Weed-Hoeing Periods in Cowpea Cultivation under Direct and Conventional Systems.

Weed coexistence with an agricultural crop can negatively affect its growth, development, and yield. From this perspective, this study aimed to evaluate weed management strategies and their effect on the agronomic parameters of cowpea cultivation in direct (SPD) and conventional (SPC) planting systems. The experiment was set up in a completely randomized block design with a split-plot arrangement with four replications. The plots received a source of variation referring to the planting systems (direct and conventional planting), and the subplots corresponded to ten weed management strategies (manual hoeing 18 days after planting (DAP); at 36 DAP; at 54 DAP; at 18 and 36 DAP; at 18 and 54 DAP; at 18 and 72 DAP; at 36 and 54 DAP; at 36-72 DAP; at 18, 36, and 54 DAP; and a control with no hoeing). Density and dry mass evaluations of the cowpea plants were performed at harvest (72 DAP) by determining the number of pods per plant, pod length, number of grains per pod, 1000-grain mass, and yield. A total of 28 species distributed in 12 botanical families were identified in the two cultivation systems. The family Poaceae showed the highest frequency, with 25% of the species identified. At the end of the assay, treatment 20 had the highest positive influence and provided significant quantitative gains to the complex of traits related to cowpea production (SPD and hoeing at 18, 36, and 54 DAP). UPGMA cluster analysis and canonical discriminant analysis were performed and allowed a better classification of the evaluated treatments. It was observed that the first two canonical variables explained 90.8% of the total variance contained in the original variables. The use of SPD with weeding at 18, 36, and 54 days after planting provides greater weed control and significant quantitative gains for the complex of characteristics related to cowpea production. The results underscore the importance of choosing the correct cropping system and implementing effective weeding practices to optimize weed control and improve crop performance.

Phosphorus kinetics in lambs experimentally infected with Trichostrongylus colubriformis with the use of 32P.

This study was conducted to evaluate the metabolism and phosphorus (P) kinetics in lambs experimentally infected with Trichostrongylus colubriformis using the isotope dilution technique and modelling. Fifteen male lambs (21.1 ±â€¯1.50 kg) of the Santa Inês hair breed of approximately six months old, distributed in the treatments infected (I, n = 8) and control (C, n = 7) were used. The infected lambs received serial infections with 5000 T. colubriformis larvae, three times per week, for 3 weeks (45 000 T. colubriformis total larvae). After 66 days of the last inoculation of infective larvae, 6.6 MBq of 32P were injected in each lamb to evaluate the P kinetics. Blood, faeces and urine samples were collected in the following seven days and the slaughter of lambs were carried out on the last day in order to collect bone and soft tissues (Liver, kidney, heart and muscle) samples. To analyse P flows, the biomathematical model with four compartments (C1 - gastrointestinal tract, C2 - plasma, C3 - bone and C4 - soft tissue) was used. Similar P intake (VI) between treatments (C and I) was verified. Lower absorption of endogenous (Vaf) and dietary P (Vaa), as well as, lower amount of endogenous P (from saliva) that reaches the gastrointestinal tract (VIT), consequently, higher excretion of dietary P (VFD) were verified in infected lambs (P < 0.1). Additionally, in infected lambs, the P bioavailability was lower compared to control lambs. With the lower absorption (VaT) of P in infected lambs, there was, consequently, lower distribution to bones and soft tissues (VeD2) and lower P deposition in the bones (VO+D). It was concluded that P metabolism of lambs infected with T. colubriformis was altered, with reduced intestinal absorption and bioavailability, increased faecal loss and reduced P flow to the bone.

Efeito da Época do Ano e Período do Dia Sobre os Parâmetros Fisiológicos de Ovelhas Morada Nova na Microrregião do Alto Médio Gurguéia / Effect of period of year and time of day on the physiological parameters of morada nova sheep in the Alto M�dio Gurgu�ia region

O conhecimento das vari�veis clim�ticas bem como sua a��o sobre as respostas comportamentais e fisiol�gicas dos animais s�o preponderantes na adequa��o do sistema de produ��o aos objetivos da atividade pecu�ria. Sendo assim, objetivou-se com este trabalho, avaliar o efeito da �poca do ano e per�odo do dia sobre par�metros fisiol�gicos de ovelhas Morada Nova na microrregi�o do Alto M�dio Gurgu�ia. Foram utilizadas oito matrizes da ra�a Morada Nova, distribu�das em um delineamento inteiramente casualizado no esquema fatorial 4x2, com quatro per�odos do dia, 7-8, 10-11, 14-15 e 17-18 h, e duas �pocas: E1 (quente e seca) outubro a novembro, e E2 (amena e �mida) mar�o a abril. Os par�metros fisiol�gicos frequ�ncia respirat�ria (FR), frequ�ncia card�aca (FC) e temperatura retal (TR), foram aferidos semanalmente, realizando-se quatro coletas por �poca, perfazendo um total de 8 coletas. Os par�metros fisiol�gicos frequ�ncia respirat�ria, frequ�ncia card�aca e temperatura retal foram influenciados (P<0,05) pela �poca do ano e pelo per�odo do dia, com valores superiores para todas as vari�veis na �poca quente e seca no turno da tarde, principalmente �s 17-18 h, provavelmente devido � maior incid�ncia de radia��o solar e, consequentemente, acumulo de calor ao longo da tarde.

Knowledge on climate and its action on the behavioral and physiological responses of animals are prevalent for the production system of the cattle industry. Therefore, The aim of this study was to evaluate the effect of season and time of day on physiological parameters of Morada Nova sheep in Alto Medio Gurgu�ia region. Eight arrays of Morada Nova were studied, in a completely randomized 4x2 factorial block, in four periods of the day, at 7-8 a.m., 10-11 a.m., 2-3 p.m and 5-6 p.m, and two seasons: E1 (hot and dry) October-November, and E2 (warm and wet) March-April. The physiological parameters respiratory rate (RR), heart rate (HR) and rectal temperature (RT) were measured weekly, performing four collections per season, totaling 8 samples. The ohysiological parameters respiratory rate, heart rate and rectal temperature were influenced (P<0.05) by season and by time of day, with higher values for all variables in the hot and dry season in the afternoon, primarily at 5-6 p.m, probably due to increased incidence of solar radiation and thus heat accumulation throughout the afternoon.