Answer:
burning land after harvest to communicate their resistance to migrant workers seeking entry into the state
Step-by-step explanation:
During the dust bowl era, Californian territories were experiencing continuous sand storms. AS a result, the crops that were planted by the farmers were covered in sand and couldn't grow properly. This caused massive harvest failures for the majority of farms in California.
This was the reason why burning land after harvest was not a form of their resistance. The foods were really scarce at that time, they know better than making more damage to the farms regardless of their hatred toward migrant workers.