Capsicum annuum L. is a significant horticulture crop known for its pungent varieties and used as a spice. The pungent character in the plant, known as capsaicinoid, has been discovered to have various health benefits. However, its production has been affected due to various exogenous stresses, including diseases caused by a soil-borne pathogen, Pythium spp. predominantly affecting the Capsicum plant in younger stages and causing damping-off, this pathogen can incite root rot in later plant growth stages. Due to the involvement of multiple Pythium spp. and their capability to disperse through various routes, their detection and diagnosis have become crucial. However, the quest for a point-of-care technology is still far from over. The use of an integrated approach with cultural and biological techniques for the management of Pythium spp. can be the best and most sustainable alternative to the traditionally used and hazardous chemical approach. The lack of race-specific resistance genes against Pythium spp. can be compensated with the candidate quantitative trait loci (QTL) genes in C. annuum L. This review will focus on the epidemiological factors playing a major role in disease spread, the currently available diagnostics in species identification, and the management strategies with a special emphasis on Pythium spp. causing damping-off and root rot in different cultivars of C. annuum L.
Drought is a major abiotic factor limiting plant growth and crop production. There is limited information on effect of interaction between biochar and Arbuscular mycorrhizal fungi (AMF) on okra growth, root morphological traits and soil enzyme activities under drought stress. We studied the influence of biochar and AMF on the growth of Okra (Abelmoschus esculentus) in pot experiments in a net house under drought condition. The results showed that the biochar treatment significantly increased plant growth (the plant height by 14.2%, root dry weight by 30.0%) and root morphological traits (projected area by 22.3% and root diameter by 22.7%) under drought stress. In drought stress, biochar treatment significantly enhanced the chlorophyll 'a' content by 32.7%, the AMF spore number by 22.8% and the microbial biomass as compared to the control. Plant growth parameters such as plant height, shoot and root dry weights significantly increased by AMF alone, by 16.6%, 21.0% and 40.0% respectively under drought condition. Other plant biometrics viz: the total root length, the root volume, the projected area and root diameter improved significantly with the application of AMF alone by 38.3%, 60.0%,16.8% and 15.9% respectively as compared with control. Compared to the control, AMF treatment alone significantly enhanced the total chlorophyll content by 36.6%, the AMF spore number by 39.0% and the microbial biomass by 29.0% under drought condition. However, the highest values of plant growth parameters (plant height, shoot dry weight, root dry weight) and root morphological traits (the total root length, root volume, projected area, root surface area) were observed in the combined treatment of biochar and AMF treatment viz: 31.9%, 34.2%, 60.0% and 68.6%, 66.6%, 45.5%, 41.8%, respectively compared to the control under drought stress. The nitrogen content, total chlorophyll content and microbial biomass increased over un-inoculated control. The soil enzymes; alkaline phosphatase, dehydrogenase and fluorescein diacetate enzyme activities significantly increased in the combined treatment by 55.8%, 68.7% and 69.5%, respectively as compared to the control under drought stress. We conclude that biochar and AMF together is potentially beneficial for cultivation of okra in drought stress conditions.
Organic residues are an important factor that directly affects fruiting tree seedlings' health at earlier stages. It provides a suitable environment for seedling growth by providing better nutrient ions, water, and aeration. However, low organic contents and high shrinkage of most organic materials mostly deteriorate ideal potting media characteristics. Low aeration, high water, and nutrients leaching decrease seedling growth and cause a significant loss of valuable resources. That is why the current study was conducted to screen out the best indigenous materials based on particle size to produce good characteristics bearing potting media. For that, eight different ingredients, i.e., "sugarcane", "coconut coir", "wheat straw", "rice straw", "corn cob", "leaf litter", "farmyard manure", and "sunflower heads" were collected. Initially, all the materials were air-dried and processes as per requirement. After grinding, three particles size (fine = < 2 mm, medium = 3 mm and coarse = 5 mm) were separated by sieving. Results showed that decreasing particle size in "rice straw", "corn cob", "farmyard manure," and "sunflower head" decreased leachate pH. Higher EC in leachates was negatively correlated with particle size in all potting media ingredients. Except for farmyard manure, fine particle size increases the water-holding ability of potting media ingredients. However, air-filled porosity was associated with a decrease in particle size of potting media in gradients. In conclusion, farmyard manure, "sunflower heads", "leaf litter" and "sugarcane" should be incorporated while making a combination for potting media. More investigations are suggested by mixing different particle size ingredients to prepare potting media.