Effects of different methods to control the parasitic weed Phelipanche ramosa (L.) Pomel in processing tomato crops

Abstract

The root-parasitic weed Phelipanche ramosa (L.) Pomel represents a major problem for processing tomato crops. The control of this holoparasitic plant is difficult, and better understanding of treatment methods is needed to develop new and specific control strategies. This study investigated 12 agronomic, chemical, biological and biotechnological strategies for the control of this parasitic weed, in comparison with the untreated situation. The trial was carried out in 2014 at the Department of Agriculture, Food and the Environment of the University of Foggia (southern Italy), using processing tomato plants grown in pots filled with soil from a field that was heavily infested with P. ramosa. After transplantation, top dressing was performed with 70 kg ha -1 nitrogen. A randomised block design with 3 replicates (pots) was adopted. During the growing cycle of the tomato, at 70, 75, 81 and 88 days after transplantation, the number of parasitic shoots (branched plants) that had emerged in each pot was determined, and the leaf chlorophyll of the plants was measured using a soil-plantanalysis-development meter. At harvesting on 8 August 2014, the major quanti-qualitative yield parameters were determined, including marketable yield, mean weight, dry matter, soluble solids, and fruit colour. The results show lower chlorophyll levels in the parasitised tomato plants, compared to healthy plants. None of the treatments provided complete control against P. ramosa. However, among the methods tested, Radicon ® biostimulant (Radicon, Inc., Elk Grove Village, IL, USA), compost activated with Fusarium oxysporum, nitrogen and sulphur mineral fertilisers, Enzone TM soil fumigant (Elliott Chemicals Ltd., Auckland, New Zealand), and a resistant tomato genotype mitigated the virulence of the attacks of this parasite. These effects should be improved by combining some of these treatments, especially for gradual and continued reduction in the seed bank of the parasite in the soil. For the tomato yields across the different treatments, there were no significant differences seen; however, the yields showed an improving trend for treatments with lower presence of the P. ramosa weed.

Recent research progress in combatting root parasitic weeds

“…In Sl-ORT1, yield loss by the mutation under non-infested field conditions was small [79]. A new improved tomato cultivar 'Red setter tilling', which was developed in the genetic background of a cultivar 'Red setter' using a targeting-induced local lesions in genomes (TILLING) platform, was resistant to P. ramosa because of a reduction in the synthesis of the germination stimulant [81]. The germination percentage of P. ramosa seeds was reduced by up to 90% with the application of extracts from tomato plants expressing the SlCCD7 antisense construct due to significantly decreased levels of SL compared with the wild type [82].…”

“…Based on the information, the integrated strategy composed of a biostimulant that contains humic substances, N or S fertilizers, compost activated with F. oxysporum, a soil fumigant and resistant tomato cultivars was designed. The strategy successfully mitigated the virulence of the attacks of P. ramosa [81]. Since it is generally believed that integrated management is the only way to cope with the parasitic weeds [1], further verification examples are needed to develop effective, economical and applicable management under each target condition.…”

Use of Olive-Mill Wastewater for the Containment of Phelipanche ramosa in Open Field of Processing Tomato Crop

“…Various methods have been tried to maintain the P. ramosa populations below the threshold levels for damage, including preventive measures, physical, chemical, agronomic, biological, biotechnological and integrated methods [8]- [10].…”

“…In agricultural systems, characterized by low external input, herbicides are largely or entirely avoided, and weeds are suppressed largely through physical and ecological strategies [11]. Therefore, many researches to control the parasitic weed paid attention towards suitable methods, such as the use of organic compounds [10], [12]- [14]. Soil fertility plays a key role in P. ramosa management.…”

Exploration of resistance to Phelipanche aegyptiaca in tomato

“…Tomato, as an important vegetable crop, is grown worldwide and is easily infected by broomrape 22 . Despite extensive screening, no single immune strategy or strong resistance against broomrape has been declared 23 .…”