Effect Of Water Stress And Summer Pruning On Flower Bud Differentiation Of Grapes

In order to prove the relationship of soil relative water content and flower bud differentiation of red globe and other grape, this experiment using red globe and summer black seedless as test material, studied the influence of water stress on flower bud differentiation and the change of physiological indicators in leaves of red globe by the water stress, the influence of flower bud formation and fruit quality of red globe and summer black seedless by different summer pruning, and made paraffin section of flower buds of red globe to observed the process of flower bud differentiation. The main results were as follows:1、Mild water stress, soil relative water content is50%to60%, is help for flower bud formation of young red globe. Moderate water stress, soil relative water content is40%, inhibit flower bud formation. Under severe water stress, soil relative water content is20%to30%, flower bud formation will be suppressed severely and hardly can form flower buds. In addition, the affect of water stress on mature red globe and young red globe is basic same. However, the mature red globe grapes still have a little ability of flower bud formation under severe water stress.2、On different degree of water stress, red globe leaves accumulated large amounts of proline and soluble sugar. The longer the stress time extend and the more serious stress level exacerbate, the higher the cumulative content increase. Howerver, leaf soluble protein content decreased, and declining with the increased stress level.3%Under the premise of leaving five sections at the top axillary shoot, when fruit branches of red globe of inflorescence are above to leave six sections to remove the topping, axillary shoot leaving four leaves, the flower bud differentiation is best. When nutrition branches of red globe of axillary shoot leaving two leaves, main shoot to leave eight sections to remove the topping,the flower bud differentiation is best.When fruit branches of summer black seedless of inflorescence are above to leave six sections to remove the topping,do not leaving axillary shoot,the flower bud differentiation is best. When nutrition branches of summer black seedless of axillary shoot leaving one leaf, main shoot to leave five sections to remove the topping,the flower bud differentiation is best.4、Combined with the fruit quality and flower bud differentiation, the research shows that under the premise of leaving five sections at the top axillary shoot, when fruit branches of red globe grape inflorescence are above to leave eight sections to remove the topping and axillary shoot of leaving two leaves, nutrition branches of red globe of axillary shoot leaving two leaves and main shoot to leave eight sections to remove the topping; fruit branches of summer black seedless grape inflorescence are above to leave six sections to remove the topping and axillary shoot of leaving three leaves, nutrition branches of summer black seedless grape inflorescence are above to leave five sections to remove the topping and axillary shoot of leaving one leaf, the fruit quality and flower bud differentiation are best.5-. The period for the main flower bud differentiation of winter buds of red globe grape can be divided into four stages:the Nondifferentiation(before June3rd), Inflorescence perimordium differentiation(June3rd to July8th), Spikelet perimordium differentiation(July8th to August12th) and the period of dormancy.