Published in Scientific Papers. Series A. Agronomy, Vol. LXIV, Issue 1
Written by Șerban Cătălin DOBRE
At ARDS Caracal, on chernozem type soil, for three years (2018-2020), 9 sunflower hybrids were tested to study the influence of leaf area on yield in the conditions in which the sowing was done at 3 different plant densities. The determination of the leaf area was done at 3 different moments spaced two weeks apart in June and July. The leaf area was determined on all the leaves on the plant, on 3 plants on each replication, using the formula of Rouphael et al. (2007). The correlation coefficients between the leaf area and yield were differentiated as direction depending on the year of experimentation being significantly positive in 2019 and significantly negative in 2018, given that the correlation was made between 27 values (9 hybrids x 3 densities) for each determination. When correlated, a percentage of 16-20% of leaf area variability was associated with yield variability. Although normally the leaf area is positively correlated with production, the results obtained in this experiment are supported by the fact that the production is higher at medium plant density but the leaf area is higher at low plant density. This aspect is highlighted by the leaf area / yield ratio which shows which leaf area of a plant contributes to the formation of one kilo of sunflower seeds. The highest values of this indicator (over 2 cm2 / plant per kilo of seed) are found at the lowest density. The results suggest that the relationship between leaf area and yield at sunflower is influenced by climatic and technological factors and a large leaf area does not always lead to high yield.
[Read full article] [Citation]
