Jagdish KumarMishra, Manish Kumar2019-06-182019-06-182004-08http://krishikosh.egranth.ac.in/handle/1/5810108898The study was taken up in Nainital district of Uttaranchal with the objectives (i) to estimate the yield gap in rice and wheat, under rice-wheat-fruits based production system, (ii) to identify production constraints in rice and wheat under the system, (iii) to estimate the intensity or severity of constraints and (iv) to prioritize the production constraints. The yield gap-I and yield gap-II were estimated for rice and wheat crop. Identification of production constraints was achieved by a review of journals, consulting scientists and extension workers. Estimation of intensity or severity of constraints was deduced by evaluating per hectare losses in yield and value for technical constraints and by noting the number of farmers in each rank group for socio-economic constraints. To prioritize the technical production constraints, value loss caused by them were arranged in descending order. Socio-economic production constraints were ranked by Garrett’s technique. The primary data was collected through survey of 80 sample farmers by personal interview on pre-structured schedule for the year 2002-03. The results from the study revealed that in rice, yield gap-II of 12.75 quintals per hectare dominated over yield gap-I of 8.78 quintals per hectare. However, in wheat with 15.22 quintals per hectare, yield gap-I dominated yield gap-II of 12.80 quintal per hectare. Among technical constraints in rice, stem borer stood at top priority (Rs.5223282.84 value loss) in the Nainital district, followed by Echinochloa colonum at second priority (Rs.5067852.03 value loss) and birds at third priority (Rs.4846105.68 value loss). Others in descending order of priority were leaf folder and white grub. Among socio-economic constraints, in rice, the topmost was non-availability of quality seeds. In wheat, Phalaris minor (Rs.8128127.37 value loss) gained topmost priority among constraints, whereas rodents were second according to priority (Rs.7522350.67 value loss). As regards the socio-economic constraints, in wheat, the topmost was non-availability of quality seeds. Integrated weed management techniques alongwith search for varietal resistance to crops and biotechnology were proposed as future strategies.ennullThesis