Studies on the Rapid Methods for Evaluating Seed Vigor of sweet Corn
Since the germination test is still the main method for evaluating seed vigor of sweet corn, it is necessary to study the rapid methods for evaluating their vigor. First, two vigor levels of 9 super sweet corn and 9 sugar enhanced corn hybrids were distinguished by accelerated ageing treatment. Next, their vigor statuses were tested by rapid methods such as electrical conductivity (EC), soluble sugar (SS), volatile aldehyde (VA), dehydrogenase activity (DA) and Q2 oxygen sensing technology. Correlation relationship was analyzed between the above tested values and vigor performances. The results showed that EC, SS, VA, DA, oxygen metabolism rate (OMR), critical oxygen pressure (COP) were all suitable to evaluate seed vigor of sweet corn. Furthermore, VA was optimal for evaluating seed vigor of super sweet corn. DA was optimal for evaluating sugar enhanced corn.
EVALUATION OF DAMAGE CAUSED BY BRUCHUS PISORUM L . ON SOME PARAMETERS RELATED TO SEED QUALITY OF PEA CULTIVARS
It was evaluated the damage caused by Bruchus pisorum on the germination ability of pea forage cultivars. Result of damage in seeds with parasitized larva was a significant decrease of the germination by 16.4% percentage points, the length and weight of primary radicle by 16.8 and 24.5%, the length and weight of plumule by 12.3 and 14.1%, the vigor index of primary radicle and plumule by 32.5 and 32.8% as well as the germination index by 17.4%. The inhibitory effect was 17.8%. Essential significant changes in regard to the studied parameters were found in damaged seeds with bruchid emergence hole. There the germination decrease by 58.3% percentage points, the length and weight of primary radicle by 34.1 and 36.2%, the vigor index of primary radicle and plumule by 81.1 and 82.1% as well as the germination index by 83.1%. The inhibitory effect was, on average 58.3%. The damaged seeds with parasitoid emergence hole provided a better possibility for growth, development of plants and stable yields. As tolerant to damage by pest distinguished Glyans cultivar for which the values of parameters related to germination and vigor of seeds were influenced of the lowest degree from the damage unlike the sensitive Pleven 4. INTRODUCTION: The germination and emergence are important stages in crop cultivation. They have essential meaning on the following stages of plant growth and development 1 and for the realization of high productivity with good quality 2 . On the other hand an important condition for implementation of this process is the use of qualitative seeds: with genetic purity, strong germination capacity, uniformity of seed size, freedom from seed borne diseases and absence of weed or other crop seeds 1, 3 . According to Wang et al. 4 seed quality is a multiple concept comprising several components. The seed vigour is an important component that can influence crop plant density and yield 5 . QUICK RESPONSE CODE DOI: 10.13040/IJPSR.0975-8232.IJP.2(7).326-34 Article can be accessed online on: www.ijpjournal.com DOI link: http://dx.doi.org/10.13040/IJPSR.0975-8232.IJP.2(7).326-34 That vigour is related to the germination and seed ability to grow rapidly and jointly. It suggested that the speed and uniformity of emergence are important parameters of seed quality 6 . Although many vigour tests are suggested only few are accepted by seed analysts and seed testing organization 7 . Some of applied tests are germination test and seed vigor test which are used to determine seed viability 8, 9, 10,11 . Seed yield and viability can be reduced by different types of environmental stress, one of which is damage of seed weevils. The final effect of seeds with a beetle infestation on the germination of host legumes can be unpredictable 12 . In some cases the larva feeding effectively kills the embryo or removes so much endosperm that the seed cannot germinate 12, 13 . Larval feeding may also create openings for pathogenic bacteria and fungi 13, 14, 15 . Even if germination occurs prior seed infestation after that the infestation may distort the development of cotyledons or prevent the formation of true leaves 13 . Depletion of cotyledon
Relationship between Laboratory Seed Quality Tests and Field Emergence of Common Bean Seed
In cool climates, early planting of bean (Phaseolis vulgaris L.) is recommended to assure a longer vegetative growth period. Early planting exposes seed to unfavorable conditions and the commonly used standard germination test cannot predict field emergence. The objective of this work was to examine the relationships between various seed quality tests and field emergence of common bean seeds. Thirty-nine strains and cultivars of bean were tested in the field and laboratory over 3 yr. Each year seed samples were tested in the laboratory and then planted in the field at very early, early, and at optimal planting dates. The viability of seeds was test by tetrazolium staining and was generally high; standard germination was above 80%, but germination in the cool test (at 10°C) varied from 0 to 99%. The percentage of seeds with broken coats varied from 0.5 to 50.3 and conductivity ranged from 7 to 45 μS cm -1 g -1 . Field emergence varied from 0 to 100%. Soil temperature at sowing appeared to be not only the most important environmental factor influencing field emergence but also a factor able to be used to differentiate the field emergence potential of a seed lot. Only the conductivity test could be used to predict seedling emergence in the field irrespective of soil temperature at sowing. At temperatures ranging from 9 to 15°C, the first and the last count of the standard germination test and the broken seed coat test should be used in conjunction with the conductivity test to estimate field emergence potential.