Scientists have developed genetically engineered plants that are pest-resistant. By adding genes to the plant's DNA, they become toxic to insects (but not to plants or animals). This means that these plants may not need to be sprayed with pesticides to ward off the insects.

Genetically modified organisms (GMOs) have altered their genomes in different ways in order to be resistant to both biotic (e.g., insect pests) and abiotic (e.g., drought) stress conditions

Explanation:

A genetically modified organism (GMO) is any organism, i.e., plant, animal, bacterium, etc., whose DNA has been altered by genetic engineering. The GMO crops can exhibit resistance to insect pests in order to increase their agronomic yields (as well as resistance to other biotic and abiotic stresses). It is for that reason that GMO crops are widely used in many countries. A commercially available GMO crop is Bt corn, which is a genetically engineered maize that expresses proteins from the bacterium Bacillus thuringiensis (Bt), which are poisonous to several insect pest species.

your answer is "the 1950's"

measuring light intensity

light meters can be used to measure light intensity. the meter is held at the soil surface and pointed in the direction of the maximum light intensity, and then the meter is read.

errors can be made when measuring light intensity by accidentally shading the light meter. the reliability of the results can be checked by taking many samples.