ABSTRACT. Cotton is one of the largest agricultural commodities that generate various sources of foreign exchange and employment worldwide. However, water deficiency is an environmental factor that limits the production of this crop, especially in semi-arid regions. We evaluated pyruvate supplementation to mitigate the effects of water stress on colored cotton. Experiments were conducted in a greenhouse. We studied two forms of pyruvate supplementation (SP1- via seed and foliar and SP2- only via foliar); three conditions of irrigation management of the plants: water restriction in the vegetative phase (VE), flowering (FL), and vegetative and flowering (VE/FL); and additional treatment (total irrigation throughout the crop cycle and without pyruvate supplementation). The experimental design included a randomized block in a 2 × 3 + 1 factorial scheme. The factors resulted in seven treatments with three replications, with a total of 21 experimental units. Gas exchange, enzyme activity, and production of components were evaluated. Water restriction in the vegetative phase does not cause losses in BRS Jade cotton when supplemented with pyruvate. However, in the flowering and vegetative phases plus flowering, it reduces gas exchange and production components and increases the activity of antioxidant enzymes in relation to plants under full irrigation. Supplementation with pyruvate via seed plus foliar (SP1) was better for BRS Jade cotton grown under water restriction.

Esta pesquisa objetivou avaliar a produção de milho Potiguar fertirrigado com urina humana e manipueira associadas à adubação mineral com NPK. Adotou-se delineamento inteiramente casualizados, composto por oito tratamentos (1 - testemunha sem fertirrigação; 2 - fertirrigações com NPK; 3 - apenas urina humana; 4 - apenas manipueira; 5 - urina humana mais manipueira; 6 - urina humana mais PK; 7 - manipueira mais NP; e 8 - urina humana, manipueira e P) e cinco repetições. Aos 110 dias após emergência foram avaliados comprimento e diâmetro da espiga, número de grão por espiga, fileiras de grãos por espigas, grãos por fileira, massa seca da parte aérea, massa seca da espiga com e sem palha, massa seca dos grãos e massa seca de 100 grãos. Com exceção da massa seca de 100 grãos, houve diferença estatística significativa entre tratamentos e entre médias analisadas. Urina humana pode substituir a adubação nitrogenada e a manipueira a potássica aplicada via fertirrigação na cultura do milho. A associação destes efluentes tem potencial para substituir a adubação mineral requerida pela cultura do milho. Com exceção dos tratamentos 1 e 4, os demais podem ser indicados como os melhores tratamentos.

This research aimed to evaluate the production of Potiguar maize fertirrigated with human urine and, cassava wastewater associated with mineral fertilization with NPK. A completely randomized design was used, consisting of eight treatments (1 - control without fertigation, 2 - fertigations with NPK, 3 - only human urine, 4 - only cassava wastewater, 5 - cassava wastewater plus human urine, 6 - human urine plus PK; - cassava wastewater plus NP, and 8 - human urine, cassava wastewater and P) and five replicates. At 110 days after emergence were evaluated the length and diameter of the spike, number of grain per spike, rows of grain per spike, grain per row, dry mass of the aerial part, dry mass of the spike with and without straw, dry mass of the grains and mass dry of 100 grains. Except for the dry matter of 100 grains, there was a statistically significant difference between treatments and between analyzed means. Human urine can substitute the nitrogen fertilization and the cassava wastewater applied via fertirrigation substitute the potassium in the maize crop. The association of these effluents has the potential to replace the mineral fertilization required by the maize crop. With the exception of treatments 1 and 4, the others can be indicated as the best treatments.

Resumo O uso agrícola de águas amarelas associadas à manipueira é uma técnica sustentável, uma vez que possibilita a redução de custos com a aquisição de fertilizantes industrializados e minimiza a poluição ambiental ocasionada pela destinação final inadequada desses efluentes. Neste contexto, objetivou-se com este trabalho avaliar os teores de macronutrientes e o crescimento do feijão vigna fertirrigado com águas amarela associada à manipueira e NPK como fonte de nutrientes. O experimento foi instalado em uma casa de vegetação localizada no Campus I da Universidade Federal de Campina Grande. Utilizou-se delineamento inteiramente casualizado composto por cinco tratamentos caracterizados por fertirrigações com fertilizantes minerais, na forma de NPK; orgânicos compostos por urina humana, manipueira, urina humana mais manipueira e organomineral composto por urina, manipueira e fósforo mineral e quatro repetições. Aos 36 dias após a semeadura foram avaliados os teores de nitrogênio, fósforo, potássio, enxofre e as variáveis: número de folhas, altura de planta, diâmetro caulinar, área foliar, massa fresca e seca da parte aérea. O uso de águas amarelas promove incrementos significativos para os teores de nitrogênio e potássio principalmente, assim como para as variáveis de crescimento e produção. Os teores de nitrogênio, fósforo e potássio apresentam valores superiores aos considerados adequados para o cultivo do feijão vigna. O uso de urina humana e a manipueira apresentam potencialidade para suprir as necessidades dos principais macronutrientes requeridos pela cultura do feijão vigna e a irrigação via fertirrigação com estes biofertilizantes pode influenciar positivamente o desenvolvimento dessa cultura.

Abstract Agricultural utilization of yellow waters associated with cassava wastewater is a sustainable technique, since it allows reduction of costs related to acquisition of industrialized fertilizers and minimizes the environmental pollution caused by the inadequate disposal of these effluents. In this context, this study evaluated the macronutrient macronutrient content and growth of cowpea fertigated with yellow water associated with cassava wastewater and NPK as source of nutrients. The experiment was set up in a greenhouse located at Campus I of the Federal University of Campina Grande. The experimental design was completely randomized, composed of five treatments characterized by: fertigation with mineral fertilizers, in the form of NPK; organic fertigation composed of human urine, cassava wastewater, human urine plus cassava wastewater; and organo-mineral fertigation composed of urine, cassava wastewater and mineral phosphorus, with four replicates. At 36 days after sowing, the following parameters were determined: contents of nitrogen, phosphorus, potassium, sulfur and the variables number of leaves, plant height, stem diameter, leaf area, shoot fresh matter and shoot dry matter. The use of yellow waters promotes significant increases for growth and production variables for nitrogen and potassium contents mainly, as well as for growth and production variables. The contents of nitrogen, phosphorus and potassium were higher than the levels considered as adequate for the cowpea crop. The use of human urine and cassava wastewater have potential to meet the needs for the main macronutrients required by cowpea and the irrigation via fertigation with these biofertilizers positively influences the development of cowpea.