ABSTRACT The work was intended to evaluate the effect of different organic compounds originating from the mixture of agroindustrial and urban wastes, as well as their doses in the physiology and production of cowpea. The experiment was conducted under a randomized block design, in a 4 x 5 + 2 factorial arrangement, with four organic fertilizers (3 composed obtained from of sewage sludge, green coconut shell, carnauba butt; and sewage sludge biochar), five doses (20, 40, 60, 80 and 100 t ha-1) and two additional treatments (without fertilization and mineral fertilization). We evaluated the leaf gas exchange in three phenological stages and the productive aspects. Regarding the physiological variables, the compounds with carnauba butt and green coconut shell promoted the best results and throughout the crop cycle, the gas exchange decreased. The productive aspects were increased by about 60%, especially due to the treatments with organic compounds. The PCA can confirm the univariate results, with emphasis on compounds with green coconut shell and carnauba butt. The high percentage of explanation found in axis 1 (60.49%) may be associated with the fact that the gas exchange and production variables are highly responsive to fertilization. The treatment with biochar caused a reduction in both in the physiological and in the productive aspects. The compounds with carnauba tip and green coconut shell promote satisfactory results, being viable alternatives to complement chemical fertilization with an indicated dose of 300g pot-1 or 60 t ha-1.

RESUMEN El objetivo de este estudio fue evaluar el efecto de diferentes dosis (0,10, 20, 30, 40 y 50 t ha-1) de fibra de coco verde en sustrato de crecimiento sobre el desarrollo temprano y la fisiología de dos cultivares de soya (Pampeana 40RR y Pampeana 60RR). El experimento se llevó a cabo en un invernadero utilizando un diseño experimental completamente al azar en un arreglo factorial de 2x6 (dos genotipos y seis dosis) con cinco repeticiones. Cada repetición estuvo formada por una planta, totalizando 60 unidades experimentales. Se evaluaron variables biométricas (altura, número de hojas, diámetro del tallo, área foliar y masa seca) y fisiológicas (fotosíntesis, conductancia estomática, transpiración, carbono interno, eficiencia en el uso del agua y pigmentos fotosintéticos). Después de obtener los datos, a los 30 d después de la siembra, las medias fueron sometidas a análisis de varianza y, cuando fueron significativas según la prueba F, fueron sometidas a análisis de regresión y comparación de medias por la prueba de Tukey. A través del análisis de regresión, fue posible calcular la dosis mínima ideal para cada variable. Se observó un aumento en la altura de la planta, el diámetro del tallo, el número de hojas, el área foliar, la masa seca de hojas, masa seca de tallo y masa seca de raíces de alrededor de 51.10%, 31.60%, 52.83 %, 61.78%, 79.65%, 81.52%, y 6.06%, respectivamente, cuando comparamos los valores de las dosis mínimas con los puntos máximos encontrados en cada variable. En cuanto al intercambio de gases, el cultivar 60 RR fue superior al cultivar 40 RR. En conclusión, el compuesto de fibra de coco verde influyó positivamente en el crecimiento y fisiología de los cultivares, obteniendo la mejor respuesta con la dosis de 30 t ha-1.

ABSTRACT This study aimed to evaluate the effect of different doses (0, 10, 20, 30, 40, and 50 t ha-1) of green coconut fiber in growth substrate on the early development and physiology of two soybean cultivars (Pampeana 40RR and Pampeana 60RR). The experiment was carried out in a greenhouse using a completely randomized experimental design in a 2x6 factorial arrangement (two genotypes and six doses) with five replicates. Each replicate was made up of one plant, totaling 60 experimental units. Biometric variables (height, number of leaves, stem diameter, leaf area, and dry matter) and physiological variables (photosynthesis, stomatal conductance, transpiration, internal carbon, water use efficiency, and photosynthetic pigments) were evaluated. After obtaining the data 30 d after sowing, the means were subjected to an analysis of variance and, when significant for the F test, they were subjected to regression analysis and comparison of means by the Tukey's test. Through the regression analysis, the ideal minimum dose for each variable could be calculated. We observed an increase in plant height, stem diameter, number of leaves, leaf area, leaf dry mass, stem dry mass, and root dry mass of around 51.10%, 31.60%, 52.83%, 61.78%, 79.65%, 81.52%, and 6.06%, respectively, when we compared the values of the minimum doses with the maximum points found in each variable. Regarding the gas exchange, cultivar 60 RR was superior to cultivar 40 RR. In conclusion, the green coconut fiber compound had a positive influence on the growth and physiology of the cultivars, with the best response being obtained at the dose of 30 t ha-1.

RESUMO O feijão-caupi é uma das principais leguminosas cultivadas na região Nordeste, com finalidade direcionada para a produção de grãos secos ou vagens verdes. No entanto, essa região sofre com variações climáticas, sendo a seca o principal fator de estresse abiótico. Portanto, objetivou-se avaliar as características fisiológicas, morfológicas e de produção de vagens em variedades tradicionais de feijão-caupi quanto à tolerância à seca e reidratação no semiárido brasileiro. As variedades foram: Pingo de Ouro 1,2 (PO), Sempre Verde (SV) e Feijão de Moita (FM). O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 3 x 2 (3 genótipos x 2 condições hídricas do solo) com 5 repetições para cada tratamento, totalizando 30 unidades experimentais. Foram avaliadas variáveis de crescimento, metabolismo do carbono e produção de vagens. Os resultados sugerem que o estresse hídrico severo afetou negativamente todos os genótipos de feijão-caupi, sendo nesses aspectos o genótipo FM o mais sensível ao déficit hídrico severo, pois, demonstrou efeitos negativos em nível morfológico e produção de vagens mais pronunciadas. No entanto, os genótipos crioulos apresentaram características fisiológicas semelhantes ao genótipo padrão de tolerância, o PO. Além disso, todos os genótipos apresentaram recuperação após a reidratação. Em termos de produção e características de vagens o genótipo PO, em geral, apresentou melhores respostas sob condição estresse.

ABSTRACT The cowpea bean is one of the main legumes grown in the Northeast region, with a purpose directed to the production of dried grains or green pods. However, this region suffers from climatic variations, with drought being the main abiotic stress factor. Therefore, the objective was to evaluate the physiological, morphological and pod production characteristics of traditional cowpea varieties in terms of drought tolerance and rehydration in the Brazilian semiarid region. The varieties were: Pingo de Ouro 1,2 (PO), Sempre Verde (SV) and Feijão de Moita (FM). The experimental design used was entirely randomized, in a 3 x 2 factorial scheme (3 genotypes x 2 soil water conditions) with 5 replicates for each treatment, totaling 30 experimental units. Growth variables, carbon metabolism, and pod production were evaluated. The results suggest that the water stress negatively affected the cowpea genotypes, especially those that had negative effects on the morphological level and pod production. In these aspects, the genotype FM was the most sensitive to the severe water stress. However, Creole genotypes showed characteristics physiology similar to the standard tolerance genotype, the PO. Also, all genotypes recovered after rehydration. In terms of pod production and characteristics, the genotype PO, in general, presented better responses under stress conditions.