Vincenzo Tabaglio

Alternative weed control using the allelopathic effect of natural benzoxazinoids from rye mulch

In conventional agriculture, weed control by herbicides is an expensive practice and can also have a negative effect on the environment. Allelopathy permits sustainable weed management while reducing the impact of agriculture on the environment. We studied the content of 2,4-dihydroxy-1,4 (2H)-benzoxazin-3-one (DIBOA) and benzoxazolin-2(3H)-one (BOA), indicated as benzoxazinoids and considered effective for weed control, in 8 cultivars of rye and 1 of triticale grown in a greenhouse. We also tested the ability of mulches to inhibit the germination of four warm-season weeds. Our results show that all rye cultivars produced DIBOA, while BOA was found only in four of them. Benzoxazinoids were absent in triticale. Total benzoxazinoid content ranged from 177 to 545 μg g−1 and was statistically different among cultivars. Rye mulches were not able to suppress velvetleaf and common lambsquarters seedlings, while redroot pigweed and common purslane were significantly affected. Weed suppression ranged from 40% to 52% for redroot pigweed and from 40% to 74% for common purslane. The inhibitory activity of triticale mulch was observed only for common purslane, with a suppression percentage of 33%. No correlation was found between total benzoxazinoid content and the number of weed seedlings suppressed, with R2 of 0.076 for redroot pigweed and R2 of 0.003 for common purslane, indicating that benzoxazinoids are not the only source of phytotoxicity.

Interspecies-cooperations of abutilon theophrasti with root colonizing microorganisms disarm BOA-OH allelochemicals

ABSTRACT A facultative, microbial micro-community colonizing roots of Abutilon theophrasti Medik. supports the plant in detoxifying hydroxylated benzoxazolinones. The root micro-community is composed of several fungi and bacteria with Actinomucor elegans as a dominant species. The yeast Papiliotrema baii and the bacterium Pantoea ananatis are actively involved in the detoxification of hydroxylated benzoxazolinones by generating H2O2. At the root surface, laccases, peroxidases and polyphenol oxidases cooperate for initiating polymerization reactions, whereby enzyme combinations seem to differ depending on the hydroxylation position of BOA-OHs. A glucosyltransferase, able to glucosylate the natural benzoxazolinone detoxification intermediates BOA-5- and BOA-6-OH, is thought to reduce oxidative overshoots by damping BOA-OH induced H2O2 generation. Due to this detoxification network, growth of Abutilon theophrasti seedlings is not suppressed by BOA-OHs. Polymer coats have no negative influence. Alternatively, quickly degradable 6-hydroxy-5-nitrobenzo[d]oxazol-2(3H)-one can be produced by the micro-community member Pantoea ananatis at the root surfaces. The results indicate that Abutilon theophrasti has evolved an efficient strategy by recruiting soil microorganisms with special abilities for different detoxification reactions which are variable and may be triggered by the allelochemical´s structure and by environmental conditions.

Agronomic and Economic Evaluation of Two Agricultural Systems: Conventional Tillage and No-Tillage

Conservation agriculture (CA) can improve sustainable rice production. This work evaluated the effect of different CA practices on rice agronomic system. A four-year experiment (2013-2016) was carried out in Crescentino (VC), North-West Italy, comparing three tillage managements (sod dry seeding, sod wet seeding and ploughing), combined with three N fertilisation levels (0-110160 kg N ha) and two straw management (straw retained and removed). Yield and yield components were influenced by both tillage practices and N fertilisation, but not by straw management. Sod seeding reduced grain yield of about 16% with respect to ploughing, because of the lower panicle density and higher sterility. Rice responded to N fertilisation, but the higher sterility limited the positive effect at high N rates. Moreover, in sod seeding, high N supply increased Apparent Recovery (AR). Straw retention improved soil quality, increasing soil organic carbon concentration.

Rural development plays a central role in food wastage reduction in developing countries

According to the Food and Agriculture Organization of the United Nations (FAO), roughly onethird of food produced for human consumption is lost throughout the Food Supply Chain. This Food Wastage (FWa) could be divided in Food Loss (decrease in mass or in nutritional value of food for human consumption), and Food Waste (food discarded because left to spoil or expired). FAO suggests to start analysis of FWa from harvesting, but several authors suggest to start from sowing because FWa can also occur between sowing and harvesting. For this reason, to limit FWa it is important to adopt better agricultural practices (seed quality, appropriate organic and synthetic fertilizers, type of rotation, multiple cropping, pruning, and pesticide control). Each item of FWa – according to FAO including only edible part losses – could be further divided in unavoidable, not economically avoidable and economically avoidable. Besides the efforts to reduce last one, it is also important trying to recycle unavoidable and not economically avoidable losses (i.e. as animal feeds or composting). In all these aspects there are great differences between Developed Countries and Developing Countries, mainly justified by available structures and infrastructures. Therefore we have carried out some experiences on FWa reduction in Dem. Rep. of Congo and India. Within established women groups, the following activities have been made: (1) planting improved seeds of rice in India has almost doubled the grain yield without any other change; (2) constructing warehouse in common to contain hand-crafted silos for cereals, in order to avoid insect attack, resulted feasible and very effective; and (3) drying or frying with palm oil fresh vegetables allows prolonged storage. To conclude, acting to reduce FWa to obtain maximum potential yield, as well as reducing the postharvest losses, recycling FWa as animal feed, composting and anaerobic digestion, limits the need for food production rise. However, uncertainties remains about the actual extent of FWa; difficult is therefore the estimating the amount of its reduction.