Showing 5 results for Cowpea
Temitope E. Arotolu, Joseph A. Adeyemi, Chris O. Adedire,
Volume 7, Issue 2 (7-2018)
Abstract
In this study, the roles of proximate composition, mineral profile and heavy metal contamination were investigated on selected biological activities of Callosobruchus maculatus (F.) that were maintained on six cowpea cultivars. The levels of heavy metals; cadmium, lead and arsenic in six cowpea cultivars; Ife Brown, Ife BPC, Oloyin, Drum, Sokoto Local, and Niger White were determined by atomic absorption spectrophotometry while those of nutrient elements; zinc, sodium, calcium and potassium were determined using flame photometry. The proximate analyses and physico-chemical characterization of the cowpea cultivars were also performed. Callosobruchus maculatus was maintained on the cowpea cultivars and biological activities such as oviposition, adult emergence, percentage seed damage, and weight loss were monitored. The levels of heavy metals, mineral elements and proximate composition differed significantly among the cultivars investigated, and the values were comparable to those reported for cowpea cultivars in other studies. Of the cowpea cultivars, the Ife Brown was the most susceptible to the bruchid C. maculatus infestation while the Drum cultivar was the least susceptible. In conclusion, the results from this study show that the cowpea cultivars differed in the levels of toxic and mineral elements. While there were significant relationships between physical parameters (e. g. seed hardness), proximate composition (moisture contents and crude fibre) and adult emergence and oviposition, there was no strong evidence that the levels of heavy metals and mineral elements play significant role on the biology of C. maculatus.
Yaghoub Fathipour, Fatemeh Baghery, Abdoolnabi Bagheri, Bahram Naseri,
Volume 9, Issue 4 (8-2020)
Abstract
The cotton bollworm, Helicoverpa armigera (Hübner), is a destructive pest on a wide range of economic crops in many parts of the world. In this research, demographic parameters of H. armigera were determined on five host plant species including cowpea (cv. Mashhad), navy bean (cv. Dehghan), chickpea (cv. Hashem), soybean (cv. 033) and corn (cv. Single cross 704). All experiments were carried out under laboratory conditions at 25 ± 1°C, 65 ± 5% RH and a photoperiod of 16: 8 (L: D) h. The results revealed that females and males had the shortest development time on chickpea (36.16 and 34.98 d, respectively) and the longest development time on corn (42.00 and 42.95 d, respectively). The highest daily and total fecundity of H. armigera were observed on cowpea and the lowest ones were on corn. The values of the intrinsic rate of increase (rm) on the above-mentioned host plants were 0.180, 0.144, 0.161, 0.161 and 0.126 day-1, respectively. Also, the values of the net reproductive rate (R0) were 365.66, 294.28, 365.67, 239.69 and 147.40 female offspring, respectively. The longest mean generation time (T) (37.90 ± 0.26 d) and doubling time (DT) (5.62 ± 0.17 d) were observed on corn. Our findings revealed that cowpea and corn were the most susceptible and resistant host plants to H. armigera, respectively.
André Dos Santos Melo, Sandra Andréa Santos da Silva, José Wilson Pereira da Silva, Pablo Henrique Almeida Oliveira, Nataly de La Pava Suárez, Erica Costa Calvet, João Everthon Silva Ribeiro,
Volume 13, Issue 4 (12-2024)
Abstract
Silicon (Si) is a mineral known to enhance pest resistance in plants belonging to the Poaceae family. However, studies suggest potential benefits of Si in other botanical families such as Fabaceae. Thus, our hypothesis that Si applied in the form of 94.6% silicate would increase cowpea resistance to the stink bug Crinocerus sanctus (Fabricius), in addition to benefiting the physiological aspects of the plant. This study evaluated the vegetative development, total chlorophyll content, yield parameters, and resistance of two cowpea varieties against C. sanctus when sprayed with different doses of Si. Two different doses of Si were administered: the recommended manufacturer's dose (1 g L-1) and a doubled dose (2 g L-1), in addition to a control group (0 g L-1). Plants treated with Si exhibited lower insect density and fewer pods with signs of injury. The peak insect population was observed at the onset of the cowpea's reproductive stage. Furthermore, the chlorophyll content increased from 42 mg m-2 (in the control group) to 48 mg m-2 in Si-treated plants. While the plant height and yield parameters of cowpea remained unaffected by Si application, there was a reduction in the dry mass of the aerial parts in Si-treated crops. This study demonstrated that cowpea can accumulate Si, and its application can enhance resistance against C. sanctus.
Volume 19, Issue 1 (1-2017)
Abstract
The impact of three different fabaceous host plants including cowpea (Vigna unguiculata), chickpea (Cicer arietinum), and mung bean (Vigna radiata) seeds was investigated using biochemical approaches on possible changes of gut proteolytic activity of the cowpea weevil, Callosobruchus maculatus at 30±1˚C and 70±5% RH and a photoperiod of 8:16 (L:D). Results revealed that pH of 4-5 and 9 was optimal for the activity of larval gut proteases using azocasein and hemoglobin as general substrates. Different serine (BApNA, SAAPFpNA, PMSF, TLCK, and TPCK) and cysteine (Z-Arg-Arg- pNA, Z-Phe-Arg-pNA and DTT) specific substrates inhibitors and activator were used as a further proof of the proteolytic profile in the gut of C. maculates. Although combinations of serine and cysteine proteases were observed, the cysteine proteases had the highest rate on the studied hosts. The protease activity, especially cystein protease, was the highest on cowpea, which was supported by hemoglobin (0.156±0.045 U mg-1), Z-Phe-Arg-pNA (2.85 U mg-1) substrates and DTT (90.00±0.10%) as an activator. Due to the importance and frequency of cysteine proteinases and their effects on biological and physiological process, it would be better to design pest management programs based on cysteine plant proteinase inhibitors as transgenic plants.
Volume 19, Issue 6 (11-2017)
Abstract
Helicoverpa armigera (Hübner) is one of the major limiting factors in host plant production in the world and Iran. In this study, the effect of semi-artificial diets based on the seeds of different cultivars of white and red kidney bean, canola, soybean, and cowpea on eco-physiological parameters of H. armigera were investigated. The results showed that the shortest (22.71 days) and longest (28.94 days) development time of H. armigera was observed on cowpea cultivar Mashhad and canola cultivar Opera, respectively. The maximum immature mortality of H. armigera was on soybean cultivars M7 and Clark. Cowpea cultivar Mashhad had the highest r (0.299 day-1). The lowest level of proteolytic activity was 2.829 U mg-1 on soybean cultivar M7 for the 3rd instar larvae, 2.525 U mg-1 on soybean cultivars Crark for the 4th instar larvae, and 2.292 U mg-1 on soybean cultivar Sari for the 5th instar larvae. Nutritional indices of 3rd, 4th, 5th, 6th and whole instar larvae of H. armigera were affected by the artificial diets, i.e. seeds of different cultivars. According to the results, semi-artificial diets containing bean seeds (specifically cowpea cultivar Mashhad and white kidney bean cultivar Daneshkadeh) were more suitable than semi-artificial diets containing soybean and canola seeds for rearing of H. armigera.