The effect of maleic hydrazide on onion sprouting during and after the storage period

Abstract

Testing of the effects of maleic hydrazide (MH) and storage conditions on onion sprouting was conducted during the seasons of 2018-2019 and 2019-2020. The trials were set up in the locality of Gospođinci. Maleic hydrazide was applied 21 days before the harvest using the commercial plant protection product Royal MH 30, in the quantity of 12.5 l -ha . During the storage period onion bulbs weight and number of sprouted bulbs, as well as the weight and length of sprouts per bilb were recorded each month (assessments I-VIII). Also, the loss of onion bulb weight compared to the beginning of the storage period was assessed at the end of the trial period. In order to determine sprouting level of onion bulbs after leaving the storage facility, the number of visibly sprouted onion bulbs was recorded every 10 days for a period of six weeks. Length of the sprout was measured on sprouted onion bulbs, while onion bulbs with no visible sprouts were cut in half at the end of the experiment, in order to determine the sprout growth inside the bulb. Under the MH treatment, depending on the trial year, weight of the treated onion bulbs was lower by 9.5-10.6%, compared to their pre-storage weight. Efficacy of MH in preventing onion sprouting was also confirmed with a significantly lower number of sprouted bulbs, as well the sprout length and weight parameters. Furthermore, after leaving the storage facilities (constant temperature 18-20oC) the total percentage of sprouted bulbs in the control was 62-68%, while in the MH treatment it was 10-16%. No internal sprouts were recorded in 53.3-54.8% of the treated onion bulbs, while in the control group only 10.5-18.8% of cut bulbs did not have internal sprouts.