ABSTRACT Exposing seeds to agents that elicit tolerance to abiotic stress, such as phytohormones and organic acids, during hydration and dehydration cycles can determine their response to later stimuli, e.g. exposure to salt stress. The aim of this study was to evaluate the action of priming cycles with different eliciting agents of salt stress tolerance on seeds of the cowpea varieties Sempre Verde and Pingo de Ouro. The seeds were subjected to the following treatments: 0.0 mM NaCl (control); 100 mM NaCl (salt stress); salt stress + three seed-priming cycles (PC) in water; salt stress + PC in gibberellic acid; salt stress + PC in hydrogen peroxide; salt stress + PC in salicylic acid; salt stress + PC in ascorbic acid. The following variables were analysed: germination, growth, dry weight, salt tolerance index, total soluble sugars, total free amino acids and proline. Salt stress (100 mM NaCl) reduced germination, length and biomass accumulation in the Sempre Verde and Pingo de Ouro varieties. These showed the best response to the priming cycles with gibberellic and salicylic acids, which promoted greater germination potential, length and biomass under a salt stress of 100 mM NaCl, affording greater tolerance via osmotic regulation, especially in the Sempre Verde variety. stimuli eg e g e.g treatments 00 0 0. control (control) 10 stress) seedpriming seed (PC water acid peroxide analysed growth weight index sugars proline (10 potential regulation variety (control 1 (1 (

ABSTRACT Effluent from fish farming with saline water is a source of water, also rich in organic matter and nutrients, that can be used in irrigation of cultivated plants and even fully or partially replace mineral fertilization. The objective was to evaluate the growth, biomass production and quality of P. maximum cultivars fertigated with fish farming effluent in a greenhouse experiment, using a randomized block design with eight replicates. Treatments were arranged in a split-split-plot scheme, with three irrigation managements in the plot (irrigation with public-supply water, irrigation with public-supply water + conventional fertilization, and irrigation with fish farming effluent), three cultivars of P. maximum (Tanzania, Mombasa, and Massai) in the sub-plot, and four cutting times in the sub-sub-plot (45, 90, 135, and 180 days after sowing). Plant height, number of tillers, production of fresh biomass, neutral detergent fiber, acid detergent fiber, ether extract, crude protein, dry matter, and mineral matter contents were analyzed. The highest growth, production, and quality of P. maximum grass occurs when irrigated with public-supply water and under conventional NPK fertilization. Fertigation with fish farming effluent reduces the growth and production of P. maximum grass, but allows obtaining better quality forage. It is possible to irrigate P. maximum grass using fish farming effluent with satisfactory yields. The growth of cv. Massai was more sensitive to irrigation with fish farming effluent than those of the cultivars Tanzania and Mombasa. nutrients fertilization P experiment replicates splitsplitplot split scheme publicsupply public supply effluent, , effluent) Tanzania, (Tanzania Mombasa subplot, subplot sub plot, sub-plot subsubplot 45, 45 (45 90 135 18 sowing. sowing . sowing) height tillers fiber extract protein analyzed forage yields cv 4 (4 9 13 1 (

ABSTRACT The umbu-cajazeira (Spondias sp.) is a fruit tree native to the semi-arid of Brazil, with significant environmental and agro-socioeconomic potential for the region. Determining leaflet area (LA) is essential for understanding the interactions between plant growth, physiology, nutrition, and environment. Thus, this research aims to construct allometric equations that non-destructively estimate the umbu-cajazeira (Spondias sp.) leaflet area, considering the leaflet dimensions (length and width). The leaflets were collected from mother plants of umbu-cajazeira (Spondias sp.) and individually measured for length (L), width (W), and LA using digitized images. These data were submitted for descriptive and regression analysis. The LA was estimated using, linear power, and exponential regression models based on the L and W of the leaflets. The best model and equation were chosen based on the following selection criteria: coefficient of determination, Willmott agreement index, root mean square error, and mean absolute error. The power model using LW presented the best equation ŷ = 0.76 * LW0.98 to estimate the leaflet area of umbu-cajazeira (Spondias sp.). This study provides a reliable, accurate, fast, and non-destructive approach for agronomic researchers and growers to determine the LA of the species. umbucajazeira umbu cajazeira Spondias sp. sp semiarid semi arid Brazil agrosocioeconomic agro socioeconomic region (LA growth physiology nutrition environment Thus nondestructively non destructively width. . width) L, , (L) W, (W) images analysis criteria determination index error 076 0 76 0.7 LW098 LW0 98 LW0.9 sp.. reliable accurate fast nondestructive destructive species (L (W 07 7 0. LW09 9 LW0.

RESUMO A umbu-cajazeira (Spondias sp.) é uma frutífera nativa do semiárido brasileiro, com grande potencial ambiental e agrossocioeconômico para região. A determinação da área foliar (LA) é importante para compreensão das interações entre o crescimento, fisiologia, nutrição das plantas e o ambiente. Assim, o objetivo desta pesquisa é construir equações alométricas que estime de forma não destrutiva a área foliar umbu-cajazeira (Spondias sp.), considerando as dimensões dos folíolos (comprimento e largura). Os folíolos foram coletados de plantas matrizes de umbu-cajazeira (Spondias sp.), e medidos individualmente quanto ao comprimento (L), largura (W) e LA por meio de imagens digitalizadas. Estes dados foram submetidos à análise descritiva e de regressão. A LA foi estimada utilizando os modelos de regressão linear, potência e exponencial, baseados no L e W dos folíolos. O melhor modelo e equação foi escolhido com base nos critérios de seleção: coeficiente de determinação, índice de concordância de Willmott, raiz do erro quadrático médio e erro absoluto médio. O modelo potência utilizando LW apresentou a melhor equação 0.76 * LW0.98 para estimar a área dos folíolos de umbu-cajazeira (Spondias sp.). Este estudo fornece uma abordagem confiável, precisa, rápida e não destrutiva para pesquisadores e produtores do meio agronômico determinarem a LA da espécie. umbucajazeira umbu cajazeira Spondias sp. sp brasileiro região (LA crescimento fisiologia ambiente Assim sp., , largura. . largura) L, (L) (W digitalizadas linear exponencial seleção Willmott 076 0 76 0.7 LW098 LW0 98 LW0.9 sp.. confiável precisa espécie (L 07 7 0. LW09 9 LW0.