Charter Seeds have been working towards all-year-round onion production in Zimbabwe for several years.
Winter production of short day onion varieties has served Zimbabwe well, but it is beset with problems. He supply of onions at the end of winter is so great that there are serious marketing problems. By the end of February the supply of dry onions has dwindled so much because of storage problems that Zimbabwe has to import.
Storage in Zimbabwe during the rainy season can be very difficult. When the Intertropical Convergence Zone (ITCZ) is overhead causing long periods of overcast weather and rain, humidity can rise above 90% – well above the recommended relative humidity for efficient storage of onions and retention of top quality. In the 2020 to 2021 season, Charter Seeds recommends two varieties of onion for production: IRATI and NGWAZI.
In a small bed on heavy soil behind the Charter Seeds Avondale offices, 12 different onion varieties were sown on 26 January 2021 and treated with the biochemical sequence Charter Seeds has been studying.
In very wet, overcast conditions with a periodically saturated soil, NGWAZI came out of the ground first like a proverbial comet. Other varieties that produced beautiful seedlings were trial varieties ON2386 and ON2612 and pink root rot-resistance (PRR) variety VERONICA – a variety of the future.
NGWAZI’s performance in the wet conditions could indicate that the variety could be sown in early January if the subsequent photoperiod is suitable for bulbing. All seedlings will now be thinned out to see what sort of bulb these early onion varieties will produce in April or May.
The sowing sequence with STARKE AYRES onions: