A comprehensive study of the effect of meteorological conditions on fruit abscission and metamitron thinning efficacy in Malus domestica Borkh

Doutoramento em Engenharia Agronómica / Instituto Superior de Agronomia. Universidade de LisboaMetamitron is an apple (Malus domestica Borkh.) fruit thinner that acts by reducing the photosynthetic capacity of trees. Thinning is a common practice among apple growers however, the effect of meteorological conditions, per si, and after metamitron spraying, is far from elucidated. In order to investigate the triggered physiological and biochemical processes, trials with shading nets (SN) during 5 days and high nighttime temperature (HNT) during 5 nights, along with high humidity (HH) for 3 h prior spraying were set in three locations, within 3 years. Lower irradiance caused a momentaneous photosynthetic decrease that led to reduced levels of leaf sucrose and sorbitol and consequent increases in fruit abscission rates. HNT pathway is a slight increment in the respiratory mechanisms, but mainly in the whole tree metabolic activity, finally resulting in a shortage in sucrose and sorbitol levels, reducing fruit growth and promoting higher abscission rates. Metamitron acts through a photosynthetic inhibition, including reductions in RuBisCO total activity, translating in less CH production. In addition, it stimulates vegetative growth, consuming CH and slowing down fruit growth rate, and finally enhancing of abscission. The combined treatments resulted in the strongest thinning efficacy, through a suppression of the CH production caused by metamitron in combination with low radiation and or through enhanced expenditure cause by HNT, frequently over-thinning. The effect of HH may enhance fruit drop under humid climates and in younger trees, more susceptible to variations in CH content. This work shows meteorological conditions, namely cloudy days, periods of HNT and increased humidity levels, may affect metamitron thinning efficacy and must be considered in order to decide which rate to apply to achieve an optimum crop loadN/

