The search for new oil seed crops in the low rainfall drought Central Anatolia has attracted researchers to profitablealternative crops like Brassica species in recent years. Breeding of a suitable oilseed crop for the Central Anatoliawill provide a new rotational break for controlling soil borne diseases, weeds and drought stress that are very difficult to manage with prevailing agricultural practices. Brassica juncea L. is an important oilseed crop and is newlyintroduced in Turkey. This study was conducted to evaluate the developmental responses to 4 different day lengthsand cosequently climatic conditions to screen 38 B. juncea genotypes for some oil yield related agronomic charachterisitics under hot humid climatic conditions of Yenimahalle, Ankara, Turkey. It was noted that early and delayedsown genotypes had synchronization towards flowering in the month of June with 15 h 01 min to 15 h to 39 min daylength photoperiod. The results showed a significant effects of sowing dates day lengths and consequently climatesupon genotypes for oil yield and agronomic traits. The maximum mean crude oil yield (38.4 g m-2)was obtained fromAK genotype. The results clearly describe that early sowing provides long period of vegetative growth with increasedintake of photosynthates to plant sinks; that is not possible under late sowings.