Techniques for studying the effects of various cropping systems on the germination of buried weed seeds

Graduation date: 1975The study of the effects of cropping systems on buried weed\ud seed is very costly. Most of the experiments of this nature were\ud conducted prior to the introduction of herbicides. New techniques,\ud material and methods are needed and could result in more research\ud in this area of study.\ud A polyester material was experimented with which provided a\ud means for mechanically washing buried weed seed packets. This was\ud accomplished through the development of an experimental seed\ud packet washer. The washer and the polyester material made it\ud possible to wash the soil from delicate seedlings growing inside\ud the packets without damage to them. They in turn could be examined\ud without removal from the seed packets making the procedure many\ud times more economical.\ud A seed removal technique was also developed which worked well\ud in separating weed seed from mineral soil samples. This was\ud accomplished by making slight modifications in the experimental seed packet washer regarding screening,.slope, water volume and\ud the usage of various sizes of soil sieves.\ud An economical bioassay method for studying the effects of crop\ud leachates on red sorrel and rice germination and growth was also\ud developed while simultaneously testing cropping system effects on\ud buried weed seed in the greenhouse and field. This method and technique\ud holds promise for other types of plant experiments involving\ud liquid and culture media.\ud Thirty-seven monoculture cropping systems were tested in the\ud greenhouse and fourteen in the field for their effects on nine\ud different buried weed seed species. Evidence is provided to show\ud that broccoli, beans, asparagus, quackgrass, tomatoes and other\ud plants fray be inhibitory to the subsequent germination and viability\ud of the buried seed of Rumex acetosella L., Rumex crispus L.,\ud Brassica campestris L. and Amaranthus retroflexus L