Effects of Aluminium Toxicity on Root and Shoot Growth Of Rice and Chickpea Seedlings

Increasing concentrations of aluminium progressively declined primary root length and number of lateral roots in rice and chickpea seedlings grown in rhizobox. It also inhibited the root and shoot length, dry weight of root and shoot of rice and chickpea seedlings grown in solution culture. On the other hand, it enhanced shoot/root length ratio and dry weight ratio for both the genera. Bangladesh J. Bot. 50(4): 1195-1201, 2021 (December)

IMPROVEMENT OF HYDROPON INSTALLATIONS

Hydroponics is a promising area of development of modern agriculture, which provides long-term cultivation of basic vegetables and greenery in small areas with minimal consumption of water and fertilizers. This technology allows you to get a fairly large harvest of fresh vegetables within large cities, including office and residential premises. Entrepreneurs and researchers are paying close attention to developing more efficient hydroponics methods and equipment to implement them in order to reduce usable space, save water, nutrients and increase air supply and plant capacity. Several hydroponics systems are known: static solution culture, continuous flow solution (NFT) culture, deep water culture, passive irrigation, underwater and drainage irrigation systems, wastewater drainage system, deep-water fertilized culture, rotary system, aeroponics, wick system. The first three of the above methods were used commercially and industrially. The system of static culture solution does not provide the necessary saturation of plant roots with air. With the implementation of the method of continuous solution culture, minor buffering is possible due to interruptions in the flow (power outage), flooding of water in some canals, in addition, there are restrictions on the maximum length of canals (12 - 15 m). The system of deep-water culture on an industrial scale is used mainly for growing lettuce. Other mentioned systems are not efficient enough in terms of commercial use. The improved hydroponic installations presented in the article were developed taking into account the following requirements: universality of use (possibility of growing different types of plants); harmonization of optimal supply of crops with water, nutrients, light and air; maximum use of space; increasing the area for each plant and maintaining its stems and shoots. Also in the article the equation for definition of the basic parameters of the developed installations is given.

An improved technique for isolation and characterization of single-spore isolates of Plasmodiophora brassicae

Clubroot, caused by Plasmodiophora brassicae, is a soil-borne disease that occurs in cruciferous crops worldwide. P. brassicae usually exists as a mixture of several pathotypes, which has hampered the research on resistance mechanisms of cruciferous crops against P. brassicae. In this study, clubroot galls were collected from a field in Shenyang, China, as a pathogen source to develop an efficient protocol for a single-spore isolation system of P. brassicae by optimizing the seedling age for inoculation, host inoculation method, and plant culture method. The operational steps of the single-spore isolation method were optimized as follows: the use of two-day-old seedlings for inoculation, substituting a cryobox (100 × 2.0 mL vials) for culture dishes, the addition of nutrient solution culture, and microscopic observations of single spores. The rate of infection success was substantially improved, and single-spore isolates of four pathotypes: 4, 8, 9, and 11, were acquired in this system. Subsequently, the optimized system was used to isolate and characterize the pathotypes of single-spore isolates of P. brassicae collected from five fields in regions in China. Approximately 4 to 9 pathotypes were isolated from each region. Among these, pathotype 4 was the most prevalent. This study provides a source of valuable information that can eventually be used for the genetic analysis of host–P. brassicae interaction.

ELABORATION OF IMPROVED HYDROPONIC INSTALLATIONS

Hydroponics is a perspective direction of development of modern agriculture that provides perennial growing of main species of vegetables and greenery on small areas and with minimal expenses of water and fertilizers. This technology allows to get large enough harvests of fresh vegetables in big cities including office and living premises. Last time entrepreneurs and inventors pay a lot of attention for elaboration of more effective methods of hydroponics and equipment for their realization in direction of decrease of using areas, economy of water, nutrients and increase of air supply and plants capacity. There are several known methods of hydroponics: static solution culture, continuous-flow solution culture (NFT), deep water culture, passive sub-irrigation, flood and drain sub-irrigation, run-to-waste system, top-fed deep water culture, rotary system, aeroponics, fogponics. Commercial and industrial use got the first three from above mentioned methods. Herewith the method of static solution culture does not provide of necessary saturation of plant’s roots with air. Under realization of the method of continuous-flow solution culture are possible little buffering against interruptions in the flow (power outages), water logging in some channels, besides there are limitations for maximal length of channels (12 – 15 m). The method of deep water culture in industrial scales is used mainly for growing of lettuce. The other mentioned methods are not enough effective from point of view of commercial utilization. The improved hydroponic installations, presented in the article, were elaborated with consideration of such demands: versatility of use (a possibility of growing of various species of plants); harmonies optimal provision of crops with water, nutrients, light and air; maximal use of premise’s space; a possibility of re-space during of the growth period, increase of area for each plant and support of its stalk and sprouts. Also, the formulas for definition of main parameters of the elaborated installations are presented in the article.

Soilless culture systems.

Soilless cultivation involves growing plants in containers, beds, trays, chambers or channels of a liquid or solid soilless medium. Soilless culture encompasses a wide range of horticultural production methods. These range from potted nursery crops in solid substrates or drip-irrigated greenhouse vegetable crops, to water culture methods. The latter is true 'hydroponics'. In modern times, hydroponics has become the term used to cover many forms of soilless production, both where a solid medium is used to support the plant and where only solution culture is employed.

Impact of saline solution on growth and photosystem II during in vitro cultivation of Bromelia antiacantha (Bromeliaceae)

In vitro cultivation is a technique with wide application for micropropagation. However, each species has specific mineral needs for this type of cultivation. The objective was to assess the impacts of the saline solution culture medium on the performance of the photosynthetic apparatus and growth of Bromelia antiacantha during in vitro cultivation, and thus to elucidate the mitigation of the nutritional imbalance that can interfere in the electron transport in the plants. Plants were cultivated in a salt concentration gradient of MS medium (0%, 25%, 50%, 75% or 100%). The growth traits and fluorescence a chlorophyll were analyzed. Intermediate concentrations of MS medium resulted in plants with a larger number of leaves and longer root length. The OJIP curves and results of the JIP test showed that the plants grown without MS salts presented less efficient photosystem II (PSII), as indicated by the performance index [Pi(total)]. In contrast, the intermediate concentrations (MS 25% and 50%) had a positive effect on the performance of the photosynthetic apparatus. The MS 25% medium can be used for in vitro cultivation of B. antiacantha, enabling the development of plants with suitable physiological qualities for planting in the field.

Hydroponics and protected cultivation: a practical guide

This book contains 14 chapters. It is a practical guide about hydroponics and protected cultivation. Topics covered include: background and history of hydroponics and protected cultivation; greenhouses and protected cropping structures; greenhouse operation and management; hydroponic systems - solution culture; substrate-based hydroponic systems; organic soilless greenhouse systems; propagation and transplant production; plant nutrition and nutrient formulation; plant Health, plant protection and abiotic factors; hydroponic production of selected crops; plant factories - closed plant production systems; greenhouse produce quality and assessment; and harvest and postharvest factors.

Hydroponic System - Solution Culture.

This paper discusses about the solution culture or 'hydroculture' systems, which are methods of crop production which do not employ the use of substrates to contain the root system and hold moisture between irrigations. It includes NFT or the nutrient film technique, deep water culture/deep flow technique - float, raft or pond systems, aeroponics, aquaponics, organic solution culture, hydroponic fodder systems, and automation for solution culture systems.