Introduction. Little is known about the impact of organic manure on andosol. Materials and methods. Two varieties of Solanum lycopersicum L. (cvs. ‘Rio grande’ and ‘Rossol VFN’) were grown under tropical andosol. The soil was silty, acidic and very poor in Bray P (3 mg·kg–1) with a strong imbalance in the (Ca:Mg:K) ratio of (74.0:25.0:0.7). Five fertilization treatments were used: (i) control with no fertilizer, (ii) minerals, with a (Ca:Mg:K) ratio of (76:18:6) and 75 mg P·kg–1 of soil; (iii) poultry manure with a (Ca:Mg:K) ratio of (68:24:7) and 450 mg P·kg–1 of soil; (iv) a combination of (ii) and (iii), and (v) mineral fertilization as applied by local farmers, with a (Ca:Mg:K) ratio of (73:25:1) and 54 mg P·kg–1 of soil. Results. All cation-balanced treatments (organic, mineral or a combination of both) significantly improved plant growth, the number of trusses and fruits per plant, the marketable fruit yield and fruit P, K, Ca and Na contents of both tomato varieties considered. The ‘Rio grande’ variety was the most productive (32–44 t·ha–1) compared with the ‘Rossol’ variety (20–22 t·ha–1). There was no major difference between the organic fertilizer and the cation-balanced mineral fertilizer. There was no effect of mineral fertilizer with an unbalanced cation composition on tomato plant growth and production as compared with unfertilized control. Conclusion. In tropical andosol poor in potassium and phosphorous and with excess of Mg, application of poultry manure in adequate dosage and at the right time is capable of sustaining tomato fruit production, as well as the application of calculated inorganic fertilizer.

Introduction. The production of high quality fruit juice involves several cultural inputs. Among other factors, fruit quality attributes are influenced by the cultivar, the climate, the harvesting time and soil fertility. Particularly, the soil fertility has a significant effect on the nutritional characteristics of the juice. Good practice as regards fertilization consists of applying rates adapted to plant optimum growth, yield and fruit quality. Materials and methods. Effects of four poultry manure rates [(0, 5, 10 and 15) t·ha–1] on the juice quality of passion fruits (Passiflora edulis var. flavicarpa) were evaluated for two cropping years (2005 and 2006). The seedlings of passion fruit vine were field-established in a randomized complete block design, and the manure treatments were replicated four times. Juice quality assessment was performed on fruits picked in December 2005, coinciding with the dry season and low soil moisture recharge, and August 2006, during the wet season and high soil moisture recharge. Results. The results obtained indicated a significant poultry manure effect on all the juice quality parameters studied; the quality of the juice increased gradually as the manure rate increased. Similarly, the season of fruit-picking had a significant effect on the juice quality. As expected, vines that received no manure produced fruits with the poorest juice quality, suggesting unfavorable nutritive conditions within the vines. The concentrations of anti-nutrient factors (tannin, hydrogen cyanide, phytate and calcium oxalate) were low in ripe yellow passion fruits, and insignificant regarding health hazards for consumers of yellow passion fruit. Conclusion. The results obtained showed that the manure rate and the harvest period affected the quality of passion fruit juice. Application of 15 t·ha–1 poultry manure generally gave the best juice quality; similarly, fruits harvested in the first cropping season had better juice quality.