Assessment of table grape progenies and correlation between seedlessness and other agronomic traits

Abstract The aim of the present study was to identify grape parent varieties that lead to greater frequency of seedless genotypes in the progenies and to understand the relationships between the seedless trait and other fruit traits. A group of 200 hybrids (F1) originating from 38 crosses among cultivars of Vitis vinifera L. and interspecific hybrids were evaluated in Juazeiro, Bahia, Brazil, over six consecutive crop seasons (2018 to 2021). The progenies were placed in three classes based on seedlessness: completely seedless (class 1), seed traces or soft seeds (class 2), and with seeds (class 3). The mean dry matter of the seeds in each class was 0 mg, 2.3 mg, and 25.7 mg respectively, which corresponded to 40 genotypes (20%) in class 1, 52 genotypes (26%) in class 2, and 108 (54%) in class 3. The interspecific cross ‘BRS Isis’ and ‘Marroo Seedless’ stood out through favoring high frequency of seedless individuals in the progeny (47.5%). The traits associated with berry size (length, diameter, and weight) had high positive correlations with each other. The results obtained make an important contribution for table grape breeding aiming at the development of new table grape cultivars

Evolução histórica do código florestal brasileiro e o impacto na produção agropecuária: Historical evolution of the brazilian forest code and the impact on agricultural production

A questão ambiental tem sido tema de reiteradas discussões no Brasil nos últimos anos. A votação do Novo Código Florestal Brasileiro (NCFB) dividiu as lideranças governamentais e a sociedade em bancadas “ambientalista” e “ruralista”. O Brasil se destaca tanto pela composição de sua biodiversidade quanto por sua expertise na produção agropecuária. Por esse motivo, é imprescindível que a legislação seja capaz de garantir o desenvolvimento econômico sem comprometer a conservação e preservação do meio ambiente. Assim, buscou-se dar um panorama das modificações do Novo Código Florestal no desenvolvimento da produção agropecuária e na conservação do meio ambiente no Brasil. Para isso foi apresentada a evolução do NCFB, e seus principais pontos para a produção agropecuária, sobretudo no que diz respeito à Reserva Legal e Áreas de Preservação Permanente. O estudo mostra que o NCFB foi uma demanda das mudanças ambientais dos últimos anos, e que a produção agropecuária deverá se adaptar às novas regras. Nota-se também a importância da produção de alimentos e da conservação ambiental exercidas pelo meio rural para a manutenção da qualidade de vida da população urbana

Nitrogen metabolism in the roots of rubber tree (Hevea brasiliensis) plants supplied with nitrate or ammonium as nitrogen source during hypoxia

Abstract The plants may be exposed to excessive soil moisture condition, in which oxygen supply (O 2 ) to the root system becomes difficult due to the low diffusion rate gas in water. Given the fundamental importance of O 2 in plants aerobic metabolism, the flooding can to affect the plants development in ecosystems. O 2 lack in the cultivation substrates negatively influences the productivity of many economically important species such as rubber tree (Hevea brasiliensis Müll.Arg.). Amazonian species undergoes flooding periods at different lifecycle stages. The application of nitrate (NO 3 − ) has been observed to increase the plant tolerance subjected O 2 deficiency. The nitrogen role in plants under O 2 deficiency is very important, but is not well understood. In this study we evaluate nitrogen metabolism changes (roots enzymatic assimilation) and the nitrogen compounds transport to the shoot in rubber trees under O 2 deficiency treated with nitrate or ammonium. Rubber tree plants were grown in nutrient solutions of Bolle-Jones (1957) 1/2 strength. When plants were 12 months-old they were divided into six treatments consisting of the complete nutrient solution of Bolle-Jones (1957) free nitrogen, with 8 mM nitrogen (KNO 3 ) or with 8 mM nitrogen ((NH 4 ) 2 SO 4 ) and two oxygen availability conditions (normoxia-control plants: roots kept under nutrient solution and continuous aeration and hypoxia-flooded plants: roots kept under nutrient solution without aeration). Root and sap xylem material was harvested for biochemical analysis every 7 days (days 7, 14 and 21). The results showed that under hypoxia, nitrate treated plants showed higher nitrate reductase (NR) activity compared to the control. Glutamine synthetase (GS), glutamine-2-oxoglutarate aminotransferase (GOGAT) and glutamate dehydrogenase (GDH) activities were significantly decreased in stressed plants regardless of the nitrogen source. However, under normoxia or hypoxia, nitrate treated plants showed higher (GS, GOGAT and GDH) activity, in comparison with the ammonium treatment. Moreover, under hypoxia nitrate treated plants, presented higher alanine and Gaba concentrations in the xylem than plants treated with ammonium. Therefore nitrogen assimilation, amino acid biosynthesis and transport are in general less affected by hypoxia, however, nitrate addition attenuates stress effects

Desempenho de mudas de pinha em diferentes doses de adubação fosfatada

Adding phosphorus in the composition of the substrate for the seedlings production contributes to a faster growth of seedlings, increases the resistance to biotic and abiotic stresses, also improves the efficiency in the use of nutrients and water in many vegetal species. The objective  of  this  research  was  to  evaluate  the  vegetative  growth and quality of Annona squamosa L. seedlings, propagated by seeds, regarding the application of single superphosphate in enriched sugarcane bagasse substrate. The completely randomized design consisted of six treatments arranged according to the following application doses (0; 0.75; 1.5; 2.25; 3.0 and 3.75 kg), using the single superphosphate in substrate, with four replicates per treatment. At 120 days after sowing, number of leaves, leaf area, shoot height, stem diameter, shoot dry mass, root dry mass, total dry mass, ratio between shoot dry mass and root dry mass, chlorophyll a, chlorophyll b, total chlorophyll, and Dickson’s Quality Index were evaluated. The maximum growth of the pine cone plants were noted when added single superphosphate to the substrate in doses ranging from 0.6 to 1.2 kg.m-3. The phosphate fertilizer favored the growth especially of the roots and leaf area and improved the quality of pine cone seedlings.A adição de fósforo na composição do substrato para produção de mudas contribui para um crescimento mais rápido das plântulas, aumenta a resistência aos estresses bióticos e abióticos e melhora ainda a eficiência no uso de nutrientes e da água em várias espécies vegetais. O objetivo desta pesquisa foi avaliar o crescimento vegetativo e a qualidade de mudas de Annona squamosa, propagada por sementes, em relação a aplicação de superfosfato simples em substrato de bagaço de cana enriquecido.  O delineamento inteiramente casualizado constou de seis tratamentos com as seguintes doses de aplicação ( 0; 0,75; 1,5; 2,25; 3,0 e 3,75 kg), usando o superfosfato simples em substrato, com quatro repetições de 10 plantas por tratamento. Aos 120 dias após semeadura, número de folhas, área foliar, altura da parte aérea, diâmetro do caule, fitomassa seca da parte aérea, fitomassa seca do sistema radicular, fitomassa seca total, relação entre as fitomassas seca da parte aérea e do sistema radicular, clorofila a, clorofila b, clorofila total e o índice de qualidade de Dickson, foram avaliados. O crescimento máximo das plantas de pinha foi observado com a adição de superfosfato simples ao substrato em doses estimadas na faixa de 0,6 a 1,2 kg m-³ de substrato. O fertilizante fosfatado favoreceu o crescimento principalmente de raízes e área foliar e proporcionou melhor qualidade de mudas de pinha