ADAPTATION OF LENTIL (LENS-CULINARIS MEDIK.) TO MEDITERRANEAN-TYPE ENVIRONMENTS - EFFECT OF TIME OF SOWING ON GROWTH, YIELD, AND WATER-USE

This study examined the adaptation of lentil (Lens culinaris Medik. cv . Digger) to dryland Mediterranean-type environments of southern Austr alia and determined the effect of time of sowing on growth, yield, and water use. Phenology, canopy development, radiation absorption, dry m atter production and partitioning, seed yield, and water use were meas ured from a range of sowing times at a number of field locations in so uth-western Australia in 1994, 1995, and 1996. Contrary to previous re sults with poorly adapted cultivars, our study showed that lentil is w ell adapted to low to medium rainfall regions (300-500 mm/year) of sou th-western Australia and that seed yields greater than 1.0 t/ha and up to 2.5 t/ha can be achieved when sown early. Even in the dry season o f 1994 when May-October rainfall was <200 mm, yields of approximately 1.0 t/ha were produced from early sowings. Seed yields were reduced wi th delayed sowing at rates of 4-29 kg/ha.day. Sowing in late April or early May allowed a longer period for vegetative and reproductive grow th, rapid canopy development, greater absorption of photosynthetically active radiation, more water use, and, hence, greater dry matter prod uction, seed yield, and water use efficiency than when sowing was dela yed. Early-sown lentils began flowering and filling seeds earlier in t he growing season, at a time when vapour pressure deficits and air tem peratures were lower, and used more water in the post-flowering period when compared to those treatments where sawing was delayed. The value s of water use efficiency for dry matter and grain production, and tra nspiration efficiency, for early-sown lentil (up to 30 kg/ha.mm, 11 kg /ha.mm, and 20 kg/ha.mm, respectively) were comparable to those report ed for cereal and other grain legume crops in similar environments. Th e development of earlier flowering cultivars than Digger with greater dry matter production together with improved agronomic packages will i ncrease and stabilise lentil yields in low rainfall environments of so uthern Australia.