i had the largest flowers on my 6 year old vines. we had an early spring, and havent seen any insects, even as of now, one honey bee this summer. i thought that i would have a 'bumper crop', but the clusters are sparse, and the fruit smaller than last year. could i use a soft brush to cross pollinate ?
Not really. I use a #6 round gold sable brush because it seems to be about the right size and softness. Brush over the flowers on one plant, then carefully (cup a hand under it) take it to the other flowers, and brush again. To pick up pollen, you'll want to hit the pistils (fairly obvious on grape flowers - they're around the edges and visibly charged with pollen), and to deposit pollen in the other flowers, you'll want to hit the stamen, which is smack in the center of the flower. That's it.