Biotic stresses affecting legumes production in the Indo-Gangetic Plain uri icon

abstract

  • On the basis of current knowledge, an attempt has been made tocategorize the biotic constraints of the grain legumes groum in the riceandwheat-based cropping systems of the Indo-Gangetic Plain (1GP) ofBangladesh, India, Nepal, and Pakistan. Diseases and insect pests rankhigh overall, whereas weeds assume greater importance in the rainyseason legumes. Nematodes are reported to affect legumes butinformation on the losses caused by them is scanty. The majorcontributors to yield losses are foliar diseases and pod borers. Despite theobvious signs of damage caused by various root diseases, their impact onyield is moderate. The diseases of food legumes are also determined byplant type (specifically the configuration of crop canopy), croppingsystem, imbalances in soil nutrients, and crop rotation but their detailedeffects on the incidence and severity of diseases remains unclear.Similarly, interaction between soilborne diseases and nematodes isobvious, but research on their combined effect on yield losses has rarelybeen documented. For each legume the important diseases, insect pests,and weeds, with prospects for alleviating the constraints, are discussed.Although availability of host plant resistance to the major bioticconstraints have so far proven to be of limited use, we suggest that geneticresistance offers greater opportunities for strategic research investments.Redesigning of crop canopies such that they support a less conducivemicroclimate for infection and spread of fungal diseases needs greaterresearch focus. Also, development of short-duration cultivars to escapedrought and drought predisposed diseases such as fusarium wilt (late) inchickpea and aflatoxin infection in groundnut, and the incorporation ofdrought-resistance traits is worth pursuing. There is a need to understandthe consequences of the intensive rice-wheat cropping system on thechanging scenario of pests of legumes

publication date

  • 2000