The value of patience in improving onion yields and quality


Over the past onion production cycle in the Northern Cape region of South Africa, trials were carried out on the effect of harvest timing on final yields.

2 varieties were harvested at 3 stages of leaf-fall, at 50 – 80% fall, 7 days later at 100% fall and at a further 7 days after that. 3 repetitions were assessed for each variety, resulting in 9 evaluations for each. Harvested bulbs were cured and stored according to normal practice after which they were evaluated for yield and quality.

The results show that there is value in waiting, with both yield and quality improvements being evident in the results. A remarkable mean average of 28 % increase in yield was observed in the 2 varieties. Both also showed improved quality parameters such as firmness, colour and scale leaf retention of bulbs. These qualities improve storability, as well as marketability and allow a more flexible marketing strategy.

The first variety evaluated was Tusker, an early maturing short-day onion variety, known for high yields.

Onion yields 1
Onion yields 12

The second variety evaluated was Terena which is a main season short-day onion variety also known for producing high yields.

Onion yields 13

When the results were combined, they showed a 27% increase in yield was achieved by waiting 7 days after 50-80% of the tops were down. This 50-80% foliar drop is often the time when growers lift the onions, especially when market prices are high.

Onion yields 14

It is clear from these results that there are significant advantages in giving onion varieties an extra few days to achieve maximum yields. It also improves bulb quality, both of which are to the growers’ advantage.