Agroecology and crop adaptation.

<title>Abstract</title> This chapter describes the production environments; phenological adaptation to the environment; flowering response to photoperiod and temperature; and the impact of abiotic stresses (water availability, waterlogging, temperature, nutrient toxicity including salinity and sodicity, and mineral deficiency), diseases, and management (sowing time, weed control, and harvesting method) on adaptation of lentil. Improvement of adaptation through understanding genotype by environment interactions in lentil is discussed. To improve adaptation, the key traits that facilitate increased production (level and reliability of seed production), farming system benefit and price (quality of seed), or reduce cost must be identified, quantified and addressed through improved production technology and breeding. More specifically, profitability is a culmination of a species interaction with the environment, in particular the quantity and distribution of rainfall and temperature which influences the length of growing season, soil characteristics and biotic stresses, and cultural practices. Farming system benefits include those involved with rotation, such as providing a disease break or improving soil nutrition, weed management, and the timing and simplicity of total farm operation.