Controlling of Meloidgyne incognita (Tylenchida: Heteroderidae) using nematicides, Linum usitatissimum extract and certain organic acids on four peppers cultivars under greenhouse conditions

Organic acids and plant extracts, which have a nemacidal action and may be used instead of nematicides that pollute the environment, are one way for controlling the pepper root-knot nematode. We provide in this study for a first time a new strategy for management Meloidgyne incognita (Kofoid and White) by using organic acids and plant extract compared to nematicides on four peppers cultivars (Super amarr, Super mard, Super noura and Werta) under greenhouse conditions compared to nematicides. This study aimed to evaluate 0.1% of organic acids (humic and salicylic acid) and 0.1% of Linum usitatissimum extract on plant parameters of pepper varieties (Super amarr, Super mard, Super noura and Werta) and control of M. incognita under greenhouse conditions compared to four nematicides (Oxamyl 24% SL, Fosthiazates 75% EC, Ethoprophos N40% EC and Fenamiphos 40% EC). Our data obtained four nematicides were more effectiveness than other treatments in reduced galls and egg masses of M. incognita. Whilst, humic and salicylic acids have remarkably higher nematicidal activity than L. usitatissimum in all lines of pepper. Therefore, plant extract and organic acids may be used a best alternative of nematicides to control PPNs and caused the longitudinal growth of plant. Also, ultimately reduce environmental risk from nematicide pollution.

Chrysin abrogates gibberellic acid-induced testicular oxidative stress and dysfunction via the regulation of antioxidants and steroidogenesis- and apoptosis-associated genes

GA3 is widely used as a growth stimulant in agricultural regions. The long-term use of GA3 can cause organs damage. Chrysin is a flavonoid found in nature that is commonly used to treat organ toxicity. In this study, we examined the effect of chrysin on the testes function of GA3-affected rats. A total of 24 male Wistar rats were divided into 4 groups. Saline was given to the control group. The chrysin group was given orally 50 mg/kg/BW of chrysin in saline. The GA3 group received a daily oral gavage of GA3 (55 mg/kg/BW). The protective group (chrysin + GA3) was given chrysin and GA3 as those described in chrysin and GA3 groups. There were an increase in MDA levels in the serum and testicular tissue of GA3-treated group. Catalase, GSH, and SOD levels were all lowered in the GA3-treated rats. Chrysin dramatically reduced the harmful effects of GA3 by restoring reproductive hormone levels, altered sperm parameters, and antioxidant capabilities. Furthermore, GA3 reduced the quantitative expression of steroidogenesis genes StAR and 3-HSD, as well as Bcl2 genes, while it increased the apoptotic marker BAX; all were alleviated by the pre-administration of chrysin. The pre-administration of chrysin protected the GA3 group from spermatogenic vacuolation, interstitial edema, necrosis, and depletion. Chrysin inhibited oxidative stress and modulated antioxidant activity, as well as apoptosis-/anti-apoptosis-related mediators in the testes. Chrysin has the potential to repair GA3-induced testicular dysfunctions. This suggests that chrysin is preferable as a medication to mitigate GA3-induced oxidative damage in the testes. PRACTICAL APPLICATIONS: Chrysin has the potential to repair GA3-induced testicular dysfunctions. This suggests that chrysin is preferable as a medication to mitigate GA3-induced oxidative damage in the testes.

Chemical evaluation of partially acidulated phosphate rocks and their impact on dry matter yield and phosphorus uptake of maize

Previous studies investigated the direct application of phosphate rock and its partially acidulated to enhance its solubility compared to soluble fertilizers. However, the interaction between the effect of particles diameter and partial acidulation of phosphate rock on phosphorus (P) availability and its effect on dry matter yield and P uptake is still elusive. This study was conducted to assess the effect of partially acidulated Egyptian phosphate rocks with different particle size diameters on P availability and its effect on dry matter yield and P uptake of maize (Zea mays L.). A pot experiment was conducted on maize plants grown on light clay soil for 42 days. Acidulation was done by mixing phosphate rock with single superphosphate or triple superphosphate at a total rate of 200 mg P kg⁻¹ with five acidulation mix ratios (100:0, 75:25, 50:50, 25:75, and 0:100). Different particle size diameters of phosphate rocks (500, 212, 75, and <45 µm included nano-particles ranged from 69.3 to 25.7 nm) were used. We found that dry matter yield and P uptake increased significantly due to the use of partially acidulated phosphate rocks especially when triple superphosphate was used for acidulation and the mixing ratio of 50:50 was the best. We also found that maize yield and P uptake increased significantly with decreasing particle size. It is recommended to use finely grounded partially acidulated phosphate rocks with particles diameter less than 45 µm at acidulation ratio 50% and no need to increase acidulation ratio above that as a slow-release phosphate fertilizer.

