Effects Of Different Matrix And Plug Size On Melon Plug Seedling Growth

Plug seedling nursery is a way of soilless seedling nursery. In plug seedling nursery, different sizes of special plugs are adopted as nursery containers, which are filled with lightweight materials such as peat, vermiculite, coconut husks as nursery matrice. It is a modern seedling nursery system with mechanized and precised sowing and seedlings were raised at one time. Since the special conditions in melon seedling nursery, such as weak roots, relative expensive seeds, easily uncontrolled and serious seedling and field diseases, it is very suitable for plug seedling nursery in melon.In this experiment, to solve the problem of choosing matrice and plugs in melon plug seedling nursery, effects of different commonly used matrice ("Fafard","Golden No.3""All Elements","Northeastern Nutrition Soil" and "Garden Soil" as the control) and different plugs (128-hole,72-hole,50-hole,32-hole) on plug seedling growth and development of both melon (Lake Sweet No.1) and muskmelon (White Pecking Melon) in different seasons were studied. Changes in physical and chemical properties of these matrice in the seedling nursery process were also investigated. It is expected to provide certain instructional informations for melon plug nursery through this study. The study is concluded as follows:1. From the effects of different matrice on spring melon seedlings, it is shown that there are both advantages and shortcomings in four matrice used in this experiment."Fafard" is the most commonly used matrix, with the highest total porosity, the highest uniformity in seedling emergence and the most developed roots, while "Golden No.3" is the second best. However, when comparing with "Farfard", the dark green leaves of "Golden No.3" melon seedlings contained higher chlorophyll, and the other physiological indicators of "Golden No.3" seedlings are better than "Farfard" as well. All the indicators of "All Elements" are relatively high, but the ability to retain water and nutrients of this matrix is relatively lower with a pH value of5.0. In melon seedling nursery, the most suitable pH may be adjusted to6.0-7.0(6.0-6.5at best), therefore "All Elements" is acidic for melon seedlings nursery. In the four matrix, worst effects in seedling nursery is observed in "Northeast Nutrition Soil", which is mainly composed of peat. Seedling nursery effect of "Northeast Nutrition Soil" is only slightly better than "Garden Soil". In general,"Golden No.3" is an ideal matrix in melon seedlings nursery.2. From the effects of different plugs on spring melon seedlings, results of this experiment show that as the number of plug holes reduces, content of nutritional substance increases. Plant height and stem diameter of seedlings cultivated in32-hole plug is the highest of the four plugs. Although no significant differences in all physiological indicators were observed in four plugs, the great changes in pH and EC values of128-hole plug in the seedling nursery process is bound to affect the quality of transplanted seedlings. Generally considering factors including seedling growth, seedling rate, ease of detachment from plugs, transportation, and combined with practical production, it is shown that72-hole and50-hole are more suitable for plug seedling nursery in melon.3. From the results of this experiment, a short nursery cycle and quick seedling emergence is observed in autumn seedling nursery when compared with spring nursery. In autumn seedling nursery, there is no significant differences among all treatments, and small increases in physiological indicators including plant height, stem diameter, hypocotyl length are observed in the process of seedling nursery. That is because the autumn melon seedling nursery cycle is short and a variety of substrates can provide sufficient nutrients for the seedlings. From the effects of different matrice on autumn melon seedling, it is found that the best seedling nursery matrix is "Golden No.3" since strong seedlings with dark green leaves and developed roots are cultivated in this matrix."Farfard" is the second best matrix because it is relatively high porosity and high ability to retain water, which are benefit for root growth. From effects of different plugs on autumn melon seedling, it is seen that there is no significant difference in different plugs due to the short seedling nursery cycle in autumn. Generally considering factors including seedling growth, seedling rate, ease of detachment from plugs, transportation, and combined with practical application, it can be seen that50-hole and72-hole are more suitable for plug seedling nursery in melon.