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.

Screening of Lentil Genotypes against Highly Aggressive Strain of Fusarium oxysporum f. sp. lentis

Lentil is one of the most nutritious pulse crops known as masur and grown as a rainfed crop throughout the world in winter season. It is rich in protein, starch, micronutrients and dietary fiber. In the global scenario, India ranked first in the area and second in the production with Bihar being one the major lentil growing state. The majority of the lentil crop is grown in Tal area of the state. As it is cultivated as a rainfed crop, it gets severely affected by several biotic and abiotic stresses. Among the biotic stresses, Fusaium wilt, caused by Fusarium oxysporum f. sp. lentis (Fol) is one of the major fungal diseases and remarkably causing severe crop damage from vegetative to reproductive stage producing significant yield reduction. Fol isolate exhibit great variability and aggressiveness based on agro- climatic conditions. AGLF-11 isolate of Fol collected from Tal area of Bihar was found to be highly aggressive based on previous studies. For this, 50 diverse genotypes were screened against this isolate under greenhouse condition, out of which 14 genotypes showed high susceptibility, 29 genotypes showed moderate susceptibility, 5 genotypes exhibited moderately resistance and only 2 genotypes (L 7920 and DPL 58) exhibited resistance reaction.

Style length and flower morphology of three eggplant (Solanum melongena L.) cultivars from Iran affected by fruit load

<p>A common feature of eggplant is its heterostyly. Long-style flowers bear fruits whereas short style ones fail to do so. Heterostyly is influenced by some factors such as genotype, climatic conditions and fruit load. In this study three eggplant cultivars from Iran were cultivated under greenhouse condition. The influence of presence of fruit (two fruits and four fruits) or absence of that on style length and some other flower morphological was studied in three positions of single, basal and additional. The presence of fruit, specially four fruits reduced style length, stigma width as well as mass of flower, pistil and stigma compared to the control in all times during fruit growth, and after fruit harvest they increased again. Fruit load didn’t affect the number of stamen and stamen length. These effects were observed in all three positons of single, basal and additional flowers of all three cultivars. Generally this study showed that fruit load has decreasing effect on style length and size of flowers forming after fruit setting, which reversed after fruit harvesting.</p>

Effect of Different Hormones on Disease Resistance against Bacterial Blight in Pomegranate

Bacterial blight in pomegranate is a major disease caused by Xanthomonas axonopodis pv. punicae, which has resulted in significant economic losses in terms of both quality and quantity. The ineffectiveness of most chemicals in controlling this disease has shifted grower attention to the quest for a new molecule and hence the use of plant growth regulators and signaling molecules is a novel approach to control the disease as well as improving quality and quantity attributes of pomegranate. Hence, the aim of present study was to determine the impact of plant hormones like ethylene, jasmonic acid and salicylic acid on bacterial blight of pomegranate. Among different hormones applied, ethrel application shown maximum disease severity (33.2%) and salicylic acid shown lowest disease severity (15.08%) under greenhouse condition.

Effect of Salicylic Acid in the Yield of Ricinine in Ricinus communis under Greenhouse Condition

Castor bean (Ricinus communis) seeds contain ricinine, an alkaloid with insecticidal and insectistatic activities. Elicitation with salicylic acid (SA) has proven to stress R. communis and might modify the ricinine concentration. The aim of this study was to evaluate the concentration of ricinine in the bagasse of seeds from R. communis elicited with exogenous SA under greenhouse conditions. Plants were grown and divided into five groups, which were sprayed with SA and drench with 50 mL 60 days after sowing with concentrations of SA (0, 100, 300, 600 and 900 µM). Clusters were mixed and separated according to the treatment, and dried. The seeds were ground, the oil was extracted by Soxhlet with hexane, and then the bagasse was extracted with methanol. Ricinine was determined by HPLC. Elicitation did not change the plant height or diameter; the control group had 9.17 µg mL−1 of ricinine; and the concentrations followed a hormesis curve with the peak at 300 µM of SA that had a ricinine concentration of 18.25 µg mL−1. Elicitation with SA might be a cost-effective technique to increase ricinine from R. communis bagasse.

Effect of Salicylic AcidFormulations on Induced Plant Defense against Cassava Anthracnose Disease

This study was to investigate defense mechanisms on cassava induced by salicylic acid formulation (SA) against anthracnose disease. Our results indicated that the SA could reduce anthracnose severity in cassava plants up to 33.3% under the greenhouse condition. The β-1,3-glucanase and chitinase enzyme activities were significantly increased at 24 hours after inoculation (HAI) and decrease at 48 HAI after Colletotrichum gloeosporioides challenge inoculation, respectively, for cassava treated with SA formulation. Synchrotron radiation–based Fourier-transform infrared microspectroscopy spectra revealed changes of the C=H stretching vibration (3,000-2,800 cm−1), pectin (1,740-1,700 cm−1), amide I protein (1,700-1,600 cm−1), amide II protein (1,600-1,500 cm−1), lignin (1,515 cm−1) as well as mainly C–O–C of polysaccharides (1,300-1,100 cm−1) in the leaf epidermal and mesophyll tissues treated with SA formulations, compared to those treated with fungicide carbendazim and distilled water after the challenged inoculation with C. gloeosporioides. The results indicate that biochemical changes in cassava leaf treated with SA played an important role in the enhancement of structural and chemical defense mechanisms leading to reduced anthracnose severity.

LED light sources improved the essential oil components and antioxidant activity of two genotypes of lemon balm (Melissa officinalis L.)

Background Nowadays, light-emitting diodes (LEDs) as a new lighting technology, have been emerged as an alternative source of light for plants due to their wavelength specificity, the narrow width of their bands, small size, solid structure, long lifetime, and low heat generation. Here we investigated the effect of different LED light sources on the essential oil components and antioxidant activity of Melissa officinalis. Two genotypes of lemon balm (Ilam and Isfahan) were subjected to four artificial light treatments, including white, red, blue, red + blue LEDs, and greenhouse light as natural lighting. Results The LED lights significantly increased shoot fresh and dry weights and leaf number in the two genotypes as compared to greenhouse condition. The results showed that the content and composition of essential oil in the two genotypes were variable under different light treatments and the total amount of compounds in the Ilam genotype was higher than the other genotype. The results of analysis of the essential oil by GC/MS indicated that the highest amount of monoterpenes in the genotypes was related to citronellal under red + blue LED lamps (15.3 and 17.2% in Ilam and Isfahan genotypes, respectively) but blue, white, and greenhouse condition had the most effect on sesquiterpenes content in both genotypes. The results showed that the observed variation between the two genotypes in the essentials oil composition was related to the relative percentage of the constituents and not to the appearance or lack of a specific component. Red + blue lighting also provided the highest radical scavenging activity in both genotypes (80.77 and 82.09% for Ilam and Isfahan genotypes, respectively). Based on principal component analyses (PCA), three main groups were identified regarding genotypes and all light treatments. Conclusions Overall, results indicated that the essentials oil composition of two genotypes of lemon balm was affected both qualitatively and quantitatively by different LED light sources; hence, LED lights might be used to improve monoterpenes, sesquiterpenes, and antioxidant activity in the selected genotypes.