Gestão dos Parques Naturais em Cabo Verde

O processo de desenvolvimento económico e a garantia do bem-estar global das sociedades humanas esteve sempre assente numa dependência directa entre o homem e o ambiente o que tem sido traduzida numa utilização desenfreada e irresponsável dos recursos naturais, o que provocaram uma série de consequências desastrosas como o êxodo rural, a crescente urbanização, a poluição dos solos, da água e do ar, o esgotamento de importantes recursos naturais e, em suma, a degradação da biodiversidade terrestre e marinha na sua forma mais abrangente. A situação preocupante desta degradação impõe uma atitude mais responsável do Homem para com o ambiente, por forma a restabelecer-se a necessária harmonia entre este e a natureza. Essa harmonia reflecte, em última instância, o conceito da sustentabilidade que irá permitir uma utilização responsável e duradoura dos recursos naturais e garantir, em consequência, às gerações vindouras um futuro diferente e promissor, pois a sua qualidade de vida depende, grandemente, do nível de conservação desses ecossistemas (MAA, 1999). Com a mudança de atitude do Homem, uma resposta às preocupações sobre o crescente impacto da actividade humana sobre os recursos naturais, em 1983 a Organização das Nações Unidas (ONU) criou a Comissão Mundial sobre Meio Ambiente e Desenvolvimento para discutir e propor meios de harmonizar os dois objectivos - desenvolvimento económico e conservação ambiental (MAA, 1999). As questões relacionadas com a conservação da diversidade biológica começaram a fazer parte da agenda de várias organizações internacionais, incluindo as Nações Unidas (MAA, 1999), a partir de 1972 em Estocolmo e confirmado na Conferencia de Rio em 1992 a Convenção sobre a Diversidade Biológica (CDB), através do consenso a volta dos princípios, recomendações e acções da Agenda 21 e sobretudo das convenções internacionais, com nova abordagem da problemática do ambiente mundial. A CDB é constituída por 42 artigos que estabelecem um programa para reconciliar o desenvolvimento económico com a necessidade de preservar todos os aspectos da diversidade biológica. Cabo verde e um arquipélago inserido na região Macaronésia com influências da região saheliana, dotada de características climáticas, geológicas, marítimas, geomorfológica, botânica e zoológicas peculiares. Esta particularidade faz com que cabo verde seja um arquipélago específico entre os outros da vasta área atlântica (MAA e DGA, 2003:3)2, devido à conjugação de vários factores, são detentora de uma diversidade biológica considerável e de importância global, apresentando no entanto um ecossistema de fraco equilíbrio, onde existe vários factores de ameaças, como a seca, as espécies exóticas e invasoras, factores antrópicos de vária ordem, interessa e vê-se como necessário a conservação e gestão sustentável dos seus recursos naturais, como condição necessária para o desenvolvimento sustentado O conceito de desenvolvimento sustentável foi proposto nos anos oitenta com a elaboração da Estratégia Mundial para a Conservação da Natureza que se traduziu pela necessidade premente de harmonizar o processo de desenvolvimento e a exploração desenfreada dos recursos que deveria ser feita dentro dos níveis que permitam a sua renovação, evitando assim a sua colocação em perigo (MAA, 1999). A natureza insular do arquipélago, aliado as acções nefastas de factores climáticos e antrópicos, vem contribuindo ao longo dos tempos para a degradação dos seus recursos naturais. Esta situação exige a implementação de medidas que garantam uma gestão sustentável dos recursos naturais de todo território nacional (MAA e DGA, 2003:3). O estado de degradação muito avançado dos recursos marinhos e terrestres de Cabo Verde, deve-se em parte, de acordo com a opinião dos especialistas e da população local, à má gestão desses recursos, A 29 de Março de 1995 Cabo Verde comprometeu-se perante a Comunidade Internacional a promover a implementação dos objectivos e princípios que constam desse documento (MAA, 1999). Cabo Verde, para confirmar a sua participação na luta contra as ameaças ambientais planetárias, ratificou as principais convenções internacionais (CCD, CBD, CCC) e comprometeu-se a implementa -las através de estratégias e planos de acção. A ligação entre a Gestão Ambiental Global e o Desenvolvimento Durável é capital para um país como Cabo Verde, tendo em conta a vulnerabilidade ambiental e no contexto de um pequeno estado insular em desenvolvimento (SIDS), devem ser bem avaliados e implementados com uma visão estratégica integrada, sinérgica e de longo prazo (ROCHA, CHARLES e NEVES.ARLINDA, 2007:12). Desde a independência nacional a 5 de Julho de 1975, os sucessivos Governos Cabo-verdianos têm-se mostrado preocupados com a questão da preservação dos ecossistemas e com o enquadramento dos organismos vocacionados para a gestão ambiental, O segundo Plano de Acção Nacional para o Ambiente (PANA II) constitui a concretização destas políticas e define as orientações estratégicas de aproveitamento dos recursos naturais bem como os seus efeitos sobre a gestão sustentável das actividades económicas. É um documento orientador de um processo contínuo caracterizado por uma dinâmica própria e que nos próximos 10 anos (2004-2014), servirá de base de trabalho, permitindo um desenvolvimento Cabo-verdiano sustentável e harmonioso, garantindo um ambiente sadio (MAAP, 2004 a 2014:12)3. A Conferência das Nações Unidas sobre o Ambiente e Desenvolvimento (conhecida como a Cimeira da Terra), realizada no Rio de Janeiro, Brasil em 1992, constitui uma referência histórica na área do ambiente marcando, assim, a mudança na abordagem da problemática ambiental a nível mundial. Como resultado deste processo, assiste-se à mobilização dos países em programas a nível nacional, regional e internacional. É a partir da Cimeira da Terra que a problemática ambiental ganha uma nova dinâmica e passa a ser integrada, de forma explícita, no processo de planeamento. De destacar, ainda a emanação a partir da Conferência do Rio de convenções específicas, designadamente, nos domínios da luta contra a desertificação, da biodiversidade e das mudanças climáticas (MAAP e DGA, 2004:11)4. Com a criação de um sistema de AP, o país deu passos importantes. A Estratégia e o Plano de Acção Nacional da Biodiversidade (1999) definiram habitats prioritários para conservação representativos do património em matéria de biodiversidade. Este exercício de definição de prioridades serviu de base para o estabelecimento legal da rede nacional de AP em 2003, Com 47 sítios compreendendo tantas áreas marinhas/costeiras protegidas (AMP) como terrestres Protegidas (AP) (PNUD et al. 2010:8)5. Em todos os países, a agricultura é a actividade que ocupa a maior parte das terras, pelo que desempenha um papel importante na transformação do ambiente pela acção do homem que modela a paisagem e as formas de vida rural natural, ao longo dos séculos. A agricultura, constitui directa ou indirectamente a base económica de subsistência da maior parte da população (MAAP e DGA, 2004:112). A estratégia política ambiental para Cabo Verde prevê uma sociedade consciente do papel e dos desafios do ambiente para um desenvolvimento económico e social sustentável, consciente das suas responsabilidades relativamente às gerações futuras e determinada a utilizar os recursos naturais de maneira durável. Para tal entende-se implementar uma abordagem integrada com base nos seguintes pressupostos: conservação dos recursos naturais; especialmente da biodiversidade terrestre e marinha; das zonas costeiras e das áreas florestais; manutenção de um ambiente urbano e rural sadio em toda a sua envolvente (PNUD et al. 2010:8). A área do ambiente é relativamente nova, o leque de instrumentos para a gestão do ambiente é fracamente desenvolvido e pouco aplicado. Refere-se por exemplo, o reduzido desenvolvimento do sector do Ordenamento do Território, as lacunas e algumas incoerências da legislação e o sistema de informação que ainda é rudimentar. A problemática ambiental ganhou uma nova dimensão a partir de 1995. Com efeito, foi institucionalizado o processo de protecção do ambiente com a criação do Secretariado Executivo para o Ambiente (SEPA), hoje Direcção Geral do Ambiente (DGA) através do Decreto-Lei n.º 8/2002 de 25 Fevereiro, que aprova a orgânica do Ministério da Agricultura e Pesca e define as atribuições no domínio do ambiente e dos recursos naturais (PNUD et al. 2010:8). O poder local, é visto pelas populações como o responsável pela resolução da maioria dos Problemas, As ONG’s e as associações nacionais e regionais estão num processo de desenvolvimento e de afirmação. Desempenham um papel cada vez mais importante no domínio da preservação do ambiente (PNUD, et al. 2010:8)

