Gas exchanges and water-use efficiency of Nopalea cochenillifera intercropped under edaphic practices

The Nopalea forage cactus (Nopalea cochenillifera) is the main xerophilic species cultivated in Brazil, highlighted as a compatible biological element with the semiarid environment. However, studies on its physiological aspects are still scarce. In this context, an experiment was performed in the Pendência Experimental Station, belonging to the State Company of Agricultural Research of Paraíba (EMEPA-PB), municipality of Soledade, state of Paraíba, Brazil, aiming to evaluate the gas exchanges and the water-use efficiency of intercropped Nopalea Cochenillifera plants in the soil under different edaphic managements. The treatments were distributed in randomized blocks, with three replications in a 2 × 5 factorial scheme, corresponding to the soil without and with mulch and five types of cultivation of Nopalea forage cactus, in monoculture and intercropped with forage watermelon, millet, sorghum, and buffelgrass. The analyzed variables were: stomatal conductance, transpiration rate, net photosynthesis rate, and internal CO2 concentration, besides the instantaneous water-use efficiency, intrinsic water-use efficiency, and instantaneous carboxylation efficiency. The use of soil mulch satisfactorily increased the photosynthetic rate of the forage cactus; this type of practice can aid in the productive development of the crop in semiarid zones, whereas the intercropping with buffelgrass and forage watermelon stimulated photosynthesis and the water-use efficiency.The Nopalea forage cactus (Nopalea cochenillifera) is the main xerophilic species cultivated in Brazil, highlighted as a compatible biological element with the semiarid environment. However, studies on its physiological aspects are still scarce. In this context, an experiment was performed in the Pendência Experimental Station, belonging to the State Company of Agricultural Research of Paraíba (EMEPA-PB), municipality of Soledade, state of Paraíba, Brazil, aiming to evaluate the gas exchanges and the water-use efficiency of intercropped Nopalea Cochenillifera plants in the soil under different edaphic managements. The treatments were distributed in randomized blocks, with three replications in a 2 × 5 factorial scheme, corresponding to the soil without and with mulch and five types of cultivation of Nopalea forage cactus, in monoculture and intercropped with forage watermelon, millet, sorghum, and buffelgrass. The analyzed variables were: stomatal conductance, transpiration rate, net photosynthesis rate, and internal CO2 concentration, besides the instantaneous water-use efficiency, intrinsic water-use efficiency, and instantaneous carboxylation efficiency. The use of soil mulch satisfactorily increased the photosynthetic rate of the forage cactus; this type of practice can aid in the productive development of the crop in semiarid zones, whereas the intercropping with buffelgrass and forage watermelon stimulated photosynthesis and the water-use efficiency

Production and selection of accessions of Opuntia spp. with resistance to false carmine cochineal

The genetic improvement program for Opuntia spp. aims to select new genotypes to meet the demands of rural producers in the Brazilian Semiarid region and to expand the genetic base of the crop. The aim of this study was to select accessions of Opuntia spp. with foraging potential and resistance to false cochineal carmine. The research was carried out at the Active Germplasm Bank (BAG) of Opuntia spp. of Paraíba Company Research, Rural Extension and Land Regularization (EMPAER), Pendência Experimental Station, Soledade, Paraíba, Brazil. Accessions were cultivated in rainfed and evaluated in August 2019, 12 months after the implementation of the BAG. The measurement of the Total Green Mass weight of the plants of 121 accessions of the BAG was carried out and the productivity (ton/ha-1) was estimated in a dense cultivation of 100 thousand plants/ha-1. The accessions of Opuntia spp. nº 10, 110, 115 and 119 have growing potential in the Brazilian Semiarid region, as a function of productivity (532.6, 118, 164 and 481 tons/ha-1, respectively) and resistance to false carmine cochineal, in addition to genetic divergence (specific agronomic characteristics) in relation to currently cultivated varieties.The genetic improvement program for Opuntia spp. aims to select new genotypes to meet the demands of rural producers in the Brazilian Semiarid region and to expand the genetic base of the crop. The aim of this study was to select accessions of Opuntia spp. with foraging potential and resistance to false cochineal carmine. The research was carried out at the Active Germplasm Bank (BAG) of Opuntia spp. of Paraíba Company Research, Rural Extension and Land Regularization (EMPAER), Pendência Experimental Station, Soledade, Paraíba, Brazil. Accessions were cultivated in rainfed and evaluated in August 2019, 12 months after the implementation of the BAG. The measurement of the Total Green Mass weight of the plants of 121 accessions of the BAG was carried out and the productivity (ton/ha-1) was estimated in a dense cultivation of 100 thousand plants/ha-1. The accessions of Opuntia spp. nº 10, 110, 115 and 119 have growing potential in the Brazilian Semiarid region, as a function of productivity (532.6, 118, 164 and 481 tons/ha-1, respectively) and resistance to false carmine cochineal, in addition to genetic divergence (specific agronomic characteristics) in relation to currently cultivated varieties