Gladiolus – A Potential cut Flower

Plant Protection

Gladiolus is a glamorous bulbous flowering plant standing for its flower of beauty and perfection. It was introduced to India sometime during earlier part of nineteenth century. Popularity of this crop as a cut flower is increasing day by day because of its long keeping quality and attractive range of spike colours. It has year round demand in cities for purpose of bouquets and flower vases. This elegant cut flower is also used for home garden, public gardens and exhibition.

The two most important types are the large-flowered varieties and the butterfly or the miniature gladioli. Both types are early, mid-season and late-lowering requiring 65-75 days to 100-120 days for flowering. The butterfly types have small spikes of various colours and in many cases with dark and attractively coloured throats. They are ideally suited for small gardens and flower arrangements. Besides, the primulinus and colvillei are two other types; the former has small florets borne on thinner spikes with a hooded top petal in each floret. Psittacinus hybrids are also popular in gardens.

The important varieties are: George Mazure, Fay, Gold Dust, Tunia's Yellow Triumph, Elizabeth the Queen, Jo Wagenear, Spice and Span, Spotlight, Dream Girl, Goeff Whiteman, Blaur Dominos, Polygoon, Banaras, Mary House, Snow Princess, Ratnas, Butterfly, Masholra Butterfly, Sylvia, Apple Blossom. Poonam, Nazrana, Happy End, Hunting Song, Oscar, Sapna, Carmine, Dhanvantri, Suchitra, Yellow stone, White Prosperity etc

Plough the land to a depth 40-cm (16 inches to provide a well ventilated as well as well drained soil). Remove rocks and make sure the plot is level. Mix 10 t FYM/acre in the soil. Before planting apply 60-kg/acre single super phosphate (SSP) and 24 kg/acre Muriate of Potash (MOP) and mix this thoroughly with the soil. Before planting, the soil has to be irrigated to have a moist while planting.

Disinfect the soil with formalin (active ingredient Formaldehyde) at a conc. of 2%, in case the planting is done on the same plot. If planting is done on new land then there is no need of disinfecting the soil. In order to get a good flower the crop may not be shaded Therefore surrounding bushes and shrubs have to be trimmed to a maximum of 1 meter.

Gladiolus is generally planted from corms. Croms size ranging from 4-5 cm are selected and stored in dry, cool well ventilated area. Never keep the corms in direct sunlight. A medium sized corn (10-x 12-cm) with a high crown is better than a larger and flatter corms. Disinfect the corms by dipping them in the solution of Bavistin (30g/15 litres of water) for half an hour.

For planting in the plains gladiolus can best be planted on ridges during August-November, approx. 75 cm (30 inches) from the centre of one ridge to the centre of the next. The corms are planted about 15 to 20 cms apart in rows spaced 30 to 40 cms apart.

The advised plant density for planting in the plains is between 50,000 and 70,000 plants per acre. Planting depth is minimum 10 cm (4 inches) from the soil surface to provide more anchorage.

In the hills the corms can best be planted on raised beds of 1-meter (3-ft) width. Land costs in the hills are considerably higher than in the plains. Therefore, planting in the hills is done on raised beds. The main reason for this being a better and more economical use of the land. The advised plant density in the hills is between 80,000 and 1,00,000 (i.e. 20 x 20 cm). Since temperature in the hills is less than in the plains, the size of the corms used can be smaller. Planting depth should be minimum 10 cm (4 inches).

After the planting is finished, cover the soil with straw, pine needles or small branches. This is to keep the structure of the soil in good condition, to avoid surface panning, to keep the soil wet and to avoid excessive high soil temperature.

After planting immediate watering is required. The plants may be watered weekly or fortnightly depending upon the weather. During winter, frequent watering may not be needed.

The plants respond better to organic manure than to artificial fertilizers. After 6 to 8 weeks of planting, the plants may be fed with liquid manure, about once a week. An application of light soot water can also be given once a month or once a fortnight. At the time of the emergence of flower spikes, a dressing of about 2.5-cm thick layer of leaf mould is beneficial in producing better flowers with stronger spikes and better development of corms.

A top dressing of CAN will improve the quality of the flowers. After 3 leaves have formed apply a concentration of 20 kg/acre. Repeat the same procedure when the sixth leaf has formed. Depending on the macro nutrients content of the soil apply 20 kg/acre N-P-K after the formation of forth leaf. Always irrigate after fertilising.

1. Earthing: After about 6 to 8 weeks of planting, the plants may be earthed up.

2. Staking: After the emergence of flower spikes, they may be staked, so that the spikes do not fall down when there is a strong wind. However, staking is not necessary when the plants are grown closely or in clumps, and it is not needed in the case of miniature, butterfly or primulinus gladioli. Care should be taken not to injure the leaves at any stage as the injury is harmful to the plants.

3. In some varieties the corms form two sprouts. Cut one of them at ground level once the second leaf has formed.

Fusarial wilt:

It is the most destructive fungal disease in Gladiolus seen during rainy season coinciding with the months between June-October.Upon infection the central shoot comes out easily on pulling detached at collar region. Corms are completely rotten emitting foul smell. It can be controlled by dipping the corms for half an hour in Bavistin (30g/15 liters of water) or Captaf (75 gm/15 liters of water) followed by soil drenching at 30 days interval with Bavistin (30 gm/15 liters of water). For better sticking addition to Teepol (or) Triton (1ml/5 liters of spray solution) will be helpful.

Botrytis : Add Benlate (Benomyl 50%) to the regular spray solution in a concentration of 23 gm per 15 liter of water or Ridomil 72 WP (Metalaxyl/Zineb) in a concentration of 30 gm per 15 liter of water.

Tips: Damage the leaves and petals by silvering them. They can be control by spraying the plants with malathion (10cc in 10 liter of water) once a fortnight or so.

Caterpillars: injure the leaves and flowers buds may be effectively control by spraying the plants with DDT or BHC, or spray with Chloropyrifos @ 30 ml/15 litres of water.

To prevent weeds, apply Stomp (pendimethalin 30 % E.C.) in a concentration of 0.3 gm/l. Stomp can only be used when the corms are just planted. Never apply stomp when the top of the sprouts are less than 2.5cm. (1 inch) covered with soil

Harvesting of Flowers      

Harvesting of flowers takes place between 85 and 140 days after planting. The flowers can be cut as soon as the first floret at the bottom of the spike starts showing colour. For the domestic market the optimum stage of harvesting is when the first buds are just about to start opening. While cutting the stems leave 2-3 healthy leaves on the soil. This enables the corms to grow again. Always cut flowers early morning.

As soon as the flowers are cut, take them to a shady place. Always put the flowers in a vertical position, to avoid bending. Pack 10-12 stems in a bunch, 4 to 5 bunches in a bundle and wrap them in newspaper. Store the flowers in vertical position at a temperature of 2 to 5⁰C.

Harvesting and storage of corms for re-use;

Harvest the corms after 8 weeks of flowering. Dry the corms in a well ventilated room for no direct sunlight on the corms. After the drying period remove remaining soil and root. Disinfect the corms in a solution of Captaf (active ingredient captafol) concentration 0.5% + Bavistin (active ingredient carbendizim) concentration 0.2%. Pack the corms in gunny bags and place them in plastic crates.

Store the corms for a period of 10 to 12 weeks in a cold storage at +2⁰C. Make sure that there is plenty of ventilation in the cold storage. After twelve weeks the corms are ready for planting again.