INFLUENZA DELL’AMBIENTE COLTURALE E DELL’EPOCA DI TRAPIANTO SU SIMBIOSI, ASSORBIMENTI NUTRIZIONALI, CRESCITA, PRODUZIONE E QUALITA’ DELLA FAVA (Vicia Faba L. major Hartz) DA CONSUMO FRESCO, IN REGIME CONVENZIONALE O BIOLOGICO, IN CAMPANIA

In 2011-12 and 2012-13 research was carried out on fababean in Portici (Naples), with the purpose to evaluate the effects of crop environment and method as well as transplanting time on Rhizobium dynamics, nutrient absorption, fresh pods yield and seeds quality. With this respect, two crop environments (open field and greenhouse), two crop methods (conventional and “organic”) and five transplanting times (27 September, 11 October, 25 October, 8 November, 22 November) were compared. The root active tubercles number was greater in open field compared to greenhouse and in the third transplanting time. There were no significant differences between the conventional and “organic” method. About 70% of roots tubercles was located in 0-15 cm soil depth, while the remaining 30% was detected between 15 and 35 cm. The cultivation environment did not significantly affect the whole plant nitrogen concentration, but the nitrogen values were significantly higher in greenhouse grown flowers than in the field ones; conversely, a greater seeds nitrogen accumulation was recorded in open field compared to that obtained in protected environment. Nitrogen concentration was higher under the first transplanting time than with the third, except for the seeds, showing no significant differences between the two crop cycles. As concerns the crop method, the “organic” management caused a higher nitrogen concentration in the whole plant, while no differences were recorded between the two methods with regard to each organ concentration. Nitrogen concentration was higher in the pods harvested in open field than in those produced in greenhouse, while the opposite trend was detected for the flowers. Moreover, the first transplanting had a better effect on flowers nitrogen concentration, whereas the third one was more beneficial to the seeds. Finally, with reference to the crop method, the highest values of the substance provided by the pods from plants grown in organic way and by the seeds obtained by the conventional method. The nitrogen concentration detected in the leaves attained the highest level in the vegetative phase and the lowest one at fruiting end. Similar trend was shown by shoots, whereas the roots nitrogen concentration displayed a reduction only at the end of crop cycle. The pods showed the highest nitrogen concentration at full fruiting, while no differences were recorded for the seeds. Phosphorus concentration was higher in greenhouse than in open field. Similarly, there was a greater phosphorus accumulation in greenhouse grown flowers than in the open field ones. Transplanting time significantly affected phosphorus concentration in the whole plant as well as in individual organs and the highest values were recorded at the first time compared to the third. Moreover, in both transplanting times the highest phosphorus concentration was detected in pods and seeds. As for crop method, the “organic” management caused the highest phosphorus concentration both in the entire plant and in the flowers, in comparison to the conventional method; conversely, a higher phosphorus concentration was found in plant pods obtained under conventional management. Pods phosphorus concentration was higher in open field than in greenhouse, while the opposite trend was recorded for the flowers. Finally, the “organic” crop management resulted in flowers with higher phosphorus values compared to the same organs obtained under conventional method; opposite results were found for the pods and seeds. Leaves phosphorus concentration attained the highest values during vegetative stage and flowering, whereas the lowest level was recorded at full fruiting. The shoot accumulation with this element decreased from the vegetative phase to early fruiting, while the roots phosphorus concentration showed a decrease at fruiting. The pods showed the highest phosphorus concentration at full fruiting, where the seeds accumulated increasing amounts from full fruiting to harvest end. The whole plant concentration of this nutrient increased up to full fruiting, thereafter decreased up to crop cycle latest stage. The dry matter values recorded in open field were significantly higher than those detected in protected environment, while there were no significant differences between the two contexts with regard to the leaf surface. The crops grown in open field showed a greater root expansion in comparison to those grown in protected environment. The fourth transplanting resulted in the highest dry matter values of the aboveground apparatus, although in protected environment it was not different from the third one, whereas the second transplanting time showed a higher LAI value. The highest dry weight of plant roots corresponded to the fourth transplanting time, while the root apparatus was most expanded with the three intermediate crop cycles. There were no growth significant differences between the plants grown under conventional regime and those cultivated “organically”, referring both to aerial and to underground apparatus. The relation between root and leaf area decreased with the crop phenological development. The roots dry matter was not affected by crop method. The fourth transplanting showed the highest fresh pods marketable yield in open field, whereas in the greenhouse the highest production was provided by the second, third and fourth transplant, due to the greater number of pods per plant. The production in the open field was significantly higher than that obtained in the protected environment in the third and fourth crop cycle, but the trend was reversed for the second and the fifth transplanting time. In addition, seed yield recorded in the greenhouse crops was significantly higher than that in the open field at the third, fourth and fifth transplanting times and these three plantings resulted in the highest values in both environments. There weren’t, however, any significant differences between the cultural methods, both for pods and seed yield. The pods average weight reached a higher value in open field than in protected only at the fourth transplanting time, while in both environments the first crop cycle got lighter pods. In greenhouse the seeds average weight was higher, regardless of the crop method, and moreover in greenhouse the organic method had a better effect than the conventional one, while in open field there were no significant differences between the two management methods. Seeds fiber content showed higher values in greenhouse compared to open field and it gradually increased from the first to the fifth transplanting time; no significant differences were found between the management “organic” that conventional. Moreover, seeds fibre percentage increased from 18.1% in the earliest harvested pods to 26.6% in the latest fruits. Seeds protein percentage recorded in open field was higher than that detected in the greenhouse (30.2 vs 28.2%, respectively). Proteins values gradually increased with the transplanting progress. Proteins percentage showed an increasing trend between the first and last fruit seeds (26.3 to 32.5%). Seeds polyphenol content attained higher values in open field grown plants than in those managed in greenhouse (29.0 vs 24.5%). Polyphenols concentration was higher under the first two transplanting times (30.5% on average). The effect of “organic” method did not differ from the conventional one on fababean seeds polyphenolic content. Seeds polyphenols concentration showed a 56.9% reduction between the second half of March and the end of April.