Determination of seed viability constants in medicinal pumpkin (Cucurbita pepo L. subsp. Pepo. Convar. Pepo var. styriaca Greb), borago (Borago officinalis L.) and black cumin (Nigella sativa L.)

Predicting seed viability would be extremely beneficial to seed producers and the prediction of seed viability depends on understanding the quantitative relationships between seed longevity, seed moisture content and storage temperature. Thus, the objective of this investigation was to quantify relationship between temperatures, seed moisture and seed deterioration and determination seed viability constants in medicinal pumpkin, borago and black cumin. Five storage temperatures (30, 35, 40, 45 and 50 ^oC) and four moisture content levels (5, 8, 11 and 14%) were used. Seed viability equation is V = Ki-p/10 KE - CWlog10m - CHt - CQt². The Ki is the initial seed quality constant, p is the storage period (days), m is moisture content (%, fresh weight basis), t is temperature (^oC) and KE, CW, CH and CQ are constants. The results showed that KE was 3.4018, 6.7485 and 4.9701 for medicinal pumpkin, borago and black cumin, respectively. The value of CW was 3.2148, 2.4195 and 1.2528 for three species, respectively. The value of CH for medicinal pumpkin, borago and black cumin was 0.131, 0.0665 and 0.0516, respectively and CQ for medicinal pumpkin, borago and black cumin was 0.00264, 0.000478 and 0.000478, respectively.