Effects of metamitron under different relative humidity conditions on the fruit abscission of Malus domestica Borkh. cultivars

Metamitron is an apple (Malus domestica Borkh.) fruit thinner that acts by reducing the photosynthetic capacityof trees. Relativehumiditymayinfluence thinningefficacy; however, thebroadness of this effect is not yet fully understood. Trials were set in Sint-Truiden (Belgium) in 2018 and Lleida and Girona (Spain) in 2019, using 4-year-old cvs. Braeburn and Elstar trees in Belgium, and 16-year-old cv. GoldenReinders trees in Spain. Four treatmentswere implemented at the stage of 12–14mmfruit diameter: (a) CTR—control, trees under natural environmental conditions; (b) HH—high humidity, trees submitted to artificially increased air relative humidity applied for 3 h prior to the beginning of the experiment; (c)MET—trees sprayedwith 247.5mg/Lmetamitron; (d)MET + HH—trees submitted to the combination of increased humidity (HH) and metamitron (MET) application. In Belgium, metamitron absorption by leaves was greater than in Spain. This might be related to morphological characteristics of the leaves which developed under greater natural relative humidity levels in Belgium than in Spain. Compared to MET alone, ‘Braeburn’ and ‘Elstar’ demonstrated significantly greater metamitron absorption, 59% and 84%, respectively, underMET + HH, accompanied by declines in leaf net photosynthesis (10% and 32%, respectively) and sucrose (31% and 26%, respectively). At harvest,MET + HH treatment reduced yield by 24% and 32% in ‘Braeburn’ and ‘Elstar’, respectively, when compared withMET alone. A large reduction (considered over thinning) in the yield of ‘Elstar’ occurred. In contrast,metamitron absorption by ‘Golden Reinders’ usingMET alone was similar toMET + HH; however, there was a slight foliar sugar reduction in the latter treatment. In addition, both treatments enhanced shoot growth and increased fruit abscission with similar improvements in fruit weight and size. In this study, high relative humidity enhanced fruit thinning efficacy under certain circumstances, such as age or genetic predisposal, which left the tree more susceptible to a negative carbohydrate balance. For instance, ‘Braeburn’ and ‘Elstar’ were easier to thin when compared to ‘Golden Reinders’. In addition, this study raises a question that requires further research regarding the impact of HH before and after spraying as well as its effect in combination with higher temperaturesinfo:eu-repo/semantics/publishedVersio

Plasticity in the shape and growth pattern of asteriscus otolith of black prochilodus Prochilodus nigricans (Teleostei: Characiformes: Prochilodontidae) freshwater Neotropical migratory fish

