Field Emergence Affected by Zea Mays L. Cultivars and Seed Soaking in Acids of Ascorbic, Citric and Humic

A field experiment was carried out during the spring season 2019 and 2020 to obtain a fast, uniform, and high field emergence ratio of maize seeds under a wide range of environmental conditions. Randomize complete block design in the split-plot arrangement was used with three replications. The first factor in the main plots was cultivars (5018, Baghdad3 and Sumer). The second factor in the sub-plots was seeds soaking with ascorbic and citric acids (100 mg L−1) each and humic (1 ml L−1) in addition to control treatment (seeds soaking with distilled water only). Results showed the superiority of soaking with humic acid significantly, as means of characteristics of field emergence in both seasons, respectively, were as follows: Last day of field emergence (12.4 and 12.6 days), time spread of field emergence (4.4 and 4.6 days), emergence at first and final counts (62.4 and 34.4 %) and (95.8 and 88.0 %), daily emergence rate (8.0 and 7.3 % day−1), mean field emergence time (8.7 and 9.3 days), emergence index rate (11.1 and 9.7 % day−1), velocity coefficient of field emergence (11.4 and 10.8) and emergence index (407.6 and 333.3). Cultivars didn’t differentiate among themselves, with the effect of seeds soaking in most traits. It can be concluded that seeds soaking with humic acid improved characteristics of emergence and seedlings, so it can be recommended to soaking maize seeds with humic acid at the concentration (1 ml L−1) when planting them in the spring season.

Influence of Chemicals, Botanicals and Growth Regulator Treatments on Plant Growth and Yield Attributing Traits of Lentil (Lens culinaris L.) Variety: K-75

The experiment was conducted in post graduate Seed Testing Laboratory and Field Department of Genetics and Plant Breeding, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj (U.P) during Rabi season 2020-2021, in order to standardize the suitable pre-sowing seed treatment for Lentil (K-75). Different pre-sowing seed treatments viz.,T0-Control (untreated), T1- KCL @1%, T2- KCL @ 3%, T3- KNO3 @ 1%, T4- KNO3 @ 3%, T5- Panchagavya @ 2%, T6 – GA3 @ 20ppm, T7 – Panchagavya @ 4%, T8 – GA3 @ 10ppm,T9 – Panchagavya @ 6%,T10 – Tulasi Leaf Extract @ 2%, T11 – Tulasi Leaf Extract @ 4%,T12 – Tulasi Leaf Extract @ 6% were evaluated by screening of 12 hour. It was found that all the pre-sowing seed treatments recorded the significant difference with that of control. In field condition highest field emergence percentage,yield and yielding attributes was found in T7 -Panchagavya @ 4%. Pre-sowing seed treatment with Panchagavya @ 4% followed by GA3 @ 10 ppm, Panchagavya @ 2%, KCL @ 1% significantly increased the germination and yielding attributes of Lentil. Pre-sowing seed treatments with Panchagavya (4%) and GA3 (10ppm) resulted in maximum increase in field emergence, vigour of Lentil seeds and found to be lowest in control seeds. Pre-sowing seed treatment that leads to a physiological condition that allows the seed to germinate more effectively and no costly equipment and chemical requirements could be used. Hence it is a simple method for overcoming weak germination and seedling establishment and helps to preserve agriculture and economical, non-toxic, eco-friendly sources.

Quality of soybean seeds submitted to different treatments and storage conditions

Chemical seed treatment is a recommended technique to protect seeds from pathogens that can affect their quality. The objective of this work was to analyse the quality of soybean seeds with different treatments under different storage temperatures. Seeds of cultivar ‘M 8378 IPRO’ produced in Mato Grosso, Brazil were used. A completely randomised design was used in a 4 × 3 two-factorial scheme. The seeds were treated with three different combinations of chemicals (fungicides, insecticides, polymer and drying powder) in addition to the control (untreated seeds) combined with three different storage temperatures (13 °C, 19 °C and uncontrolled temperature), with three repetitions. Quality was assessed by the germination test (TG), accelerated aging (AA), field emergence (FE), tetrazolium test (TZ) and isoenzyme analysis. The uncontrolled storage temperature negatively influenced the variables germination, accelerated aging and field emergence. The vigour and viability of the tetrazolium test showed that untreated seeds had better physiological quality than seeds with chemical treatment. The expression of isoenzymes showed a difference between treatments. Even with the stress caused by the seed treatment, this tool is very important for the initial protection of the seedlings.

EFFECT OF MAIZE SEEDS SOAKING WITH ACIDS OF ASCORBIC, CITRIC AND HUMIC ON FIELD EMERGENCE

A field experiment was conducted during two spring seasons in 2019 and 2020 to achieve rapid, uniform, and high ratio of field emergence of maize seeds (cv. Baghdad3). Randomize complete block design was used with three replications. Seeds were soaked in acids of ascorbic and citric (100 mg l-1) and humic (1 ml l-1) for 18 hours, as well as control treatment (seeds soaking in distilled water only). The results showed the significant superiority of soaking treatment in humic acid, which gave averages of field emergence properties in both seasons as follows: last day of field emergence (12.6 and 12.9 days), difference between first and last day of field emergence (4.8 and 4.9 days), ratio of field emergence at first count (49.5 and 55.5%), ratio of field emergence at final count (93.2 and 93.2%), daily average of field emergence (7.8 and 7.8 days), average of field emergence time (9.0 and 8.8 days) and index of field emergence average (10.5 and 10.7 days). It can be concluded that seeds soaking in humic acid improved properties of emergence and seedlings; therefore it can be recommended to soak maize seeds in humic acid (1 ml l-1) for 18 hours when planting in the spring season.

