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Water Management

  • Pigeonpea uses about 20-25 cm water to produce about 11 ha-1 of grain under traditional production systems. Most pigeonpea-growing regions in India receives 60-140 cm annual rainfall.
  • The moisture available in soils is generally sufficient to meet pigeonpea's requirements in northern and central India. There is often a need to remove excess water rather than to irrigate. Moisture availability in peninsular India is relatively poor, and the length of the growing, season in many areas is only 90-120 days.
  • Since medium duration pigeonpea genotypes are generally grown in this region, they suffer from terminal drought stress. The application of these irrigations doubled yields on Alfisols, but only increased yields by about 20 per cent on vertisols.
  • As moisture is only available for 90-120 days on Alfisols, genotypes with relatively shorter duration may do well under such conditions. Genotypes maturing in 150 days have yielded over 1.51 grain may do well under such conditions. Genotypes maturing in 150 days have yielded over 1.5 t grain ha-1 in the same environment where 180 days genotypes gave less than 1t ha-1.
  • The intensively managed pigeonpea systems that involve short duration pigeonpea have a higher water requirement because they are grown at high densities estimated water use by T 21 to be in the range of 55-60 cm. In years of low rainfall, or when the crop is grown on soil of low water holding capacity, the amount of water available to the crop may fall short of its requirement.
  • Significant responses to one or two supplemental irrigations on sandy loam soils at Kanpur, India. In this study a single irrigation applied at the pod filling stage gave a better response than application on the basis of a cumulative pan evaporation demand of 80 or 120 mm. In Rajasthan, India water applied at the early vegetative stage reduced yield by 14 per cent, whereas when it was applied at the branching stage, it increased yield by upto 34 per cent, on the other hand, reported no response to applied irrigation.
  • Chauhan et al (1987b) did not observe any response to applied irrigation on an Alfisol in a normal (about 700 mm) rainfall year.
  • However, three or four irrigations, each of 5 cm significantly improved the yield in the second and third harvests. These studies indicate that injudicious use of water may not help the pigeonpea crop sown in the rainy season, rather it may harm the crop.
  • The crop should be irrigated when it shows stress, indicated by the leaves pointing towards the sun at noon. Irrigation of the crop before plants show drought stress, as well as benign wasteful of water, can cause waterlogging and make the crop more prone in infection by such diseases as Fusarium wilt (Fusarium udum) and phytophthora blight (Phytophthora drechslerif.sp. cajani).
  • Such irrigations may also delay maturity, thus affecting the prospects of subsequent crops.

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Karnataka