Yield of prickly pear cactus irrigated with saline water in soils of the semi-arid region

Knowing the tolerance of plants grown in the Brazilian semi-arid region to salt stress is of paramount importance for the sustainability of regional agriculture. This study was developed to examine the growth and yield of prickly pear cactus ‘Orelha de Elefante Mexicana’ (Opuntia stricta Haw) irrigated with increasing water salinity levels (0.75, 3.0, 5.25 and 7.50 dS m-1 to 25 ºC) and grown on soils representative of the Brazilian semi-arid region (chromic Luvisol, Solonetz and Fluvisol). Total fresh weight decreased linearly, with a 21.42% reduction when we compare the average fresh weight per plant in the lowest and highest saline level treatments. The chromic Luvisol and Solonetz soils showed the best fresh weight and dry matter yields under the present experimental conditions.

Chemical Characterization of Different Products from the Tunisian Opuntia ficus-indica (L.) Mill.

Various dried (by-)products from the Tunisian O. ficus-indica were elucidated for their proximate composition, fatty acid (FA) composition, inorganic elements, sugars, and polyphenols. Nopal and prickly pear peel and seeds were abundant in fiber (respectively, 28.39, 12.54, and 16.28%). Seeds had also high protein (17.34%) and may be source of an edible oil, due to lipids (9.65%) poor in saturated FAs (14.12%) and rich in linoleic acid (61.11%). Nopal and peel showed the highest levels of Mg (493.57 and 345.19 mg/100 g), K (6949.57 and 1820.83 mg/100 g), Mn (59.73 and 46.86 mg/Kg) and Fe (23.15 and 15.23 mg/Kg), while the fruit pulp predominantly constituted of sugars, glucose and arabinose being predominant (42.57 and 13.56 g/100 g). Total polyphenols widely varied among the Opuntia products (108.36–4785.36 mg GAE/100 g), being mainly represented by hydroxycinnamic and hydroxybenzoic acids, and flavonoids as well. In particular, peel may be revalorized for these valuable bioactives, including 4-hydroxybenzoic acid (484.95 mg/100 g), cinnamic acid (318.95 mg/100 g), rutin (818.94 mg/100 g), quercetin (605.28 mg/100 g), and several isorhamnetin and kaempferol glycosides. Overall, the Tunisian prickly pear cactus could encourage a sustainable production, an effective waste management, and may provide several benefits for human health, in accordance with the model of the Mediterranean diet.

Development of the prickly pear cactus Opuntia stricta (Haw.) Haw. (Cactaceae) in vitro in response to the replacement of potassium nitrate for a commercial kno 3 fertilizer

ABSTRACT: In micropropagation, potassium nitrate (KNO3), an ACS reagent grade chemical, used in the preparation of growing mediums is expensive and its procurement depends on bureaucratic procedures, as it is controlled by the Brazilian Army. This research to assessed the effect of replacing the ACS KNO3 for a commercially available fertilizer (KNO3- based) on the micropropagation of the prickly pear cactus (Opuntia stricta (Haw.) Haw. cv. Elephant Ear. Treatments used six different fertilizer concentrations (0, 0.5, 1, 1.5, 2 and 2.5 g L-1) and a control consisting of 1.9 g L-1 KNO3, as shown in the MS salts. The survival, size and number of sprouts and the value of fresh biomass were evaluated. After seedling acclimation, we assessed the survival, number of sprouts, length, and number of roots, racket formation, average fresh biomass mass, macronutrient absorption and morphological changes of the seedlings. Explants inoculated with fertilizers at concentrations of 0.0; 2.0 and 2.5 g L-¹ did not grow. The response of explants at concentrations of 0.5 and 1.5 g L-1 of the fertilizer were the same as those developed in a KNO3 medium, and at a concentration of 1.0 g L-1, in all variables, the means were higher than those of the control medium. Therefore, it showed the feasibility of using fertilizers in the in vitro cultivation of the prickly pear cactus, which may remove bureaucratic barriers and reduce product costs by 99.12%.