GERMINABILITY OF VARIETIES OF BEAN (Phaseoulos Vulgaris L.) AND OKRA (Abelmoschus Esculentus L. Moench) UNDER LOW TEMPERATURE STORAGE CONDITION

Bean and okra are common vegetables cultivated in the most regions of Sri Lanka. The seeds of these crops are mainly stored in cold storage as bulk before releasing retail lots to sales outlets. Commercial growers and gardeners buy seeds in bulk or in packages at retail stores. Although certified seeds are frequently tested by the seed testing laboratories, they do not guarantee the maximum field emergence. Certified seed lots of two pole bean varieties, ‘Keppetipola Nil’ (KN) and ‘Bandarawela Green’ (BG) and two okra varities,’MI-5’ and ‘Haritha’ were stored in poly sack and polypropylene bags under controlled temperature (17±1 °C) and relative humidity (RH) (52-55%) over a two-year period. Bulk seeds of bean and okra varieties packed in polypropylene and poly sack bags depicted a high germination percentage throughout the storage period for two years. Seed quality parameters, seed germination, seed moisture, field emergence and vigour index significantly varied with the storage duration and declined in varieties. Significant differences in moisture, field emergence and vigour index were recognized as affected by the packing materials in all varieties except MI-5. Both Poly sack and polypropylene packing materials were found suitable to maintain viability at the minimum seed certification standards for two years of storage period. Poly sack was more appropriate than polypropylene to keep viability for more than 2 years of storage under low temperature and RH condition. These findings would help seed handlers including seed producers and seed sellers to store crop seeds between growing seasons in the tropical environment.

Radicle emergence test as a quick vigour test to predict field emergence performance in rice (Oryza sativa L.) seed lots

An experiment was made to standardize the radicle emergence test to predict the field emergence performance in ten different seed lots [L1 to L4: high vigour lots (> 90 % germination), L5 to L7: medium vigour lots (80-90 % germination) and L8 to L10: low vigour lots (< 80 % germination)] of rice cv. CO 51. The results showed that the significant differences are observed in physiological and biochemical parameters in different seed lots. The seed vigour was classified into three groups viz., high, medium and low vigour based on the relationship between mean germination time and field emergence. When the Mean Germination Time (MGT) was < 34 hours, the field emergence was > 85 per cent, which was considered as high vigour; when the MGT was 34-35 hours, the field emergence was 80-85 per cent, that was considered as medium vigour; when the MGT was > 35 hours, the field emergence was < 80 per cent, that was considered as low vigour. The radicle emergence test (2mm radicle length) was highly negatively correlated with mean germination time (-0.930**) followed by mean just germination time (-0.852**) and electrical conductivity of seed leachate (-0.827**) and it was positively correlated with field emergence (0.894**) followed by germination (0.878**) and dehydrogenase activity (0.864**). The R2 values between seed vigour parameters and radicle emergence test were significantly higher in 2mm length of radicle emergence when compared with 1mm length of radicle emergence. Finally, the study concluded that 36 hour MGT with the attainment of 2mm radicle emergence percentage could be used as a quick method to assess rice seed lots' quality by the seed analysts and seed industry.

Seed dormancy of Lolium perenne L. related to the maternal environment during seed filling

Lolium perenne L. (perennial ryegrass) shows variable levels of seed physiological dormancy (PD), which depends on the genotype and environmental condition during seed development. To analyse the effect of field temperature and precipitation during seed filling on the PD, two cultivars were sown on five dates in 2014 and 2015. After harvest, the level of seed PD was 4–28%. High-temperature stress (>29°C) in the field during seed development, measured as heat stress units (HSUs), reduced seed PD (increased germination) at harvest. After 9 months of dry afterripening under laboratory conditions, mean dormant seed values were reduced from 15 ± 8 to 8 ± 7%. An increment in the seed PD level reduced seedling emergence in the field. Seed with 20% PD produced only 50% of field emergence, under optimal environmental conditions. Different vigour tests were conducted and each was compared with field emergence. The speed of germination, through the first count at 5 d of the standard germination test, and the shoot length at 10 d were better associated with the seedling establishment in the field. The HSU could be useful to establish a possible PD range in the seed of perennial ryegrass after the growing season. The development of models considering the HSU and other climatic parameters could motivate future studies.

Accelerated aging predicts the emergence of rice seedlings in the field

Selecting the most appropriate vigor test for rice to predict seedling emergence remains a challenge. This is mainly attributed to the diversity of available tests that evaluate vigor; however, there is a critical need for tests that can show a high correlation with field emergence. Thus, this study aimed to determine which vigor tests are the most efficient in predicting the emergence of rice seedlings, to facilitate correct selection for quality control analyses and pre-sowing for rice seed commercialization. Across two growing seasons, 2016/17 and 2017/18, different seed lots of ‘SCS122 Miura’ rice were subjected to vigor evaluations including germination test, electrical conductivity, cold test, low temperature germination, accelerated aging, root and shoot length, seedling dry weight, emergence speed, and emergence speed index, and greenhouse and field emergence tests. A completely randomized design with four replicates was used for the experiments. All statistical analyses were performed using R software. The germination rate for ‘SCS122 Miura’ seed lots in both growing seasons was greater than 80%. In both growing seasons, unlike the similar results obtained for field emergence, in the laboratory tests, differences were observed between these same seed lots. Electrical conductivity and emergence speed showed a negative correlation with greenhouse and field emergence. The vigor tests for accelerated aging, emergence speed, and dry weight are more efficient in predicting the emergence of rice seedlings. Among the tested methods, accelerated aging (41 °C for 120 h) is one of the most efficient for predicting the emergence of rice seedlings and the best option for laboratory analysis of quality control and pre-sowing owing to its practicality and time required for execution.