Treatment with insecticide and fungicide on the physiological quality of lentil seeds

The low Brazilian productive index and the high demand have aroused interest in the cultivation of lentils, however the legume is little known and needs further studies. The objective of this study was to analyze and identify the effects of treatments with insecticides and fungicides on the physiological quality of lentil seeds, CA-1512 strain. The experiments were conducted in the seed laboratory in a completely randomized design with seven treatments and four replicates. Seed treatment with Thiophanate-methyl; Fluazinam® (180 ml) + Pyraclostrobin; Thiophanate-methyl; Fipronil® (150 ml) promoted higher levels of germination under accelerated aging, lower number of abnormal seedlings and longer lengths of shoot and radicle for the emergence in paper. Treatment with Carboxin; Thiram® (250 ml) + Imidacloprid® (150 ml) allowed a higher value in the first count of germination in sand, lower number of dead seeds under accelerated aging and longer root length, in the emergence in sand. Shoot length in the emergence in sand increased after seed treatment with Metalaxyl-M; Fludioxonil® (75 ml) + Pyraclostrobin; Thiophanate-methyl; Fipronil® (150 ml). Treatments with fungicides and insecticides considerably improved the physiological properties of the seeds, thus being able to guarantee greater phytosanitary qualities in the field, generating healthier seedlings and with protection against possible pests and diseases, and consequently guaranteeing greater productivity.

Physiological potential and health of peanut seed treated with ozone

Peanut seed can be infected by pathogen diseases that adversely affect the oil crop’s value chain. Ozone gas (O3) can be an alternative for the control of fungal diseases due to its high oxidizing potential. In this study, we investigated the effects of O3 exposure time on physiological and health characteristics of seed from three peanut cultivars. Seed from peanut cultivars Granoleico, IAC OL3, and IAC 503 were analyzed for their health (blotter test) and physiological potential (germination, first count, and seedling length) after exposure to O3 for 0, 1, 8, and 16 h. Peanut seed physiological quality and health differed among cultivars. Exposure of seed from peanut cultivars IAC OL3, IAC 503, and Granoleico to O3 at a rate of 600 mg h-1 did not affect the development of normal seedlings as measured by the first count and germination, but seedling length increased, decreased, or was not affected in cultivars Granoleico, IAC 503, and IAC OL3, respectively. Also, O3 did not eradicate fungal infections in peanut seed treated with O3 at a rate of 600 mg h-1 for up to 16 h, but the incidence of the fungus Rhizopus sp. in seed from cultivars IAC OL3, Granoleico, and IAC 503 increased, decreased or was not affected, respectively, after 8 h.

Physiological and sanitary quality of ryegrass seeds submitted to different defoliation frequencies

ABSTRACT: This study determined the effect of different defoliation frequencies in a long-cycle ryegrass cultivar on yield components and the physiological and sanitary quality of seeds. Four defoliation frequencies were applied (without, one, two, and three defoliations). The time between defoliations was 350 degree-days. At the first, second, and third defoliation time, the plants were 15 cm, 20 cm, and 35 cm, respectively, and were lowered to half their height. The yield components and plant structure were evaluated through the tillers, along with the physiological quality of the seeds, which was verified by germination tests, first germination count, accelerated aging, tetrazolium test, field emergence, and weight of a thousand seeds. For the sanitary quality analysis, the percentage (%) of fungi incidence in the seeds was verified. The second defoliation determined the seeds’ high physiological and sanitary quality due to the higher amount of primary and secondary tillers produced concerning the other treatments. However, there was no significant difference for the third defoliation since the aerial tillers issued the same quality of seeds originated from primary and secondary tillers. The average incidence of fungi such as Colletotrichum sp., Fusarium sp., Phoma sp., and Dreshslera spp. was lower in ryegrass plants subjected to three defoliations.

Improving the method for determining the physiological and sanitary potential of Gherkin seeds

Gherkin seeds usually show irregular physiological quality. Seed production requires fast and reliable tests to evaluate seed quality. Germination test is considered a recognized analysis method; however, seed technology has pursuit the improvement of vigor tests aiming the evaluation of seed’s physiological potential. Thus, the objective of this work was to evaluate procedures to perform the test of accelerated aging and determine the physiological and sanitary potential of gherkin seeds. Four seed lots of cultivar Liso Calcuta were used in the study. To evaluate the initial physiological quality the water content was determined and germination and emergence tests, as well as indices of germination speed and emergence speed were used. The accelerated aging test was performed as traditionally and with saturated saline solution, with 48, 72 and 96 hours, at temperatures of 41oC and 45oC. After aging, the water content was determined, and seeds’ germination and sanity tests were performed. The experiment was set under a completely random design in factorial 4x3x2 (lots x aging periods x temperatures). The standard accelerated aging test and the test with saturated saline solution at 41oC for 96 hours were efficient to evaluate the vigor of gherkin seeds. Saturated saline solution provides uniform water absorption and deterioration in gherkin seeds, allowing to discriminate seed lots in different vigor levels. The salinity test after accelerated aging with saline solution reduces the incidence of some fungi.