Utilizing biomass energy for improving summer squash greenhouse productivity during the winter season

The objective of this present research is to use agricultural residues as a source of energy for heating greenhouses during winter seasons and sequestrating soil carbon dioxide through adding biochar to the soil media. To fulfill the objective of the research work, summer squash was transplanted in a constructed greenhouse and heated using an attached biomass-burning system. The performance of the attached biomass-burning system was experimentally studied under different agricultural residues (corn stalks, cotton stalks and okra stalks), heating fluids (water and oil) and air fan operating periods (10, 15 and 20 min/h). Results indicated that the biomass-burning system allowed increasing temperature and relative humidity inside the greenhouse up to 27.2 and 80 %, respectively. The maximum biomass-burning system efficiency of 81 % was achieved with the use of okra stalks as a source of energy and oil as a heating fluid side by side with adjusting the suction fan operating period at 15 min/h. Adding bio-charcoal to the soil media, enhanced the soil carbon, resulting in a total fresh yield of 3.7 and 2.9 kg/pot with a total number of leaves per plant of 55 and 47 leaves under conditions of with and without charcoal addition, respectively.

Species richness, abundance, distributional pattern and trait composition of butterfly assemblage change along an altitudinal gradient in the Gulmarg region of Jammu & Kashmir, India

Despite enormous diversity, abundance, and role in ecosystem processes, little is known about how butterflies differ across altitudinal gradients. For this, butterfly communities were investigated along an altitudinal gradient of 2700–3200 m a.s.l, along the Gulmarg region of Jammu & Kashmir, India. We aimed to determine how the altitudinal gradient and environmental factors affect the butterfly diversity and abundance. Our findings indicate that species richness and diversity are mainly affected by the synergism between climate and vegetation. Alpha diversity indices showed that butterfly communities were more diverse at lower elevations and declined significantly with increase in elevation. Overall, butterfly abundance and diversity is stronger at lower elevations and gradually keep dropping towards higher elevations because floristic diversity decreased on which butterflies rely for survival and propagation. A total of 2023 individuals of butterflies were recorded belonging to 40 species, represented by 27 genera and 05 families. Six survey sites (S I- S VI) were assessed for butterfly diversity from 2018 to 2020 in the Gulmarg region of Jammu & Kashmir. Across the survey, Nymphalidae was the most dominant family represented by 16 genera and 23 species, while Papilionidae and Hesperiidae were least dominant represented by 01 genera and 01 species each. Among the six collection sites selected, Site I was most dominant, represented by 16 genera and 21 species, while Site VI was least dominant, represented by 04 genera and 04 species.

The impact of insecticides and plant extracts on the suppression of insect vector (Bemisia tabaci) of Mungbean yellow mosaic virus (MYMV)

Mungbean yellow mosaic virus (MYMV) is an important constraint in successful production of mungbean (Vigna radiata L.) in many countries, including Pakistan. The MYMV spreads by insect vector whitefly (Bemisia tabaci Gennadius). The use of resistant cultivars is the most effective management tactics for MYMV. Twenty mungbean varieties/lines were screened against insect vector of MYMV under field condition in the current study. Resistance levels for varieties/lines were assessed through visual scoring of typical disease symptoms. Furthermore, the impacts of two insecticides 'Imidacloprid' and 'Thiamethoxam' and two plant extracts, i.e., neem (Azadirachta indica), and Eucalyptus (Eucalyptus camaldulensis) were tested on the suppression of whitefly. Field screening indicated that none of the tested varieties/lines proved immune/highly resistant, while significant variations were recorded among varieties/lines for resistance level. All varieties/lines were systemically infected with MYMV. The varieties 'AARI-2006' and 'Mung-14043' were considered as resistant to MYMV based on visual symptoms and the lowest vector population. These varieties were followed by 'NM-2006' and 'NL-31', which proved as moderately resistant to MYMV. All remaining varieties/lines were grouped as moderately to highly susceptible to MYMV based on visual symptoms' scoring. These results revealed that existing mungbean germplasm do not possess high resistance level MYMV. However, the lines showing higher resistance in the current study must be exploited in breeding programs for the development of resistant mungbean varieties/lines against MYMV. Imidacloprid proved as the most effective insecticide at all concentrations to manage whitefly population. Therefore, use of the varieties with higher resistance level and spraying Imidacloprid could lower the incidence of MYMV.

