Rogério Haruo Sakai

Physico-chemical and sensory parameters of tomato cultivars grown in organic systems

The objectives of this research were to perform the physical, chemical and sensorial characterization, for hybrid and open pollinated tomato, within the Santa Cruz and Italian groups, aiming fresh consumption. A total of 14 fresh market tomato cultivars was used, six of them being experimental varieties and eight were commercial ones. The experimental design was of randomized blocks with six replicates and five plants per plot. For the chemicophysical analysis, samples of ripe fruits were randomly extracted from five plants in each plot, labeled and maintained under refrigeration at 5oC until the next day after harvest. Afterwards, fruits of all cultivars were mixed, ground and divided in triplicates to be submitted to the physicochemical analysis. From the physicochemical analysis it was observed that the value of the ratio between soluble solids (SS)/titratable acidity (TA) was higher in the cultivars IAC 6 and IAC 3. In relation to the SS content, the highest values were obtained by cultivars IAC 1 and IAC 6. In order to evaluate the commercial value of the cultivars, a sensorial analysis was carried out with fruits tasted by 75 individuals, using a hedonic scale of seven points. The data were analyzed by variance analysis and grouping of means. The cultivars of the Italian group IAC 4, IAC 6, Netuno and Bari; as well as the cultivars of the Santa Cruz group IAC 1, IAC 5, HTV 0601 and Debora Victory reached the best scores in all the sensorial traits evaluated. All the cultivars presented reasonable quality of the fruits, with SS/TA ratio values higher than 16 and SS values higher than 4oBrix.

Univariate and multivariate procedures for agronomic evaluation of organically grown tomato cultivars

Tomato is one of the most important crops, the worldwide production in 2012 reached 161.8 million tons. Considering the lack of agronomic information on already available cultivars as well as on the varieties under development by breeding programs for organic systems, the objectives of this work were determine the yield components of 14 tomato cultivars in the organic system, through univariate and multivariate analysis. The experimental design was randomized blocks with six replications and five plants per plot. Evaluations consisted of total, marketable and non-marketable yield and number of marketable fruits per plant, in 2010. We carried out analysis of variance, using test F 5%. The effect of cultivar was fixed and the block effect was random. Then, means were ranked according to Scott-Knott 5%. Differences among cultivars were significant for total yield, number of marketable fruits per plant and marketable yield. The mean for total yield among cultivars was 51 t/ha and for marketable yield was 41 t/ha. Cultivars IAC 1 and Santa Clara were the least dissimilar (0.38). On the other hand, cultivars HTV 0601 and IAC 3 were the most dissimilar (10.63). The score dispersion graph showed two distinct groups. The second group contained cultivars HTV 0601, Granadero, Bari and Netuno, which stood out in the evaluation for the organic production system, presenting the highest total yield, marketable yield and number of marketable fruits per plant. Multivariate analysis was effective in identifying clusters of cultivars.

Performance of lettuce in sole cropping and intercropping with green manures

The performance of lettuce in sole and intercropped with green manures was assessed under different establishment times. The lettuce fresh and dry weight, number of leaves per plant, diameter and length of head, and fresh and dry weight of green manure were evaluated. The intercropping design was additive and both cash and cover crops were planted in rows. The experimental design was of randomized complete blocks in split plot scheme, with six replicates. The plots represented the green manure sowing days (0, 20, 40 and 60 before transplanting of lettuce), and the sub-plots were assigned by cropping systems (lettuce in sole crop and intercropped with black oat, cowpea or white lupin). Simultaneous planting in the intercropping did not affect the lettuce performance. However, when the green manures were sown before lettuce, they influenced it in a negative way. Among the green manures, cowpea increased biomass and had a higher negative effect on lettuce performance compared to white lupin, which appeared to produce less competition. The sole crop and the intercropping with simultaneous planting of the green manures resulted in a better lettuce performance.