Sowing date as a factor determining French bean yield for processing

Field studies were conducted in the years 2003-2005 in the Experimental Farm of the University of Life Sciences in Lublin. Beans from four cultivars - ‘Paulista’ and ‘Hit’ (green pods) and ‘Korona’ and ‘Galopka’ (yellow pods) - were grown on fawn soil, formed of loess deposits, on chalky marls, containing 1.4% organic substances on average. There were six sowing terms, every 6-7 days starting from the middle of May to the end of June. French bean harvest was performed once, when about 75% of the pods on the plants were in the phase of technological maturity, which fell between the third ten days of July and the first ten days of September. From the plot and plant the number and yield of the pods were determined: total, marketable and non-marketable small pods, unshapely and overripe pods, as well as those with symptoms of disease. The highest total and marketable pod yields - on average, 15.45 and 11.06 t ha^-1, respectively - were obtained from plants sown in the first ten days of June, whereas the lowest - 12.54 and 9.54 t ha^-1 - were from those sown in the middle of May. As a result of performing a one-time French bean pod harvest, the share of non-marketable pod yield in the total yield was on a similar level (24-28%), depending on the growing term. Variability was demonstrated in the share of particular non-marketable yield fractions (small pods, undersized, unshapely, and overripe pods, as well as those with disease symptoms), depending on the sowing date. Growing four French bean cultivars from sowing in the period from the middle of May to the end of June allowed us to extend the period of fresh pod harvest to six or seven weeks.