Vegetable intercropping has advantages over single cultivation in terms of less environmental impact. However, to convince farmers to adopt this production system, it is necessary to prove greater efficiency in the production of more food per unit area and therefore an increase in productivity. An experiment was carried out aiming to evaluate the effect of the chicory transplant time in intercrops with collard greens on crop yields and land use efficiency index (LUE). The experimental design was a randomized block, with nine treatments in a 2 × 4 + 1 factorial scheme, and four replications. Crop systems (intercrop and monoculture) and chicory transplant time (0, 14, 28 and 42 days after transplant (DAT) of collard greens) were evaluated. The collard greens yield increased as the chicory transplant time was delayed. The total and per harvest yields of chicory were not influenced by its transplant time. Regardless of chicory transplant time, collard greens and chicory intercropping provided greater LUE than their monocultures and reached the maximum value (52% higher) when the chicory was transplanted 42 days after collard greens. Highlights: The collard green yield increased by 11 kg ha-1 for each day of delay in the chicory transplant (0 to 42 days). The total and per harvest chicory yields were not influenced by its transplant time in relation to collard green transplant. The collard green and chicory intercropping provided 52% higher land use efficiency than their monocultures when the chicory was transplanted 42 days after collard green.

A propagação vegetativa de floríferas por estaquia é uma alternativa viável para a produção em larga escala, e quando associado a substratos regionais, essa alternativa possibilita obter mudas que atendam às exigências do mercado consumidor, além de reduzir o custo de produção. Buscou-se avaliar com a pesquisa, proporções crescentes de caule decomposto de babaçu (CDB), acrescida de casca de arroz carbonizada (CAC) na propagação vegetativa de Polyscias guilfoylei. O experimento foi conduzido em casa de vegetação com 70 % de interceptação luminosa entre os meses de agosto a outubro de 2019. Foi utilizado o delineamento inteiramente casualizado, com seis tratamentos nas seguintes proporções: 100% de CAC; 20% de CDB + 80% de CAC; 40% de CDB + 60% de CAC; 60% de CDB + 40% de CAC; 80 % de CDB + 20 % de CAC; 100 % de CDB. As variáveis foram: número de folhas; área foliar; número de brotações; altura da brotação; diâmetro da brotação; comprimento da raiz; volume da raiz; massa fresca da parte aérea; massa fresca da raiz; massa seca da parte aérea; massa seca da raiz; diâmetro das estacas; percentual de sobrevivência e índice de qualidade de Dickson. Após 60 dias verificou-se que não é interessante produzir mudas de P. guilfoylei nas proporções de 100% de CAC e 100% de CDB. No entanto, as estaquias de Polyscias guilfoylei responderam positivamente quando utilizado as proporções de 60% de CDB + 40% de CAC e 80% de CDB + 20% de CAC, sendo estas proporções recomendadas.

Phosphate fertilizers when applied to the soil, besides being harvested by the crops, promote a residual effect that can be offered to subsequent crops. The objective of this research was to evaluate the residual effect of phosphate fertilization applied to maize cultivation on the successor crop, cowpea, in the Cerrado region in Maranhao. The research was carried out in the experimental area of Federal University of Maranhão (UFMA), located in the city of Chapadinha, MA (3˚44'30"S, 43˚21'37''W). The experimental design was in randomized blocks, with six treatments and four replications. The treatments were composed of the following residual P doses: 0, 60, 70, 80, 90, 100 kg·ha ) and a greater profit margin (US $326.26). Thus, it is feasible to grow cowpea in previously cultivated areas, in order to take advantage of residual phosphate fertilization.

Arugula is a short-cycle species with a high demand for nutrients. In the plant, each nutrient performs one or more specific functions, so its deficiency will negatively impact the crop growth and development, being important to recognize the nutritional symptoms to help in decision making. In this context, the objective of this study was to describe the evolution of N, K, and Mg deficiencies symptoms and their effect on the growth of arugula plants. One at a time, the nutrients were omitted from the nutrient solution. At 13, 16, 18, and 20 days after transplanting (DAT) the seedlings to the - Nutrient Film Technique (NFT) system, plants were collected, symptoms characterized, and leaves were scanned in JPEG (1.200 pixels). At 10 DAT of arugula, plants grew in a nutrient solution N-depleted shown the initial visual symptoms of N deficiency and at 16 DAT was recorded the first symptoms of K and Mg depletion in nutrient solution. At 20 DAT, the plants showed severe N deficiency symptoms, the old leaves presented intense and generalized chlorosis, followed by necrosis. Deficient plants in K exhibited chlorosis at the edge of old leaves advancing to the center of the leaves and small white dots. For Mg, the older leaves developed interveinal chlorosis from the leaf tip towards the central vein. The omission of nitrogen resulted in plants with lower height, leaf area, and number of leaves when compared to arugula plants grown in a complete nutrient solution.

Nitrogen is the second nutrient most demanded by arugula. However, the positive effect it has on yield can negatively impact the quality of this vegetable, with negative effects on human health. Two experiments (summer and autumn) were carried out to evaluate the effect of N rates (0, 50, 100, 150, 200 and 250 kg ha−1) on the arugula growth, yield and quality (nitrate content). Each experiment was set up in a randomized block design with four replications. Increasing rates of N reflected positively on leaf N content and thus, higher and desirable values of height, leaf number, leaf area and plant dry mass were obtained in both growing seasons. Consequently, the yield had significant increase, which N was maximized in summer (4.9 kg m−2) and autumn (2.6 kg m−2) and leaf N of 29.4 and 27.0 g kg−1, respectively, at rates of 250 and 213 kg ha−1 and both growing seasons. The higher rate the higher foliar nitrate content of arugula, in summer (2931.3 mg kg−1) and autumn (4218.4 mg kg−1). The foliar nitrate content in both crop season do not reach the risk level to human being heath.