Biocontrol of Anthracnose Disease on Chili Pepper Using a Formulation Containing Paenibacillus polymyxa C1

Anthracnose disease on chili pepper has been known to seriously interfere with the plant growth and obviously reduce the yield. The disease is caused by Colletotrichum spp. In Bali, Indonesia, six species of Colletotrichum have been identified: Colletotrichum scovillei, C. acutatum, C. nymphaeae, C. gloeosporioides, C. truncatum, and C. fructicola. However, among them the C. scovillei was found to be the most prevalent cause of anthracnose on chili pepper in Bali. Two species of antagonist against C. scovillei, namely Paenibacillus polymyxa C1 and Bacillus siamensis C7B, have been identified. In this study the effectiveness of P. polymyxa C1 formulation was evaluated under greenhouse condition on chili pepper cultivars Cabe Besar. Application of formulation was conducted by a mini hand sprayer once to five times with a week interval. Results of the study showed that treatment with five applications significantly (p < 0.05) reduced the disease incidence, disease intensity, and the yield loss of chili pepper cultivar Cabe Besar. Alose relationship was observed between the number of applications with disease intensity, with coefficient of determination (R2) at 0.929. These results revealed that the formulation of P. polymyxa C1 effectively control the anthracnose disease on chili pepper, particularly on chili pepper cultivar Cabe Besar, and thus can be recommended for field testing to confirm its stability under field conditions.

Heat-tolerant pepper cultivar exhibits high rates of chlorophyll, photosynthesis, stomatal conductance and transpiration in heat stress regime at fruit developing stage

Relevance. Abiotic stress, as heat, significantly affect plant and floral organs growth and development, fruit set, productivity, the quality, and survival of crops. Heat injury occurs when plants are exposed to these temperatures for a long period of time. Depending on the intensity and duration of exposure to the high temperatures, photosynthesis, respiration, membrane integrity, water relations and the hormone balance of the plants may affected.Material and methods. In this study used the commercial pepper cultivar “NW Bigarim” (HT37) released in South Korea and accessions “Kobra” (HT1) and “Samchukjaere” (HT7) selected as heat tolerant and susceptible, respectively. Total chlorophyll index and photosynthetic activities measured using a SPAD meter (Konica, Japan) and portable photosynthesis measurement system (LI-6400, LI-COR Bioscience, Lincoln, NE, USA), respectively.Results. To evaluate the positive effects of high temperature regime (40/28°C day/night, 14/10-h light/dark cycle) on the response of photosynthetic parameters in pepper plants with different heat susceptibility, we measured the total chlorophyll content (CHL) and photosynthetic activities such as photosynthesis (Pn), stomatal conductance to H2O (Gs) and transpiration rate (Tr) in a heat-tolerant (HT1) and -susceptible cultivars (HT7) in comparison with released cultivar (HT37) at fruit development stage. Heat-tolerant cultivars showed higher and more stable index of the CHL, Pn, Gs and Tr than those in heat-sensitive cultivars for 14 days of heat treatment (HT) period. However, the initial index of Pn, Gs and Tr showed significant alteration among pepper plants regardless of thermotolerance rate before HT on day 0 and day 7 after recovery at normal treatment condition (NT) except for CHL, meaning that plants response to high temperature regime is different from that in normal condition. These results suggest that constant high rates of Pn, Gs and Tr as well as of CHL in heat stress condition periods confer to avoid from heat injury during reproductive growth stages.

Suitability of Ornamental Pepper Cultivars as Banker Plants for the Establishment of Predatory Mite Amblyseius swirskii in Controlled Production

A banker plant system is a rearing and release method for biological control agents, and in recent years has gained serious attention among plant propagators for its use in regulating common greenhouse and nursery pests. In the current study, the suitability of four ornamental pepper (Capsicum annuum L.; Solanales: Solanaceae) banker plant candidates, Black Pearl (BP), Explosive Ember (EE), Masquerade (MA), Red Missile (RM), and a commercial pepper cultivar, Blitz (BL), were evaluated with three main objectives: (1) to assess host preference of three major arthropod pests of agricultural importance, Bemisia tabaci Gennadius, Polyphagotarsonemus latus Banks, and Frankliniella occidentalis Pergande among selected pepper cultivars; (2) to determine the susceptibility of plant cultivars to three different pests; and (3) to assess the effect of tuft domatia on the abundance of the predatory mite Amblyseius swirskii Athias–Henriot. In choice and no-choice assays, BL and BP were highly susceptible to P. latus with a moderately high damage rating index of >3.5/5; B. tabaci and F. occidentalis were abundant on BL and EE. A positive correlation was observed between the number of tuft domatia and the A. swirskii count. Although all ornamental pepper cultivars exhibited varying degrees of susceptibility to different arthropod pests, if used strategically, cultivars MA and RM can be used to develop a banker plant system and help reduce multiple pests in greenhouses or interiorscapes.

