I apologize for the language barrier. I hope this translates so it makes sense....... the only reliable way to tell when harvest time has arrived is to monitor your trichomes with a 30x or better 60x magnifying glass. You want to harvest with the highest percentage of cloudy milky trichomes as possible. Clear trichomes = not ready. cloudy = reaching maximum thc level. amber = too late your thc is converting to cbd and other less desirable compounds. You will get different effects depending on when you harvest. A early harvest with several clear trichs will give you more of an energetic high where a late harvest with a lot of amber will give you more of a sedative couchlock effect. It is really something you have to experiment with to see what you like. With that being said it looks like your plant may have a couple weeks left to go. I start monitoring mine when the pistils are about 50% brown and they are usually ripe at about 80% brown pistils. Hope this helps