Harvesting delay in physiological quality of soy seeds

Soybeans are a grain-producing species of high international demand and occupy a prominent position in the Brazilian economy. The success of this crop in Brazil is due to public and private investments in production technologies and to breeding programs. It is through the seed that the genetic advances reach the producer. In this context, the success of a cultivar and high productivity depend on the quality of the seed. In view of the above, the objectives of the study were to evaluate the physiological quality of soybean cultivar seeds at different harvesting times. The experiment was conducted in an experimental area located at Fazenda Capim Branco, belonging to the Federal University of Uberlândia, in the 2016/2017 harvest. Ten soybean cultivars were evaluated (CD 2737 RR, UFUS 7415, UFUS 7910, UFUS Milionária, UFUS 7801, NA 5909 RG, UFUS 8301, TMG 7062 IPRO, UFUS Xavante and UFUS 6901) at four harvest times (R7, R8, R8+15, R8+30), constituting a 10 x 4 factorial. The experiment was carried out in a randomized complete block design with four replicates. For the evaluation of the physiological quality, germination, electrical conductivity and fresh matter and dry matter of seedlings tests were performed. In all tests the physiological quality of the seeds decreased with the harvest delay. Emphasis was placed on the cultivar NA 5909 RG, which showed the best means to delay the harvest in 15 and 30 days.

Harvest delay, storage and physiological quality of soybean seeds

Soybean is one of the leading commodities in Brazilian agribusiness. Its cultivation is widespread in different seed-producing regions of the country, where it generates income and local development. In this context, the soybean seed is a fundamental input, as its quality strongly influences the success of the crop. However, the period after the achievement of physiological maturity is critical for the maintenance of seed quality. For that reason, this study aimed at evaluating the effect of harvest delay on both the initial and final qualities of soybean seeds. The research consisted of four harvest times, in which the initial quality was assessed through tests of first germination count, germination, accelerated aging and tetrazolium. After 120 days of storage, the germination and accelerated aging tests were once again conducted. The experiment complied with a completely randomized block design with eight replications. The rainfall was monitored during the pre-harvest phase. All variables experienced negative impacts due to the delay in harvesting. Also, the seeds suffered more damage as the delay progressed, and the variables germination and seed vigor decreased after the storage period.

Lignin and Activity Enzymatic in Susceptibility to Weathering Damage on Soybean Seeds

The aim of this study was to evaluate the isoenzyme activity in soybean seeds with different lignin contents subjected to harvest delay with artificial incidence of rainfall before and after storage. The experiment was conducted in a randomized block design with three replicates and a 5 × 3 × 2 factorial design, being five soybean cultivars, three harvest seasons (R8, R8 + one pre-harvest rainfall simulation, and R8 + two pre-harvest rainfall simulations), and two storage seasons (0 and 180 days). The pre-harvest rainfall simulations were performed through irrigation at the intensity of 30 mm of water until the pods were soaked and then collected after reached 18% water content. Seeds were evaluated regarding chemical composition (lignin content), physiological quality (germination, accelerated aging), and enzymatic activity (catalase, esterase, alcohol dehydrogenase, malate dehydrogenase, and isocitratelyase). The cultivar AS 7307 RR showed higher lignin content in the integument and higher physiological quality. The harvest delay and the artificial incidence of rainfallpromotesvariation in the electrophoretic pattern of the enzymes catalase, esterase, alcohol dehydrogenase; malate dehydrogenase, and isocitratelyase for stored and non-stored seeds.

