ASSESSMENT OF YIELD LOSS DUE TO THE MILLET HEAD MINER, HELIOCHEILUS-ALBIPUNCTELLA (LEPIDOPTERA, NOCTUIDAE) USING A DAMAGE RATING-SCALE AND REGRESSION-ANALYSIS IN NIGER

Linear equations for five pearl millet varieties were established for yield losses due to damage by the millet head miner, Heliocheilus albi punctella De Joannis (Lepidoptera: Noctuidae), using a panicle damage rating scale. A very high positive correlation (r>0.90; P=0.001) was f ound between damage rating and percent yield loss, and also between ob served and predicted yield loss. The low percent absolute deviation (% ad) and deviation ratios (dr) between observed and predicted yield lo ss demonstrated the reliability of the damage rating scale, and the es tablished yield loss equations. In addition, the damage rating on farm ers' fields by farmers and a team of technicians showed that the metho d can be used for quick on-farm assessment of yield loss by extension agents and farmers. In four farmer's fields, the estimated yield loss for the local variety (Sadore local) ranged from 11.7 to 41.9%. Implic ations in the use of the method in future crop loss assessment in pear l millet are presented and discussed.