Chemical Composition and Insecticidal Potential of Six Essential Oils from Morocco against Dactylopius opuntiae (Cockerell) under Field and Laboratory Conditions

The carmine cochineal Dactylopius opuntiae (Cockerell) is the major insect pest of the prickly-pear cactus Opuntia ficus-indica (L.) in Morocco. The present study investigated the insecticidal activities of six essential oils (EOs) against nymphs and adult females of D. opuntiae applied singly or in combination with a detergent under laboratory and field conditions. Under laboratory conditions, M. pulegium and O. vulgare L. essential oils showed a high level of insecticidal activity at 5%, with 98% and 92% females’ mortality, respectively, 5 days after treatments. The M. pulegium and O. vulgaris oils at 5% applied in combination with black soap at (60 g/L) induced the highest toxic activity on adult females, 100% and 96% at 5 days after treatments, respectively. Under field conditions, M. pulegium and O. vulgare oils at 5% in combination with black soap (60 g/L) showed the highest adult female mortalities with 96.33 and 92.56%, respectively, 7 days after the first application. The double application of M. pulegium oil at 5% significantly increased the mortality of adult females up to 91%, 5 days after the second spray. GC-MS analysis revealed that the most abundant constituent of M. pulegium and O. vulgare oils was pulegone (84.69%) and durenol (76.53%), respectively. These findings showed that the use of M. pulegium and O. vulgare in combination with black soap or in double sprays could be incorporated in the management package for the control of the wild cochineal D. opuntiae, as a safe and natural alternative to chemical insecticides.

BIOSORPTION OF LEAD HEAVY METAL ON PRICKLY PEAR CACTUS BIOMATERIAL: KINETIC, THERMODYNAMIC AND REGENERATION STUDIES

The potential of Tunisian prickly pear cactus as a low-cost adsorbent for Pb(II) ions from aqueous solution was investigated in batch mode. To determine the optimum adsorption conditions, experiments were conducted varying the operating parameters, as follows: pH of the solutions (2-10), initial concentration of metal ions (0.98-2.4 mmol/L) and temperature (30-60 °C). The adsorption isotherm data were analyzed by applying the Langmuir, Freundlich, Dubinin–Raduskevich, Temkin and Redlich–Peterson models. The experimental results were better fitted by the Freundlish model. The pseudo-first order, pseudo-second order, Elovich and intraparticle diffusion models were applied to the description of the kinetic data. The best fit was achieved for the pseudo-second order model, and the presence of both film and intraparticle diffusion mechanisms was demonstrated. Thermodynamic studies indicated that the biosorption on the cladode powder is an exothermic and chemical process. The desorption/regeneration process was also investigated. The obtained results revealed over 90% desorption of Pb(II) metal ions from the total metal-loaded mass of the adsorbent and good stability of the cactus adsorbent for four successive adsorption/desorption cycles.

The “Secret Recipe” of Galápagos

Galápagos tortoises demonstrate the special “creative force” of evolution in the archipelago, having radiated into 15 species—each with a characteristic shell shape—within the last 3.2 million years. Formed over an active mid-ocean volcanic hotspot, Galápagos islands have also changed dramatically in the same period, providing new and diverse “petri dishes” for tortoise evolution. In these new homes, which are low, dry islands, where the tortoise’s main food is prickly pear cactus (which has concurrently evolved a protective treelike stature), tortoises evolved impressive new features, including saddlebacked shells and extra-long limbs. On all the islands where they occur, tortoises serve as “ecological engineers,” building suitable niches for themselves (and incidentally for other species). In the case of domed-shell tortoises, those niches include tortoise-maintained wallows, meadows, and migration trails. Heavily hunted in Galápagos history, most tortoise species are rebounding today, some from tortoises rediscovered in the novel places they had been carried by early mariners in their quest for food.

Physical and chemical attributes of prickly pear cactus (Opuntia ficus-indica) varieties Copena, Pelon Blanco and Pelon Rojo

Objective: attest and compare the fundamental attributes for fresh raw cactus cladodes and its chemical constituent’s quality when dried and grounded for three varieties of prickly pear cactus “Copena”, “Pelon blanco” and “Pelon rojo”. Design/methodology/approach: measurements of the physical attributes and chemical constituents were made by using proved and reliable techniques. Data will aid to explore the potential for these cactus materials when being handled from basic to complex processes, considering its need for size and quality of storage and their effect when they interact with processing devices and handling apparatus for the new product being elaborated. Results: the physical attributes among the three assessed cactus varieties showed slight differences in their parameters, but length, wide and electric conductivity. While for their chemical analysis, cactus cladodes were chopped, dried and grounded. Chemical compounds showed slight differences between the three varieties, but Pelon blanco had a higher fat percentage and the lowest zinc and potassium concentration. None of the varieties had iron. Limitations on study/implications: there was no management on the prickly pear cactus production. The assessment of the cultivars’ attributes was as they were from the field. Stabilization of the chemical constituents of Pelon blanco could be necessary, according to the expected features of new products, or lead to a new line of by-products. Findings/conclusions: mechanical handling of raw cladodes around the premises is facilitated, and its uses and maintenance are fewer management costs. Flour from each variety was kept at around 10 % water content to safeguarding storage. Regard the protein and carbohydrates content, flour of the three varieties ensure integration with other compounds and guarantees new products with high protein content.