Interseeding To Enhance Vegetable Crop Seedling Emergence Through Crusted Soils And The Emergence Force Of Crops

The predictive values of standard and non-standard germination temperatures, standard accelerated ageing (AA) and saturated salt accelerated ageing (SSAA) tests were investigated. Germination tests were performed at standard and non-standard temperatures of 10??, 20??, 20??/30?? and 30ʻC for cabbage and tomato, and 10??, 15??, 20?? and 30ʻC for onion. The AA and SSAA tests were conducted using four relative humidities: standard AA (RH100), NaCl (RH75), Ca(NO3)2 (RH43) and MgCl2 (RH32). Emergence trials were also conducted at a range of temperatures (winter, 15??/25?? and 30ʻC) and media (Hygromix and soil) using seedling trays. Correlations were calculated to evaluate the relationship between laboratory and emergence test results. Three onion seed lots that have different vigour levels were primed with PEG or NaCl and were germinated and planted under varying temperatures and levels of salinity. There were vigour differences among different seed lots of cabbage, onion and tomato seeds used in this study. Using the different laboratory tests, seed lots were distinguished as high, medium and low vigour seed lots. The low temperature germination test (10ʻC) for cabbage and onion: and 20ʻC for tomato were found to be effective for separation of seed lots according to their vigour levels. All SSAA vigour tests were also useful in differentiating seed lots based on their physiological stage of deterioration. Using the standard AA (RH100) the seed moisture content was high (29 to 45%), resulting in fungal growth. However, in the SSAA test the moisture content was below 14% and no fungal growth was observed. Ageing of seed lots using NaCl and MgCl2 resulted in a low narrow range of moisture contents, but using Ca (NO3)2 the range of the moisture content between seed lots was higher. For all crop seeds, there was no significant difference in the percentage emergence between the two growth media but larger seedlings were observed from the commercial growth medium (Hygromix). For cabbage, highly significant correlations were obtained between germination percentage at 10ʻC and RH32 and all emergence trials. In onion, the correlations were not consistent: highly significant correlations were observed from germination capacity (GC), 15ʻC, 20ʻC, 30ʻC, RH75 and RH32: and emergence parameters at specific conditions. However, the germination percentage from 30ʻC correlated significantly with the final emergence percentage and seedling vigour index. Germination of tomato seeds at 20ʻC and all SSAA had highly significant correlation with all emergence parameters. The germination rate parameters: MGT (mean germination time) and GI (germination index) were valuable in categorising seed lots with moderate vigour levels, however, except GE in cabbage and onion, all other germination rate characters failed to correlate with any emergence parameters. The radicle percentage germination (viability or GC) and final emergence percentage (FEP) were not enhanced by priming in all seed lots in the germination and emergence trials at all temperatures. The percentage of normal seedling was increased due to priming when seeds were subjected to low temperature and higher salinity levels. Priming was effective in improving the rate, uniformity of germination/emergence: and increased the seedling dry mass of onion seeds when grown under relatively cold environmental conditions. Priming was more beneficial for low vigour seed lots (seed lot A) than for high vigour seed lots (B, C). Priming also improved germination rate and uniformity at all salinity levels, but faster rate of emergence, more uniform and higher seedling dry mass were only observed when seeds were watered with low salinity levels (25 mM of NaCl). No significant difference was observed using NaCl or PEG as priming agent. Onion seeds are tolerant to salinity during germination and the effect of priming was more beneficial at emergence.

This book introduces readers to both seed treatment and seedling pretreatments, taking into account various factors such as plant age, growing conditions and climate. Reflecting recent advances in seed priming and pretreatment techniques, it demonstrates how these approaches can be used to improve stress tolerance and enhance crop productivity. Covering the basic phenomena involved, mechanisms and recent innovations, the book offers a comprehensive guide for students, researchers and scientists alike, particularly Plant Physiologists, Agronomists, Environmental Scientists, Biotechnologists, and Botanists, who will find essential information on physiology and stress tolerance. The book also provides a valuable source of information for professionals at seed companies, seed technologists, food scientists, policymakers, and agricultural development officers around the world.

Cover crops slow erosion, improve soil, smother weeds, enhance nutrient and moisture availability, help control many pests and bring a host of other benefits to your farm. At the same time, they can reduce costs, increase profits and even create new sources of income. You¿ll reap dividends on your cover crop investments for years, since their benefits accumulate over the long term. This book will help you find which ones are right for you. Captures farmer and other research results from the past ten years. The authors verified the info. from the 2nd ed., added new results and updated farmer profiles and research data, and added 2 chap. Includes maps and charts, detailed narratives about individual cover crop species, and chap. about aspects of cover cropping.