Effects of microwave irradiation by means of a horn antenna in the process of seed extraction on Scots pine (Pinus sylvestris L.) cone moisture content and seed germination energy and capacity

Abstract

The paper presents the results of experiments involving the exposure of Scots pine (Pinus sylvestris L.) cones to microwave radiation. The pine cones were obtained from the Maskulińskie and Brzesko Forest Districts (both in Poland). Pine cone length, thickness, and weight were determined and found to be significantly different between the two locations. Pine cones were exposed to 2.45-GHz microwaves emitted by a horn antenna, which was either fixed or moving at a speed of 0.002 m s -1 over the cones. Total microwave emission time ranged from 30 to 441 s, depending on the test variant. The measured parameters included changes in pine cone moisture content as well as the germination capacity and viability class of the extracted seeds. It was found that pine cone moisture content decreased on average by 0.3 to 6 %, depending on the amount of microwave radiation applied. It was found that pine cone size, the amount of microwave radiation, and the distance between the cones and the horn antenna affected seed germination and viability class. In most experimental variants, the seeds were damaged by microwaves. Viable seeds (classes I and II) were obtained after 30 s of exposure to microwave radiation from a fixed horn antenna positioned at a distance of 0.04 m over the cones. The application of a moving antenna positioned 0.14 m over the cones resulted in seeds of viability classes II and III following a single microwave sweep over the seeds.

Salt-tolerant and plant-growth-promoting bacteria isolated from high-yield paddy soil

“…Germination energy reflects the rate at which this process occurs and is given as the proportion of seeds which germinate half-way into the expected germination period. Germination capacity is the proportion of planted seeds which form normal sprouts at the maximum time needed for all viable seeds to germinate (Aniszewska and Słowiński, 2016) The experiment was repeated three times.. The measured parameters included the following:…”

The effectiveness of short-term microwave irradiation on the process of seed extraction from Scots pine cones (Pinus sylvestris L.)

“…The increased seed extraction heat in cones exposed to microwaves was associated with the fact that their temperature surged in the first extraction step. Aniszewska (2016) reported that cone temperature rose to 52°C after 5 s of microwave irradiation and to almost 100 °C after 15 s. Aniszewska & Slowinski (2016) and Rukuni (1997) reported that cone exposure to 800 W microwave irradiation for up to 30 s did not compromise seed viability. The former authors irradiated cones placed one next to another on a tray, with the irradiation distributed across all cones.…”

“…The effects of microwave irradiation on Pinus sylvestris cones were described by Aniszewska & Slowinski (2016), who determined safe cone exposure time in terms of ensuring seed quality. Furthermore, Aniszewska (2016) investigated surface temperature changes in cones exposed to microwaves for different periods.…”

The Kinematics of Scale Deflection in the Course of Multi-Step Seed Extraction from European Larch Cones (Larix decidua Mill.) Taking into Account Their Cellular Structure

“…In Poland, seeds from larch cones are extracted using pine and spruce extraction programs in seed extraction cabinets using two-step extraction programs with variable drying temperature [ 26 ] to prevent thermal damage to the seeds [ 1 ]. Researchers seek new devices and technological solutions to make the process more effective, for example, by microwave irradiation of cones in the initial stage of seed extraction [ 27 , 28 ].…”