Responses of garlic to environmental and agronomic factors. I. Dynamics of dry matter production and leaf growth

Abstract

The timing of planting (PD) and the size of garlic (Allium sativum L.) cloves (CS) are known to affect crop growth and its response to environmental conditions. This study aimed to understand the effects of environmental factors on garlic dry matter production in Balcarce (37°45′50″ S and 58°17′20″ W), Argentina. Experiments were conducted over two growing seasons, with treatments combining four PDs and two CS levels. No significant effects of PD or CS were found on the rate of total dry matter yield increase per degree day accumulated (DDA). Similarly, the relationship between bulb dry matter yield (BDMY) and DDA was consistent across all PDs, with BDMY tending to decrease with delayed planting. BDMY was slightly higher in Year 2. In Year 2, small seed cloves resulted in an earlier onset of bulbing with the latest PD. Bulb fresh matter yield (BFMY) increased steadily at early PDs, but slowed down with the latest PD. Leaf dry matter yield increase per DDA was higher in earlier PDs, particularly in Year 1, with no clear CS effect. While leaf area (LA) expansion per DDA showed no differences among PDs, it tended to decrease as PD was delayed. Overall, PD, CS, and the year of study significantly influenced leaf dry weight and LA. The onset of bulbing, defined by the bulb base diameter-to-pseudostem diameter ratio, was significantly modified by PD and CS. A strong relationship was found between LA and BFMY, which was also affected by PD and CS. The most notable effect of the year was on the rate of bulb and leaf growth, expansion, and the bulbing ratio. Environmental conditions, primarily temperature, combined with agronomic practices (PD and CS), affected these crop traits. These findings are expected to contribute to improve garlic production in southeastern Buenos Aires province.