I grew this crop as part of my fodder crop and also for crop rotation. My little research showed that a crop like sunflower was good to add to a crop rotation program as they have deep roots. This would help keep the soil structure and nutrients balanced especially when rotated with a shallow rooted crop like maize.
Sunflower in general is not a difficult crop to grow. Its spray program for me was mostly to control insects. I did see much, if any, in form of fungal diseases that affected it.
Most people round the farm couldn't understand why I would want to do sunflower farming, especially as a fodder crop. I has however researched and seen that it was a good energy source and required a shorter growing period as compared to maize, which is the most popular crop for fodder.
Sunflower has various varieties I tried a non hybrid one with low fat content as well as a hybrid, high fat content. The hybrid, high fat content one seemed to do better. I guess the better genetics through hybrid vigour.
I thought heliotropism was a myth(sunflower plants following the course of the sun throughout the day), but once my plants developed flowers I actually witnessed it. It was fascinating to see the flower heads facing the east as the sun came up, and west when it set. Nature is amazing!
I didn't let my crop of sunflower get to maturity and dry. As soon as the plants had flowers had filled up their flower heads about half way, I harvested the crop for chopping up and ensiling. I must say it isn't the most appetizing feed to cows, or maybe it was because they weren't used to it. But the cows never really ate the sunflower silage with the zest they do maize or sorghum silage.
Another reason I did the sunflower was because I knew it was a good forage crop for the bees. I also wanted to taste what the honey would taste like when the bees foraged on the sunflower. However,by the time the sunflower crop was harvested, the bees had not put enough honey on the combs to cap it. I had to wait another 3-4 months for my taste of sunflower infused honey. I remember it has some nice smell and taste to it. This is especially because most of the honey I consume is harvested in the lowlands which is hotter and drier. Maybe the lack of a lot and diversified forage makes the honey not have much of a bouquet.
The one big problem I had with sunflower farming was birds. These little critters are tenacious. I had to employ a number of method from hanging wind blown shiny artifacts in the farm, to actually employing someone to shoo away the birds. If left unchecked, these can cause 100% loss of the crop.
Would I grow it again?
Sunflower is a good crop to take care of in the early stages. The headache comes in once they have heads which are filling out with seed. This is the most tiresome stage. Also because I was the only farmer to grow the crop in about a 10km radius, and the acreage was small, was the reason I got so much bird trouble.
For the bird problem alone, which I guess even with larger acreage will still compound, I wouldn't grow sunflower again.