John Kuriyan, KUsha Kumari, RKAU2020-07-202020-07-201980http://krishikosh.egranth.ac.in/handle/1/5810149400PGThe cyst nematode Heterodera cryzioola was observed to be an important pest of rice , affecting the growth and yield of paddy plant . However detailed investigations on this nematode was done earlier. The present study was hence undertaken to study the extent of loss, host range and control of this cyst nematode. The extent of loss caused by Hetrodera cryzicola on rice variety Triveni was studied at four inoculum levels of 6,000, 9,000, 12,000 and 18,000 larvae per sq.m. in the field experiment and 5, 10, 20 and 30 cysts per pot in pot culture study. There was considerable reduction in growth and yield of the paddy plant in both field and controlled conditions at all the different levels tried. This nematode caused considerable damage to the crop by supressing the height of the plant, number of tillers, number of leaves, earhead length, shoot weight, root weight, total yield and grain weight.ennullThesis