 As such, corn hybrids which are tolerant to drought , and heat would produce more consistent yields compared to the hybrids which are not tolerant to these stresses.
<clarity>  As such, corn hybrids which are tolerant to drought , and heat would produce more consistent yields compared to the hybrids which are not tolerant to these stresses.
 As such, corn hybrids which are tolerant to drought and heat stress would produce more consistent yields compared to the hybrids which are not tolerant to these stresses.