Growing Chrysanthemums: BARI Varieties, Propagation, Fertiliser and Pest Control

In December 2024, at the height of the winter flower season, The Agro News published a guide to growing chrysanthemums in Bangladesh. It covered the varieties developed by the Bangladesh Agricultural Research Institute (BARI) and official advice on propagation, fertiliser, care and pest control, largely matching the e-krishi guidance of the Agricultural Information Service (AIS).

The chrysanthemum belongs to the daisy family, Asteraceae. Most species are native to East Asia, and the plant has been cultivated in China since as far back as the 15th century BCE, according to Wikipedia. It is a late-season flower, which is why winter is its main season in Bangladesh.

BARI developed two chrysanthemum varieties, BARI Chandramallika-1 and BARI Chandramallika-2. The variety list of the Bangabandhu Sheikh Mujibur Rahman Agricultural University Digital Herbarium shows both were released in 2009, followed by BARI Chandramallika-3 (2009) and BARI Chandramallika-4 (2016).

It prefers cool weather and a sunny spot, in well-drained loam or sandy loam rich in organic matter, at a soil pH of 6.0 to 7.0. Utah State University Extension in the United States likewise advises fertile, well-drained soil and full sun.

Seedlings give poor flowers and bloom late, so growers in Bangladesh usually raise plants from stem cuttings or suckers. The guide's main steps were:

• From mid-July, 8 to 10 cm cuttings taken at a slant from sturdy one-year-old stems are rooted in a bed or container.
• When flowering ends in February, plants are cut back to 15 to 20 cm above the ground, and suckers grow from the cut base.
• Suckers 5 to 7 cm long are separated from the mother plant and set in a shaded nursery bed or pot.
• Young plants are shielded from rain and strong sun from May to July.
• Final planting in the field or in pots is done in October and November.

Chrysanthemums are heavy feeders. Per hectare, the guide recommended 10 tonnes of rotted cow dung or compost, 400 kg urea, 275 kg TSP, 300 kg muriate of potash, 165 kg gypsum and 12 kg each of boric acid and zinc oxide. Dung or compost goes in 10 to 15 days before planting and the other fertilisers except urea 7 to 10 days before. Urea is split: half at 25 to 30 days after planting, half at 45 to 50 days, worked in around the plant and watered.

Beds and pots should be kept weed free. Pinching out the tips about a month after planting makes the plant bushy rather than tall, and any early flowers on young plants are removed at once. For large blooms, growers disbud by keeping the central bud and removing the two side buds; for medium blooms, the central bud is removed instead.

Plant in the afternoon, firm the soil and water lightly; chrysanthemums do not tolerate standing water. Because the flowers are heavy for the stems, a bamboo stake matched to the variety's height should be set a little away from the base at planting time; staking later can wound the roots and let disease in. AIS puts the average yield at 30 to 40 flowers per plant a year, depending on the variety.

Thrips are tiny, ash-coloured insects that suck sap from leaves and flowers, leaving spots; leaves and blooms dry up, and a heavy attack can kill the plant. The guide advised spraying 2 ml of malathion per litre of water every 7 to 10 days, and Utah State University Extension also lists malathion for aphids and thrips, used according to the label.

Aphids, which are dark green, purple or black, are the flower's main pest. Young and adult aphids suck sap from new shoots and flowers, cutting growth and yield. According to the guide, they can be controlled with Novacron (0.1%) or Rogor (1%).

Photo: BRPever / Wikimedia Commons (CC BY-SA 4.0)

Sources: The Agro News (Staff Correspondent), Agricultural Information Service (e-krishi), Bangabandhu Sheikh Mujibur Rahman Agricultural University Digital Herbarium, Utah State University Extension, Wikipedia