Crop intensification and stress tolerance in hybrid napier

Abstract

Hybrid Napier (Pennisetum glaucum X Pennisetum purpureum) is a popular fodder grass among dairy farmers of Kerala due to its high production potential. However, there is a significant gap between fodder demand and supply, given the limited land availability in the State. Expanding fodder cultivation through crop intensification with the inclusion of fodder legumes in the existing cropping system is a viable option to boost fodder production and quality. Understanding the salt and flood tolerance of hybrid napier can help the farmers select suitable cultivars for coastal and flood-prone areas, to ensure fodder availability. In this context, an investigation entitled ‘Crop intensification and stress tolerance in hybrid napier’ was conducted at the Agronomy Farm, Department of Agronomy, College of Agriculture, Vellanikkara, Kerala from 2019 to 2021. The objectives were to assess the suitability of intercropping legumes with hybrid napier, its effect on growth, yield, quality, as well as soil health, and to study the response of a few popular hybrid napier cultivars to salinity stress and short-term flooding. The investigation comprised of three experiments (i) the production potential of hybrid napier-based legume intercropping systems (ii) tolerance of high-yielding hybrid napier cultivars to salinity stress and (iii) tolerance of high-yielding hybrid napier cultivars to short-term flooding. The field experiment on hybrid napier-based legume intercropping systems (HN+legume) was conducted during the two-year period from 2019 to 2021. It was laid out in randomized block design with four replications. The treatments consisted of hybrid napier in normal rows (60cm x 60cm) (T1), hybrid napier in paired rows (45/90cm) (T2), HN in paired rows + fodder cowpea (T3), HN in paired rows + stylosanthes (T4) and HN in paired rows + horse gram (T5). Three additional treatments of sole crops of fodder cowpea (T6), stylosanthes (Stylosanthes guianensis) (T7), and horse gram (T8) were included for comparison of production efficiency in the intercropping system under study. The results of the study indicate the possibility of intercropping hybrid napier planted in paired rows with legumes, in Kerala. Among the legumes, stylosanthes were the most suitable in terms of yield, net profit, and B-C ratio. Varieties IGFRI-3 and CO-3 were found inherently tolerant to mild levels of salinity stress compared to CO-5 and Suguna. Considering fodder yield, varieties CO-5 was found better suited to areas amenable to shortterm flooding (3-4 cm water depth, up to 15 days), and flooding immediately after harvesting was identified as the susceptible stage.