Articles
THE EFFECT OF THE HARVEST DATE ON THE QUALITY OF ONIONS GROWN FOR SETS
The plants harvested prematurely did not show any signs of the closing vegetation but the bulbs were already formed.
The second date of harvest fell on the beginning of breaking over of tops with the foliage partial drying.
The third harvest date was when the tops were fully broken over and dried down to a big extent, while the bulbs were covered with clearly visible dry scales.
With a delay of the date of harvest, the onion cultivated for sets achieved better physiological maturity.
A drop of fresh yield was observed (on the average by 5.5% at the second date and by 7.8% at the third). On the other hand, a significant growth of total and marketable yields of sets was found out.
A yield increase at the second date of harvest was small in the Rawska variety (2–3%) but quite considerable in the Wolska variety (21–28%). At that date of harvest, the marketable yield had a very high proportion of sets, 10–15 mm in diameter (49.9%) on the average), which is considered to be the most valuable yield fraction.
The greatest sets yield was obtained from the third date of picking (on the average over 35 t/ha – total yield and over 30 t/ha – marketable yield). However, a higher decrease of the proportion of marketable yield in the total yield was observed since the proportion of the big onion with over 25 mm in diameter was greater.