ABSTRACT Using morphometric measurements and wavelets functions, the asterisci otoliths of curimatã, Prochilodus nigricans were analysed to identify the variation in shape and growth increment of individuals from Solimões, Japurá and Negro rivers of the Amazon basin, Brazil. The morphometric and morphological analyses did not reveal evidences of population segregation among rivers, but variations were found in the estimation of otolith growth increment. Also, the otolith shape showed a high variability between individuals, identifying four morphotypes. Morphotype 1 shows a more oval shape with a posterior zone clearly rounded; Morphotype 2 shows the posterior zone rounded, but the anterior end is more elongated; Morphotype 3 shows a completely different shape, elliptic-pentagonal and Morphotype 4 shows the posterior zone rounded, but the anterior end is more elongated and it is the pattern with antirostrum and rostrum more pointed and a deep notch. Therefore, the otolith shape exhibited a phenotypic plasticity that it was not associated with the metabolism of otolith growth. Whereas the otolith shape indicated a homogeneity in the sound perception through Amazon basin, the growth rates revealed an adaptive mechanism to environmental conditions or migratory process of this species.</div

Produtividade do feijoeiro de inverno sob diferentes palhadas de espécies forrageiras e épocas de aplicação de nitrogênio

O uso intensivo de gramíneas em áreas de implantação de sistemas consorciados de produção agrícola sob sistema plantio direto (SPD), pode promover uma imobilização temporária do nitrogênio (N) no solo. O presente trabalho objetivou avaliar o efeito da adubação nitrogenada (70 kg N ha-1), em dose única na semeadura ou em cobertura sobre a nutrição, os componentes da produção e a produtividade de grãos do feijoeiro de inverno em sucessão ao consórcio das culturas do milho e capim-xaraés, sob diferentes palhadas de plantas de cobertura em condições irrigadas no Cerrado. O experimento foi instalado em delineamento de blocos casualizados, com quatro repetições, em esquema fatorial 4x2x2. Os tratamentos foram constituídos por 4 espécies de plantas forrageiras (aveia preta cv. IAPAR 61, sorgo forrageiro cv. Volumax, milheto e capim-tanzânia) semeadas em 2 épocas (junho e julho), visando a formação de palhada para o cultivo das culturas do milho e capim-xaraés em consórcio, além de 2 épocas de adubação nitrogenada na cultura do feijão de inverno em sucessão. As espécies antecessoras ao cultivo do milho em consórcio com o capim-xaraés, não alteraram a nutrição, os componentes da produção e produtividade de grãos do feijoeiro de inverno em sucessão. Em áreas de solo argiloso, com características de implantação do SPD (primeiros 3 anos), a adubação nitrogenada com toda a dose em semeadura aumentou a produtividade de grãos de feijão de inverno em condições de Cerrado de baixa altitude

Metamitron and Shade Effects on Leaf Physiology and Thinning Efficacy of Malus × domestica Borkh

Thinning strategies, namely shade or photosynthetic inhibitors, rely on the reduction of carbon supply to the fruit below the demand, causing fruit abscission. In order to clarify the subject, seven field trials were carried out in Lleida, Girona, and Sint-Truiden (2017 + 2018), using orchards of ‘Golden’ and ‘Gala’ apple trees. At the stage of 9–14-mm fruit diameter, four treatments were implemented: (A) CTR-control, trees under natural environmental conditions; (B) SN-shaded trees, trees above which shading nets reducing 50% of irradiance were installed 24 h after metamitron application date—without application of metamitron—and removed after five days; (C) MET-trees sprayed with 247.5 ppm of metamitron; (D) MET + SN-trees submitted to the combined exposure to metamitron application and shading nets. Low radiation significantly increased metamitron absorption (36–53% in the three locations in 2018) and reduced its degradation. Net photosynthesis and stomatal conductance were strongly reduced in all treatments, with minimum values 2 days after spraying (DAS) and incomplete recovery 10 DAS in MET + SN. All treatments resulted in leaf sucrose and sorbitol decreases, leading to a negative carbon balance. SN and MET + SN promoted the highest thinning efficacy, increasing fruit weight and size, with MET + SN causing over-thinning in some trials. Leaf antioxidant enzymes showed moderate changes in activity increases under MET or MET + SN, accompanied by a rise of glutathione content and a reduction in ascorbate, however without lipid peroxidation. This work shows that environmental conditions, such as cloudy days, must be carefully considered upon metamitron application, since the low irradiance enhances metamitron efficacy and may cause over-thinninginfo:eu-repo/semantics/publishedVersio

