Wetenschap - 12 september 1996

Integrated strategy protects tobacco

Integrated strategy protects tobacco

An integrated management strategy is the best way to control broomrape (Orobanche cernua) in tobacco (Nicotiana tabacum), according to PhD researcher Grama Nanjappa Dhanapal. There is no single method of controlling broomrape in all the different stages of its development that is both effective and economical. The germination phase is the most critical stage in the life cycle of broomrape, and control should focus on this stage.

Indian agronomist Dhanapal looked into different approaches to broomrape control during his PhD research. Broomrape is a parasitic weed which affects all tobacco growing areas in India. Broomrape germinates near the roots of the tobacco plant. It then attaches itself to the host and draws water and nutrients out from the tobacco's root system. Broomrape infestation in tobacco leads to average yield losses of 30% to 50%. Removing broomrape by hand is the most common way of controlling the weed. Dhanapal states that a combination of physical, chemical, cultural and biological methods offers the key to success. Different methods of control are needed for the different stages of development of the parasite. According to Dhanapal one possible strategy would be to grow a trap crop or to chemically stimulate the germination of the parasite before the tobacco crop starts to grow. This would then be followed by a herbicide treatment. Later in the growing season additional hand weeding or a
treatment of coconut or sunflower oil would be carried out to remove the last broomrape spikes.

Dhanapal, who carried out his PhD research under the sandwich programme, will defend his thesis on 16 September 1996.