Agricultural and Forest Meteorology 116 (2003) 61–72 Regression models for lentil seed and straw yields in Near East A. Sarker ∗ , W. Erskine, M. Singh International Center for Agricultural Research in the Dry Areas (ICARDA), P.O. Box 5466, Aleppo, Syria Received 30 October 2001; received in revised form 12 November 2002; accepted 3 December 2002 Abstract Lentil (Lens culinaris Medikus subsp. culinaris) is traditionally grown as a rainfed crop globally, except in Sudan and Egypt, where it is grown under supplemental irrigation. Its seed is a rich source of protein for human consumption, and the straw is a valued animal feed in Near East. In the Mediterranean environment, lentil productivity is limited primarily by the amount and distribution of rainfall and temperature extremes. This study aimed to develop simple models to predict lentil seed and straw yields as a function of seasonal weather data (rainfall and temperature). Historical weather and yield trial data over 39 environments from three contrasting locations in Syria and Lebanon were used. Best-fit models for seed and straw yields in terms of climatic variables based on stepwise regression were developed. These accounted for over 77% variance in yield for both models. The overall responses to total seasonal rainfall were 5.16 kg ha -1 mm -1 seed yield and 10.7 kg ha -1 mm -1 for straw yield. Although May (period of pod-filling) rain contributed substantially to seed yield, high May temperatures reduced yield drastically. For straw yield, absolute minimum temperature and February temperature are important factors, in addition to total seasonal rainfall. The simple regression models developed from historical data not only describe the variation in lentil yields but can also be used for yield prediction purposes in the Near East. © 2002 Elsevier Science B.V. All rights reserved. Keywords: Lentil; Seed and straw; Climatic variables; Yield models 1. Introduction Lentil (Lens culinaris Medikus subsp. culinaris) is the most important food legume crop of rainfed cropping systems in Near East, traditionally grown in rotation with barley and wheat in low- and medium- rainfall areas, respectively. Lentil seed is a rich source of protein (up to 28%) for human consumption and its straw is a valued animal feed. In dry years, the income from lentil straw may equal that from seed in many parts of Near East. The crop is adapted to less favorable environments, where it is predominantly ∗ Corresponding author. Tel.: +963-21-2213433/2213477; fax: +963-21-2213490. E-mail address: a.sarker@cgiar.org (A. Sarker). grown in winter in regions where the annual average rainfall ranges between 300 and 400 mm. The amount and distribution of rainfall and win- ter temperature affect lentil growth and seed yield (Erskine and El Ashkar, 1993). Using data of two cul- tivars sown at six sites in Syria to quantify the effects of climatic variables on seed yield, they reported that total seasonal rainfall accounted for 41% of the vari- ance in mean seed yield. At Tel Hadya (a site also used in this study), the variation in total seasonal rain- fall accounted for 78.6% of the fluctuation in seed yield. Zhang et al. (2000) reported the relationship of seed yield, water use and water-use efficiency in lentil with total seasonal rainfall at a single location (Tel Hadya) over 12 years. For common vetch (Vicia sativa L.), a comparable legume grown for biomass, 0168-1923/02/$ – see front matter © 2002 Elsevier Science B.V. All rights reserved. doi:10.1016/S0168-1923(02)00247-2