ÉPOCAS DE SEMEADURA E PERÍODOS DE COLHEITA DE SOJA VISANDO PRODUÇÃO DE ÓLEO E PROTEÍNAS

O presente trabalho foi realizado com o objetivo de avaliar os teores de óleo e proteína dos grãos em cultivares de soja em função do retardamento da colheita e verificar a influência da época de semeadura sob condições de baixa latitude. No ano agrícola de 2015/16, foram realizados dois ensaios de competição de cultivares de soja em Palmas-TO, sendo o primeiro instalado em 17 de dezembro de 2015 e o segundo em 04 de janeiro de 2016. O delineamento experimental utilizado em cada época de semeadura foi de blocos casualizados com setenta tratamentos e cinco repetições. Os tratamentos foram dispostos em um esquema de parcelas subdivididas, representados por dez genótipos de soja (PRISMA, TMG 132 RR, M 8647 RR, M 8372 RR, BONUS, RAÇA, ST 820 RR, OPUS, TMG 1180 RR e M 9144 RR), nas parcelas, e por sete estádios de colheita dos grãos (R6, R7, R8, R8+7, R8+14, R8+21 e R8+28 dias), nas subparcelas. Houve efeito das épocas de plantio e dos estádios de colheita nos teores de óleo e proteína dos grãos. As cultivares apresentaram comportamentos diferenciados nas duas épocas de semeaduras, a cultivar M9144 RR obteve um crescente aumento nos teores de proteína na segunda época com retardamento da colheita dos grãos. A partir do estádio R8 de desenvolvimento, o teor de óleo nos grãos de três cultivares foi maior na primeira época de semeadura. Na segunda época, quatro cultivares mostram aumento no teor de óleo a partir de R8.Palavras-chave: Glycine Max L.; retardamento; composição química dos grãos. EPOCH AND AFTER DELAYED OF SOYBEAN HARVEST VISUALIZING OIL AND PROTEIN PRODUCTION ABSTRACT: The present work was carried out with the objective of evaluate the oil and protein contents of the grains in soybean cultivars as a function of the harvest delay and to verify the influence of the sowing season under conditions in low latitude. In the agricultural year 2015/16, two competition trials of soybean cultivars were carried out in Palmas-TO, the first one being installed on December 17, 2015 and the second on January 4, 2016. The experimental design used at each time were randomized blocks with seventy treatments and five replications. The treatments were arranged in a scheme of subdivided plots, represented by ten soybean genotypes (PRISMA, TMG 132 RR, M 8647 RR, M 8372 RR, BONUS, RAÇA, ST 820 RR, OPUS, TMG 1180 RR e M 9144 RR, on the plots, and seven stages of grain harvest (R6, R7, R8, R8+7, R8+14, R8+21 e R8+28 dias) in the subplots. There was an effect of planting times and harvest stages on the oil and protein contents of the grains. The cultivars presented different behaviors in the two sowing seasons; the cultivar M9144 RR obtained an increasing increase in the protein content in the second season with grain harvest delay. From the R8 development stage, the oil content in the grains of three cultivars was higher in the first sowing season. In the second season, four cultivars show an increase in oil content from R8.Keywords: Glycine max L.; retardation; chemical composition of grains.

DESSECAÇÃO QUÍMICA E RETARDAMENTO DE COLHEITA EM SOJA VISANDO À PRODUÇÃO DE SEMENTES

Estudos sobre o efeito da dessecação e retardamento de colheita, nas qualidades das sementes de soja, são escassos em cultivos sob baixa latitude. Objetivou-se avaliar o efeito da aplicação de dessecante em soja, avaliando o retardamento da colheita em duas cultivares, observando as respostas fisiológicas, químicas e produtividade das sementes. No ano agrícola 2016/17, foi realizado experimento em Gurupi-TO, em delineamento de blocos casualizados, com três repetições, sendo os tratamentos dispostos em esquema de parcelas subsubdivididas, alocados nas parcelas duas cultivares com tipos de crescimento diferentes (NA 8015 RR-indeterminado; M 8349 IPRO-determinado), nas subparcelas dois sistemas de manejo (com dessecação e testemunha) e nas subsubparcelas quatro épocas de colheita (R8, R8+7, R8+14, R8+21). O dessecante utilizado foi herbicida com princípio ativo paraquat, na dosagem recomendada para a soja (1,5 L ha-1), aplicado no estádio R7.2 da cultura. Após a colheita, as sementes foram submetidas aos testes de germinação em laboratório, emergência em campo, produtividade, teores de óleo e proteína dos grãos. Não houve efeito da dessecação química e do retardamento de colheita na composição química dos grãos. O retardamento da colheita afeta negativamente a germinação, emergência e produtividade das sementes. A cultivar M 8349 IPRO é mais tolerante ao retardamento de colheita.Palavras-chave: épocas de colheita, Glycine max, herbicida dessecante. CHEMICAL DETERMINATION AND DELAY OF HARVESTING IN SOYBEANS FOR SEED PRODUCTION ABSTRACT: Studies on the effect of desiccation and crop delay on the qualities of soybean seeds are scarce in crops under low latitude. The objective of this study was to evaluate the effect of the application of desiccant in soybean, evaluating the delay of the harvest in two cultivars, observing the physiological, chemical and seed productivity responses. In the agricultural year 2016/17, an experiment was carried out in Gurupi-TO, a randomized complete block design, with three replications. The treatments were arranged in a sub-split plots scheme, with two cultivars with different growth types (NA 8015 RR-undetermined; M 8349 IPRO-determined) in the subplots two management systems (with desiccation and control) and in sub-subplots four harvest times (R8, R8+7, R8+14, R8+21). The desiccant used was herbicide with paraquat active ingredient, at the recommended dosage for soybean (1.5 L ha-1), applied at the R7.2 stage of the crop. After the harvest, the seeds were submitted to germination tests in the laboratory, field emergence, yield, oil content and grain protein. There was no effect of chemical desiccation and crop delay on the chemical composition of the grains. Harvest delay negatively affects seed germination, emergence and yield. The cultivar M 8349 IPRO is more tolerant to crop delay.Keywords: harvest time, Glycine max, desiccant herbicide.

