Dosage and timing of nitrogen fertilizer application on snap beans

Snap beans (Phaseolus vulgaris L.) belong to the same species as common beans and require similar management practices. Studies aimed at nitrogen fertilization in pod beans are scarce, but necessary, considering the demand from farmers for greater productivity of these beans. The objective of this study was to evaluate the effects of nitrogen fertilization in various doses and times of application on the snap beans production. The experimental design was completely randomized in a factorial scheme (2×7) + 1, represented by two doses of nitrogen (30 and 60 kg ha-1) and seven fertilization strategies (100% of the dose provided at sowing or phenological stages V3, V4, or R6; split, with 50% at sowing and 50% at V3, 50% at sowing and 50% at V4, or 50% at sowing and 50% at R6), plus a control (no added N). We analyzed stem length, stem basal diameter, number of trefoils, number and mass of commercially viable pods, and number and mass of total pods. Nitrogen fertilization with 30 kg ha-1 N divided 50% at sowing and 50% at V4 or 50% at sowing and 50% at R6 yielded larger and more numerous pods from plants with greater stem diameters

Fruit sizes and methods of seed extraction in Physalis physiological potential

Physalis peruviana L., a small fruit belonging to the Solanaceae family, is known for the high vitamins A and C, iron, and phosphorus content. As it presents numerous opportunities for adding value to family producers, it has been gaining space in the consumer market. Characteristics such as fruit size and seed extraction methods can interfere with the physiological potential of the seeds. Thus, the objectives of this study were to evaluate the relationship between fruit size and physiological quality of Physalis seeds and to establish an effective method for the extraction of its seeds. The experiment was conducted at the Phytotechnics Laboratory of the State University of Londrina, using a completely randomized design in a 3×2 factorial scheme, with 4 replications of 50 seeds. The factors consisted of three fruit sizes (small, medium, and large) and two extraction methods (manual and mechanical). The averages obtained were compared using the Tukey test (p ≤ 0.05). After 28 days of germination, the following evaluations were made: percentage of germination, first germination count, germination speed index, length, and dry mass of seedlings. The physiological potential of the seeds was influenced by the size of the fruits. The method of manual seed extraction proved to be superior and more efficient than the mechanical method

Physiological potential of corn seeds with different sizes and vigor levels subjected to micronutrient treatment

Micronutrients are used in small amounts by plants and changes in metabolic processes of seeds can improve germination and vigor; however, little is known about the effects of the combination of Zn, Co, and Mo on corn seeds. Thus, the objective of this study was to evaluate the effects of the application of Zn, Co, and Mo on the physiological potential of corn seeds of different sizes and levels of vigor. A randomized 2×2×3 factorial design was adopted, with two levels of vigor (high and low), two seed sizes (18 and 22 mm), and three doses of liquid fertilizer containing micronutrients (0, 2, and 4 mL kg-1). The physiological potential of the seeds was evaluated based on germination and vigor tests. High vigor corn seeds had greater physiological potential compared to low vigor seeds. Regarding size, small seeds (18 mm) had higher percentages of germination and vigor than the large seeds (22 mm). Seed treatment with micronutrients (Co, Mn, and Zn) resulted in improved emergence in the field, shoot length, and dry mass of large and small seeds with the application dose of 2 mL kg-1, and the application dose of 4 mL kg-1 enhanced emergence in the field of large seeds and germination after the cold test of low vigor seeds of both sizes

Efeito residual de herbicidas pré-emergentes no desenvolvimento inicial e na composição bioquímica de plântulas de feijão-vagem

