The objective of this study was to evaluate the influence of the spacing of lettuce rows on the production of a lettuce-rocket intercropping system over two growing seasons (11 August to 25 September 2011 and 12 January to 24 February 2012) in Jaboticabal, São Paulo, Brazil. We evaluated 11 treatments in each season: lettuce-rocket intercrops with five row spacings for the lettuce (0.20, 0.25, 0.30, 0.35 and 0.40 m) and the rocket planted midway between the lettuce rows, sole crops of lettuce at the same five row spacings and a sole crop of rocket. Fresh and dry masses of the lettuce and rocket and number of lettuce leaves per plant were highest with a lettuce row spacing of 0.40 m, but the productivities of the lettuce and rocket were higher with a lettuce row spacing of 0.20 m. The productivities and fresh and dry weights of the lettuce and rocket and the number of lettuce leaves per plant were highest in the sole crops, but the fresh and dry weights of the rocket were higher with intercropping. The land equivalent ratios were >1.0 in both seasons in all intercrops and were highest for the densest crop (1.41). Intercropping was therefore 41% more efficient than sole cropping for the production of lettuce and rocket.

Nitrogen (N) is the second most important nutrient required by watermelons that can limit their growth and affect fruit quality when deficient. We evaluated the soil (N-nitrate) and foliar N contents and soluble-solid content of the watermelon 'Top Gun' in Brazil at six rates of N fertilization (0, 50, 100, 150, 200 and 250 kg ha-1). N-nitrate and foliar N levels increased linearly with rate. Number of total and marketable fruit, weight of total and marketable fruit and total and marketable yields varied quadratically with rate. N rates of 187 and 184 kg ha-1 produced the highest total and marketable yields, respectively. The rate of N fertilization did not significantly affect total-solid content.

The interactive effects of N (6, 9, 12 and 15 mmol L^-1) and K (3, 5, 7, and 9 mmol L^-1) concentrations in nutrient solutions were evaluated on bell pepper grown in a coconut-coir substrate and fertilized without drainage. An additional treatment with drainage was evaluated using N and K concentrations of 12 and 7 mmol L^-1, respectively. The hybrid Eppo cultivar of yellow bell pepper was cultivated for 252 days beginning 9 November 2012. Electrical conductivity (EC), the N and K concentrations in the substrate solution, marketable fruit yield, total dry weight and macronutrient concentrations in shoots were periodically evaluated. Fruit production was lower in the system without drainage, regardless of the N and K concentrations, compared to the recommended 10–20% drainage of the volume of nutrient solution applied. Higher K concentrations in the nutrient solution did not affect plant production in the system without drainage for the substrate with an initial K concentration of 331.3 mg L^-1. Fruit yield was higher without drainage at a nutrient-solution N concentration of 10.7 mmol L^-1. The upper EC limit of the substrate solution in the system without drainage was exceeded 181 days after planting. Either lower nutrient concentrations in the nutrient solution or a drainage system could thus control the EC in the substrate solution.

Crop fertilization with P is a practice that constantly needs to be improved because of its high cost, natural reserve constraints, and environmental impact caused by the excessive use of nutrients. Phosphorus rates (0, 120, 240, 360, 480, 600, and 720 kg P2O5 ha(-1)) in the cultivation of 'Fuyutoyo' cabbage (Brassica oleracea L. var. capitata) in a P-rich Eutrustox soil (93 mg P dm(-3)) in Jaboticabal (21 degrees 15'22 '' S, 48 degrees 15'58 '' W; 575 m a.s.l.), Sao Paulo, Brazil, were evaluated in an experiment with a randomized complete block design with three replicates. Phosphorus rates influenced plant characteristics and soil P content. Maximum leaf and soil P content was obtained with 720 kg P2O5 ha(-1), but maximum values of leaf area, leaf dry mass, cabbage head mass, and productivity were obtained with 420, 310, 430, and 437.5 kg ha(-1) P2O5, respectively. Results indicate that even crops grown in a P-rich soil benefit from applying P fertilizer, which has a positive effect on the growth and productivity of the 'Fuyutoyo' cabbage