The developmental and metabolic effects of different magnesium dozes in pepper plants under salt stress

Morphological and biochemical effects of different magnesium (Mg) doses on pepper plants under salt stress were investigated in this study. Experiments were conducted under controlled conditions of a climate cabin at 25 oC temperature, 70% relative humidity and 16/8 hours light/dark photoperiod. The developmental and metabolic effects of different magnesium doses in plants under salt stress were investigated by examining leaf antioxidant enzyme activities, Malondialdehyde (MDA) levels and chlorophyll contents. Seedlings of ‘Demre’ pepper cultivar (Capsicum annuum L. cv. ‘Demre’) were grown in Hoagland nutrient solution supplemented with 100 mM NaCl to generate salt stress. Besides salt treatments, different Mg doses (Mg 1 = 24.64 ppm, Mg 2 = 49.28 ppm, Mg 3 = 73.92 ppm, Mg 4 = 98.56 ppm, Mg 5 = 123.20 ppm) were applied to plants. On the 20th day of salt treatments, the total weight of the plants which is one of the growths and development parameters of pepper plants was measured, and plant samples were taken for analyses. A slight increase was observed in total weights of salt-treated plants with increasing Mg doses. The greatest plant weight was obtained from Mg 4 + salt treatments. It was observed that increasing Mg doses had positive effects on the development of plants under salt stress. Chlorophyll contents and antioxidant enzymes activities increased and MDA (malondialdehyde) levels, the product of lipid peroxidation, which indicates the amount of damage to plant cells, decreased with increasing Mg doses. Present measurements and analyses and resultant findings revealed that Mg treatments at increasing doses partially alleviated negative effects of salt stress on pepper seedlings.

The Amelioration of Post Tin Mining Sand Tailing Medium with Chicken Manure for Pepper Cultivation

Inonu I, Kusmiadi R, Yuliana A, Nurtjahya E. 2020. The amelioration of post tin mining sand tailing medium with chicken manure for pepper cultivation. Jurnal Lahan Suboptimal: Journal of Suboptimal Lands 9(1): 31-40. Pepper cultivation in tin mining sand tailings requires the amelioration of organic matter to improve soil characteristics. The paper investigates the effect of chicken manure dosage on the growth of three pepper cultivars in sand tailing medium. This study was conducted on April-August 2016 at Experiment Station of Universitas Bangka Belitung, Balunijuk Village, Bangka Island. This study was arranged in a completely randomized design with two factors and three replications. The first factor was the dosage of chicken manure (5 kg; 6 kg; 7 kg/plant). The second factor was pepper cultivars (Lampung Daun Lebar; Lampung Daun Kecil; Merapin). The. result of the analysis of variance showed that the treatment of chicken manure dosage significantly affected only on total leaf area. The treatment of pepper cultivars significantly affected the total of chlorophyll, root dry weight, and shoot dry weight. There was no interaction between chicken manure dosage and pepper cultivar. Pepper cv. Lampung Daun Lebar tends to grow better than the other cultivars in the sand tailing medium.

Use of an Infectious cDNA Clone of Pepper Veinal Mottle Virus to Confirm the Etiology of a Disease in Capsicum chinense

The pepper cultivar Yellow Lantern, one of the spiciest pepper varieties, is a local germplasm of Capsicum chinense, cultivated exclusively on Hainan Island, China. However, this variety is susceptible to viral diseases that severely affect its production. In this study, we report that pepper veinal mottle virus (PVMV) is associated with foliar chlorosis and rugosity symptoms in Yellow Lantern. To verify this correlation, we constructed a full-length cDNA clone of a PVMV isolate named HNu. The virus progeny derived from the cDNA clone replicated and moved systemically in the pepper, inducing the same symptoms as those induced by PVMV-HNu in Yellow Lantern peppers in the field. The results support that PVMV-HNu is the causal agent of foliar chlorosis and rugosity disease in Yellow Lantern. This knowledge will help in the diagnosis and prevention of disease caused by PVMV. Furthermore, the cDNA clone serves as a reverse genetic tool to study the molecular pathogenesis of PVMV.

Effect of aboveground plant conditioner treatment on arbuscular mycorrhizal colonization of tomato and pepper

We aimed to test the hypothesis that treatment with an aboveground plant conditioner has an effect on important vegetable crops inoculated with arbuscular mycorrhizal fungi (AMF) and on their colonization by AMF. Potting experiments were set with pepper and tomato plants inoculated with commercial AMF inoculum and plants were treated with an aboveground plant conditioner. After harvesting, the dry weight of shoots and roots were measured, and the AMF colonization of the roots was quantified. We found a significant effect of the treatment on fungal colonization: the AMF colonization, the hyphal colonization rate and the frequency of the arbuscules in the roots of both vegetables were lower when aboveground plant conditioner was applied. Although the two species differed, no significant effect of the treatment on the growth of the plants was detected. Based on our findings we assumed that the lower AMF colonization more greatly influenced the growth of the pepper cultivar studied. We demonstrated that treatment with a commercial aboveground plant conditioner had an antagonistic effect on AMF colonization, which, in addition to many other effects, might influence the growth vegetable crops. The interaction of different practices applied simultaneously should be tested to effectively help the development suitable agriculture systems.