In vivo and in vitro management of Meloidogyne incognita (Tylenchida: Heteroderidae) using rhizosphere bacteria, Pseudomonas spp. and Serratia spp. compared with oxamyl

Biological control using rhizosphere bacteria, Pseudomonas spp. and Serratia spp. is a prospective alternative technique to overcome plant parasitic nematodes infection. So, the current study was conducted in vitro on five egg-masses, 100 free eggs and 100 infective juveniles (IJs) of Meloidogyne incognita as well as greenhouse treatments on Luffa aegyptiaca L. to evaluate the nematicidal potential of six strains belong to Pseudomonas spp. and Serratia spp. as compared to oxamyl. Results showed that the inhibitory effect and juvenile mortality varied according to bacteria species, strains and exposure time. All the tested bacteria significantly (P ≤ 0.05) inhibited egg hatching and increased juvenile mortality in vitro. After 3 days of treatment, Pseudomonas spp. were more effective against eggs (48.31to 55.15%) and IJs (20.98 to 25.30%) than Serratia spp. (44.55 to 49.75% with eggs) and (19.06 to 21.61% with IJs), respectively. In the pot experiment, Luffa aegyptiaca L. treated with Serratia spp. and Pseudomonas spp. displayed significantly higher (P ≤ 0.05) levels of growth (as indicated by root length, fresh roots weight and fresh shoots weight) compared to control plants and significantly (P ≤ 0.05) suppressed galling (number of galls) and reproduction (as indicated by number of egg-masses on roots and number of eggs and juveniles in pot soil). Meanwhile, among the treated plants, Serratia spp. and Pseudomonas spp. gave the best results in shoot weight of pots infected by eggs of M. incognita than those infected with IJs as compared with positive control. While, oxamyl treatment gave the best results in pots infected by eggs and IJs. The lowest galling (gall index), number of eggs and juveniles in soil was observed in the treatment with mixture of Serratia spp. and Pseudomonas spp. as well as, enhanced growth of sponge gourd more than application each of them alone. Pots treated with oxamyl overwhelmed those treated with mixture of Serratia spp. and Pseudomonas spp.

Survival and reproduction of Meloidogyne incognita on tomato as affected by humic acid

Abstract

The commercial products humic acid (Actosol®), humic acid (Actosol®) + NPK and humic acid (Actosol®) + micro-elements (Fe, Mn, Cu) were tested against the root-knot nematode, Meloidogyne incognita, in vitro and in vivo on tomato and compared with the nematicide, Vydate. In vitro, Vydate at 2 ml l–1 water was the best treatment for inhibiting hatch (30.8% inhibition) and was significantly more effective than all other treatments, except Vydate at 4 ml l–1. Humic acid + micro-elements (2 ml l–1 water) was the least effective treatment for inhibiting hatch. Humic acid supplemented with micro-elements was significantly better than other products in reducing the number of surviving juveniles and achieving the highest percentage of nematode inhibition (49.2%), followed by the two concentrations of Vydate, which were not significantly different from one another. In vivo, all treatments significantly reduced the numbers of galls, embedded stages in roots, final population and population build-up (Pf/Pi) in all types of soil as compared to the untreated control. Materials appeared to be more effective at preventing nematode penetration of roots in sandy loam soil than in the other two soil types (sandy and clay). The double application of humic acid + NPK gave the best plant growth (fresh and dry weights) in sandy loam soil. All treatments reduced plant content of NPK in sandy soil except for humic acid + micro-elements and the two doses of Vydate.

Interactions of three species of plant-parasitic nematodes with arbuscular mycorrhizal fungus, Glomus macrocarpus, and their effect on grape biochemistry

Abstract

The arbuscular mycorrhizal fungus (AM fungus),Glomus macrocarpus, and the nematodes, Meloidogyne incognita and Tylenchulus semipenetrans, have negative reciprocal effects on spore production, nematode development and reproduction when coinfecting grape roots. Glomus macrocarpus was antagonistic to Rotylenchulus reniformis development and reproduction whilst the nematode was synergistic to spore production. Glomus macrocarpus alone or in combination with M. incognita or T. semipenetrans increased root protein, total soluble sugars, total carbohydrates and decreased lipids and dry matter. Glomus macrocarpus together with R. reniformis decreased protein, total soluble sugars, total carbohydrates and dry matter and greatly increased lipids. Compared to the healthy control, G. macrocarpus alone or in combination with M. incognita or R. reniformis decreased the N, P and K content of leaves. Glomus macrocarpus together with T. semipenetrans improved N, P and K concentrations but the latter was still less than that of healthy plants.