Effects of Metamitron under Different Relative Humidity Conditions on the Fruit Abscission of Malus domestica Borkh. Cultivars

Metamitron is an apple (Malus domestica Borkh.) fruit thinner that acts by reducing the photosynthetic capacity of trees. Relative humidity may influence thinning efficacy; however, the broadness of this effect is not yet fully understood. Trials were set in Sint-Truiden (Belgium) in 2018 and Lleida and Girona (Spain) in 2019, using 4-year-old cvs. Braeburn and Elstar trees in Belgium, and 16-year-old cv. Golden Reinders trees in Spain. Four treatments were implemented at the stage of 12&ndash;14 mm fruit diameter: (a) CTR&mdash;control, trees under natural environmental conditions; (b) HH&mdash;high humidity, trees submitted to artificially increased air relative humidity applied for 3 h prior to the beginning of the experiment; (c) MET&mdash;trees sprayed with 247.5 mg/L metamitron; (d) MET + HH&mdash;trees submitted to the combination of increased humidity (HH) and metamitron (MET) application. In Belgium, metamitron absorption by leaves was greater than in Spain. This might be related to morphological characteristics of the leaves which developed under greater natural relative humidity levels in Belgium than in Spain. Compared to MET alone, &lsquo;Braeburn&rsquo; and &lsquo;Elstar&rsquo; demonstrated significantly greater metamitron absorption, 59% and 84%, respectively, under MET + HH, accompanied by declines in leaf net photosynthesis (10% and 32%, respectively) and sucrose (31% and 26%, respectively). At harvest, MET + HH treatment reduced yield by 24% and 32% in &lsquo;Braeburn&rsquo; and &lsquo;Elstar&rsquo;, respectively, when compared with MET alone. A large reduction (considered over thinning) in the yield of &lsquo;Elstar&rsquo; occurred. In contrast, metamitron absorption by &lsquo;Golden Reinders&rsquo; using MET alone was similar to MET + HH; however, there was a slight foliar sugar reduction in the latter treatment. In addition, both treatments enhanced shoot growth and increased fruit abscission with similar improvements in fruit weight and size. In this study, high relative humidity enhanced fruit thinning efficacy under certain circumstances, such as age or genetic predisposal, which left the tree more susceptible to a negative carbohydrate balance. For instance, &lsquo;Braeburn&rsquo; and &lsquo;Elstar&rsquo; were easier to thin when compared to &lsquo;Golden Reinders&rsquo;. In addition, this study raises a question that requires further research regarding the impact of HH before and after spraying as well as its effect in combination with higher temperatures

Comparação de benziladenina e metamitrão como substâncias de monda química nas cultivares de macieira ‘Gala’, ‘Kanzi®’, ‘Pink Lady®’ and ‘Red Delicious’

Mestrado em Engenharia Agronómica - Instituto Superior de Agronomia - ULThis experiment was conducted in PCFruit Research Station orchards in Sint-Truiden, Belgium in 2015, in ‘Gala’, ‘Kanzi®’, ‘Pink Lady®’ and ‘Red Delicious’. Four treatments were tested: untreated, manual thinning, two applications of 165 ppm of metamitron at 8 and 12 mm and one application of 150 ppm of benzyladenine between 8 and 12 mm fruit diameter. All cultivars were sprayed on the same days. Fruit drop was counted, phytotoxicity evaluated after June drop, fruit growth rate was assessed and photosynthetic efficiency was measured. Fruit drop was higher in all cultivars with metamitron application than with benzyladenine (P<0.05). A greater growth rate in fruits treated with metamitron was registered, as well as, a positive correlation between the sum of the PSII efficiency and the thinning percentage (R2=0.98). A relation between the duration of the blocking effect of metamitron and phytotoxicity level in the trees was observed. At harvest, metamitron and manual thinning showed the best results in average fruit weight, in all cultivars. Despite the size improvements, the only influence in quality was observed in ‘Pink Lady®’ Brix° values. All cultivars thinned with 150 ppm benzyladenine were far from the ideal crop load for fruit size, probably due to the poor weather conditions after application, while with two times 165 ppm metamitron sprays had the same results as manual thinning. ‘Pink Lady®’ was the easiest cultivar to thin, with a slight over thinning effect, followed by ‘Gala’, that achieved the ideal crop load and ‘Red Delicious’ was the most difficult to thin. It was not possible to compare ‘Kanzi®’ with the other cultivars due to the poor fruitset observed before the product’s application. Metamitron doses can be adjusted to achieve optimum results; in ‘Pink Lady®’ the dose should be lower while in ‘Red Delicious’ higher. A simpler version of the Greene model was tested the percentage of error was 7.5% for fruits treated with metamitron while in benzyladenine treated fruits was 18%

