Crop-weed competition in Napier Bajra hybrid (Pennisetum purpureum × Pennisetum glaucum) under different planting materials

A field experiment was conducted to find out critical period of crop-weed competition and to determine the extent of green fodder yield loss in Napier Bajra hybrid (Pennisetum purpureum × Pennisetum glaucum) at forage research farm, Ludhiana, Punjab, during 2014 and 2015. The experiment was laid out in split-plot design, keeping two planting materials (rooted slips and stem cuttings) in main plot and weed-infestation durations (weed infested till initial 10, 20, 30, 40 and 60 days after planting and weed-free for initial 10, 20, 30, 40 and 60 days after planting) in subplot. Rooted slips recorded significantly higher green fodder yield than stem cutting. The higher fodder yield with rooted slips might be owing to more vigorous plant growth at early stage. The reduction in fodder yield in the control (weedy check) was 43.2% as compared to weed-free conditions. The critical period of crop-weed competition was found to be 10–30 days after planting on the basis of different weed-infestation durations. Gompertz and logistic equations fitted to yield data in response to increasing period of weed control and weed interference showed that rooted slips (4–32 days) had longer critical period that stem cutting (5–27 days). Critical weed-free period for rooted slips planting was more than stem planting by 6 days during both years. However, Napier Bajra hybrid planted with rooted slips significantly overcome the weed pressure than stem cutting during both years.