ABSTRACT. The scarcity of surface water has led to the use of underground sources as an alternative for crop irrigation by farmers in semi-arid regions. However, these water sources generally have high salinity, which prevents agricultural production. The objective of this study was to determine the effects of pre-germination treatments with plant growth regulators and bioactivators on melon seeds to attenuate salt stress caused by irrigation water during germination and seedling development. Two trials were carried out separately with the hybrids, Goldex and Grand Prix. The design was completely randomized in a 4 × 3 factorial scheme (four seed treatments and three dilutions of irrigation water). Seeds were treated with salicylic acid and gibberellic acid and the insecticide, thiamethoxam, in addition to the control. Local supply water, artesian well groundwater, and dilution of these waters at a 1:1 ratio were employed for irrigation. Fourteen days after sowing, morphological and physiological analyses were performed, and the material was collected for biochemical determination. The use of saline well water affected the initial development of melon seedlings of the Goldex and Grand Prix hybrids. Pre-germination treatment of Goldex hybrid seeds with gibberellic acid was inefficient at mitigating salt stress. However, the effects of irrigation water salinity on Grand Prix melon seeds pretreated with salicylic acid and thiamethoxam were attenuated.

RESUMO O pré-tratamento de sementes resulta em emergência de plântulas mais rápida e estande uniforme, principalmente, quando sob estresse. Sendo assim, objetivou-se avaliar a ação de reguladores vegetais como atenuantes de estresse durante a germinação e desenvolvimento inicial de plântulas de abóbora, cv. Baiana Tropical, irrigadas com água salina. Para isso, estabeleceu-se o delineamento inteiramente casualizado, em esquema fatorial 4 x 3, em quatro repetições. Os tratamentos foram constituídos de quatro tipos de água (A1 – 100% água de abastecimento; A2 – 100% efluente de piscicultura; A3 – 100% água de poço artesiano; A4 - mistura de 50% efluente de piscicultura + 50% água de poço artesiano) e três tratamentos de sementes (controle, ácidos salicílico e giberélico). As variáveis mensuradas foram germinação, primeira contagem de germinação, comprimento da parte aérea e raiz, massa seca da parte aérea e raiz, açúcares solúveis totais, aminoácidos totais e prolina. Os dados foram submetidos a análise de variância e teste de Scott-Knott. As plântulas de abóbora realizaram ajustamento osmótico em condições salinas da água A4. Além disso, o tratamento de sementes de abóbora com reguladores vegetais (ácidos giberélico e salicílico) beneficia a germinação e o desenvolvimento inicial de plântulas sob condições de estresse salino.

ABSTRACT Pretreatment of seeds results in faster emergence of seedlings and uniform stand, especially under stress. Thus, the objective was to evaluate the action of plant regulators as stress attenuators during germination and initial development of pumpkin seedlings, cv. ‘Baiana Tropical’, irrigated with saline water. For this, a completely randomized design was established, in a 4 x 3 factorial scheme, with four replications. Treatments consisted of four types of water (W1 - 100% supply water; W2 - 100% fish farming effluent; W3 - 100% artesian well water; W4 - mixture of 50% fish farming effluent + 50% artesian well water) and three seed treatments (control, salicylic acid and gibberellic acid). The variables measured were germination, first germination count, shoot and root length, shoot and root dry mass, total soluble sugars, total amino acids and proline. The data were subjected to analysis of variance and Scott-Knott test. Pumpkin seedlings performed osmotic adjustment under saline conditions of W4 water. In addition, the treatment of pumpkin seeds with plant regulators (gibberellic and salicylic acids) favors the germination and initial development of seedlings under conditions of salt stress.

RESUMO Physalis angulata L. (Solanaceae), conhecida popularmente como camapu, possui elevado potencial farmacológico e agroindustrial. No entanto, por ser uma espécie essencialmente silvestre, os estudos sobre a qualidade fisiológica de suas sementes ainda são escassos. Neste sentido, objetivou-se avaliar o desempenho fisiológico de sementes de P. angulata, em função de tratamentos pré-germinativos com promotores químicos. Para isso, realizou-se testes de germinação, primeira contagem de germinação, índice de velocidade de germinação e emergência de plântulas. O substrato foi previamente umedecido com soluções de ácido giberélico - GA3 (0,00; 0,02; 0,04; 0,06 e 0,08%), nitrato de potássio - KNO3 (0,0; 0,2; 0,4; 0,6; 0,8 e 1,0%), e Stimulate® (0,00; 0,25; 0,50; 0,75; 1,00; 1,25 e 1,50%). Cada promotor químico constituiu um experimento independente, em delineamento inteiramente casualizado, com quatro repetições de 25 sementes. Os três promotores químicos estimularam o desempenho fisiológico de sementes de P. angulata, e as concentrações de 0,05% de GA3, 0,4% de KNO3 e 1,0% de Stimulate® foram as mais adequadas.

ABSTRACT Physalis angulata L. (Solanaceae), popularly known as ‘camapu’, has high pharmacological and agroindustrial potential. However, because it essentially is a wild species, studies on the physiological quality of its seeds are still scarce. In this sense, the objective was to evaluate the physiological performance of P. angulata seeds as a function of pre-germination treatments with chemical promoters. For this, germination, first germination count, germination speed index and seedling emergence tests were performed. The substrate was previously moistened with solutions of gibberellic acid - GA3 (0.00, 0.02, 0.04, 0.06 and 0.08%), potassium nitrate - KNO3 (0.0, 0.2, 0.4, 0.6, 0.8 and 1.0%) and Stimulate® (0.00, 0.25, 0.50, 0.75, 1.00, 1.25 and 1.50%). Each chemical promoter constituted an independent experiment, in a completely randomised design, with four replicates of 25 seeds each. The three chemical promoters enhanced the physiological performance of P. angulata seeds, and the concentrations of 0.05% GA3, 0.4% KNO3 and 1.0% Stimulate® were most suitable.