EVALUATION OF A SEED STORAGE FACILITY IN RELATION TO PRESERVING SEED MOISTURE, VIGOUR AND GERMINATION

The performance of a solar energy-assisted seed storage room was evaluated through an ordinary 22-/m3 room that was retrofitted with a solar collector, inlets and chimney. The structure was made of a solar collector to heat the ambient air before entering the chimney. The chimney circulated the air inside the structure and inlets. To compare the performance of the modified storage room, a room with a similar capacity and without the retrofitted components (control storage room) was used. Twelve 8 kg bags of maize were stored in each storage room for a period of three months. Samples were taken every two weeks to determine germination rate, moisture content and seed vigour. The temperature and relative humidity (RH) was measured during storage. The RH in the control storage was significantly higher (P≤0.05) (60.6 ± 5.87%) than in the modified storage (40.1 ± 3.21%) during the day. However, at night, the RH in the control storage room was significantly lower (P≤0.05) (58.5 ± 7.32%) than in the modified storage (63.7 ± 6.28%). The RH in the modified storage room increased from 40.1% during the day to 63.7% at night. The RH in the control storage room decreased slightly from 60.6% to 58.5% during the day and night. The seed moisture content in the modified storage facility was significantly lower (P≤0.05) (12.6 ± 0.21%) than in the control storage room (13.3 ± 0.52%). The moisture content in the modified storage room decreased from 12.6% to 12.4%, whereas in the control room, moisture content increased from 12.6% to 13.8% in three months. The seed germination rate obtained after three months of storage in the modified storage room was significantly higher (P≤0.05) (98.5 ± 0.85%) than in the control storage room (96.8 ± 1.49%).The seed vigour obtained in the modified storage room was significantly higher (93.6 ± 0.35%) than in the control room (91.7 ± 2.08%) (P≤0.05). Seed stored in the control storage lost vigour at a faster rate, compared to the seeds stored in the modified storage room. Therefore, the modified naturally-ventilated seed storage room maintained seed quality better than the control storage room.