Harvest, Handling, and Storage Recommendations for Improving Postharvest Quality of Blackberry Cultivars

Maintaining shelf life and postharvest quality of blackberries (Rubus subgenus Rubus) from harvest to consumer is challenging for growers and packers due to several postharvest issues including fresh weight (FW) loss, red drupelet reversion, and fruit leakiness. The time of day blackberries are harvested, the time from harvest to cold storage, and the time in cold storage are factors that may alter the incidence and severity of these postharvest problems. In this experiment, blackberries from 10 cultivars were picked at two different times (7:00–7:30 am and 10:00–10:30 am), delivered to cold storage either immediately or following a 90-minute delay, and evaluated after 1 or 2 weeks in cold storage for FW loss, red drupelet reversion, and leakiness. The response of blackberry postharvest quality to time of harvest, delay to cold storage, and storage length was cultivar-specific. In summary, time of harvest, delay to cold storage or storage length did not affect cultivars Arapaho and Ouachita. Different harvest times did not affect FW or incidence of reddening, but increased leakiness in ‘Chester’ and ‘Triple Crown’; thus, these two cultivars should be preferably harvested early in the morning. Our recommendation for ‘Chester’, ‘Triple Crown’, ‘Osage’, ‘Prime-Ark® Traveler’, and ‘Von’ is to store the fruit of these cultivars as soon as possible. Limiting cold storage to 1 week maintained postharvest quality for at least one attribute of most cultivars (all but Arapaho and Ouachita) compared with 2 weeks of storage.

Physiological and enzymatic changes in soybean seeds submitted to harvest delay1

ABSTRACT Harvest delay may affect the physiological quality of soybean seeds due to the occurrence of unfavorable environmental conditions in the field. This study was conducted to investigate the physiological and enzymatic changes in soybean seeds submitted to harvest delay. A randomized block design, with eight seed harvest periods (0; 5; 10; 15; 20; 25; 30; and 35 days after the R8 phenological stage - full maturity) of the BRS 820 RR® cultivar, with four replicates, was used. At each harvest period, the moisture content, 1,000-seed weight, germination, seedling emergence, emergence speed index, accelerated aging, vigor and viability (tetrazolium test), electrical conductivity, enzymatic expression and seed yield were measured. Harvest delay up to 35 days after the R8 phenological stage do not affect the 1,000-seed weight and seed yield. The delayed harvest from the R8 stage results in increased damage by stink bugs and moisture. The harvest delay of seeds from the 10th day after the R8 stage impairs the seed vigor and, from the 15th day, seed germination. Seeds harvested with a delay after the R8 stage have lower expressions of the following isoenzymatic systems: malate dehydrogenase, alcohol dehydrogenase, esterase, isocitrate lyase and superoxide dismutase, especially after 15 days of harvest delay.

Incidence of pathogens and field emergence of soybean seeds subjected to harvest delay

This study aimed at evaluating seed health quality, as well as seedling emergence in the field, of eight soybean cultivars (UFV-16, Splendor, Vencedora, Confiança, UFV-18, UFV-TN 105, Garantia, and Celeste) subjected to different harvest periods. To this, seeds were harvested at the growth stages R8, R8+15 days, and R8+30 days, and then submitted to health test and to the test of seedling emergence in field. Results showed that although seeds harvested at 15 and 30 days after the stage R8 had shown a significant increase of fungi infection, especially by Fusarium spp., Phomopsis spp., and Epicoccum spp., the percent seedling emergence in the field was reduced only to seeds harvested 30 days after the reproductive stage R8. Cultivars have shown differentiated behavior between each other in relation to the percent incidence rate of fungi and seedling emergence in the field; and the seeds least infected by fungi were those allowing the highest percent emergence of seedlings in the field.

Delayed harvest affects mineral and NDF concentrations, and digestibility of timothy

A 1-wk delay after late heading in the harvest of timothy spring growth reduced dietary cation-anion difference (-17%), in vitro digestibilities of dry matter (-7%) and neutral detergent fiber (-10%), and increased neutral detergent fiber concentration (+5%). In summer regrowth, the harvest delay tended to have similar effects, but variations (1-6%) were smaller. Key words: Nutritive value, stages of development, Phleum pratense L., metabolic disorders