Bean seed quality: associated germinability

الملخص EN

This work aimed to investigate the influence of different levels of bean seed quality on germinability (laboratory study), growth, yield and its components (green pod and dry seed yield) under field conditions.

To achieve this study, the seed lot of bean (cv.

Giza 3) was manually separated into three classes ; light (33.79-38.02g 100-1 seeds ; in 2005 season) and (34.39-37.13g 100-1seeds ; in 2006 season) ; ungraded (37.70-42.85g 100-1 seeds ; in 2005 season) and (40.02-49.81g 100-1seeds ; in 2006 season) and heavy (47.20-57.60g 100-1 seeds ; in 2005 season) and (48.75-57.13g 100-1 seeds ; in 2006 season).

Under field conditions, seeds of bean were sown during two summer successive seasons of 2005 and 2006 at the experimental station, Faculty of Agriculture, Fayoum University, Egypt.

The obtained data could be summarized as follows : High-weight class of bean seeds usually exhibited faster and more uniform rates of radicle emergence (as indicator of germination) than low-weight and ungraded ones.

Seedling produced from heavier seeds had greater rates of QI, VI, length of radical hypocotyl and accumulation of fresh and dry weights than those from light seeds.

The water uptake %, EC and the quantity of materials leached from the seed (Na, K, Pi, sugars, free amino acids and Ao260 and Ao280 absorbing materials) during imbibition were inversely related to seed weight.

It is suggesting that interferences existed during seed development or deterioration had occurred in the low weight seed.

It can be noticed that seed quality of bean significantly affected field performance of bean plants and resulted in an increase of the studied plant growth traits (plant height, No.

of leaves, No.

of branches, leaf area leaf-1, leaf area plant-1, fresh and dry weights of leaves plant-1, fresh and dry weights of branches plant-1, and total fresh and dry weights of shoot plant-1) with increasing the level of seed quality class.

It can be seen that there was a close relation between seed quality of bean and green pods yield and its components.

In this respect, No.

of green pods plant-1, weight of green pod, green pod yield plant-1 and feddan-1 were increased as seed quality class was increased.

It was found that bean dry seed yield and its components ; empty and seeded pods plant-1, total No.

of pods plant-1, grades of dry seeded pods, No.

of seeds plant-1, seed yield plant-1 and feddan-1 and seed index (100-seed weight) was positively correlated with the class of sown seeds, the seeds which gave plants with high yield of dry seeds and its components were high in their quality and vice versa.

It was shown that seed quality class markedly affected chemical constituents concentration of the different organs of bean plants produced from the different seed classes.

In this respect, the high seed quality class significantly increased total sugars (total soluble carbohydrates in dry seeds), protein, N, P, K, Fe, Mn and Zn in leaves, green pods and dry seeds over that of light and ungraded seed classes.

Finally, in the light of the preceding results, it may be concluded that the results obtained suggest that the weight-seed separation of bean may enable for significantly improved germination and seedling growth.

Also, high quality bean seeds to exhibit higher percent field performance and resulted in uniformity and establishment which reflected in high green pods and dry seed yield of bean either plant or feddan-1.

Thus, it concluded that it is likely that farmers by sowing seeds of high seed quality, will obtain yield increases of bean (green pods and dry seed).