Similarity between corn hybrids using sanitary and physiological seed parameters

One of the elements capable of explaining the epidemics of diseases in the fields of corn production is the amount of initial inoculum present in seeds. The objective of this paper was to study the health and physiological quality of maize hybrids grown in the 2019 crop. The experiment was carried out using 22 hybrids represented by: 13K21PW Morgan©, 14K185PW Morgan©, 230 PRO 3 DKB©, 290 PRO 3 DKB© , 3040 VIP3 LG©, 3055 VIP3 LG©, 30F35 Pioneer ©, 310 PRO 3 DKB©, 345 PRO 3 DKB©, 8882 Coded DKB, CBS15C385PW Morgan©, CBS15D089PW Morgan©, CBS15SE137PW Morgan©, Coded x40K205 (3898) Pioneer, K9606 VIP3 KWS©, MG580PW Morgan©, MG652PW Morgan©, SH 7930 PRO 2 Sta Helena©, SH 7990 PRO 2 Sta Helena©, SX5885 VIP3 Syngenta©, SX71715 VIP3 Syngenta© and SX8934 VIP3 Syngenta© that were grown in the municipality of Ipameri, GO. Analyzed the percentage of primary root emission (ERP),% of shoot emission (EPA),% of microorganism incidence, % of fungus genera (% GF). Sixteen fungi were detected representing the microflora detected in the seeds of the evaluated hybrids recognized as Penicillium sp., Aspergillus sp., Curvularia sp., Fusarium verticillioides, Gliomastix sp., Cladosporium sp., Gliocladium sp., Bacillus sp., Geotrichum sp. , Trichoderma sp., Mucor sp., Stenocarpela maydis, Pythium sp., Chaetomium sp., Sporotrix sp. and Scopulariopsis sp. The multivariate analysis jointed the cultivars with highest physiological activity represented by SX 8934 Vip3 SYN®, SX 71715 Vip 3®, 3040 Vip3 LG®, SHS 7990 PRO2, SX 5885 Vip3, MG 652 PW®, K9606 Vip3®, DKB 345 PRO3. The lowest incidence of microorganism was in hybrids DKB 345 PRO3 and 8882 cod.

Physiological Quality of Swingle Citrumelo Seed after Refrigerated Storage of Fruits and Seeds

For citrus, there is no definition of the ideal fruit harvesting point for seed extraction. Some studies have shown the positive effect of postharvest refrigerated storage of fruits to obtain quality seeds. This study aimed to evaluate the influence of the fruit maturation stage on the germination of Swingle citrumelo (CS) seeds after the refrigerated storage of fruits and seeds. CS fruits were harvested at 180 days after anthesis (DAA); 210 DAA and 240 DAA. Fruits and seeds were stored in cold chamber for 0, 15, 30, and 45 days. Physicochemical analyses were performed on fruits (colour, soluble solids, acidity and ratio) and seeds (water content, germination, and emergence). Germination of seeds extracted from fruits harvested at 180, 210, and 240 DAA, without refrigerated storage, showed a positive correlation with colour index. The refrigerated storage of fruits and seeds extracted from fruits harvested at 210 DAA, increased the seed germination rate. Peel colour (IC) was correlated positively with the germination of Swingle citrumelo seeds. The results of this study revealed that the absence of refrigerated storage, harvesting Swingle citrumelo fruits, with ripe characteristics (end of harvest), results in a high seed germination rate. On the other hand, refrigerated storage of fruits and seeds extracted from fruits harvested at mid-harvest increases the seed germination rate.

Determining Seed Viability During Fruit Maturation to Improve Seed Production and Availability of New Citrus Rootstocks

In recent years, the pressure for replanting and resetting huanglongbing (HLB or citrus greening) affected citrus groves has led to an inadequate seed supply for the most popular rootstock cultivars in the State of Florida, United States. Early fruit harvesting of citrus rootstock source trees might reduce fruit losses and enhance seed availability, especially in HLB-endemic and hurricane susceptible areas, if the physiological quality of the seeds is adequate. The effects of fruit maturity on seed quality and seedling performance of US-802, US-897, and US-942 citrus rootstocks were investigated for two consecutive growing seasons. The study included the evaluation of seed germination and nursery performance of the citrus rootstock seedlings. The germination test was performed in vitro, where seeds were hand-peeled, surface-sterilized and placed in culture tubes containing basal Murashige and Skoog medium. For the emergence test, seeds were sown in seedling trays containing sterilized growing substrate in a greenhouse with controlled-environment conditions. Rootstock fruits from all three varieties harvested in August and September had seeds with higher germination potential, as more than 90% of the seeds generated seedlings. US-942 had more % of emergence than US-802 and US-897, resulting in faster seed germination; in contrast, US-802 had the faster shoot growth rate. Assays on fruit abscission response showed that by August, fruit from all three varieties were responsive to ethylene and abscised, although response varied and was higher in US-942, suggesting the seeds were mature enough. Taken together, our findings indicate that fruits these three rootstocks can be harvested as early as August in contrast to the current procedures without losing germination potential. This will result in an increase in available seeds for nurseries in Florida.