Stability of seed yield and seed quality of some soybean genotypes under different planting dates

Abstract EN

A two-year field experiment was conducted at Sakha Agricultural Research Station, Kafr El-Sheikh, Egypt in 2013 and 2014 to study the effect of four planting dates (May 3, May 14, May 24, and June 4) on seed yield and seed quality of eighteen soybean genotypes, including eight cultivars(Giza21, Giza22, Giza35, Giza82, Giza83, Giza111, Clark and Crawford), eight promising lines (H2L12, H2L20, H1L10, L105, L153, L155, H117 and DR101) and two exotic varieties (Toano and Holladay).

The results showed highly significant mean squares for soybean genotypes, environments and (G x E) interaction, indicating that the tested genotypes differed in their response to environmental conditions, and G12, G1, G9 and G16 (L105, Giza 21, H2 L12, and Toano), being the most stable ones.

Also, delayed planting date from May 3 to June 4 significantly decreased number of days to flowering and maturity (40.46 and 142.09 days, to 30.80 and 117.67 days), respectively, shortened the reproductive growth stage from 102.10 to 86.88 days, decreased plant height from 95.05 to 84.14 cm and number of pods/plant from 103.62 to 78.95, along with reducing of 100-seeds weight from 17.91 to 15.44 g, and seed yield from 1790.90 to 1185.25 kg per feddan.

On contrary, seed protein content and seed germination were increased from 34.80 and 70.25 (%) to 39.06 and 91.93 (%), respectively, while oil content and electrical conductivity were decreased by delaying planting from 23.14 to 19.58 (%) and 59.10 to (29.66) µ-mhos, respectively.

The soybean genotypes varied in all studied traits, where DR 101 was the latest in flowering and maturity (48.42 and 155.79 days, respectively), Giza21, Giza111, L105 and L153 were the highest in 100-seed weight (18.49, 19.17, 18.73 and 18.07 g), respectively.

Giza 82 and Giza 83 were the earliest in maturity (126.47 and 126.79 days) and the lowest in 100-seed weight (14.45 g).

Giza 111 cultivar and L105 line produced the highest seed yields (1946.38 and 1898.17 kg/fed.).

Giza 111cultivar, L105 and L153 lines produced the highest number of pods per plant (133.91, 126.46 and 126.92), while L155 and L153 lines produced the tallest plants (132.42 and 134.06 cm).

Data showed also that DR101 was the best in seed germination over all planting dates with an average of 89.96(%), while, Clark recorded the lowest electrical conductivity (32.72 µ-mhos), Toano variety produced the highest oil % content (22.02%) and L153 line and DR101 produced the highest protein contents (38.61 and 38.43 %).

It could be concluded that Giza82, Clark, L105, H117, Toano and DR 101 could produce acceptable seeds with more than 80(%) seed germination when planted in early June, while the earlier genotypes Giza21, Giza22, Giza83, Giza111, Crawford, Clark, H2L12, L155 and Holladay have to be planted starting from early May to produce high yields with high quality and seed viability.