Osmotic conditioning of sweet pepper seeds (Capsicum annuum L.) and its effects on germination and emergence

Agustín Ajaro U.1 y Leonor Wyneken H.2

During 1983/84, seeds of sweet pepper (Capsicum annuum L.) cv. Yolo Y, were conditioned osmoticaly by soaking in -3 to -18.6 bar solutions of polyethylene glicol, magnesiurn sulphate and sodium chloride, at 25ºC for 9 days. Treated seeds were dried and exposed to laboratory germination tests, cold tests and seedling growth tests. Primed seeds were also sown in the field, evaluating seedling emergence and perfomance up to two rnonths after establishment. Non treated seeds were considered as control. The priming did not affect the final germination percentage, but shortened germination time and gaye more uniforrn germination, reducing in about 7 days the period to get 95 per cent of final germination. Also the necessary time to obtain 5 to 95 per cent of final germination was reduced between 20 to 70 per cent. Results of seedling growth tests dernonstrated a high respiratory rate in treated seeds, accelerating the germination process. Osrno-conditioning also accelerated the germination under low temperature (10ºC; 15ºC and 20ºC). Likewise, conditioned seed emerged faster than the check during the coid test. Priming did not affect the final emergence percentage and the uniformity of this process in the field. However, it improved the emergence rate and speed, reducing the number of days necessary to obtain 95 per cent of final emergence in about 6 days. Some treatrnents induced a greater plant developrnent, measured by the number of true bayas. After priming, sorne seeds werealso kept in dry storage for 140 days. After this storage period,effects on the gerrnination and emergence process were still detectad. Best results were obtained by conditioning the seed with solutions at osrnotic potencials between -11 and -18.6 bar.

1 Estación Experimental La Platina (INIA), Casilla 5427, Santiago, Chile.
2 Hernén Cortés 2818-H, Santiago, Chile.