what does logan stop doing to janie

There are a number of things that Logan stops doing to (and for) Janie shortly after their marriage begins. Theirs is not a marriage based on love. Given the social standing of women, and particularly black women, at the time, Janie marries Logan for security and protection. Logan essentially marries Janie to have another hand to work around the house and the farm. At the very beginning of chapter 4, Hurston writes:

Long before the year was up, Janie noticed that her husband had stopped talking in rhymes to her. He had ceased to wonder at her long black hair and finger it. Six months in he had told her, "If Ah kin haul de wood heah and chop it fuh yah, look lak you oughta be able tuh tote it inside. Mah fust wife never bothered me 'bout choppin' no wood nohow. She'd grab dat ax and sling chips lak uh man. You done been spoilt rotten."

This description presents an excellent synopsis of how things have changed for Janie. While he never showed any true affection, aside from providing food and a place to live, Logan has stopped putting on any airs at all. Not only does he stop feigning affection, but he also begins to require Janie to do more and more of the farm work. Shortly after this, he expects her to start working in the fields alongside him. She despises this, and it isn't long before Joe Starks enters the picture and her thoughts begin to turn to the promises that he makes to her.