lime 2-6 tonnes/ha depending on the existing soil pH. Soil application of 300-400 g/ha of sodium or ammonium molybdate or drenching at a 0.25 g/litre at transplanting is desirable.
Chlorosis of Cauliflower
Chlorosis shows an interveinal, yellow mottling of lower older leaves. Since cauliflower has a high magnesium requirement, its deficiency causes chlorosis when grown on high acidic soil. This can be corrected by applying magnesium oxide @ 300 kg/ha. Liming soil and the use of chemical fertilizer containing soluble magnesium keep this in control.
The hollow stem of Cauliflower
In this case, hollow areas extend from below curd when the core or fleshy center splits due to an uneven growth rate with the rest of the plant. The cavity may extend to either end of the plant to produce a cavity to the outside environment. In heavily fertilized soils, particularly with nitrogen, rapidly growing plants of cauliflower develop hollow stems and curd. It may be corrected by close spacing and optimum use of nitrogenous fertilizers.
Harvesting and post-harvest management
Cauliflower is harvested when curds are compact, attain the proper size, and retain their original color. Delayed harvesting results in non-marketable, loose and discolored curds. Medium-size, white and compact curds are mostly preferred in the market. The plant is cut at ground level with a sharp cutting knife, sickle, or ‘Khurpi’. The trimming of leaves depends upon the mode of packing and transportation. When packing in crates, most of the leaves are removed leaving a small portion of the stalk close to the curd surface. While transporting in gunny bags, inner leaves covering the curd surface and the next whorl are left intact; when loading directly onto the trucks more leaves are retained and trimmed only after their unloading in the market.
The yield varies greatly depending upon the variety and the time of maturity. The early-maturing varieties have an average yield of 6-10 tonnes/ha, and mid and late varieties (maturing during Nov-Feb) yield 25-35 tonnes/ha.
There is now greater demand for pre-packed fresh vegetables in the supermarkets and major stores. The use of polythene packing provides a modified atmosphere and consequently reduces decaying, softening, loss of total solids and weight. Consumer package of cauliflower should be ventilated which helps in vacuum cooling and prevents CO₂ injury. Thin and gas-permeable film consumer packages maintain cauliflower flavor for a longer period. After harvesting, the curds can be stored for 2-4 days at room temperature. In cold storage, the curd is stored at 0°C and 85-90% relative humidity keep well for about 30 days.