Genetic engineering has enabled us to grow potatoes, corn, and cotton that contain some DNA from bacteria that encodes (I.e contains the recipe for) a protein, referred to as Bt Crystal Toxin, that disrupts the metabolism of some major pests. They are regarded as safe for humans because it requires both a higher pH (alkaline) and specific receptors that humans lack in order to do damage to an organism.
Though the technology isn't harmless either. Let's assume sufficient care is and perpetually will be taken to avoid major disasters. What remains is amoral for-profit companies that now have far more ability to engineer food for market fit. Why is this bad? Because carrots and apples will slowly turn into the equivalents of Snickers and Cheetos - those are the products we get when not constrained by nature.
My personal experience matches. Our apple and cherry and peach harvests are hit or miss. Our pawpaw, hickory, and passion fruit harvests ae always exceptional.
The problem with monocultures is you have no breaks where competition from other bug species, birds, animals, etc, keeps an ecosystem in balance. So you end up creating this environment where a pest can take off without any resistance.
This is usually not done out of a desire to maximize yields. Farmers don't want to take up space with trees that are 'not producing'. But the other way to look at it is that those other plants and trees are producing a ton of value, they're just not producing a crop per se. That said, many companion plants can also be valuable crops in their own right.
I am all for it (even though it needs to be watched and not used for any sort of chemical increase only decrease) why not?
The reason why most people don't do that is because it's expensive. So, the reason that spraying is more conventionally popular is not because it's the only way, but because it's cheaper. And the reason it's cheaper is because – as I've mentioned elsewhere – the negative externalities are not paid by the producer, but are rather covered by society.
That is to say, if food producers aren't having to pay the cost on society's health, or on the ecosystem's health, then it's the road most farms are going to take. The solution would be for society to cover the equivalent cost in not doing those practices. I.e., dramatically increasing funding for farms that take sustainable approaches.
Half the food that is produced ends up wasted, and a serious amount of crops isn't even counted in that total figure because it's destined from the start for fucking biofuel.
Get rid of that waste, get rid of fossil fuels, and you can feed the world comfortably without having to turn farms into chemical weapon dispensers against all kinds of wildlife.
You can't eliminate food waste - but many well off Americans have no clue about how to properly feed themselves while minimizing waste.
If you need it spelled out what you need to do: limit portion sizes in restaurants (where a lot of the food waste happens, also contributing to the insane rat infestation issues [3]) by law since Americans seem to love extensive portions, educate people how to cook and how to plan cooking, ban ultra large food packaging that no reasonable family can use before the product goes bad, and introduce actual public transit on all levels from local over regional to interstate to reduce your dependency on fossil fuels.
As for food waste in developing countries, it would be a good starter idea to invest into electrical grids and microgrids, it's hard to keep food from perishing when you don't have a stable grid to run a fridge. But that's a monumental task that needs international cooperation.
[1] https://www.rts.com/resources/guides/food-waste-america/
[2] https://zerowasteeurope.eu/our-work/eu-policy/waste-manageme...
[3] https://www.npr.org/sections/thesalt/2012/11/27/165907972/fo...
https://www.imdb.com/title/tt8969332/
Maybe biodiversity is the solution.
Additionally, avoiding monoculture orchards and incorporating diverse trees, such as oak, known for enhancing biodiversity, could be beneficial.
https://www.gardeningknowhow.com/edible/fruits/apples/apple-...