The use of herbicides must be made in a rational way, giving priority to reduce possible adverse effects on subsequent crops. The objective was to evaluate the residual effect of pre-emergent herbicides on growth and initial development as well as the biochemical composition of snap bean seedlings. The experimental design used was the completely randomized, with four replications in factorial scheme 3x4, three snap bean cultivars (Macarrão Favorito, Macarrão Preferido e Macarrão Trepador) and three pre-emergent herbicides, plus a control (without herbicide). Was use the residual doses of pre-emergent herbicides sulfentrazone in 0.3 g ha-1, diclosulam in the concentrations of 0.126 g ha-1 and imazethapyr in 0.05 g ha-1. The work was developed in a seeds analyze laboratory with the purpose of minimizing possible adverse effects of the environment. The seeds were sowing on germitest paper moistened with solutions containing the herbicides, with each respective treatment. The following characteristics were evaluated: germination (GER), germination speed index (GSI), seedling length (SL) and seedling dry mass (SDM) and soluble protein content (PROT) in addition to the enzymatic activity of catalase (CAT), peroxidase (PER) and phenylalanine ammonia-lyase (PAL). The phytometric variables SL, SDM, GER and GSI reduced in the presence of herbicides, and for the levels of PROT and enzymatic activity of CAT, PER and PAL there was observed a variation according to the genotype. The sulfentrazone showed up as the product of higher toxicity, as well as the Macarrão Trepador as the genotype with lower tolerance.O uso de herbicidas deve ser feito de forma racional, dando prioridade em evitar possíveis efeitos adversos nas culturas subsequentes. O objetivo foi avaliar o efeito residual dos herbicidas pré-emergentes no crescimento e no desenvolvimento inicial, bem como a composição bioquímica das plântulas de feijão vagem. O delineamento experimental utilizado foi o completamente ao acaso, com quatro repetições, em esquema fatorial 3x4, três cultivares de feijão-vagem (Macarrão Favorito, Macarrão Preferido e Macarrão Trepador) e três herbicidas pré-emergentes, além de um controle (sem herbicida). Utilizou-se de doses residuais de herbicidas pré-emergentes sulfentrazone 0,3 g ha-1, diclosulam 0,126 g ha-1 e imazethapyr 0,05 g ha-1. O trabalho foi desenvolvimento em laboratório de análise de sementes com a finalidade de minimizar possíveis efeitos adversos do meio. As sementes foram semeadas em papel germitest umedecidos com as soluções contendo os herbicidas, respectivas a cada tratamento. Avaliou-se as seguintes características: germinação (GER), índice de velocidade de germinação (GSI), comprimento de plântulas (SL), massa seca de plântulas (SDM) e teor de proteína solúvel (PROT) além da atividade enzimática da catalase (CAT), peroxidase (PER) e fenilalanina amônia-liase (PAL). As variáveis fitométricas SL, SDM, GER e GSI reduziram na presença de herbicidas, já para os teores de PROT e atividade enzimática da CAT, PER e PAL houve variação de acordo com o genótipo. O sulfentrazone mostrou-se como o produto de maior toxicidade, bem como o Macarrão Trepador como o genótipo de menor tolerância

Fruit sizes and methods of seed extraction in Physalis physiological potential

Physalis peruviana L., a small fruit belonging to the Solanaceae family, is known for the high vitamins A and C, iron, and phosphorus content. As it presents numerous opportunities for adding value to family producers, it has been gaining space in the consumer market. Characteristics such as fruit size and seed extraction methods can interfere with the physiological potential of the seeds. Thus, the objectives of this study were to evaluate the relationship between fruit size and physiological quality of Physalis seeds and to establish an effective method for the extraction of its seeds. The experiment was conducted at the Phytotechnics Laboratory of the State University of Londrina, using a completely randomized design in a 3×2 factorial scheme, with 4 replications of 50 seeds. The factors consisted of three fruit sizes (small, medium, and large) and two extraction methods (manual and mechanical). The averages obtained were compared using the Tukey test (p ≤ 0.05). After 28 days of germination, the following evaluations were made: percentage of germination, first germination count, germination speed index, length, and dry mass of seedlings. The physiological potential of the seeds was influenced by the size of the fruits. The method of manual seed extraction proved to be superior and more efficient than the mechanical method

Physiological potential of corn seeds with different sizes and vigor levels subjected to micronutrient treatment

Micronutrients are used in small amounts by plants and changes in metabolic processes of seeds can improve germination and vigor; however, little is known about the effects of the combination of Zn, Co, and Mo on corn seeds. Thus, the objective of this study was to evaluate the effects of the application of Zn, Co, and Mo on the physiological potential of corn seeds of different sizes and levels of vigor. A randomized 2×2×3 factorial design was adopted, with two levels of vigor (high and low), two seed sizes (18 and 22 mm), and three doses of liquid fertilizer containing micronutrients (0, 2, and 4 mL kg-1). The physiological potential of the seeds was evaluated based on germination and vigor tests. High vigor corn seeds had greater physiological potential compared to low vigor seeds. Regarding size, small seeds (18 mm) had higher percentages of germination and vigor than the large seeds (22 mm). Seed treatment with micronutrients (Co, Mn, and Zn) resulted in improved emergence in the field, shoot length, and dry mass of large and small seeds with the application dose of 2 mL kg-1, and the application dose of 4 mL kg-1 enhanced emergence in the field of large seeds and germination after the cold test of low vigor seeds of both sizes