Development and problems in the spread of new improved rice varieties in Central Java ProvinceResty Puspa Perdana, Adang Agustian, Wahyudi, Kurnia Suci Indraningsih and Chaerul MuslimE3S Web Conf., 316 (2021) 02032DOI: https://doi.org/10.1051/e3sconf/202131602032