The students of Sri Krishnadevaraya College of Horticulture Sciences in the district, using crop rotation method, have grown a crop of marigold flowers and are reaping good results.
On the same farm under a shade net, the students had previously grown solanaceous crops like tomato and cucumber but there were severe incidences of disease as well as soil-borne pathogens, especially nematodes(worms) affecting the crop.
To tackle this problem, the college dean had suggested adopting the crop rotation technique with marigold, and selected a new variety known as Arka Agni from the Indian Institute of Horticulture Research in Bangalore.
In the exercise carried out as part of the Experimental Learning Programme (ELP), the students were asked to attain the experience of crop cultivation first-hand through land preparation, sowing, watering, and up to the marketing stage.
Assistant Professor (Floriculture) Jeevan pointed out that marigold was an excellent crop for rotation under framed structures like polyhouse and shade net houses. Marigold plants naturally synthesize a compound called alpha-terthienyl in roots which helps in suppressing the root-knot nematode along with disease-promoting soil-borne organisms such as bacteria, insects, and viruses, Mr. Jeevan explained.
Once the crop is raised, the plants automatically absorb the inoculums (material for inoculation) leading to the complete eradication of unwanted bacteria in the soil, improving the soil health for successive new crops, said N.N Reddy, Associate Dean.
Students who were part of this experiment - Lahir, Pavan, Devendra, Munessha, Divyasri, Malathi, and Sreeja adopted some precision farming techniques like single-pinching operation 30 days after transplanting, drip irrigation, plastic mulch, and proper fertigation at the right time. The crop was harvested in time for the Devi Navaratri and the students sold marigolds at ₹60 a kilogram.