Pseudochylothorax Combined with Spontaneous Pneumothorax: Case Report of a Rare Complication of Rheumatoid Arthritis

Pleural involvement is the most frequent thoracic complication of rheumatoid arthritis (RA), usually occurring in patients with known RA. Typical rheumatoid pleural effusion is an exudate characterized by low pH and glucose levels and high LDH activity. Rarely, it has features of pseudochylothorax. Other uncommon complications are pneumothorax, hydropneumothorax, empyema, and bronchopleural fistula. The case of a 51-year-old man with a spontaneous, small, and asymptomatic hydropneumothorax with features of pseudochylothorax is presented. After careful clinical and laboratory evaluation, he was diagnosed with rheumatoid arthritis, and we admitted that the pleural changes were secondary to the connective tissue disease. He started immunosuppressive treatment and maintained stability during follow-up, without need of specific pleural treatment. We hypothesized that the pleural nodule found on the chest computed tomography scan was related with the simultaneous occurrence of pleural effusion and pneumothorax. This is a rare presentation and complication of RA, highlighting the utility of a comprehensive clinical and laboratory evaluation and focusing on the importance of pleural rheumatoid nodules in the pathogenesis of RA pleural disease

Response of Malus x domestica Borkh to metamitron and high night temperature: Effects on physiology and fruit abscission

Periods of high nighttime temperature may induce carbohydrate (CH) shortage by increased dark respiration. Metamitron is a thinning agent that inhibits photosynthesis and enhances fruit abscission due to a reduction in CH production. To clarify how both interact in apple tree physiologic mechanisms and on fruit abscission, five field trials were carried out in Lleida, Girona and Sint-Truiden (2017 + 2018), using orchards of ‘Golden’ apple trees. At the stage of 12–14 mm fruit diameter, four treatments were established: (A) CTR – control, trees under natural environmental conditions; (B) HNT – high nighttime temperature, trees exposed to artificially increased nighttime temperature during 5 nights after the day of spraying, without metamitron application; (C) MET - 247.5 ppm of metamitron application and (D) MET + HNT - trees submitted to the combined exposure to metamitron application (MET) and to artificially increased nighttime temperature (HNT). HNT did not affect metamitron absorption, net photosynthesis (Pn) and stomatal conductance however, promoted significant reductions in leaf CH content mainly before sunrise, especially in sucrose (18–45%) and in sorbitol (19–26%). Metamitron significantly reduced Pn to about 50% of CTR, which resulted in decreases in leaf sucrose and sorbitol, reaching minimum values 5 days after spraying, between 21 and 57% and 19–26%, respectively. Fruit growth rate of both treatments was retarded by 30%, 2 days after either metamitron application or HNT. Both treatments originated a similar reduction in the number of fruits and size improvement. The combined exposure (MET+HNT) promoted similar Pn reductions as MET, but showed the greatest sucrose (44–60%) and sorbitol (73–84%) decreases which resulted in the strongest thinning efficacy. Lipid peroxidation was not affected by the treatments however, antioxidant enzyme activity showed moderate changes with activity increases mainly under MET and MET + HNT, accompanied by a rise in glutathione content and reduction in ascorbate. This work shows that the overlap of photosynthesis inhibition (reducing CH production) by means of metamitron spraying, and likely greater respiration (increased CH consumption), by HNT imposition, translates less CH production than the growing fruits demand (negative CH balance) leading to a metamitron thinning effect enhancement. Periods of high nighttime temperature must be considered when deciding the best metamitron rate to achieve an optimal crop load result.info:eu-repo/semantics/acceptedVersio