Seed health evaluation of farmer-rice (Oryza sativa L.) seeds

Seed health evaluation of farmer seeds in Cavite, Laguna and Quezon, in 1993-1995, and in Iloilo and Nueva Ecija [Philippines] 1995 wet season, revealed that the physical seed quality of farmer seeds had 88-95 percent seed purity, rice mixture of 4-12 percent, weed seed contamination of 22-35 weed seed/40 g, and 80 percent germination. Those physical qualities indicate that farmer seeds are way below the quality standard set for certified seeds. Nueva Ecija farmers' seeds with a purity of 96.7 percent, best seeds of 50 percent, high germination index and low lethal seed infection were better than farmer seeds from Iloilo followed by farmer seeds from Cavite-Laguna-Quezon. Farmer seeds from Cavite-Laguna-Quezon are characterized by low rate of germination index (below 70 percent), more rice mixtures and weed seed contamination, suggesting the poor condition of seeds for planting. Under the Farmers Participatory Research (FPR), the performance of high quality IR64 seeds is signficantly better than farmers IR64 seeds in terms of physical seed quality and seedling vigor and had less seed infection. The yield of high quality IR64 was 8 percent to 14 percent more than the farmers' IR64 seeds. IR64 high quality seeds was 9 percent to 18 percent higher in yield compared to the rice yield of farmers not involved in FPR. These yields increase averaged P2,866.00/ha during the 3 seasons' trial in Nueva Ecija. Farmer seed practices like winnowing, flotation, physical seed sorting, chemical and biological control agent for seed treatment were evaluated in IRRI [International Rice Research Inst., Los Banos, Laguna, Philippines] Farm. Using farmer seeds of varying qualities the seed treatment practices demonstrated varying effectiveness in improving seed quality before planting and yield response. Physical seed sorting on selected farmer seeds gave significant yield increase of 8-20 percent over the untreated original farmer seeds. This indicates that farmers can still do seed management practices that would improve his available seeds before planting and improve the yield. Based on 8 farmer seedlots used in the 4 seasons of yield trial, chemical seed treatment gave an average increase in yield of 6.75 percent which translates to P2,457.35/ha; the use of BCA (1.6 percent) equivalent to P604/ha; flotation with 3.8 percent valued at P1788/ha; winnowing and flotation combination with 4.34 percent valued at P1,359/ha; and physical seed sorting with 14.88 percent and valued at P5195/ha. The farmer seeds needed improvement in seed purity, removal of varietal mixtures, and weed seed contaminants. Winnowing and flotation of rice seeds were effective in removing partly filled grains, other plant parts and majority of weed seeds. Physical seed sorting by trained persons was efficient in improving seed purity, in removing discolored seeds and other impurities